A hybrid breeding method for a solid high-yield product of oenanthe stolonifera d. don

Abstract

The application discloses a hybrid breeding method for a solid high-yield Oenanthe stolonifera product, and the method is characterized in that the time window of the female parent stigma available period and the male parent pollen vitality is precisely controlled, the female parent flower is emasculated and isolated 2-3 days before the female parent flower opens, fresh pollen of the male parent flower opened on the same day is used for pollination at 9-12 the next day, and the processes such as bagging isolation and sand storage for germination are combined, so that the problems of natural hybridization difficulty and low seed germination rate caused by the space-time separation of female and male organs of the Oenanthe stolonifera are solved. The hybrid seed setting rate is increased to more than 70%, and the seed germination rate is more than 85%, which provides efficient technical support for the improvement of the Oenanthe stolonifera variety.

Description

Technical Field

[0001] This invention pertains to agricultural breeding technology, specifically relating to a hybrid breeding method for improving the yield of high-yield varieties of solid dryland Chinese water celery through appropriate key techniques. Background Technology

[0002] Water celery (scientific name: Oenanthe javanica (Blume) DC., also known as wild celery or water celery, is a traditional Chinese aquatic vegetable. However, its long-term reliance on asexual reproduction has led to varietal degeneration and a narrow genetic base. Current technologies face the following bottlenecks: 1. Self-pollination barrier: Water celery is a hermaphroditic plant, a cross-pollinated crop, with male and female organs mismatched in space and time, making self-pollination and hybridization difficult. Studies have shown that its stigma can pollinate from the day of flowering to the third day, and the pollination ability weakens on the fourth day; pollen viability remains above 70% within 6 hours after flowering, and almost drops to zero after 24 hours.

[0003] 2. Difficulty in seed germination: Water celery seeds have deep dormancy and long-term wild characteristics, resulting in inconsistent seed development. Moreover, the seeds are still green when they fall off and are not fully mature. Under natural conditions, the germination rate is less than 20%.

[0004] 3. Low hybridization efficiency: Traditional methods result in a seed set rate of less than 30% because they do not accurately match the activity windows of male and female gametes.

[0005] 4. Although the existing technology CN201510529062.6 / 105075852A discloses a method for hybridizing water celery, it does not solve the problem of simultaneously optimizing pollen viability and stigma receptivity, as well as the problems of low hybridization rate and germination rate. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies, find the temporal patterns of key parameters in the reproductive biology of water celery, and based on this, construct a standardized hybridization process, proposing a water celery hybridization breeding method that can better perform water celery hybridization, with a high hybridization success rate and a high germination rate. The specific technical solution includes, but is not limited to, the following steps: A method for hybrid breeding of high-yielding solid dryland varieties of Chinese water celery, including but not limited to the following steps: First, select male and female parent materials that coincide in the flowering period of water celery, as they differ greatly in traits and come from different regions; 2. Two days before the mother plant is about to bloom, use pointed tweezers to remove the stamens along with the petals, being careful not to damage the stigma, and then bag the plant.

[0007] 3. Two to three days after emasculation, between 9 and 12 in the morning, collect pollen from the flowers that bloomed on the same day of the male parent for artificial pollination; 4. After pollination, the seeds are bagged and isolated. Once the seeds mature, the hybrid seeds are harvested and subjected to sand storage and variable temperature germination treatment.

[0008] Furthermore, male and female parent materials that coincided during the flowering period of water celery were selected, and the two were very different in traits. The female parent of water celery was "Chinese Water Celery" from Liaoning, and the male parent of water celery was "Multi-lobed Solid Water Celery" from Jieyang, Guangdong.

[0009] Furthermore, the bagging uses sulfuric acid paper bags.

[0010] Furthermore, the artificial pollination is performed on the 2nd to 3rd day after the female parent flowers, when the stigma peroxidase activity reaches its peak, i.e., 30-40% to the strongest; the male parent flowers on the same day, and its pollen viability is ≥70%.

[0011] Furthermore, the pollination time is from 9 a.m. to 12 p.m. daily, and the pollination method is by smearing.

[0012] Furthermore, the harvesting of hybrid seeds is carried out when the seeds are about to fall off, and the sand storage treatment involves mixing the seeds with moist fine sand at a ratio of 1:3 and storing them at room temperature for 30 to 40 days.

[0013] Furthermore, the conditions for the variable temperature germination treatment are alternating between 8 hours of treatment at 10℃ and 16 hours of treatment at 22℃ per day, for a period of 10-25 days.

[0014] The beneficial effects of this invention are as follows: Based on the results of the water celery stigma receptivity test (benzidine-hydrogen peroxide method) and pollen viability staining (MTT method), the optimal pollination period for the female parent is determined to be the 2nd to 3rd day after flowering, when the stigma peroxidase activity reaches its peak (30-40% to the strongest); at the same time, high-viability pollen (viability ≥70%) from the male parent is used 0-6 hours after flowering. Pollen / ovule synergistic regulation: Water celery has 2 ovules per flower and a pollen-ovule ratio of 3050-4015, which is consistent with the characteristics of obligate crossbreeding; Seed activation technology is used: physiological dormancy is broken by sand storage, and combined with alternating temperature germination (10℃ / 22℃), the hybridization seed setting rate is increased to over 70%, and the germination rate is increased to over 85%, providing efficient technical support for the improvement of water celery varieties. Detailed Implementation

[0015] The present invention will now be described in detail: Example: Standardized hybridization process 1. Parental preparation: - The maternal parent was selected from "Chinese Water Celery" from Liaoning, and the paternal parent was selected from "Multi-lobed Solid Water Celery" from Jieyang, Guangdong.

[0016] - Planting time: Both should be planted at the same time, such as in February or late October to early November, to ensure that the flowering periods coincide.

[0017] 2. Pollination procedure: - Demasking: Retain 8-10 uniformly developed flowers that are about to bloom from each inflorescence, and remove unopened and unevenly developed buds. Use arrow-shaped tweezers to remove the buds along with the petals, anthers, and filaments. Cover the inflorescence with a 10 cm * 10 cm parchment paper bag. It is best to do this before 9:00 AM or after 4:00 PM.

[0018] 3. Pollen collection: Between 9 a.m. and 12 p.m., collect pollen with a brush within one hour after the male parent flowers for later use.

[0019] 4. Key parameter control: Based on the fact that the stigma of the emasculated female parent is receptive on the second day after flowering, when the stigma peroxidase activity reaches its peak and is more receptive to exogenous pollen, hybridization is more likely to succeed. The male parent's pollen viability is strongest on the day of flowering (viability ≥70%). Pollination should be done by brush application or directional shaking to avoid self-pollination contamination.

[0020] Before pollination, remove any open flowers around the bagged mother plant to prevent contamination during hybridization. Pollination is most successful on sunny mornings between 9 and 12 pm. After pollination, promptly cover the plant with a 10 cm x 10 cm parchment paper bag and label it. After about 7 days, observe the seeds for swelling (swelling indicates successful hybridization) to confirm the results. At this point, remove the bag to allow the seeds to fully develop.

[0021] Water celery seeds will fall off when they reach a certain stage of development (about 30 days), are still green and not fully mature. Therefore, it is important to regularly observe the seed development and harvest the seeds promptly when they are about to fall off.

[0022] 5. Seed treatment: - Mix the harvested seeds with moist fine sand at a ratio of 1:3 and store at room temperature for 30-40 days.

[0023] - Germination: Daily temperature variation treatment at 10℃ (8h) / 22℃ (16h), with 12h / d light exposure (water celery seeds are light-requiring seeds), for 15 consecutive days.

[0024] Comparison of experimental data A comparison of the effects of the method of the present invention with conventional hybridization methods shows that the hybridization seed setting rate of the method of the present invention is 72.5% (compared to 28.3% for the conventional method) and the seed germination rate is 86.4% (compared to 19.7% for the conventional method).

[0025] This program has successfully bred a hybrid water celery variety, a new leafy water celery variety with a 40% increase in yield compared to the male and female parents, providing a standardized and scalable technical system for water celery hybrid breeding.

[0026] The foregoing description provides a detailed explanation of the technical solution of this invention. Obviously, this invention is not limited to the described content. Based on the foregoing description, those skilled in the art can make various modifications, but any modifications equivalent to or similar to this invention fall within the scope of protection of this invention.

Claims

1. A method for hybrid breeding of high-yielding, dry-seeded varieties of Chinese water celery, characterized in that... It can better perform water celery hybridization, with a high hybridization success rate and a high germination rate, including but not limited to the following steps: First, select male and female parent materials that coincide in the flowering period of water celery, as they differ greatly in traits and come from different regions; 2. Two days before the mother plant is about to bloom, use pointed tweezers to remove the stamens along with the petals, being careful not to damage the stigma, and then cover it with a bag.

3. Two to three days after emasculation, between 9 and 12 in the morning, collect pollen from the flowers that bloomed on the same day of the male parent for artificial pollination; 4. After pollination, the seeds are bagged and isolated. Once the seeds mature, the hybrid seeds are harvested and subjected to sand storage and variable temperature germination treatment.

2. The method according to claim 1, characterized in that, The maternal parent of the water celery was selected from "Chinese Water Celery" from Liaoning, and the paternal parent was selected from "Multi-lobed Solid Water Celery" from Jieyang, Guangdong.

3. The method according to claim 1, characterized in that, The bagging uses sulfuric acid paper bags.

4. The method according to claim 1, characterized in that, The artificial pollination was performed on the 2nd to 3rd day after the female parent flowered, when the stigma peroxidase activity reached its peak, i.e., 30-40% to the strongest; and on the day the male parent flowered, its pollen viability was ≥70%.

5. The method according to claim 1, characterized in that, The pollination time is from 9 a.m. to 12 p.m. daily, and the pollination method is by smearing.

6. The method according to claim 1, characterized in that, The harvested hybrid seeds are collected when they are about to fall off. The sand storage treatment involves mixing the seeds with moist fine sand at a ratio of 1:3 and storing them at room temperature for 30 to 40 days.

7. The method according to claim 1, characterized in that, The conditions for the variable temperature germination treatment are alternating between 8 hours of treatment at 10℃ and 16 hours of treatment at 22℃ per day, for a period of 10-25 days.