A method for accelerating flowering and fruiting of awnless bromeliad indoors and its application

Abstract

This invention belongs to the field of plant breeding and cultivation regulation technology, and provides a method for accelerating flowering and fruiting of awnless bromegrass indoors and its application. The method includes: (1) seedling growth stage: awnless bromegrass seedlings are placed under long-day and high-temperature conditions for cultivation; (2) short-day induction stage: awnless bromegrass seedlings cultivated in step (1) are transferred to short-day and low-temperature conditions for induction cultivation; (3) long-day flowering stage: plants induced in step (2) are transferred to long-day and high-temperature conditions for continued cultivation to induce flowering and fruiting of plants and the formation of mature seeds. The method of this application is applicable to the regulation of flowering period of awnless bromegrass, hybridization and generation propagation, and provides a powerful tool for its breeding and research.

Description

Technical Field

[0001] This invention belongs to the field of plant breeding and cultivation regulation technology. Specifically, this application provides a method for accelerating flowering and fruiting of awnless bromeliad indoors and its application. Background Technology

[0002] Awnless brome (Bromus inermis Leyss.) is a wind-pollinated, cross-pollinated perennial grass belonging to the Poaceae family. Awnless brome is a short-day plant; its flower induction process requires short days, while flower organ formation requires long days. Under field conditions, awnless brome is generally sown in spring or autumn, with flowering and fruiting occurring from June to August. Spring-sown awnless brome typically yields mature seeds in about six months, but the first-year seed yield is low. Autumn-sown awnless brome requires an even longer time to reach mature seeds.

[0003] Photoperiod is the length of time a plant is exposed to a predetermined light and dark state each day. It promotes flowering by influencing the plant's physiological and biochemical responses. As a short-day plant, awnless bromegrass requires a period of growth under short-day conditions (8-14 hours of light) before it can flower and bear fruit under long-day conditions (≥15 hours of light).

[0004] Temperature changes throughout a plant's life cycle are another environmental clue that causes significant variations in flowering time. Generally, high temperatures accelerate flowering, while low temperatures delay it. Awnless bromegrass needs to grow at 10-21℃ for a period of time before flowering and fruiting at 20-25℃.

[0005] The propagation of awnless bromegrass seeds has always relied on natural field conditions, which has limited the progress of awnless bromegrass breeding and research on flowering, fertilization and fruit setting in my country. At present, there is little research on the induction of flowering in awnless bromegrass. Summary of the Invention

[0006] This invention aims to solve the problems of long breeding cycles and difficulty in stable flowering and fruiting in the same year under natural conditions for awnless bromegrass. It provides a method to induce awnless bromegrass to flower and fruit earlier by artificially controlling the duration of light and temperature conditions, so as to achieve generational breeding.

[0007] On one hand, the present invention provides a method for accelerating the flowering and fruiting of awnless bromeliads indoors, the method comprising:

[0008] (1) Seedling growth stage: Place the awnless bromegrass seedlings under long-day and high-temperature conditions for cultivation;

[0009] (2) Short-day induction stage: The awnless bromegranate seedlings cultured in step (1) are transferred to short-day and low-temperature conditions for induction culture;

[0010] (3) Long-day flowering stage: The plants induced and cultured in step (2) are transferred to long-day and higher temperature conditions for further cultivation in order to induce the plants to produce spikes and flowers, as well as select plants to produce mature seeds.

[0011] Furthermore, the culture conditions for the short-day induction stage described in step (2) are: day duration 7-9h / d, temperature 15-20℃, light intensity 80-120 μmol·m⁻²·s⁻¹, and induction culture time 5-11 weeks.

[0012] Furthermore, the culture conditions for the short-day induction stage described in step (2) are: 8h / d sunshine duration, 15-20℃ temperature, 100 μmol·m⁻²·s⁻¹ light intensity, and 5-11 weeks of induction culture.

[0013] Furthermore, in step (2), the temperature is 20°C and / or the induction culture time is 11 weeks.

[0014] Furthermore, the cultivation conditions for the seedling growth stage described in step (1) are: 20-25 h / d sunshine duration, 22-28℃ temperature, 300-400 μmol·m⁻²·s⁻¹ light intensity, and 2-4 weeks of cultivation time.

[0015] Furthermore, the cultivation conditions for the seedling growth stage described in step (1) are: 22 h / d sunshine duration, 25℃ temperature, 200 μmol·m⁻²·s⁻¹ light intensity, and 3 weeks of cultivation time.

[0016] Furthermore, the cultivation conditions for the long-day flowering stage described in step (3) are: day length 20-24 h / d, temperature 22-28℃, and light intensity 350-400 μmol·m⁻²·s⁻¹.

[0017] Furthermore, the cultivation conditions for the long-day flowering stage described in step (3) are: day length 22 h / d, temperature 25℃, and light intensity 380 μmol·m⁻²·s⁻¹.

[0018] Furthermore, in the method, the awnless bromegranate seedlings are planted in 8×8×12cm flowerpots filled with cultivation substrate, which is composed of potting soil, vermiculite and peat moss in a volume ratio of 1:1:2.

[0019] Furthermore, in steps (1) and (2), water is applied according to the dryness or wetness of the substrate to keep the surface of the substrate moist, without applying any additional nutrients.

[0020] Furthermore, in step (3), potassium dihydrogen phosphate water-soluble fertilizer is applied, and water is applied according to the dryness and wetness of the substrate to keep the surface of the substrate moist; watering is stopped after the plant enters the waxy maturity stage to promote seed maturation.

[0021] Furthermore, in step (3), maintaining the long-day flowering stage conditions after the plant has flowered and headed can promote some plants to further bear fruit and form mature ears and mature seeds.

[0022] Furthermore, the awnless bromegrass seedlings are seedlings formed from germinating seeds.

[0023] The method is applicable to flowering induction of awnless brome materials with different phenotypes or ecotypes, such as, but not limited to: materials with hairless stems, materials with hairy stems, materials with smooth leaves, materials with hairy leaves, materials with flat leaves, materials with curled leaves, materials with large leaves, and materials with small leaves.

[0024] In one specific embodiment, the present invention provides the following method:

[0025] The germinating awnless bromegranate seedlings were cultured for 3 weeks under the conditions of 22 h / d day, 25℃ temperature and 200 μmol·m⁻²·s⁻¹ light intensity;

[0026] Subsequently, the culture was transferred to a condition with a day duration of 8 h / d, a temperature of 20℃, and a light intensity of 100 μmol·m⁻²·s⁻¹ for 11 weeks for induction.

[0027] Finally, the plants were transferred back to a long-day condition with 22 h / d sunshine, 25℃ temperature, and 380 μmol·m⁻²·s⁻¹ light intensity for further cultivation. During the long-day period, potassium dihydrogen phosphate water-soluble fertilizer was applied and the surface of the substrate was kept moist until the plants produced spikes, flowers, and mature seeds. Watering was stopped after the plants entered the seed wax ripening stage.

[0028] On the other hand, this application provides for the application of the above method in any of the following uses:

[0029] (1) Identification of flowering characteristics of awnless bromeliad;

[0030] (2) Regulation of flowering period of awnless bromeliad;

[0031] (3) Preparation of awnless bromeliad hybrid materials;

[0032] (4) Spawnless bromeliads were bred by generation.

[0033] Beneficial effects:

[0034] Compared with existing methods that rely on the natural environment to complete the reproductive growth conversion of awnless bromegrass, the present invention has at least the following beneficial effects:

[0035] This invention, by controlling the duration of light and temperature conditions in stages, can induce awnless bromegrass to transform from vegetative growth to reproductive growth under artificial control, thereby achieving heading, flowering, and fruiting.

[0036] The method of this invention has a clear technical route and well-defined cultivation conditions, making it easy to implement in greenhouses, artificial climate chambers, or other controllable cultivation environments, and it has good operability and repeatability.

[0037] The method of this invention is applicable to the regulation of flowering of awnless bromegrass, synchronization of flowering period, preparation of hybrid materials and generation breeding.

[0038] After treatment using the method of this invention, the plants exhibited normal overall flowering and heading behavior, and the inflorescence and related morphological traits remained basically stable, providing a material basis for subsequent research. Attached Figure Description

[0039] Figure 1 The development cycle of awnless bromegrass.

[0040] Figure 2 Image of mature awnless bromegranate seeds under optimal light and temperature induction conditions.

[0041] Figure 3 Flowering induction effect of awnless bromegrass.

[0042] Figure 4A Plant height of awnless bromeliad during flowering under different light and temperature induction conditions.

[0043] Figure 4B The number of tillers during flowering of awnless bromeliad under different light and temperature induction conditions.

[0044] Figure 4C The number of reproductive branches during flowering of awnless bromeliad under different light and temperature induction conditions.

[0045] Figure 4D The flag leaf length of awnless bromeliad during flowering under different light and temperature induction conditions.

[0046] Figure 4E The width of the flag leaf during the flowering period of awnless bromeliad under different light and temperature induction conditions.

[0047] Figure 4F The length of inflorescence during flowering of awnless bromeliad under different light and temperature induction conditions.

[0048] Figure 4G The number of spikelets during flowering of awnless bromeliad under different light and temperature induction conditions.

[0049] Figure 4H Spikelet length during flowering of awnless bromeliad under different light and temperature induction conditions.

[0050] Figure 4IFlowering number of awnless bromeliads under different light and temperature induction conditions.

[0051] Figure 5 Awnless bromeliads with hairless stems vs. bromeliads with hairy stems and flowering conditions.

[0052] Figure 6 Smooth leaves vs. hairy leaves and flowering conditions of awnless bromeliads.

[0053] Figure 7 Awnless bromegrass with curled leaves vs. flat leaves and flowering conditions.

[0054] Figure 8 Flowering status of awnless bromegrass with large leaves vs. small leaves.

[0055] Figure 9 The number of days from the restoration of long daylight to the start of flowering for different ecotypes of the awnless bird. Detailed Implementation

[0056] Unless otherwise specified, the awnless bromegrass seedlings in all embodiments were planted in 8×8×12cm flowerpots. The cultivation substrate consisted of potting soil, vermiculite, and peat moss in a volume ratio of 1:1:2. During the seedling growth stage and the short-day induction stage, water was applied promptly according to the substrate's moisture level to keep the surface moist, without additional nutrient application. During the long-day flowering stage, potassium dihydrogen phosphate water-soluble fertilizer (0.2g / L) was applied, and water was applied according to the substrate's moisture level to keep the surface moist; watering was stopped after the plants entered the seed wax ripening stage. Except for the temperature and duration of the short-day induction stage, the remaining cultivation conditions and maintenance management methods for each treatment in Example 1 were the same. The following examples are provided to better understand the invention, but are not intended to limit it. These examples are for illustrative purposes only and do not limit the scope of protection of the invention.

[0057] Example 1: Effect of different light and temperature induction conditions on the flowering induction efficiency of awnless bromeliad

[0058] Seedlings formed from germinating awnless bromegrass seeds were used as material, and one control group (CK) and six photo-temperature induction treatments were set up (Table 1). Except for the CK, which did not include a short-day induction phase, the other treatments included the seedling growth stage, the short-day induction phase, and the long-day flowering stage. The main difference between the different induction treatments was the temperature and duration of the short-day induction phase.

[0059] Table 2 shows the statistical results of the number of flowering seedlings induced under different treatments. The results indicate that the control group (CK) did not show significant flowering under continuous long-day conditions, suggesting that long-day conditions and high temperatures alone are insufficient to effectively induce flowering in awnless bromeliads; the plants need to undergo short-day and relatively low-temperature induction processes. Under the same temperature conditions, the flowering rate generally increased with the extension of short-day induction time. Taking the 20℃ treatment as an example, the flowering rates at 5, 8, and 11 weeks of induction were 33.33%, 50.00%, and 75.00%, respectively. Under the short-day duration set in this embodiment, the 20℃ treatment was generally better than or close to the 15℃ treatment. In summary, the treatment of 20℃, 8 h / d short-day, and 11 weeks of induction showed better flowering induction effects.

[0060] Table 1. Culture conditions

[0061]

[0062] Table 2. Statistics on the number of seedlings induced to flower

[0063]

[0064] Example 2: Developmental cycle and generation rate analysis

[0065] To verify the effectiveness of the method of this invention in promoting generation conversion of awnless bromeliads, the number of days from the day long-day conditions were restored to heading, flowering, and seed maturity were recorded for different treatments, and the entire generation cycle from sowing to maturity was calculated. Figure 1 Taking the 20℃ 5W treatment as an example, after 5 weeks of short-day induction, the seeds will sprout in about 17 days after being moved to a long-day environment, followed by the initial flowering stage in about 13 days. Seeds mature and can be harvested in about 19 days after flowering. The entire generation cycle from sowing to initial flowering is about 86 days, and from sowing to seed maturity is about 105 days. Based on the observations in this example, it is estimated that approximately three generations can be completed in one year under artificially controlled conditions. Taking the 20℃ 11W treatment as an example, although the short-day induction time is longer, the flowering rate is higher, and the entire generation cycle from sowing to seed maturity is about 160 days. Based on the observations in this example, it is estimated that more than two generations can still be completed in one year under artificially controlled conditions, and mature seeds with intact appearance, normal grain shape, and good plumpness can be obtained. Figure 2 The above results indicate that the method of the present invention can not only induce awnless bromeliads to head and flower, but also, under preferred conditions, further promote seed setting and the formation of mature seeds.

[0066] Example 3: Flowering Induction Effect of Awnless Broccoli

[0067] The induction system determined in this invention was used to treat awnless bromegranate breeding materials, and the phenotypic characteristics and agronomic traits of flowering plants were observed and statistically analyzed.

[0068] (1) Observation of flowering phenotype

[0069] like Figure 3 As shown, under artificial control conditions, the treated awnless bromegranate population exhibited high uniformity in heading, moderate plant height, and no obvious morphological deformities. Individual plants showed relatively complete inflorescence development, densely arranged spikelets, and normal floral organ structure. Upon entering the flowering stage, normal anther elongation and pollen shedding were observed.

[0070] (2) Statistics on agronomic traits during flowering period

[0071] For effective plants that had headed and entered the initial flowering stage under the treatments of 20℃ for 5W, 15℃ for 8W, 20℃ for 8W, 15℃ for 11W, and 20℃ for 11W, the following traits were measured and compared: number of tillers, number of reproductive branches, plant height, flag leaf length, flag leaf width, inflorescence length, number of spikelets, number of florets per spike, and spikelet length. The results are shown in Figure 4. Different letters in Figure 4 represent significant differences (P < 0.05).

[0072] Figures 4A-4I The results showed that traits such as tiller number, reproductive branch number, plant height, and inflorescence length differed among different treatments. Overall, longer induction times were more conducive to nutrient accumulation and reproductive branch formation. Flag leaf width differed from other treatments under the 20℃ 5W treatment. Spikelet length differed from other treatments under the 15℃ 11W treatment. Meanwhile, the number of spikelets and the number of florets per spike showed little difference among most treatments, indicating that the basic structure of the awnless bromeliad inflorescence remained generally stable after induction using the method of this invention.

[0073] The above results demonstrate that the induction system of this invention can not only induce awnless bromegrass to head and flower, but also obtain plants with normal inflorescence structure and stable overall agronomic traits, providing a material basis for subsequent hybridization, fruit setting observation and generational propagation.

[0074] Example 4: Verification of flowering of awnless bromegrass of different ecotypes

[0075] To verify the applicability of the method of this invention to different types of awnless bromegrass materials, awnless bromegrass materials with different phenotypic characteristics were selected, and flowering induction treatment was performed under preferred conditions. Their heading and flowering performance was recorded. Referring to the morphological characteristics described in the "Description Specification and Data Standard for Awnless Bromegrass Germplasm Resources," the following representative phenotypes were selected: hairless stems vs. hairy stems (…). Figure 5 Smooth leaves vs. hairy leaves Figure 6 Flat leaves vs. inward-curling leaves Figure 7 Large-leaf type vs. small-leaf type Figure 8The induction treatment was conducted under the following conditions: seedling growth stage: 22 h / d light, 25℃ for 3 weeks; short-day induction stage: 8 h / d light, 20℃ for 11 weeks; long-day flowering stage: 22 h / d light, 25℃ for 1 week, until heading and flowering. Results showed that all the above-mentioned phenotypic materials could achieve heading and enter the flowering stage under the treatment method of this invention. After the restoration of long-day conditions, all types of materials exhibited relatively normal inflorescence development and flowering, with no obvious abnormalities in floral organs. Taking the day of restoration of long-day conditions as day 0, the initial flowering time of each phenotypic material was concentrated between 33-40 days, with a maximum difference of ≤7 days. Figure 9 This indicates that the system can achieve good synchronization of flowering time among materials of different ecotypes, which provides convenience for subsequent hybridization and matching.

Claims

1. A method for accelerating the flowering and fruiting of awnless bromeliad indoors, characterized in that, The method includes: (1) Seedling growth stage: Place the awnless bromegrass seedlings under long-day and high-temperature conditions for cultivation; (2) Short-day induction stage: The awnless bromegranate seedlings cultured in step (1) are transferred to short-day and low-temperature conditions for induction culture; (3) Long-day flowering stage: The plants induced and cultured in step (2) are transferred to long-day and higher temperature conditions for further cultivation in order to induce the plants to produce spikes and flowers, as well as select plants to produce mature seeds.

2. The method according to claim 1, wherein the culture conditions for the short-day induction stage in step (2) are: day length 7-9h / d, temperature 15-20℃, light intensity 80-120 μmol·m⁻²·s⁻¹, and induction culture time 5-11 weeks.

3. According to the method of claim 2, the culture conditions for the short-day induction stage in step (2) are: sunshine duration of 8h / d, temperature of 15-20℃, light intensity of 100 μmol·m⁻²·s⁻¹, and induction culture time of 5-11 weeks.

4. The method according to claim 3, wherein the temperature in step (2) is 20°C and / or the induction culture time is 11 weeks.

5. The method according to any one of claims 1-4, wherein the cultivation conditions for the seedling growth stage in step (1) are: 20-25 h / d sunshine duration, 22-28℃ temperature, 300-400 μmol·m⁻²·s⁻¹ light intensity, and 2-4 weeks of cultivation time; preferably, the cultivation conditions for the seedling growth stage in step (1) are: 22 h / d sunshine duration, 25℃ temperature, 200 μmol·m⁻²·s⁻¹ light intensity, and 3 weeks of cultivation time.

6. The method according to any one of claims 1-5, wherein the cultivation conditions for the long-day flowering stage in step (3) are: day length 20-24 h / d, temperature 22-28℃, and light intensity 350-400 μmol·m⁻²·s⁻¹; preferably, the cultivation conditions for the long-day flowering stage in step (3) are: day length 22 h / d, temperature 25℃, and light intensity 380 μmol·m⁻²·s⁻¹.

7. The method according to claim 1, wherein the awnless bromegranate seedlings are planted in 8×8×12cm flowerpots filled with cultivation substrate, wherein the cultivation substrate is composed of potting soil, vermiculite and peat moss in a volume ratio of 1:1:

2.

8. According to the method of claim 1, in steps (1) and (2), water is applied according to the dryness and wetness of the substrate to keep the surface of the substrate moist, without applying additional nutrients; And / or, in step (3), apply potassium dihydrogen phosphate water-soluble fertilizer, water according to the dryness and wetness of the substrate, and keep the surface of the substrate moist; stop watering after the plant enters the waxy maturity stage to promote seed maturation; And / or, in step (3), if the plant continues to be cultured under the conditions of long-day flowering stage after the plant has flowered and headed out, it can promote some plants to further bear fruit and form mature ears and mature seeds.

9. The method according to claim 1, wherein the awnless bromegrass seedling is a seedling formed from germinating seeds.

10. The application of the method according to any one of claims 1-9 in any of the following uses: (1) Identification of flowering characteristics of awnless bromeliad; (2) Regulation of flowering period of awnless bromeliad; (3) Preparation of awnless bromeliad hybrid materials; (4) Spawnless bromeliads were bred by generation.

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