A short cultivation process peony hybrid new variety cultivation method

Abstract

The present application is suitable for peony cultivation technical field, and provides a short cultivation process peony hybrid new variety cultivation method, which comprises the steps of stock culture, hybrid offspring seedling, cultivation management and propagation, etc. By grafting 1-year-old hybrid seedlings and Fengdan seedlings, flower bud differentiation is promoted, the hybrid mother plant flowers in the fourth year, and after selecting excellent single plants, in-situ grafting propagation is carried out, and in the sixth year, the number of seedlings required for DUS test can be met. Compared with the traditional method, the breeding period is shortened by 4-5 years, the cost of land, labor, etc. is saved, the loss risk of excellent single plants is reduced, and it is beneficial to the development, protection and popularization of peony new varieties.

Description

Technical Field

[0001] This invention belongs to the field of peony cultivation technology, and in particular relates to a method for cultivating new hybrid peony varieties with a short cultivation process. Background Technology

[0002] Peony breeding is a complex and lengthy process. Traditional hybridization breeding requires a series of operations, such as collecting pollen, refrigerating pollen, removing emasculation, bagging, pollination, and seed selection, in order to obtain superior seeds.

[0003] Traditional breeding methods have significant technical problems. On the one hand, peonies have a long growth period in their early stages. Traditional hybridization breeding typically results in the first flowering after 5 years, and in some cases, it takes up to 8 years. After identifying superior individual plants that meet the breeding objectives, it is necessary to observe and record their traits for another 3 years, leading to an excessively long breeding cycle. According to relevant requirements, breeders need at least 10 years, or even longer, to meet the material quantity requirements for DUS testing of new varieties. On the other hand, during the long breeding period, losses caused by natural disasters or human-caused calamities, such as plant death or loss, are irreparable. Moreover, the observation of trait stability and consistency during the propagation and breeding of peonies is the biggest obstacle to applying for new peony plant variety rights. Summary of the Invention

[0004] The purpose of this invention is to provide a method for breeding new hybrid peony varieties with a short breeding process, aiming to solve the technical problems existing in the prior art as identified in the background art.

[0005] This invention is achieved by providing a method for cultivating new hybrid peony varieties with a short cultivation process, the method comprising:

[0006] Choose a sunny, high-lying, well-drained sandy loam plot as the rootstock nursery. One to two months before planting, deeply plow, prepare and disinfect the land, and apply organic fertilizer as base fertilizer.

[0007] In the autumn of the year of hybridization breeding, two-year-old seedlings of *Pterocarya stenoptera* were transplanted to the rootstock nursery, covered with soil for overwintering, and then cared for as rootstock the following year.

[0008] Mature hybrid seeds are harvested in groups and sown in the second half of August of the harvest year; raised beds are used for row sowing, each seed is individually numbered and marked, and after sowing, the seeds are covered with soil, tamped down, and watered, and covered with mulch in winter;

[0009] In the spring of the second year, hybrid seeds germinated to obtain hybrid seedlings, which were numbered and cared for. In the autumn, the entire hybrid mother plant was dug up, and seedlings of *Pteris vittata* with no diseases or pests and a root neck diameter of 2 cm were selected from the rootstock nursery for grafting in place and marked.

[0010] In the third year, grafted hybrid mother plants are cultivated so that the branches of the hybrid mother plants grow to 5-10cm in the autumn of that year, the terminal buds differentiate into flower buds, and 2-3 basal buds are formed at the root neck.

[0011] In the spring of the fourth year, when the hybrid mother plants bloom, select superior individual plants that meet the breeding objectives and mark them. Observe and record their specificity. In the autumn, cut the main branches as scions and graft them in the rootstock nursery to obtain at least one propagated hybrid seedling.

[0012] In the fifth year, continue to maintain the seedlings and observe the specificity, uniformity and stability of the flowering seedlings during the flowering period. In autumn, at least two scions should be cut from the mother plant and at least one scion should be cut from the propagation mother plant. Repeat the in-situ grafting method to obtain at least three propagation seedlings. In addition to the hybrid mother plant and the propagation mother plant, a total of five seedlings will be obtained.

[0013] Repeat the method from year 5 in year 6 to bring the total number of plants up to the DUS test requirements.

[0014] As a further embodiment of the present invention, the two-year-old seedlings of *Pteris vittata* are transplanted into the rootstock nursery at a plant spacing of 20-25 cm and a row spacing of 50-60 cm.

[0015] As a further embodiment of the present invention, the seeds are sown in the second half of August of the harvesting year, and the hybrid seeds are soaked in clean water for 1-2 hours before sowing.

[0016] As a further embodiment of the present invention, the raised beds are 15-20 cm high, 120 cm wide, 30 cm apart, and 2-3 cm deep.

[0017] As a further embodiment of the present invention, the on-site connection specifically refers to:

[0018] Remove more than 10 centimeters of soil from one side to expose the root neck. Cut off the branches above the root neck, leaving the roots in the soil. Use a grafting knife to cut the bark of the hybrid mother plant and rootstock from one side.

[0019] As a further embodiment of the present invention, in the 6th year, the survival rate is calculated using the formula 85%*95% based on 85% branching capacity and 95% grafting survival rate.

[0020] The beneficial effects of this invention are:

[0021] This method enhances root nutrient absorption and plant resistance by grafting one-year-old hybrid seedlings with robust 2-3 year old peony seedlings in the autumn of the second year, enabling flowering in the spring of the fourth year and shortening the flowering time. After selecting superior individual plants, they can be propagated through in-situ grafting, meeting the minimum quantity requirements for DUS testing of new varieties by the sixth year. Compared with traditional breeding methods, this shortens the time by 4-5 years. Early flowering and propagation also ensures that irreparable losses are not caused by the accidental death or loss of superior individual plants. At the same time, this method does not require a grafting nursery, saving land use fees and a lot of manpower, material resources, and financial resources, which is conducive to the development, protection, and promotion of new peony varieties. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0023] A method for breeding new hybrid peony varieties with a short breeding process, the method comprising:

[0024] I. Rootstock Cultivation Stage

[0025] (I) Site selection and land preparation

[0026] Site selection: Select a sunny, high-lying sandy loam plot with good drainage and irrigation in advance as the rootstock nursery to ensure that the plot has sufficient sunlight and is not prone to waterlogging, which is conducive to the growth of rootstock roots.

[0027] Soil treatment: 1-2 months before planting, deep plow the land to a depth suitable for root development; after deep plowing, disinfect the land (e.g., apply disinfectant) to kill soil pathogens and insect eggs; apply organic fertilizer as base fertilizer, the amount of fertilizer to be determined according to soil fertility.

[0028] (II) Cultivating Rootstock

[0029] Transplanting time and specifications: In the autumn of the same year of hybridization breeding, select healthy 2-year-old seedlings of *Pterocarya stenoptera* and transplant them to the rootstock nursery at a plant spacing of 20-25 cm and a row spacing of 50-60 cm.

[0030] Overwintering and maintenance: After transplanting, cover the soil to overwinter. In the following year, carry out weeding, fertilization (combination of organic and chemical fertilizers), water management (watering during drought and drainage during rainy season), and pest and disease control, and cultivate backup rootstocks.

[0031] II. Seedling stage of hybrid offspring

[0032] (I) Treatment of Hybrid Seeds

[0033] Seed harvesting: Hybrid seeds are harvested in groups after they mature to avoid confusion between different combinations.

[0034] Soaking treatment: Before sowing in late August of the same year, soak the seeds in clean water for 1-2 hours to allow the seed coat to absorb water and swell, promoting germination.

[0035] (II) Sowing Method

[0036] Bed preparation and sowing: High-bed row sowing is adopted, with a bed height of 15-20 cm, a bed width of 120 cm, a row spacing of 30 cm, and a sowing depth of 2-3 cm. Each hybrid combination is individually numbered and marked.

[0037] Covering and management: After sowing, cover with soil, tamp it down, and water thoroughly. In winter, cover with straw, leaves, or mulch to keep warm and moist, which is beneficial to root growth.

[0038] (III) Hybrid Seedling Management

[0039] Seedling cultivation: After the seeds germinate in the following spring, hybrid mother plants are obtained, numbered according to combination and carefully cared for (watering, fertilizing, weeding).

[0040] Approach grafting: In autumn, dig up the hybrid mother plant, select a healthy 'Fengdan' seedling with a root neck diameter of 2 cm from the rootstock nursery, remove the top 10 cm of soil on one side of the rootstock to expose the root neck, cut off the branches above the root neck, and retain the roots; use a grafting knife to cut the bark on one side of the hybrid mother plant and the rootstock to approach graft, bind and fix it and mark it (the number is consistent with the mother plant).

[0041] The entire one-year-old hybrid mother plant is dug up, while the rootstock of the *Pterocarya stenoptera* seedling is not dug up. Grafting is performed in situ to advance the grafting process and improve the survival rate. Furthermore, the roots of both the hybrid mother plant and the rootstock can simultaneously absorb nutrients from the soil, nourishing the hybrid mother plant and promoting vigorous growth of the grafted seedling. This lays a solid foundation for flower bud differentiation and propagation through grafting in the third year. This process is at least 1-2 years earlier than conventional grafting propagation.

[0042] III. Cultivation, Management, and Propagation Stage

[0043] (I) 3rd Year Management

[0044] Carefully cultivate the grafted mother plant and ensure nutrient supply. In the autumn of the same year, the branches will grow to 5-10 cm, the terminal buds and flower buds will differentiate, and 2-3 basal buds will form at the root neck.

[0045] (II) Operation in the 4th year

[0046] Flowering selection: When the mother plant flowers for the first time in spring, select superior individual plants that meet the breeding objectives (such as A-1) and mark them, recording their specific characteristics (flower shape, color, flowering period, etc.).

[0047] The grafted hybrid mother plant flowers for the first time, allowing for the early selection of superior individual plants that meet the breeding objectives; and it also allows for the early acquisition of propagation hybrid seedlings (i.e., propagation mother plants). This is at least 1-2 years earlier than the conventional method of selecting superior individual plants for new varieties (5-6 years).

[0048] Propagation and grafting: In autumn, when the branches of the mother plant grow to 10-15 cm, 1-2 lateral branches will sprout from the basal buds. The main branches are cut off as scions and grafted in the rootstock nursery to obtain at least one propagation seedling. The seedling number is the same as that of the mother plant. At this time, a total of 2 seedlings are obtained.

[0049] (III) Operation in the 5th year

[0050] Flowering period observation: Maintain seedlings and observe the distinctiveness, uniformity and stability of flowering seedlings.

[0051] Propagation process: In autumn, take at least 2 scions from the mother plant and 1 scion from the propagation seedling. Repeat the grafting process in situ to obtain at least 3 propagation seedlings. Add the mother plant and the propagation seedlings from the previous year to obtain a total of 5 seedlings.

[0052] (iv) Operation in the 6th year

[0053] Propagation and Calculation: Following the method of the 5th year, 4 propagation seedlings are obtained from 1 mother plant, 2 seedlings are obtained from 1 propagation mother plant, and 3 seedlings are obtained from 3 new propagation mother plants, for a total of 14 seedlings; based on 85% branching ability and 95% grafting survival rate, at least 11 seedlings of different ages are obtained for DUS testing.

[0054] IV. Specific Implementation Examples (Taking "Gathering Together" as an Example)

[0055] (I) 2015

[0056] Spring hybridization (Tianxiang Zhanlu female parent × Xiangyu male parent) yielded 12 seeds in late July, which were treated and sown in late August and marked (A).

[0057] Simultaneously, select rootstock nurseries, prepare the land and fertilize, and transplant 2-year-old seedlings of *Pteris vittata* for maintenance.

[0058] (II) 2016

[0059] Eight seeds germinate in spring, marked A-1 to A-8, and are regularly fertilized with a special nutrient solution.

[0060] In autumn, the hybrid seedlings are dug up and grafted on-site at the rootstock nursery and marked.

[0061] (III) 2017

[0062] Grafted seedlings grow on single branches, with terminal buds and flower buds differentiating, and 2-3 dormant buds growing at the root neck.

[0063] (iv) 2018

[0064] The plant that flowers for the first time in spring is marked as a superior single plant A-1, and its specificity is recorded.

[0065] In autumn, terminal buds were cut and grafted in situ to obtain one propagation seedling, for a total of two seedlings.

[0066] (V) 2019

[0067] During the flowering period, two scions were cut from the mother plant in autumn, and one propagation seedling was cut to obtain three new propagation seedlings, for a total of five seedlings.

[0068] (vi) 2020

[0069] The process was repeated to obtain 14 seedlings, which were then subjected to DUS testing.

[0070] (vii) 2021

[0071] Approved by the Peony and Paeonia Branch of the China Flower Association.

[0072] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for breeding new hybrid peony varieties with a short breeding process, characterized in that, The method includes: Choose a sunny, high-lying, well-drained sandy loam plot as the rootstock nursery. One to two months before planting, deeply plow, prepare and disinfect the land, and apply organic fertilizer as base fertilizer. In the autumn of the year of hybridization breeding, two-year-old seedlings of *Pterocarya stenoptera* were transplanted to the rootstock nursery, covered with soil for overwintering, and then cared for as rootstock the following year. Mature hybrid seeds are harvested in groups and sown in the second half of August of the harvest year; raised beds are used for row sowing, each seed is individually numbered and marked, and after sowing, the seeds are covered with soil, tamped down, and watered, and covered with mulch in winter; In the spring of the second year, hybrid seeds germinated to obtain hybrid seedlings, which were numbered and cared for. In the autumn, the entire hybrid mother plant was dug up, and seedlings of *Pteris vittata* with no diseases or pests and a root neck diameter of 2 cm were selected from the rootstock nursery for grafting in place and marked. In the third year, grafted hybrid mother plants are cultivated so that the branches of the hybrid mother plants grow to 5-10cm in the autumn of that year, the terminal buds differentiate into flower buds, and 2-3 basal buds are formed at the root neck. In the spring of the fourth year, when the hybrid mother plants bloom, select superior individual plants that meet the breeding objectives and mark them. Observe and record their specificity. In the autumn, cut the main branches as scions and graft them in the rootstock nursery to obtain at least one propagated hybrid seedling. In the fifth year, continue to maintain the seedlings and observe the specificity, uniformity and stability of the flowering seedlings during the flowering period. In autumn, at least two scions should be cut from the hybrid mother plant and at least one scion should be cut from the propagation hybrid mother plant. Repeat the in-situ grafting method to obtain at least three propagation seedlings. In addition to the hybrid mother plant and the propagation hybrid mother plant, a total of five seedlings will be obtained. In the 6th year, the method of the 5th year was repeated to bring the total number of plants to the DUS test requirements. The two-year-old seedlings of *Pteris vittata* were transplanted to the rootstock nursery at a spacing of 20-25 cm between plants and 50-60 cm between rows. The seeds are sown in the second half of August of the harvesting year, and the hybrid seeds are soaked in clean water for 1-2 hours before sowing. In the raised bed row sowing, the bed height is 15-20 cm, the bed width is 120 cm, the row spacing is 30 cm, and the sowing depth is 2-3 cm; The on-site docking specifically refers to: Remove more than 10 centimeters of soil from one side to expose the root neck. Cut off the branches above the root neck, leaving the roots in the soil. Use a grafting knife to cut the bark of the hybrid mother plant and rootstock from one side.

2. The method according to claim 1, characterized in that, In the 6th year, based on 85% branching capacity and 95% grafting survival rate, the survival rate is calculated using the formula 85%*95%.