A method for crossing tagetes
By specifically cutting and artificially pollinating marigold buds, the problem of difficult artificial pollination in marigold hybridization has been solved, enabling hybridization of any marigold variety. This method has the advantages of low cost, simple operation, and short cycle.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHENGUANG BIOTECH GRP CO LTD
- Filing Date
- 2024-10-30
- Publication Date
- 2026-06-02
AI Technical Summary
In existing technologies, marigold hybridization mainly relies on male-sterile dual-purpose lines, which are difficult to pollinate artificially and make it hard to achieve effective hybridization between fertile flowers.
By performing specific cutting treatment on marigold flower buds to remove the outer ray florets without stamens, and then conducting artificial pollination at the appropriate time, hybridization between fertile flowers can be achieved by utilizing the developmental characteristics of marigold flowers.
It breaks free from the constraints of male-sterile dual-purpose lines, enabling the creation of hybrids of any two marigold varieties, maximizing the utilization of germplasm resources, and is low-cost, simple to operate, and has a short cycle.
Smart Images
Figure FT_1 
Figure FT_2 
Figure FT_3
Abstract
Description
Technical Field
[0001] This invention relates to the field of plant cultivation technology, and more specifically, to a method for hybridizing marigolds. Background Technology
[0002] marigold( Tagetes erecta L Marigold (Mallotus truncata) is an annual herbaceous plant belonging to the genus Marigold in the family Asteraceae, native to Mexico. Marigold flowers are rich in natural pigments, such as lutein, zeaxanthin, and quercetin, which can be used as raw materials for food, feed, and medicine. The α-terthiophene in marigold roots is an effective soil insecticide. Simultaneously, the flowers and leaves of marigolds can be used medicinally, possessing properties that clear heat, resolve phlegm, nourish blood, promote menstruation, and remove blood stasis and promote tissue regeneration. Therefore, marigolds hold an important position in the fields of chemical engineering, food, environmental protection, and medicine.
[0003] Currently, marigold seed production mainly relies on male-sterile dual-purpose lines, and there are no reports of artificial pollination between fertile flowers. Marigold flowers are capitula with numerous florets, divided into ray florets and disc florets, making artificial emasculation difficult and unfavorable for hybridization. Therefore, it is necessary to further study hybridization methods for marigolds. Summary of the Invention
[0004] One of the objectives of this invention is to provide a new method for producing marigold hybrids without relying on male-sterile dual-purpose lines.
[0005] This invention provides a method for hybridizing marigolds. When the outermost ray florets on the maternal parent flower bud grow to 0.5-1 cm beyond the calyx, the maternal parent is treated and then used for hybridization with the paternal parent.
[0006] The processing of the parent plant includes:
[0007] (1) Trim along the tip of the calyx to remove the ligulate petals that extend beyond the calyx;
[0008] (2) Cut at the bottom of the flower bud to remove part of the flower bud, forming a notch that exposes the small flowers in the remaining flower bud;
[0009] The order of steps (1) and (2) is not limited;
[0010] (3) Remove all the small flowers with stamens from the remaining flower buds through the gap;
[0011] If the parent plant only includes ray florets, then the florets refer to ray florets; if the parent plant includes both ray florets and disc florets, then the florets refer to both ray florets and disc florets.
[0012] This invention utilizes the characteristics of the outermost ray florets of marigold flowers to develop a novel method for producing hybrid varieties that does not rely on male-sterile dual-purpose lines. Specifically, marigolds have capitulum inflorescences, with each flower containing multiple florets. Depending on the marigold variety, some marigolds have only ray florets, while others have florets that include both ray and disc florets. Disc florets are complete flowers, containing stamens and pistils, and possess the ability to self-pollinate. However, this invention has discovered that some ray florets in various marigold varieties lack stamens, making them naturally sterile florets that can only produce seeds through pollination from other florets. These stamen-less florets are generally located on the outermost edge of the flower, while marigold flowering is characterized by the rapid development of outer florets and slower development of inner florets. Based on this, this invention develops a novel method for marigold hybridization through artificial pollination between fertile florets by specifically cutting the buds of the female parent at a specific developmental stage.
[0013] The artificial pollination method between fertile flowers of the present invention breaks free from the constraints of male-sterile dual-purpose lines, can create hybrids of any two marigold varieties, maximizes the utilization of hybrid vigor among marigold germplasm resources, and is low in cost, simple to operate, and short in cycle, which is conducive to its promotion and application.
[0014] During the research and development of this invention, an attempt was made to retain only one stamen-less floret in the center of each marigold flower as the parent plant. However, experiments revealed that this method resulted in the floret remaining in the center of the flower easily drying out and falling off, making it unsuitable as an effective parent plant. Therefore, after repeated research, the invention solution utilizing the peripheral stamen-less ray florets as the parent plant was finally obtained.
[0015] In this invention, the timing of treating the mother plant is crucial. The mother plant should be treated when the outermost ray florets on the flower buds have grown to 0.5-1 cm beyond the calyx. If treatment is done too early, the flower buds will be too small, and the inner florets will be too small, making subsequent removal difficult. If treatment is done too late, the flower buds will be too large, and the petals of the outer florets will be too long, making it easy to cut the stigma when removing the exposed petals, thus failing to obtain a suitable mother plant for pollination. Therefore, this invention specifically sets reasonable treatment times based on the developmental characteristics of various marigold varieties.
[0016] In step (1) of the method of the present invention, the column head is avoided during the flush trimming.
[0017] In step (2) of the method of the present invention, the bottom of the flower bud is cut along the direction perpendicular to the longitudinal axis of the flower bud.
[0018] This invention cuts the flower buds, which not only removes some of the florets with stamens, saving time in subsequent operations, but also provides an operational gap and space for removing the florets with stamens from the remaining flower buds. This allows subsequent operations to be carried out smoothly while preserving the florets (ray flowers without stamens) without easily damaging the surrounding target.
[0019] In step (2) of the method of the present invention, the removed flower buds account for 1 / 3 to 1 / 2 of the entire flower bud.
[0020] The size of the flower buds to be removed in this invention is not limited, as long as it facilitates the smooth removal of small flowers carrying stamens.
[0021] In the method of the present invention, the parent plant is bagged after treatment for later use.
[0022] In the method of the present invention, pollination is carried out after the petals emerge from the stigma of the remaining florets after the parent plant has been treated.
[0023] Generally, 1-2 days after the treatment of the parent plant, the stigmas of the remaining ray florets will sprout petals, allowing for subsequent hybridization and pollination. Seeds can be harvested 15-20 days after pollination.
[0024] In the method of this invention, when hybridizing with the male parent, pollen from the healthy and robust male parent is collected and applied to the stigma of the remaining florets after the treatment of the female parent.
[0025] In the method of the present invention, when applying pollen, the remaining small flowers after the parent plant treatment are temporarily fixed (e.g., held by hand) to prevent them from falling off during pollination.
[0026] In the method of this invention, the number of pollination times is 1-3 times, preferably 2 times.
[0027] In the method of this invention, the interval between each pollination is 24 hours.
[0028] The beneficial effects of this invention are at least as follows:
[0029] (1) This invention breaks free from the constraints of male-sterile dual-purpose lines and can create hybrids of any two marigold varieties, maximizing the use of hybrid vigor among marigold germplasm resources; (2) The method of this invention has the advantages of low cost, simple operation and short cycle. Attached Figure Description
[0030] Figure 1 These are photos of marigolds before and after hybridization treatment. The left image shows the marigold female parent to be treated; the right image shows the treated female parent.
[0031] Figure 2 The first image shows the mother plant that continued to grow after treatment; the second image shows the mother plant with petals emerging from the stigma after treatment; the third image shows the mother plant that bore fruit after hybridization and pollination; and the fourth image shows the control mother plant that was not pollinated after treatment.
[0032] Figure 3 Photographs of ray florets (left) and disc florets (right). Detailed Implementation
[0033] The preferred embodiments of the present invention will now be described in detail with reference to specific examples. It should be understood that the following examples are given for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art can make various modifications and substitutions to the present invention without departing from its spirit and essence.
[0034] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available or prepared according to conventional methods in the art.
[0035] Specific information on the marigold materials used in the embodiments of this invention is shown in Table 1.
[0036] Table 1
[0037]
[0038] For Scarlet No. 1, please refer to the literature Chen Liwen, Tang Nan. Evaluation of the main agronomic traits of different varieties of pigmented marigolds [J]. Anhui Agricultural Sciences, 2021, 49(4): 53-55.
[0039] Guanying can be purchased from Chifeng Zhongguan Seed Industry Co., Ltd. Shanshan can be purchased from Jiuquan Jinqiu Horticulture Seedling Co., Ltd.
[0040] Example 1
[0041] This embodiment provides a method for marigold hybridization, as detailed below:
[0042] 1. Test materials
[0043] Scarlet One was used as the male parent and Crown Winner as the female parent.
[0044] 2. When the outermost ray florets on the mother plant's flower buds grow to more than 1 cm beyond the calyx (see...) Figure 1 The left image in the image is used for parent text processing, as follows:
[0045] (1) Trim the calyx at the same level (be careful not to cut off the stigma), remove the ray florets that extend beyond the calyx, and avoid the petals blocking the stigma during pollination to improve the seed setting rate.
[0046] (2) Cut a notch in the flower bud from the bottom.
[0047] Specifically, in this embodiment, a flush cut is made at the bottom of the flower bud along a direction perpendicular to the longitudinal axis of the flower bud, removing half of the flower bud and forming a notch that exposes the small flowers in the remaining flower bud.
[0048] (3) Clean out all the small flowers with stamens from the remaining flower buds through the gap formed above.
[0049] Specifically, following the opening, clean out the small flowers inside, observing whether each flower has pollen sacs. If so, remove them until only ligulate florets without pollen sacs remain around the flower bud. See the photo of the treated mother plant. Figure 1 The right image in the text.
[0050] (4) After trimming, put the bag (parchment paper bag) on the bag for later use.
[0051] 3. Pollination after collecting pollen from the male parent.
[0052] When the stigma of the mother plant flower (only the ligulate flowers without stamens remain) sprouts petals (see...) Figure 2 After pollination (see left image), select a healthy and robust male parent plant as a backup for pollen collection. Gently use a paintbrush to collect pollen from the male parent's flowers, then transfer the pollen to the treated female parent flowers. During pollination, hold the female parent's florets (the remaining stamen-less ray florets after the above treatment) in place and gently apply the pollen from the brush to the stigma to prevent the florets from falling off. Finally, cover the flowers with a parchment bag and record the pollination time and pollinator variety information. Perform artificial pollination twice using the same method, once a day.
[0053] 4. Seed harvesting
[0054] Seven days after pollination, the seeds of successfully pollinated florets will turn black and harden (see...). Figure 2 (The middle image). Seeds can be harvested 15-20 days after pollination.
[0055] The control parent plant, which was treated but not pollinated, produced no seeds (see [reference]). Figure 2 (The image on the right).
[0056] 5. Results Statistics
[0057] 120 seeds were randomly selected from the harvested seeds for a planting experiment. No sterile plants appeared in the offspring, indicating that the obtained seeds were hybrids and not produced by self-pollination of the female parent.
[0058] The formula for calculating the hybrid seed setting rate is: Hybrid seed setting rate (%) = (Number of hybrid seeds / Number of female florets used in hybridization) × 100%.
[0059] In this experiment, a total of 900 female florets were pollinated, and a total of 416 hybrid seeds were harvested, with a hybrid seed setting rate of 46.22%.
[0060] Example 2
[0061] This embodiment provides a method for marigold hybridization, which is basically the same as the method in Embodiment 1, except that Scarlet No. 1 is used as the male parent and Mountain is used as the female parent (photographs of some of its ray florets and disc florets can be found in...). Figure 3 Among them, the main stem of Scarlet No. 1 is purple, and the main stem of Mountain is green. Purple is dominant over green. The mother plant is treated when the outermost ray florets on the mother plant flower buds grow to more than 0.5 cm beyond the calyx. The order of the mother plant treatment steps (1) and (2) is reversed.
[0062] In this experiment, a total of 82 female florets were pollinated, and 30 hybrid seeds were harvested, resulting in a seed setting rate of 36.59%. The 30 hybrid seeds were sown, and the color of their main stems was observed. The results showed that the main stems of all 30 hybrid seeds were purple, indicating that the purity of the hybrid seeds obtained using the method of this invention was 100%.
[0063] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.
Claims
1. A method for hybridizing marigolds, characterized in that, When the outermost ray florets on the female parent flower bud grow to 0.5-1 cm beyond the calyx, the female parent is treated and then used for hybridization with the male parent. The processing of the parent plant includes: (1) Trim along the tip of the calyx to remove the ligulate petals that extend beyond the calyx; (2) Cut at the bottom of the flower bud to remove part of the flower bud, forming a notch that exposes the small flowers in the remaining flower bud; The order of steps (1) and (2) is not limited; (3) Remove all the small flowers with stamens from the remaining flower buds through the gap; If the parent plant only includes ray florets, then the florets refer to ray florets; if the parent plant includes both ray florets and disc florets, then the florets refer to both ray florets and disc florets. In step (1), when trimming flush, avoid the column head.
2. The method according to claim 1, characterized in that, In step (2), the bottom of the flower bud is cut along the direction perpendicular to the longitudinal axis of the flower bud.
3. The method according to claim 1 or 2, characterized in that, In step (2), the removed flower buds account for 1 / 3 to 1 / 2 of the entire flower bud.
4. The method according to claim 1 or 2, characterized in that, The parent plant is bagged after processing and is ready for use.
5. The method according to claim 3, characterized in that, The parent plant is bagged after processing and is ready for use.
6. The method according to claim 1, 2, or 5, characterized in that, After the stigmas of the remaining florets after the parent plant has been treated have emerged with petals, pollination will be carried out.
7. The method according to claim 3, characterized in that, After the stigmas of the remaining florets of the parent plant have emerged and petals have appeared, pollination will be carried out.
8. The method according to claim 4, characterized in that, After the stigmas of the remaining florets after the parent plant has been treated have emerged with petals, pollination will be carried out.
9. The method according to claim 1, 2, 5, 7 or 8, characterized in that, When hybridizing with the male parent, pollen from the healthy and robust male parent is collected and applied to the stigma of the remaining florets of the female parent after treatment.
10. The method according to claim 3, characterized in that, When hybridizing with the male parent, pollen from the healthy and robust male parent is collected and applied to the stigma of the remaining florets of the female parent after treatment.
11. The method according to claim 4, characterized in that, When hybridizing with the male parent, pollen from the healthy and robust male parent is collected and applied to the stigma of the remaining florets of the female parent after treatment.
12. The method according to claim 6, characterized in that, When hybridizing with the male parent, pollen from the healthy and robust male parent is collected and applied to the stigma of the remaining florets of the female parent after treatment.
13. The method according to claim 9, characterized in that, When applying pollen, temporarily fix the remaining small flowers after the parent plant treatment to prevent them from falling off during pollination.
14. The method according to any one of claims 10-12, characterized in that, When applying pollen, temporarily fix the remaining small flowers after the parent plant treatment to prevent them from falling off during pollination.
15. The method according to claim 6, characterized in that, Pollination should be performed 1-3 times.
16. The method according to claim 7 or 8, characterized in that, Pollination should be performed 1-3 times.
17. The method according to claim 15, characterized in that, Pollination is performed twice.
18. The method according to claim 16, characterized in that, Pollination is performed twice.
19. The method according to claim 15, 17 or 18, characterized in that, Each pollination session should be spaced 24 hours apart.
20. The method according to claim 16, characterized in that, Each pollination session should be spaced 24 hours apart.