COMPOSITIONS AND METHODS FOR POLLEN STORAGE

Abstract

The invention provides novel compositions and methods for storing and delivering pollen to a female reproductive part of a recipient plant. The provided pollen storage composition includes at least one perlite particle and pollen. The provided methods include storing the pollen storage composition and applying the pollen storage composition to at least a first female reproductive part of a recipient plant, thereby pollinating the female reproductive part with pollen from the donor plant.

Description

COMPOSITIONS AND METHODS FOR POLLEN STORAGE REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of United States Provisional Application No. 63 / 155.714, filed on March 2, 2021, which is incorporated herein by reference in its entirety. FIELD OF INVENTION

[0002] This disclosure relates to the field of agricultural biotechnology and more specifically to compositions and methods for short-term pollen storage. BACKGROUND OF THE INVENTION

[0003] Pollen viability is substantially affected by environmental conditions and can decline rapidly once released from the plant. Pollen from the Poaceae plant family, which includes many economically important crops such as maize, rice, and wheat, remains viable for a particularly short time after dispersal. Methods aimed at improving pollen viability and fertilization potential after pollen storage are invaluable to the agricultural industry. BRIEF DESCRIPTION

[0004] In one aspect, the present description provides a pollen storage composition comprising: (a) at least one perlite particle and (b) pollen. In some embodiments, the at least one perlite particle is present in the composition in a vol:vol ratio of approximately 0.1:1 to approximately 9:1 with respect to the pollen. In specific embodiments, the at least one perlite particle is present in the composition in a vol:vol ratio of approximately 1:1 to approximately 2:1 with respect to the pollen. In some embodiments, the at least one perlite particle may comprise expanded perlite or undiluted perlite. In one embodiment, the pollen is pollen from a monocotyledonous plant.In certain embodiments, the at least one pearlite particle comprises approximately 70% to approximately 80% silicon dioxide by weight or approximately 10% to approximately 15% aluminum oxide by weight. In one embodiment, the at least one pearlite particle comprises approximately 70% to approximately 80% of. 238414 1680693 of 29 silicon dioxide and approximately 10% to approximately 15% aluminum oxide by weight. In another embodiment, the at least one perlite particle comprises approximately 2% to approximately 6% sodium oxide by weight. In yet another embodiment, the pollen storage composition comprises a plurality of perlite particles having a mean diameter of approximately 30 µm to approximately 600 µm, approximately 30 µm to approximately 350 µm, or approximately 30 µm to approximately 150 µm. In one embodiment, a pollen storage composition provided herein is defined as free or substantially free of an added liquid, for example, water or another liquid. In other embodiments, such a composition may be defined as a dry or substantially dry pollen storage composition.

[0005] In another aspect, the present description provides a method for storing pollen comprising storing pollen in the presence of at least one perlite particle. In certain embodiments, storage is carried out at approximately 0.5°C to approximately 10°C or at approximately 90% to approximately 100% relative humidity. In some embodiments, storage is carried out for up to approximately 14 days or for from approximately 1 day to approximately 7 days. In one embodiment, the pollen is from a monocotyledonous plant. In another embodiment, the pollen is capable of germination after storage. In certain embodiments, the at least one perlite particle and the pollen are contained in a pollen storage composition described herein.The pollen storage composition may comprise, for example, a perlite-to-pollen vol:vol ratio of approximately 0.1:1 to approximately 9:1 or approximately 1:1 to approximately 2:1, expanded perlite, raw perlite, approximately 70% to approximately 80% silicon dioxide by weight, approximately 10% to approximately 15% aluminum oxide by weight, approximately 2% to approximately 6% sodium oxide by weight, or a plurality of perlite particles having a mean diameter of approximately 30 pm to approximately 600 pm, approximately 30 pm to approximately 350 pm, or approximately 30 pm to approximately 150 pm. 238414 1680693 of 29

[0006] In another aspect, the present description provides a method for supplying pollen to a female reproductive part of a recipient plant. The method comprises the following steps: (a) obtaining a pollen storage composition comprising at least one perlite particle and pollen from a donor plant; and (b) supplying said storage composition to at least a first female reproductive part of the recipient plant, thereby pollinating the female reproductive part with pollen from the donor plant. In one embodiment, the pollen storage composition is stored according to the pollen storage methods described herein before supplying the storage composition to at least a first female reproductive part of the recipient plant.The pollen storage composition can be stored, for example, for up to approximately 14 days, from approximately 1 day to approximately 7 days, at approximately 0.5°C to approximately 10°C, or at approximately 90% to approximately 100% relative humidity before supplying the storage composition to at least one first female reproductive part of the recipient plant. In one embodiment, the plant is a maize plant. In another embodiment, the method produces a substantially equivalent number of seeds compared to the number of seeds produced by pollination using unstored pollen. In yet another embodiment, the method further comprises collecting the seeds obtained from pollination, or repeating steps (a) and (b) on two or more consecutive days.In one embodiment, the method further comprises crossing a descendant plant grown from a seed obtained by pollination with itself or with a second plant. In another embodiment, the supply comprises the manual or mechanical application of the pollen. In yet another embodiment, the pollen storage composition is supplied as a composition that is free or substantially free of an added liquid, for example, water or another liquid. In yet another embodiment, the pollen storage composition is supplied as a pollen storage composition that is defined as dry or substantially dry. In one embodiment, the pollen storage composition is mixed with a liquid before being supplied to a recipient plant.In another embodiment, the pollen storage composition is supplied as a liquid pollen suspension solution. 238414 1680693 of 29 DETAILED DESCRIPTION

[0007] Modern plant reproduction relies on cross-pollination to generate offspring with specific heritable traits. These breeding strategies play a crucial role in the development and integration of traits within the F1 generation. Maize (Zea mays), rice (Oryza sativa), and wheat (Triticum aestivum), belonging to the Poaceae family and the Liliopsida class (monocots), are examples of economically important agricultural crops where reproduction has been hampered by inefficient controlled cross-pollination procedures. Conventional cross-pollination methods for these species, such as maize, involve emasculating female plants and interplanting rows of male parent plants.This process is inefficient, as it depends on the effective flow of pollen to the female plants, which is vulnerable to wind and requires that the male and female plants enter the reproductive phase at the same time.

[0008] Storing pollen in a way that maintains its viability and fertilization potential would ensure pollination that does not depend on active pollen dispersal, timing with the receptivity of the female flower, or the use of male sterility. Pollen viability typically declines rapidly once it has been released from the plant, and pollen from the Poaceae family of plants, such as maize (Zea mays), rice (Oryza sativa), and wheat (Triticum aestivum), remains viable for a particularly short period. Therefore, improved methods for maintaining pollen viability and fertilization potential during storage are needed and are of incalculable value to the agricultural industry.

[0009] Environmental conditions, such as temperature and humidity, substantially affect pollen viability. In fact, it has been well established that storage under conditions of high humidity and low temperature considerably increases pollen viability (Sartoris, Am J Bot, pp. 395-400, 1942). On the other hand, storage at low temperature (e.g., 2°C) can significantly increase pollen viability, even when relative humidity is not controlled (Pfahler and Linskens, Planta, 111(3): 253-259, 1973).

[0010] The invention represents a significant advance in the art, because it allows the successful mechanical application of stored pollen. The application of stored pollen to the 238414 The scale required for seed production in the field, as described in 1680693 of 29, has not been feasible until now. The present invention, however, remarkably overcomes the limitations of the prior art by enabling cross-pollination using stored pollen, eliminating the need to develop female and male plants synchronously in the field and minimizing the effects of variable weather conditions. Furthermore, the pollen compositions and storage methods provided herein guarantee full seed production. Therefore, the pollen compositions and storage methods of the present invention can be used for the mechanical distribution of stored pollen across entire fields.

[0011] This disclosure, therefore, enables the implementation of high-throughput methods for delivering stored donor pollen to a recipient female reproductive part of a plant. The methods provided herein substantially reduce the time and effort previously required to facilitate cross-pollination in plants. This is of particular importance since modern plant breeding programs may require thousands or even millions of individual crosses per year to produce a new plant variety with improved traits. Pollen storage compositions

[0012] In one aspect, the present invention provides a pollen storage composition comprising at least one perlite particle and pollen. As used herein, “pollen” refers to at least one pollen grain and may comprise a plurality of pollen grains. The term “approximately” is used to indicate that a value includes the standard deviation from the mean for the device or method being used to determine the value. Non-limiting examples of pollen that may be used according to the compositions and methods of the invention include pollen collected from a dicotyledonous plant, a monocotyledonous plant, a plant of the Poaceae family, a maize plant, a rice plant, or a wheat plant. As used herein, “perlite” refers to a composition comprising silicon dioxide and aluminum oxide. Perlite may be mined as amorphous volcanic glass or may be produced synthetically.Raw perlite can be expanded by heating it to a temperature that causes the water molecules that are... 238414 1680693 of 29 trapped inside are transformed into vapor. Raw perlite can be expanded, for example, by heating to a temperature of approximately 850°C to approximately 900°C. In one example, raw perlite can be expanded by heating to a temperature above approximately 870°C.Ejemplos no limitativos de perlita incluyen Harborlite® 200, Harborlite® 500, Harborlite® 600, Harborlite® 635, Harborlite® 700, Harborlite® 700S, Harborlite® 800, Harborlite® 800S, Harborlite® 900, Harborlite® 900S, Harborlite® 1500, Harborlite® 1500S, Harborlite® 1800, Harborlite® 1800S, Harborlite® 1900, Harborlite® 1950S, Harborlite® 2000, Harborlite® 2000S, Harborlite® 2100S, Dicalite® HP100, Dicalite® HP110, Dicalite® HP120, Dicalite® HP125, Dicalite® HP200, Dicalite® HP210, Dicalite® HP220, Dicalite® HP225, Dicalite® HP900 y Dicalite® HP910, Dicalite® HP920, Dicalite® HP925, Dicalite® HP1500, Dicalite® HP1510, Dicalite® HP1520, Dicalite® HP1525, Dicalite® HP2000, Dicalite® HP2010, Dicalite® HP2020, Dicalite® HP2025, Dicalite® HP2035, Dicalite® HP2300, Dicalite® HP2310, Dicalite® HP2320, Dicalite® HP2325, Dicalite® HP2335. En algunas formas de realización, los componentes para usar en la composición de almacenamiento de polen pueden ser optimizados para una aplicación particular.These parameters can be determined empirically using the methodology described herein. In general, it is desirable to use a composition containing components that maintain pollen viability and fertilization potential and that facilitate uniform pollen dispersal. As used in this context, a “vol:vol ratio” refers to the volume-to-volume ratio of two substances. When these two substances are, for example, at least one perlite particle and pollen, the ratio is calculated by comparing the volume of the at least one perlite particle with the volume of the pollen. By way of non-limiting example, the volume of the at least one perlite particle and the pollen can be measured in mm³, cm³, or m³. In some embodiments, the at least one perlite particle is present in the composition in a vol:vol ratio of approximately 0.1:1 to approximately 9:1 with respect to the pollen.In specific embodiments, at least one perlite particle is present in the composition in a vol:vol ratio of approximately 1:1 to approximately 2:1 with respect to pollen. The at least one perlite particle may be present, for example, in the composition in a vol:vol ratio of approximately 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1; 1:1, 1:1, 2:1, 2:1, 3:1, 4:1, 5:1, 5:1, 6:1, 7:1, 8:1, or 9:1 with respect to pollen, inclusive of all intervals. 238414 1680693 of 29 intermediate derivable ranges. In some embodiments, the at least one pearlite particle may comprise expanded pearlite or raw pearlite. In some embodiments, the at least one pearlite particle comprises approximately 70% to approximately 80% silicon dioxide by weight or approximately 10% to approximately 15% aluminum oxide by weight. The at least one pearlite particle may comprise, for example, approximately 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, or 80% silicon dioxide by weight or approximately 10%, 11%, 12%, 13%, 14%, or 15% aluminum oxide by weight, including all intermediate derivable ranges. In one embodiment, the at least one pearlite particle comprises approximately 2% to approximately 6% sodium oxide by weight.The at least one pearlite particle may comprise, for example, approximately 2%, 3%, 4%, 5%, or 6% sodium oxide by weight, including all intermediate derivable ranges. The at least one pearlite particle may further comprise potassium oxide, iron oxide, calcium oxide, or sulfur oxide. The at least one pearlite particle may comprise, for example, approximately 0% to approximately 9% potassium oxide, approximately 0% to approximately 3% sulfur oxide, approximately 0% to approximately 5% iron oxide, or approximately 0% to approximately 5% calcium oxide by weight.The at least one particle of pearlite may comprise, for example, approximately 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8% or 9% of potassium oxide, approximately 0%, 0.5%, 1%, 1.5%, 2%, 2.5% or 3% of sulfur oxide, approximately 0%, 0.5%, 1.0%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5.0% of iron oxide, or approximately 0%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5% of calcium oxide by weight, including all derivable intermediate ranges. In another embodiment, the pollen storage composition comprises a plurality of perlite particles having an average diameter of approximately 30 pm to approximately 600 pm, approximately 30 pm to approximately 350 pm, or approximately 30 pm to approximately 150 pm.The plurality of perlite particles can have, for example, an average diameter of approximately 30 pm, approximately 40 pm, approximately 50 pm, approximately 60 pm, approximately 70 pm, approximately 80 pm, approximately 90 pm, approximately 100 pm, approximately 120 pm, approximately 140 pm, approximately 160 pm, approximately 160 pm, approximately 180 pm. 238414 1680693 of 29 approximately 200 pm, approximately 220 pm, approximately 240 pm, approximately 260 pm, approximately 280 pm, approximately 300 pm, approximately 330 pm, approximately 350 pm, approximately 400 pm, approximately 450 pm, approximately 500 pm, approximately 550 pm or approximately 600 pm, including all intermediate derivable intervals. Non-limiting examples of perlite particles of this type include Harborlite® 1500S, Dicalite® HP100, Dicalite® HP120, Dicalite® HP200, Dicalite® HP220, and Dicalite® HP900. Harborlite® 1500S has an average particle size of approximately 37.6 pm and comprises approximately 76.8% silicon dioxide, 12.8% aluminum oxide, 5.3% potassium oxide, 3.7% sodium oxide, 0.6% iron oxide, and 0.5% calcium oxide. Dicalite® HP100 has an average particle size of approximately 300-330 pm and comprises approximately 70-80% silicon dioxide, 10-15% aluminum oxide, 2-6% sodium oxide, 0-3% potassium oxide, 0-3% sulfur oxide and 0-5% other inorganic trace minerals.Dicalite® HP120 has an average particle size of approximately 300–330 µm, is siloxane-coated, and comprises approximately 70–80% silicon dioxide, 10–15% aluminum oxide, 2–6% sodium oxide, 0–3% potassium oxide, 0–3% sulfur oxide, and 0–5% other inorganic trace minerals. Dicalite® HP200 has an average particle size of approximately 110–125 µm and comprises approximately 70–80% silicon dioxide, 10–15% aluminum oxide, 2–6% sodium oxide, 0–3% potassium oxide, 0–3% sulfur oxide, and 0–5% other inorganic trace minerals. Dicalite® HP220 has an average particle size of approximately 110-125 pm, is coated with siloxane and comprises approximately 70-80% silicon dioxide, 10-15% aluminum oxide, 2-6% sodium oxide, 0-3% potassium oxide, 0-3% sulfur oxide and 0-5% other inorganic trace minerals.Dicalite® HP900 has an average particle size of approximately 80-90 µm and comprises approximately 70-80% silicon dioxide, 10-15% aluminum oxide, 2-6% sodium oxide, 0-3% potassium oxide, 0-3% sulfur oxide, and 0-5% other inorganic trace minerals. In one embodiment, a pollen storage composition provided herein is defined as free or substantially free of an added liquid, for example, water or another liquid. In other embodiments, such a composition may be defined as a dry or substantially dry pollen storage composition. 238414 1680693 of 29 Plant pollen storage

[0013] In another aspect, the invention provides a method for storing pollen, comprising storing pollen in the presence of at least one perlite particle. In some embodiments, the storage conditions can be optimized for a particular application or a particular type of pollen. These parameters can be determined empirically using the methodology described herein. To promote cross-pollination, for example, it may be desirable to use pollen storage compositions and methods containing components that facilitate uniform pollen dispersal, maintain high pollen grain viability, and do not significantly hinder fertilization and seed development when applied to the female reproductive part of a recipient plant.Non-limiting examples of pollen that may be used according to the compositions and methods of the invention include pollen collected from a dicotyledonous plant, a monocotyledonous plant, a plant of the Poaceae family, a corn plant, a rice plant, or a wheat plant.

[0014] In certain embodiments, storage can be carried out at approximately 0.5°C to approximately 10°C or at approximately 90% to approximately 100% relative humidity. Storage can be carried out, for example, at approximately 0.5°C, 1°C, 2°C, 3°C, 4°C, 5°C, 6°C, 7°C, 8°C, 9°C, or 10°C, or at approximately 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% relative humidity, including all derivable intermediate ranges. In one embodiment, the pollen can be stored in a humidity chamber. In another embodiment, the airflow rate in the humidity chamber is between approximately 5.0 liters / min (l / min) and approximately 20.0 l / min.The airflow rate, for example, may be approximately 5.0 l / min, 6.0 l / min, 7.0 l / min, 8.0 l / min, 9.0 l / min, 10.0 l / min, 11.0 l / min, 12.0 l / min, 13.0 l / min, 14.0 l / min, 15.0 l / min, 16.0 l / min, 17.0 l / min, 18.0 l / min, 19.0 l / min, or 20.0 l / min, including all derivable intermediate ranges. In another embodiment, the airflow rate is an airflow rate sufficient to maintain a humidity chamber at approximately 0.5°C to approximately 10°C and / or at approximately 90% to approximately 100% relative humidity. An airflow rate of approximately 5.0 l / min to approximately 20.0 l / min, for example, is sufficient to maintain the humidity chamber at approximately 0.5°C up to approximately 10°C and approximately 90% up to. 238414 1680693 of 29 approximately 100% relative humidity for pollen volumes from 1 grain to approximately 45 liters; however, the required airflow rate may be higher as the pollen volume increases. The airflow rate required to maintain a humidity chamber at approximately 0.5°C to approximately 10°C and approximately 90% to approximately 100% relative humidity for any pollen volume can be determined empirically by employing the methods described herein, and potentially any airflow rate could prove useful according to the invention. In some embodiments, storage is carried out for up to approximately 14 days or for approximately 1 day to approximately 7 days.Storage can be carried out, for example, for approximately 1 second, 15 seconds, 30 seconds, 45 seconds, 1 minute, 5 minutes, 15 minutes, 30 minutes, 45 minutes, 1 hour, 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 13 days, or 14 days, including all derivable intervals in between. In one embodiment, the pollen is pollen from a monocotyledonous plant. In another embodiment, the pollen retains germination capacity after storage. In certain embodiments, at least one perlite particle and the pollen are included in a pollen storage composition described herein.The pollen storage composition may comprise, for example, a vol:vol perlite to pollen ratio of approximately 0.1:1 to approximately 9:1, a vol:vol perlite to pollen ratio of approximately 1:1 to approximately 2:1, expanded perlite, raw perlite, from approximately 70% to approximately. 80% silicon dioxide by weight, approximately 10% to approximately 15% aluminum oxide by weight, from approximately 2% to approximately 6% sodium oxide by weight, or a plurality of pearlite particles having an average diameter of approximately 30 pm to approximately 600 pm, from approximately 30 pm to approximately 350 pm, or from approximately 30 pm to approximately 150 pm. Supply of stored pollen for plant pollination

[0015] The present invention remarkably enables the cross-pollination of virtually any flowering plant or herb using stored pollen. The methods provided herein include obtaining a storage composition 238414 1680693 of 29 pollen comprising at least one perlite particle and pollen from a donor plant, and supplying the storage composition to at least a first female reproductive part of the recipient plant, thereby pollinating the female reproductive part with the pollen from the donor plant. In one embodiment, the pollen storage composition is supplied as a composition that is free or substantially free of an added liquid, for example, water or another liquid. In another embodiment, the pollen storage composition is supplied as a composition defined as dry or substantially dry. In yet another embodiment, the pollen storage composition is mixed with a liquid before supplying the pollen storage composition to a recipient plant.In another further embodiment, the pollen storage composition is supplied as a liquid pollen suspension solution. In some embodiments, the methods of the invention can be optimized for a particular application, a particular plant species, or a particular pollen type. These parameters can be determined empirically using the methodology described herein. Non-limiting examples of plants that can be used according to the methods of the invention include dicotyledonous plants, monocotyledonous plants, plants of the Poaceae family, maize plants, rice plants, and wheat plants. In some embodiments, the supply comprises the manual or mechanical application of pollen. As used in this context, the term “manual application” refers to the transfer of pollen by hand to the female reproductive part of a recipient plant.Non-limiting examples of manual application include applying pollen with a cotton swab or small brush and using a dosing spoon to transfer pollen from a container, such as a bag or graduated tube, to the female reproductive part of a recipient plant. As used in this context, “mechanical application” refers to applying pollen using a mechanical device. Non-limiting examples of such a mechanical device include an air-driven pollen applicator or a pollen applicator with a common agricultural nozzle. In one embodiment, the agricultural nozzle can be adjusted for “fine” or “very fine” spraying.In one embodiment, the mechanical application can be carried out, for example, using a pollen applicator with an air outlet velocity of approximately 1 m / s to approximately 10 m / s, including all intermediate derivable intervals. In another embodiment, the composition of. 238414 1680693 of 29 Pollen storage can be applied at a pressure of approximately 10 psi, approximately 15 psi, approximately 20 psi, approximately 25 psi, approximately 30 psi, approximately 35 psi, or approximately 40 psi. In yet another embodiment, air-driven spraying is used to produce a spray of the pollen storage composition with a volume-weighted average droplet diameter of between approximately 30 µm and approximately 600 µm, between approximately 30 µm and approximately 350 µm, or between approximately 30 µm and approximately 150 µm. The spray of the pollen storage composition can have a volume-weighted average droplet diameter of, for example, approximately 30 µm, approximately 40 µm, approximately 50 µm, approximately 60 µm, approximately 70 µm, approximately 80 µm, approximately 90 µm, or approximately 100 µm. approximately 120 pm, approximately 140 pm, approximately 160 pm, approximately 160 pm, approximately 180 pm, approximately 200 pm, approximately 220 pm, approximately 240 pm, approximately 260 pm, approximately 280 pm, approximately 300 pm, approximately 330 pm, approximately 350 pm, approximately 400 pm, approximately 450 pm, approximately 500 pm, approximately 550 pm, or approximately 600 pm, including all derivable intervals in between. Air-driven spraying is also described in U.S. Provisional Application No. 63 / 005.260, which is incorporated herein by reference.

[0016] In certain embodiments, the pollen storage composition is stored according to the methods described herein before supplying the storage composition to at least one first female reproductive part of the recipient plant. The pollen storage composition can be stored, for example, for up to approximately 14 days, from approximately 1 day to approximately 7 days, at approximately 0.5°C to approximately 10°C, or at approximately 90% to approximately 100% relative humidity, before supplying the storage composition to at least one first female reproductive part of the recipient plant.

[0017] To stimulate cross-pollination, it may be desirable to use a pollen storage composition containing components that facilitate uniform pollen dispersal, maintain high pollen grain viability, and do not hinder 12 238414 1680693 of 29 considerably improve fertilization and seed development when applied to the female reproductive part of a recipient plant. Examples of components of this class include, but are not limited to, Harborlite® 1500S, Dicalite® HP100, Dicalite® HP120, Dicalite® HP200, Dicalite® HP220 and Dicalite® HP900.

[0018] In particular embodiments, the methods described herein may comprise repeating the steps of obtaining a pollen storage composition comprising at least one perlite particle and pollen from a donor plant and supplying the storage composition to at least one first female reproductive part of the recipient plant on two or more consecutive days. These steps may be repeated, for example, for two consecutive days, three consecutive days, four consecutive days, or five or more consecutive days. In maize, for example, it has been found that repeating the supply steps on two or three consecutive days can result in increased seed production.

[0019] In other embodiments, the methods described herein may involve pollinating flowers that are male-sterile at the time of pollination. Depending on the evolutionary stage of the plant, the donor pollen applied for cross-pollination may compete with the pollen produced by the recipient plant. To improve the efficiency of cross-pollination, it may be advantageous in some cases for the recipient plant to be male-sterile in an effort to reduce competition with itself. For this reason, a male sterility system could be employed with the female parent plant in a particular cross. Many of these male sterility systems are well known, including cytoplasmic male sterility (CMS) and gene male sterility (GMS).CMS and GMS facilitate the production of hybrid seeds for many crops and thus allow farmers to control the yield gains associated with hybrid vigor. The use of a gametocide presents an alternative method for producing male sterility. Gametocides affect the processes or cells involved in development, maturation, or pollen release. Plants treated with such gametocides become male-sterile but usually remain female-fertile. The use of chemical gametocides is described, for example, in U.S. Patent No. 4,936,904, the disclosure of which is specifically incorporated herein by reference in its entirety. Furthermore, the herbicide Roundup is used in combination with glyphosate-tolerant corn plants to produce sterile corn plants. 238414 The 1680693 of 29 males is described in PCT Publication WO 98 / 44140. Several gametocides have proven effective in inducing pollen sterility in various crops and are well known in the art. These gametocides include sodium methyl arsenate, 2,3-dichloroisobutyrate, sodium 2,2-dichloropropionate, gibberellic acid, maleic hydrazide (1,2-dihydropyridazine, 3,6-dione), 2,4-dichlorophenoxyacetic acid, ethyl 4-fluorooxanilate, trihalogenated methylsulfonamides, and ethyl and methyl arsenates (Ali et al., 1999). Physical emasculation of the recipient plant presents another alternative for producing male sterility. After emasculation, the plants continue to grow and natural cross-pollination occurs as a result of wind action, which is normal in the pollination of grasses, including corn.As a result of emasculating the female parent plant, all the pollen from the male parent plant is available for pollination, since the male reproductive parts, and therefore the pollen-bearing parts, have been previously removed from all the plants of the parent plant being used as the female parent in the hybridization. Of course, during this hybridization procedure, the parent varieties are cultivated in a way that keeps them isolated from other plants to minimize or prevent accidental contamination with pollen from other sources. These isolation techniques fall within the standard knowledge of those trained in this practice.

[0020] In particular embodiments, the methods described herein are implemented to produce a substantially equivalent number of seeds compared to the number of seeds produced using pollen that has not been stored. Substantial equivalence is assessed by comparing the seed production achieved using stored pollen with the seed production achieved using unstored pollen. As used in this context, “substantially equivalent” refers to a characteristic in which the mean ± standard deviation of the test population does not deviate by more than approximately 20% from the mean ± standard deviation of the control population.In maize, at least the following pollen storage compositions were found to produce a substantially equivalent number of seeds, compared to the number of seeds produced using unstored pollen: Harborlite® 1500S and Dicalite® HP900 (Table 12).

[0021] A stage of collecting the seeds obtained from pollination can also be carried out using a pollen storage composition of the invention. In a form 238414 In particular embodiment 1680693, a descendant plant produced from the collected seeds can be crossed with itself or with a different plant. In certain embodiments, the present description provides a method for producing hybrid seeds, comprising producing a pollen storage composition of the invention, supplying the pollen storage composition to a female reproductive part of a recipient plant, thereby pollinating the female reproductive part with pollen from the donor plant, harvesting the seeds produced from the pollination, and identifying the hybrid progeny. Furthermore, a seed or descendant plant obtained from pollination with the pollen storage composition can be selected.The identification and selection of progeny could be facilitated by using a polymorphic marker allele contained in the pollen donor, which serves to identify plants or seeds descended from that donor. Morphological, biochemical, or protein markers have been commonly used as tools for selecting plants with desirable traits for breeding. Molecular marker techniques that have been widely used and are especially promising for application in plant breeding include restriction fragment length polymorphisms (RFLPs), amplified fragment length polymorphisms (AFLPs), randomly amplified polymorphic DNA (RAPD), microsatellites or single sequence repeats (SSRs), and single nucleotide polymorphisms (SNPs) (Al-Khayri et al., 2016).

[0022] The methods disclosed in this description can be implemented for the improved cross-pollination of virtually any plant. These plants may include, without limitation, members of the Poaceae family, non-limiting examples of which are maize, wheat, and rice. Genetically modified plants and seeds

[0023] One aspect of the invention provides for the selection of offspring plants and seeds obtained by the methods described herein. In some embodiments, the offspring plants and seeds can be defined as comprising a detectable modification with respect to the female parent plant. One method for producing such plants and seeds consists of utilizing an allele produced by plant genetic transformation. Suitable methods for transforming host plant cells for use with the 238414 The methods described in 1680693 of the present invention are well known in the art and include any method by which DNA can be introduced into a cell (for example, when a recombinant DNA construct is stably integrated into a plant chromosome). Some widely used methods for cell transformation are Agrobacterium-mediated transformation, microprojectile bombardment-mediated transformation, and cell-penetrating peptide-mediated delivery of DNA-modifying agents.

[0024] Another method for producing modified plants and seeds is based on genome editing. As used in this context, the term “genome editing” refers to the use of genome editing methods and a site-specific genome-modifying enzyme to modify a nucleotide sequence. In some embodiments, donor pollen can be transformed using known techniques to contain one or more reagents that mediate the specific modification of the genome in a plant. Pollen grains according to the invention, comprising such reagents from loci generated using said reagents in any current or prior generation, can be employed.

[0025] Suitable methods for altering a wild-type DNA sequence at a predetermined chromosomal site include any method known to the art. Targeted modification of plant genomes using genome editing methods and reagents can be used to create improved plant lines by modifying the plant's genomic DNA. Furthermore, genome editing methods and reagents can facilitate the targeted insertion of one or more nucleic acids of interest into a plant's genome.Representative methods for introducing donor polynucleotides into a plant genome or modifying a plant's genomic DNA include the use of genome editing reagents such as sequence-specific recombinases, endonucleases, zinc finger nucleases, engineered or native meganucleases, TALE endonucleases, RNA-guided endonucleases (e.g., a Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) / Cas9 system, a CRISPR / Cpf1 system, a CRISPR / CasX system, a CRISPR / CasY system, a CRISPR / Cascade system), and CRISPR-associated transposases (Strecker et al., 2019; Klompe et al., 2019). Several embodiments relate to genome editing methods employing oligonucleotides. 238414 1680693 of 29 single-stranded DNA to introduce precise base pair modifications in a plant genome, as described by Sauer et al. (Plant Physiol. 170(4):1917-1928; 2016).

[0026] As used in this context, the term “site-specific genomic modification enzyme” refers to any enzyme that can modify a nucleotide sequence in a sequence-specific manner. In some embodiments, a site-specific genomic modification enzyme modifies the genome by inducing a single-strand break or a double-strand break. In some embodiments, a site-specific genomic modification enzyme comprises a cytidine deaminase or an adenine deaminase. In this disclosure, site-specific genomic modification enzymes include endonucleases, recombinases, transposases, deaminases, helicases, and any combination thereof. In some embodiments, the site-specific genomic modification enzyme is a sequence-specific nuclease. EXAMPLES Example 1. Development of pollen storage compositions

[0027] Pollen grains can be obtained from a donor plant and stored as a pollen storage composition prior to the pollination of a recipient plant. The components and concentrations in the pollen storage composition are important for the composition's effectiveness, as they influence not only pollen viability but also the success rate of hybrid seed production in the pollinated plants. While effectiveness can be improved by optimizing the components and concentrations in a given pollen storage composition, numerous substitutions and modifications are possible while still achieving pollination. Table 1 includes the results obtained using different pollen application methods on different days with different female recipient plants.However, the results presented in Table 1 are representative of the potential of some pollen storage compositions to achieve relatively high seed production, compared to other pollen storage compositions that were relatively unsuccessful. The results in Table 1 are also representative of the potential of some pollen storage compositions to achieve seed production. 238414 1680693 of 29 relatively high, compared to pollen stored in the absence of a pollen storage composition. Table 1. Pollen storage compositions specimens and representative number of grains, produced after 3-7 days of pollen storage before pollen application. Pollen storage composition (ratios are additive:pollen; vol:vol) Number of grains produced Pollen only (Fresh) 307.7 ± 5.5 Pollen only (Stored, 5 days) 84.7 ± 63.5 Perkasil® SM 660® SM 660 (1:1) 108.7 ± 13.5 Dicalite® HP100 (2:1) 125.8 ± 29.9 Dicalite® HP120 (2:1) 90.8 ± 28.8 Dicalite® HP200 (2:1) 129.7 ± 26.7 Dicalite® HP200 (3:1) 179.0 ± 45.7 Dicalite® HP220 (2:1) 186.4 ± 36.5 Dicalite® HP900 (2:1) 259.3 ± 50.7 Dicalite® HP900 (3:1) 254.3 ± 51.4 Harborlite® 1500S (2:1) 267.7 ± 21.4 Harborlite® 1500S (1:1) 104.0 ± 13.0 Harborlite® 1500S (1:2) 22.3 ±7.3

[0028] Tests were conducted to develop pollen storage compositions that maintain high pollen viability and produce seeds when applied to the female reproductive part of a recipient plant. A number of additives were tested for use in the pollen storage composition, including Perkasil® SM 660, Dicalite® HP100, Dicalite® HP120, Dicalite® HP200, Dicalite® HP220, Dicalite® HP900, and Harborlite® 1500S. The Harborlite® product line is manufactured by Imerys®. The Dicalite® product line is manufactured by Dicaperl®. With the stored pollen compositions comprising Dicalite® HP900 and Harborlite® 1500S, seed production comparable to that obtained with fresh pollen was achieved (Table 1). 238414 1680693 of 29

[0029] Based on the results obtained from experiments testing individual pollen storage compositions, it was determined that beneficial components for a pollen storage composition include, without limitation, the following: Perkasil® SM 660, Dicalite® HP100, Dicalite® HP120, Dicalite® HP200, Dicalite® HP220, Dicalite® HP900 and Harborlite® 1500S, all of which yield increased seed production, compared to pollen stored without additive.

[0030] In certain embodiments, the solutions and methods described herein may be used with any plant. In specific embodiments, the provided compositions and methods may be used with cultivated plants, for example, monocotyledonous crops. Non-limiting examples of cultivated plants that may be used with the compositions and methods described herein include maize, wheat, barley, rice, sorghum, and soybeans. Example 2. Analysis of seed production after manual pollination using stored maize pollen

[0031] Achieving full seed production using stored pollen is challenging. Pollen viability can be lost in minutes to hours, depending on the species and environmental conditions. Exposure to dry air and high temperatures is particularly detrimental. Furthermore, many additives that preserve pollen viability react negatively with corn silk, resulting in reduced seed production. Pollen compositions and storage methods have been developed to overcome these challenges and achieve full seed production using stored pollen.

[0032] Suitable pollen storage compositions were evaluated by examining seed production following hand pollination with pollen stored using one of the following pollen storage compositions (ratios are given in vol:vol additive:pollen): 1) fresh maize (M08) pollen; 2) maize (M08) pollen stored in Perkasil® SM 660 (1:1); 3) maize (M08) pollen stored in Harborlite® 1500S (2:1); 4) maize (M08) pollen stored in Harborlite® 1500S (1:1); or 5) maize (M08) pollen stored in Harborlite® 1500S (1:2). The pollen storage compositions were stored in a humidity chamber at 3.8°C and 97% humidity with an airflow of 8.0 L / min for 7 days prior to hand pollination. 32 mg of pollen were used for each 238414 Pollination and seed production were evaluated 10 days after pollination. Pollinations for each pollen storage composition were performed in triplicate. Pollen storage compositions comprising Harborlite® 1500S (2:1) resulted in high seed production following hand pollination (Table 2). Table 2. Seed production after manual pollination using M08 maize pollen stored for 7 days. Composition Cob 1 Cob 2 Cob 3 Average Fresh Pollen 156 403 N / A 279.5 ± 123.5 Perkasil® SM 660 (1:1) 119 82 125 108.7 ± 13.5 Harborlite® 1500S (2:1) 246 214 135 198.3 ± 33.0 Harborlite® 1500S (1:1) 103 127 82 104.0 ± 13 Harborlite® 1500S (1:2) 36 11 20 22.3 ± 7.3

[0033] Suitable pollen storage compositions were evaluated by examining seed production following hand pollination with stored pollen using one of the following pollen storage compositions (ratios are given in vol:vol additive:pollen): 1) fresh pollen (M02); 2) stored maize pollen (M02); 3) maize pollen (M02) stored in Perkasil® SM 660 (1:1); or 4) maize pollen (M02) stored in Harborlite® 1500S (2:1). The pollen storage compositions were stored in a humidity chamber at 3.8°C and 97% humidity with an airflow of 8.0 L / min for 5 days prior to hand pollination. 32 mg of pollen were used for each pollination, and pollinations for each pollen storage composition were performed in triplicate. Six replicate pollinations were carried out using fresh M02 pollen.Pollinations using fresh M02 pollen yielded 300, 384, 265, 188, 243, and 223 kernels per ear, respectively. Pollen germination was assessed on storage day 3 and storage day 5 (Table 3). Fresh M02 pollen had an average germination rate of 62.9 ± 1.0% on day 0. Seed production was assessed 13 days post-pollination. Pollen storage compositions comprising Harborlite® 1500S (2:1) resulted in high seed production following hand-pollination (Table 4). 238414 1680693 of 29 Table 3. Germination of maize pollen M02 stored in compositions comprising Perkasil® SM 660 or Harborlite® 1500S. Composition % Avg. Germ. Day 3 % Avg. Germ. Day 5 Perkasil® SM 660 (1:1) 37.2 ± 6.4 7.5 ± 2.5 Harborlite® 1500S (2:1) 37.1 ± 1.8 17.6 ± 2.1 Table 4. Seed production after manual pollination using M02 maize pollen stored for 5 days in compositions comprising Perkasil® SM 660 or Harborlite® 1500S. Composition Cob 1 Cob 2 Cob 3 Average Fresh pollen 267.2 ± 68.6 Stored pollen 10 4 8 7.3 ± 3.1 Perkasil® SM 660 (1:1) 163 193 199 185.0 ± 19.3 Harborlite® 1500S (2:1) 325 322 344 330.3 ± 11.9

[0034] Suitable pollen storage compositions were evaluated by examining seed production following hand pollination with stored pollen using one of the following pollen storage compositions (ratios are given in vol:additive vol:pollen): 1) fresh maize pollen (M02); 2) stored maize pollen (M02); 3) maize pollen (M02) stored in Harborlite® 1500S (2:1); 4) maize pollen (M02) stored in Dicalite® HP200 (2:1); 5) maize pollen (M02) stored in Dicalite® HP200 (3:1); 6) maize pollen (M02) stored in Dicalite® HP900 (2:1); or 7) maize pollen (M02) stored in Dicalite® HP900 (3:1). The pollen storage compositions were stored in a humidity chamber at 4.0°C and 96.5% humidity with an airflow of 20.0 L / min for 5 days before manual pollination. 32 mg of pollen were used per pollination.Pollinations for each pollen storage composition were performed in triplicate. Pollen germination was assessed on storage day 5 (Table 5). Seed production was assessed 15 days post-pollination. Pollen storage compositions containing Dicalite® HP900 showed high seed production following hand pollination (Table 6). 238414 1680693 of 29 Table 5. Germination of maize pollen M02 stored in compositions comprising Harborlite® 1500S, Dicalite® HP200 or Dicalite® HP900. Composition % Avg. Germ. Day 5 Fresh Pollen 73.1 ± 0.4 Stored Pollen 33.5 ± 2.6 Harborlite® 1500S (2:1) 37.9 ± 1.4 Dicalite® HP200 (2:1) 41.6 ± 0.4 Dicalite® HP200 (3:1) 26.7 ± 1.4 Dicalite® HP900 (2:1) 30.0 ± 4.4 Dicalite® HP900 (3:1) 23.7 ± 5.8 Table 6. Seed production after hand pollination using M02 maize pollen stored for 5 days in compositions comprising Harborlite® 1500S, Dicalite® HP200 or Dicalite® HP900. Composition Cob 1 Cob 2 Cob 3 Average Fresh Pollen 298 308 317 307.7 ± 5.5 Stored Pollen 4 40 210 84.7 ± 63.5 Harborlite® 1500S (2:1) 235 172 73 160.0 ± 47.2 Dicalite® HP200 (2:1) 81 135 173 129.7 ± 26.7 Dicalite® HP200 (3:1) 126 270 141 179.0 ± 45.7 Dicalite® HP900 (2:1) 308 312 158 259.3 ± 50.7 Dicalite® HP900 (3:1) 199 207 357 254.3 ± 51.4

[0035] Suitable pollen storage compositions were evaluated by examining seed production following hand pollination with pollen stored using one of the following pollen storage compositions (ratios are given in vol:vol additive:pollen): 1) fresh corn (M08) pollen; 2) stored corn (M06 and M08) pollen; 3) corn (M06 and M08) pollen stored in Harborlite® 1500S (2:1); or 4) corn (M06 and M08) pollen stored in Dicalite® HP900 (2:1). The pollen storage compositions were stored in a humidity chamber at 4.0°C and 96.5% 238414 1680693 of 29 humidity with an airflow of 20.0 L / min for 7 days prior to hand pollination. 32 mg of pollen were used per pollination, and pollinations for each pollen storage composition were performed in quadruplicate. Pollen germination was assessed on storage day 7 (Table 7). Seed production was assessed 13 days post-pollination. Pollen storage compositions comprising Harborlite® 1500S and Dicalite® HP900 yielded high seed production following hand pollination (Table 8). Table 7. Germination of maize pollen M06 and M08 stored in compositions comprising Harborlite® 1500S or Dicalite® HP900. Composition % Avg. Germ. Day 7 Fresh Pollen (M08) 69.8 ± 4.6 Stored Pollen (M08) 27.7 ± 10.4 Harborlite® 1500S (M08) 20.7 ± 6.6 Dicalite® HP900 (M08) 25.9 ± 3.2 Stored Pollen (M06) 22.0 ± 2.4 Harborlite® 1500S (M06) 4.8 ± 3.3 Dicalite® HP900 (M06) 8.0 ± 3.3 Table 8. Seed production after hand pollination using M08 and M06 maize pollen stored for 7 days in compositions comprising Harborlite® 1500S or Dicalite® HP900. Composition Cob 1 Cob 2 Cob 3 Cob 4 Average Fresh Pollen (M08) 348 363 296 379 346.5 ± 36.0 Stored Pollen (M08) 239 313 265 215 258.0 ± 42.0 Harborlite® 1500S (M08) 247 290 295 250 270.5 ± 25.5 Dicalite® HP900 (M08) 381 308 269 326 321.0 ± 46.5 Stored Pollen (M06) 225 299 249 252 256.3 ± 31.0 Harborlite® 1500S (M06) 84 158 63 135 110.0 ± 44.0 238414 1680693 of 29 Composition Cob 1 Cob 2 Cob 3 Cob 4 Average Dicalite® HP900 (M06) 233 270 284 239 256.5 ± 24.5 Example 3. Analysis of seed production after mechanical pollination using stored maize pollen.

[0036] Suitable pollen storage compositions were evaluated by examining seed production following mechanical or manual pollination with pollen stored using one of the following pollen storage compositions (ratios are given in vol:vol additive:pollen): 1) fresh maize (M08) pollen; 2) maize (M08) pollen stored in Harborlite® 1500S (2:1), manual pollination; or 3) maize (M08) pollen stored in Harborlite® 1500S (2:1), mechanical pollination. The pollen storage compositions were stored in a humidity chamber at 4°C and 97% humidity for 5–7 days prior to manual or mechanical pollination. Mechanical pollination was carried out using an applicator test bench with agitation and an air outlet velocity of 2.13 m / s. 32 mg of pollen were used for each pollination.Mechanical pollination was performed on three consecutive days corresponding to storage days 5, 6, and 7. Pollen germination was assessed on storage days 5, 6, and 7, both before and after mechanical application. Fresh M08 maize pollen had an average germination rate of 64.7 ± 1.4% on day 0. Mechanical pollination had no effect on pollen germination rates (Table 9). Seed yield was assessed 19 days after the first pollen application. Pollen storage compositions comprising Harborlite® 1500S yielded similar seed production following mechanical pollination compared to hand pollination (Table 10). Table 9. Germination of M08 corn pollen stored in Harborlite® 1500S before and after mechanical application. Storage Day % Avg. Germ. (pre-application) % Avg. Germ. (post-application) 5 22.8 ± 1.9 24.3 ± 4.4 6 10.6 ± 2.4 13.0 ± 0.9 238414 1680693 of 29 Storage Day % Average Germination (pre-application) % Average Germination (post-application) 7 8.3 ± 1.2 6.0 ± 0.8 Table 10. Seed production after manual or mechanical pollination using M08 corn pollen stored in Harborlite® 1500S. Composition Cob 1 Cob 2 Cob 3 Average Harborlite® 1500S, hand pollination 202 N / A / A 202 Harborlite® 1500S, mechanical pollination 230 269 304 267.7 ± 21.4

[0037] Suitable pollen storage compositions were evaluated by examining seed production following mechanical pollination with stored pollen using one of the following pollen storage compositions (ratios are given in vol:additive vol:pollen): 1) fresh or stored maize (M08) pollen; 2) maize (M08) pollen stored in Harborlite® 1500S (2:1); 3) maize (M08) pollen stored in Dicalite® HP100 (2:1); 4) maize (M08) pollen stored in Dicalite® HP120 (2:1); 5) maize (M08) pollen stored in Dicalite® HP200 (2:1); 6) maize (M08) pollen stored in Dicalite® HP220 (2:1); 7) maize (M08) pollen stored in Dicalite® HP900 (2:1); 8) corn pollen (M08) stored, placed at 4°C in the desiccator 1.5 hours before application; 9) corn pollen (M08) stored in Harborlite® 1500S (2:1) and placed at 4°C in the desiccator 1.5 hours before application.Pollen storage compositions were stored in a humidity chamber at 4°C and 97% humidity with an airflow of 8.0 L / min for 3 days prior to mechanical pollination. It should be noted that numerous experiments have shown that airflows between approximately 5.0 L / min and approximately 20.0 L / min yield the same results. Mechanical pollination was performed using an applicator test bench with agitation and an air outlet velocity of 2.13 m / s. Thirty-two mg of pollen were used per pollination. Mechanical pollination was carried out on three consecutive days using either fresh pollen or pollen stored for 3 days. Four or five replicates of mechanical pollination were performed for each pollen storage composition. Pollen germination was assessed on storage day 3 (Table 11). Fresh M08 maize pollen had an average germination rate of 88.6 ± 1.5% on day 0. The production of. 238414 1680693 of 29 seeds were evaluated 17 days after the first pollen application. Nine replicates of manual pollination (3 per day) were performed as a positive control. Manual pollination yielded 282.0 ± 73.8 kernels / ear. Pollen storage compositions comprising Harborlite® 1500S, Dicalite® HP200, Dicalite® HP220, and Dicalite® HP900 resulted in high seed production after 3 days of storage and mechanical pollination. (Table 12). Table 11. Germination of M08 maize pollen stored in Harborlite® 1500S, Dicalite® HP100, Dicalite® HP120, Dicalite® HP200, Dicalite® HP220 or Dicalite® HP900. Composition % Avg. Germ. Day 3 Pollen alone 80.5 ± 1.1 Harborlite® 1500S 73.0 ± 1.5 Dicalite® HP100 61.0 ± 0.5 Dicalite® HP120 53.7 ± 8.5 Dicalite® HP200 63.5 ± 0.7 Dicalite® HP220 58.8 ± 1.6 Dicalite® HP900 68.4 ± 4.3 Pollen alone, desiccator chamber 58.3 ± 0.6 Harborlite® 1500S, desiccator chamber 60.3 ± 2.9 Table 12. Seed production after mechanical pollination using M08 maize pollen stored in Harborlite® 1500S, Dicalite® HP100, Dicalite® HP120, Dicalite® HP200, Dicalite® HP220 or Dicalite® HP900. Composition Cob 1 Cob 2 Cob 3 Cob 4 Cob 5 Average Fresh pollen, day of storage 0 285 330 261 233 N / A 277.3 ± 41.1 Harborlite® 1500S, day of storage 0 315 276 228 210 N / A 257.3 ± 47.5 238414 1680693 of 29 Composition Cob 1 Cob 2 Cob 3 Cob 4 Cob 5 Average Dicalite® HP100, storage day 0 159 275 168 259 N / A 215.3 ± 60.2 Dicalite® HP120, storage day 0 319 296 267 280 N / A 290.5 ± 22.4 Dicalite® HP200, storage day 0 278 256 234 251 N / A 280.0 ± 50.8 Dicalite® HP220, storage day 0 283 274 328 312 N / A 299.3 ± 25.1 Dicalite® HP900, storage day 0 287 309 357 275 N / A 307.0 ± 36.2 Pollen stored, storage day 3 217 139 135 102 121 142.8 ± 43.9 Harborlite® 1500S, storage day 3 270 201 135 250 312 233.6 ± 68.1 Dicalite® HP100, storage day 3 154 142 86 102 145 125.8 ± 29.9 Dicalite® HP120, storage day 3 65 140 78 87 84 90.8 ± 28.8 Dicalite® HP200, storage day 3 180 176 176 234 189 191.0 ± 24.6 Dicalite® HP220, storage day 3 213 174 147 235 163 186.4 ± 36.5 Dicalite® HP900, storage day 3 266 276 184 272 265 252.6 ± 38.6 Pollen only, desiccator chamber 1.5 h,storage day 3 154 160 244 159 63 156.0 ± 64.1, 238414 1680693 of 29 Composition Cob 1 Cob 2 Cob 3 Cob 4 Cob 5 Average Harborlite® 1500S, drying chamber 1.5 h, storage day 3 149 160 112 215 257 178.6.0 ± 57.3

Claims

1. A pollen storage composition comprising: (a) at least one perlite particle; and (b) pollen, characterized in that the at least one perlite particle is present in the composition in a volume:volume (vol:vol) ratio of 1:1 to 5:1 with respect to said pollen. 25 Claims follow