Annual rapid breeding method for pansy

Abstract

The invention discloses an annual rapid breeding method for pansy, and belongs to the technical field of plant breeding, the method roughly comprises the steps of sowing treatment, light and temperature regulation and control, seedling stage management, reproduction intervention, seed treatment and generation circulation, and specifically adopts a photoperiod and temperature combined precise regulation and control and seed treatment technology. According to the method, the period of a single generation of viola tricolor is shortened to about 110 days, efficient breeding of continuous three generations in one year is achieved, the efficiency is improved by 2-3 times compared with a traditional method, the method is suitable for factory-like rapid breeding of viola tricolor, and an innovative technical scheme is provided for viola plant breeding.

Description

Technical Field

[0001] This invention belongs to the field of plant breeding technology, specifically relating to a rapid year-round breeding method for pansies. Background Technology

[0002] Traditional pansy breeding faces the following technical bottlenecks: (1) Under natural conditions, only one generation can be completed each year, and the cycle of each generation during the breeding process is as long as 210-250 days / generation. (2) Inaccurate control of light and temperature coupling leads to a long seedling period and late flowering. (3) Seed dormancy characteristics lead to difficulty in germination and uneven germination, and intergenerational connection takes 5-7 weeks. For example, CN102440136A discloses "a method for hybrid seed production of pansies," which is a conventional field cultivation and breeding method that can only complete one generation per year; CN104813919A discloses "a breeding method for pansies," which involves hybrid pollination and seed tissue culture, but does not involve generation acceleration; CN103141265A discloses "a method for industrialized tray seedling production of pansies," but does not involve generation acceleration or hybridization breeding; CN119183819A discloses "a method for regulating the early flowering of safflower using photoperiod," which, for safflower of the Asteraceae family, uses 20 hours of long light combined with high temperature (29℃ day / 24℃ night) to shorten the time from sowing to flowering to 84 days, but the technology is only applicable to safflower (Asteraceae family) and its applicability to Violaceae plants has not been verified; moreover, it does not design seed dormancy release measures or intergenerational succession to achieve multi-generational cycling.

[0003] Wang Junwei, Niu Fu, Wang Jianzhong, et al., Pansy hybridization seed production technology [J]. Northern Horticulture, 2000, (01): 63, disclosed the technology of field pansy hybridization seed production under natural conditions. The seed production cycle of this technology is relatively long, and only one generation can be completed each year. Liu Hongyu, Li Fanghua. Pansy hybridization seed production technology in greenhouse in Jiuquan area [J]. Shanghai Vegetables, 2012, (03): 15-16, disclosed the technology of pansy hybridization seed production using protected areas (including solar greenhouses). Although temperature control is involved, the daily light duration mainly depends on natural conditions and does not involve precise control of photoperiod and light-temperature coupling. Only 1-2 generations can be completed each year. Summary of the Invention

[0004] In order to overcome the technical defects of the existing technology, this invention proposes a rapid year-round breeding method for pansies.

[0005] To achieve the above objectives, the technical solution adopted by this invention is: a rapid year-round breeding method for pansies, comprising the following steps: (1) Sowing treatment: Pansy seeds are first soaked in warm water at 45-55℃ for 10-15 minutes (to sterilize and prevent seedling diseases), and then soaked at room temperature for 12-36 hours (to soften the seed coat and promote germination); the seeds are sown in 100-300 cell trays, the substrate is a water-saturated mixture of peat moss:vermiculite = 1~2:1 (v / v), the seeds are covered with vermiculite about 0.4-0.6 cm thick to avoid light, and then the trays are covered with perforated plastic film to keep them moist. They are cultured at 23±1℃ in the dark until the cotyledons unfold. (2) Light and temperature control: After emergence, implement a daily light cycle of 18-26 hours, dynamic temperature control of daytime temperature 20±1℃ / nighttime temperature 18±1℃; when the moisture content of the substrate in the seedling tray decreases and becomes lighter, replenish water in time; the light cycle includes 2 hours of dark treatment; (3) Seedling management: After the seedlings have 3-4 true leaves, they are transferred to nutrient pots or flower pots for cultivation. The substrate is peat moss: vermiculite: garden soil = 4:2:4 (v / v). Every 2 weeks, the leaves are sprayed with calcium nitrate solution or potassium nitrate solution or similar compound fertilizer. Water is added in time according to the plant's growth needs. (4) Reproductive intervention: Artificial directional pollination is carried out during the flowering period, and insect-proof net bags are used for isolation. The daytime temperature is 22±1℃ / nighttime temperature is 19±1℃. 22-25 days after fruit set, when the capsules are upright, they are harvested in time, ventilated and dried, and the seeds are extracted. (5) Seed treatment: Harvested seeds are treated at a low temperature of 2-6℃ for 12-16 days to break dormancy; (6) Generation cycle: Repeat steps (1)-(5) to achieve three consecutive breeding generations per year, with each generation cycle controlled at around 110 days.

[0006] Preferably, the peat soil is original Danish Pins peat soil with a particle size of less than 10 micrometers.

[0007] Preferably, in step (2), the 2-hour dark treatment time point is any two consecutive hours from 24:00 to 4:00 before dawn, ensuring that the seedling room is dark during the 2-hour dark treatment.

[0008] Preferably, in step (2), a 22-hour daily light cycle is implemented after seedling emergence.

[0009] Preferably, in step (2), the light intensity is 3000~3500 lux.

[0010] Preferably, in step (4), artificial pollination is carried out between 9:00 and 11:00 in the morning. After pollination is completed, an insect-proof net bag is put on to prevent non-target pollen from contaminating the seeds and to prevent the seeds from being lost due to the fruit not being harvested in time.

[0011] The beneficial effects achieved by this invention are: By employing ultra-long light exposure (3000~3500 lux) combined with suitable temperature, the growth of pansies and the transition from vegetative to reproductive growth were significantly accelerated, resulting in earlier flowering. This breakthrough compressed the generation cycle of pansies to 40-48% of that of conventional methods (110 days vs. 210-250 days). It achieved three generations per year, and this technology can complete six generations in two years, purifying inbred lines. Conventional methods require 5-6 years to complete inbred line purification, significantly shortening the breeding cycle. The innovative seed treatment process shortened the seed dormancy time (14 days vs. 50-70 days), improved the germination rate, and reduced seedling diseases. Attached Figure Description

[0012] Figure 1 Pansy seedlings treated with 16-hour light / 8-hour dark light and 22-hour light / 2-hour dark light were photographed on the 50th day after sowing. The temperature control was 23±1℃ after sowing and 20±1℃ during the day and 18±1℃ at night after emergence. Figure 2 The pansy seedlings were photographed on the 80th day after sowing, with a 16-hour light / 8-hour dark light cycle. The temperature control was 23±1℃ after sowing and 20±1℃ during the day and 18±1℃ at night after emergence. Figure 3 The pansy seedlings were photographed on the 80th day after sowing, with a 22-hour light / 2-hour dark light cycle. The temperature control was 23±1℃ after sowing and 20±1℃ during the day and 18±1℃ at night after emergence. Figure 4 The seeds of pansy were harvested under a 16-hour light / 8-hour dark light cycle. The temperature control was 23±1℃ after sowing and 20±1℃ during the day and 18±1℃ at night after emergence. Figure 5 The seeds of pansies were harvested under a 22-hour light / 2-hour dark light cycle. The temperature control was 23±1℃ after sowing and 20±1℃ during the day and 18±1℃ at night after emergence. Detailed Implementation

[0013] The present invention will be further described below through specific embodiments. Example

[0014] 1. Facility Preparation A seedling room equipped with a supplemental lighting system (light intensity 3500 lux) and environmental control equipment; 2. Sowing operations 200-cell seed trays were used with a water-saturated mixture of peat moss and vermiculite in a ratio of 2:1 (v / v). One seed was sown in each cell, and the seed was covered with 0.5 cm of vermiculite. The seed trays were covered with perforated plastic film and incubated in the dark at 23±1℃ for 5-7 days until seedlings emerged. 3. Seedling Management After the seedlings have 3-4 true leaves, transplant them into 12×14 cm nutrient pots or flower pots for cultivation. The substrate is peat moss: vermiculite: garden soil = 4:2:4. Spray the leaves with 0.01% calcium nitrate solution or potassium nitrate solution or similar compound fertilizer every 2 weeks, and water in time according to the plant's growth needs. 4. Environmental control After emergence, turn on the lighting equipment promptly, setting the photoperiod to 5:00-3:00 the next day (22 hours of light), and the temperature: 20±1℃ during the day and 18±1℃ at night; 5. Pollination and Seed Harvesting Artificial directional pollination should be carried out during the flowering period. Before flowering and after pollination, the flowers should be isolated with mesh bags. 22-25 days after fruit set, when the capsules are upright, they should be harvested in time, ventilated and dried, and the seeds should be extracted. 6. Key Data (1) From sowing to initial flowering: 51±2 days; (2) From pollination to seed collection: 23±2 days; (3) Generation succession: After the first generation is collected, the seeds are immediately treated at 4℃ for 14 days, and then the second generation is soaked and sown, completing 3 complete generations in one year.

[0015] Table 1 compares the flowering period, seed harvest time, and seed quality of pansies under two photoperiod treatments. Table 1

[0016] The above results indicate that a longer photoperiod can promote flowering in pansies; our comparative experiment showed that, in the long photoperiod treatment, a 22-hour / 2-hour (light / dark) photoperiod was significantly better than a 16-hour / 8-hour (light / dark) photoperiod in promoting pansy seedling growth and accelerating flowering. Figure 1 Pansies treated with a 22-hour / 2-hour (light / dark) photoperiod began to flower 51 days after sowing and reached full bloom on the 60th day, approximately 14 days and 20 days earlier than those treated with a 16-hour / 8-hour (light / dark) photoperiod, respectively. Figure 2 and Figure 3 (Table 1); Pansies treated with a 22-hour / 2-hour (light / dark) photoperiod could be harvested on day 91, 25 days earlier than those treated with a 16-hour / 8-hour (light / dark) photoperiod (Table 1); Although the thousand-seed weight of pansies treated with a 22-hour / 2-hour (light / dark) photoperiod was slightly lower than that of the light / dark (16-hour / 8-hour) photoperiod treatment (Table 1), the seed size, plumpness, and germination rate were not significantly affected. Figure 4 and Figure 5 (Table 1) can still produce healthy seedlings that flower and bear fruit normally, and reproduce offspring, so it has little impact on breeding work.

[0017] The above specific embodiments are used to explain and illustrate the present invention, but not to limit the present invention. Any modifications and changes made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A rapid year-round breeding method for pansies, characterized in that, Includes the following steps: (1) Sowing treatment: Pansy seeds were first soaked in warm water at 45-55℃ for 10-15 minutes, and then soaked at room temperature for 12-36 hours; the seeds were sown in 100-300 cell trays, the substrate was a water-saturated mixture of peat moss:vermiculite = 2~1:1 (v / v), the seeds were covered with vermiculite about 0.4-0.6 cm thick to avoid light, and then the trays were covered with perforated plastic film to keep them moist. They were cultured at 23±1℃ in the dark until the cotyledons unfolded. (2) Light and temperature control: After emergence, implement a daily light cycle of 18-26 hours, dynamic temperature control of daytime temperature 20±1℃ / nighttime temperature 18±1℃; when the moisture content of the substrate in the seedling tray decreases and becomes lighter, replenish water in time; the light cycle includes 2 hours of dark treatment; (3) Seedling management: After the seedlings have 3-4 true leaves, they are transferred to nutrient pots or flower pots for cultivation. The substrate is peat moss: vermiculite: garden soil = 4:2:4 (v / v). Every 2 weeks, the leaves are sprayed with calcium nitrate solution or potassium nitrate solution or similar compound fertilizer. Water is added in time according to the plant's growth needs. (4) Reproductive intervention: Artificial directional pollination is carried out during the flowering period, and insect-proof net bags are used for isolation. The daytime temperature is 22±1℃ / nighttime temperature is 19±1℃. 22-25 days after fruit set, when the capsules are upright, they are harvested in time, ventilated and dried, and the seeds are extracted. (5) Seed treatment: Harvested seeds are treated at a low temperature of 2-6℃ for 12-16 days to break dormancy; (6) Generation cycle: Repeat steps (1)-(5) to achieve three consecutive breeding generations per year, with each generation cycle controlled at around 110 days.

2. The method as described in claim 1, characterized in that, The two-hour darkness period refers to any consecutive two hours between 24:00 and 4:00 before dawn.

3. The method as described in claim 1, characterized in that, In step (2), a 22-hour daily light cycle is implemented after seedling emergence.

4. The method as described in claim 1, characterized in that, The illumination intensity is 3000~3500 lux white light.

5. The method as described in claim 1, characterized in that, The peat soil used is original Danish Pins peat soil with a particle size of 0-10 micrometers.

6. The method as described in claim 1, characterized in that, In step (4), artificial pollination is carried out between 9:00 and 11:00 in the morning. After pollination is completed, an insect-proof net bag is put on.

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