Compound agent for improving high-temperature heat damage resistance in flowering and filling stages of rice and application of compound agent

Abstract

The invention discloses a compound agent for improving high-temperature heat damage resistance in flowering and filling stages of rice and application of the compound agent. The effective components of the compound agent comprise 28-homobrassinolide and gibberellin GA4 + 7. Under the condition of high temperature, a compound agent mixed solution containing 0.03 mg / L of 28-homobrassinolide and 1.5 mg / L of gibberellin GA4 + 7 is sprayed one week before heading of the rice and at the full heading stage respectively. The compound agent can be used for reducing the harm of high-temperature heat damage in the flowering stage and the filling stage to the rice, and is beneficial to improving the maturing rate and the thousand seed weight, so that the rice yield is remarkably increased. The compound agent can be applied to planting areas where high-temperature heat damage frequently occurs in the flowering stage and the filling stage of rice, and has wide application value.

Description

Technical Field

[0001] The invention belongs to the technical field of rice cultivation, and particularly relates to a compound agent for improving the resistance of rice to high temperature heat damage during the flowering and grain filling period and application thereof. Background Art

[0002] my country is the world's largest rice producer and consumer, with rice being the staple food for over 60% of its population. However, heat damage caused by global warming has become the most significant negative factor impacting rice production. Therefore, effective measures to improve rice's tolerance to high-temperature stress and mitigate the impact of heat damage on rice production are crucial for increasing rice yields and ensuring national food security.

[0003] High temperatures affect rice growth throughout its entire growth period, particularly during the flowering and grain-filling stages, which are crucial for yield formation. Rice is extremely sensitive to high temperatures during the flowering stage. Sustained high temperatures can cause pollen abortion, anther dehiscence, and obstructed pollen dispersal, leading to an increased empty shell rate and a decreased seed set rate. High temperatures during the grain-filling stage primarily cause premature senescence of rice leaves, shorten the grain-filling period, and cause "forced ripening," reducing grain weight and quality. Screening for heat-resistant rice germplasm and developing new heat-tolerant rice varieties is an important method for combating heat damage. Heat-tolerant varieties generally have less impact on seed set and grain weight under high-temperature stress conditions. Adjusting cultivation practices is also an important agronomic measure, such as early or delayed sowing to avoid naturally high-temperature periods during the flowering and grain-filling stages, and using fertilizer and water regulation to mitigate the adverse effects of heat damage on rice pollination and grain filling. Exogenous spraying of chemical regulatory substances is also an effective measure to cope with high temperature heat damage in rice production. In particular, the application of plant hormone growth regulators has the advantages of low cost, high safety and significant effect.

[0004] Brassinolide is a sterol plant hormone that plays an important role in promoting plant cell elongation and division, photosynthesis, and stress resistance. Studies have shown that brassinolide can promote rice seed germination and seedling growth, increase leaf photosynthetic rate, and thereby increase rice yield. Regarding stress resistance, exogenous application of brassinolide growth regulators can enhance rice's resistance to cold, drought, heat, and heavy metal toxicity. For example, brassinolide treatment can increase pollen viability and seed set in rice under high-temperature stress, promote the accumulation and distribution of photosynthetic substances, and contribute to yield improvement. Gibberellic acid has important physiological effects in breaking dormancy, promoting seed germination, cell division and growth, inducing flowering, and enhancing plant stress resistance. Exogenous application of gibberellins can control ineffective tillering in rice, increase ear formation rate, and boost yield.

[0005] Plant hormones can exhibit synergistic or antagonistic effects. Brassinolide and gibberellins exhibit synergistic effects in regulating certain important physiological processes. For example, a combination of brassinolide and gibberellins has shown significant synergistic effects in promoting seed germination and tobacco leaf development in Leymus chinensis, preventing flower and fruit drop in navel oranges, delaying leaf senescence and increasing yield in buckwheat, and improving cold tolerance in litchi. However, there are currently few reports on the application of brassinolide and gibberellin combinations in rice, particularly regarding whether these combinations are more effective than exogenous application of brassinolide alone in enhancing rice resistance to heat damage and increasing yield. Summary of the Invention

[0006] The purpose of the present invention is to provide a compound agent for improving the resistance of rice to high temperature heat damage during the flowering and filling period and its application, so as to solve the problem that high temperature heat damage has an adverse effect on rice yield.

[0007] To achieve the above objectives, the present invention provides a technical solution for improving the resistance of rice to high temperature heat damage during the flowering and grain filling period. The solution includes the preparation and use of a compound agent for resisting high temperature heat damage during the flowering and grain filling period of rice, and its application in conventional rice and hybrid rice. The solution specifically comprises the following steps:

[0008] (1) 28-homobrassinolide and gibberellin GA 4+7 The compound agent mixtures were prepared to have final concentrations of 0.03 mg / L and 1.5 mg / L, and then 0.1% by volume of Tween 20 was added to the mixtures.

[0009] (2) Spray the prepared compound agent mixture evenly on the surface of rice plants one week before heading and at the heading stage. Avoid spraying on rainy days and at noon on sunny days. The dosage per mu is 30L.

[0010] (3) The application of the above compound agent to conventional rice varieties Jiuxiangnian and Ganwanxian 30, as well as hybrid rice varieties Jiafengyou 2 and Weiliangyou 8612, can effectively enhance their ability to resist high temperature heat damage during the flowering and filling period, significantly improve the fruit set rate and 1000-grain weight, and increase yield.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] The compound described in the present invention, which improves rice's resistance to high-temperature heat damage during the flowering and grain-filling period, is superior to single-ingredient formulations in its effectiveness, overcoming the long-standing problem of unsatisfactory results from the use of single chemical control agents or other chemical control compound formulations. The compound described in the present invention, when applied to both conventional and hybrid rice, effectively mitigates the harmful effects of high temperatures during the flowering and grain-filling period, significantly increases seed set rate and 1,000-grain weight, and contributes to increased rice yield. It has a wide range of applications and significant effectiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings described herein are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0014] Figure 1 It is an exogenous single spray of 28-homobrassinolide and gibberellin GA 4+7 Effects of spraying a mixture of two ingredients on the yield increase of conventional rice (A: Jiuxiangnian; B: Ganwanxian No. 30; * indicates significant difference, P<0.05).

[0015] Figure 2 It is an exogenous single spray of 28-homobrassinolide and gibberellin GA 4+7 Effects of spraying a mixture of two ingredients on the yield increase of hybrid rice (A: Jiafengyou 2; B: Weiliangyou 8612; * indicates significant difference, P<0.05). DETAILED DESCRIPTION

[0016] This section will describe in detail the specific embodiments of the present invention. The embodiments enable a more intuitive and vivid understanding of each technical feature and the overall technical solution of the present invention, but should not be understood as limiting the scope of protection of the present invention.

[0017] Our research group found that brassinolide and gibberellin have a significant enhancing effect in improving the resistance of rice to high temperature heat damage during the flowering and grain filling period. 4+7 Compared to single ingredients, the combination of the two has a greater effect on increasing rice seed set rate, 1000-grain weight, and yield under high-temperature stress conditions. Therefore, the compound described in the present invention can be applied to rice growing areas where high-temperature heat damage is frequent during the flowering and grain filling stages, and has a wide range of applications.

[0018] In order to illustrate the technical solution described in this application, specific embodiments are provided below.

[0019] Example 1: Application of compounding agent in conventional rice varieties Jiuxiangnian and Ganwanxian 30

[0020] (1) Two conventional rice varieties, Jiuxiangnian and Ganwanxian 30, were selected for field trials in the experimental fields of Jiangxi Agricultural University. The sowing dates were adjusted to allow the two rice varieties to be exposed to naturally high temperatures during the flowering and grain filling stages. Jiuxiangnian was sown on April 25, transplanted on May 20, and heading on July 20; Ganwanxian 30 was sown on April 15, transplanted on May 10, and heading on July 23.

[0021] (2) 28-homobrassinolide and gibberellin GA 4+7A single-component preparation and a two-component mixture were prepared with final concentrations of 0.03 mg / L and 1.5 mg / L, respectively. 0.1% by volume of Tween 20 was added to the single-component preparation and the two-component mixture, and the mixtures were mixed and set aside.

[0022] (3) Use a sprayer to evenly spray the prepared single-component preparation and the two-component mixed preparation on the surface of the aboveground organs of Jiuxiangnian and Ganwanxian No. 30 plants one week before heading and at the full heading stage, avoiding the rainy days and the noon time on sunny days. The dosage of the compound preparation is 30L / mu.

[0023] (4) After the rice is mature and harvested, the yield and yield components of the two conventional rice varieties are statistically analyzed. The yield components include the number of effective panicles, the number of grains per panicle, the fruit set rate, and the thousand-grain weight.

[0024] The test results are shown in Table 1 and Appendix Figure 1 As shown, for Jiuxiang sticky, a single spray of 28-homobassinolide and gibberellin GA 4+7 Spraying the two-ingredient mixed compound agent can significantly increase the fruit setting rate, 1000-grain weight and yield, among which the yield increased by 11.34%, 6.22% and 17.61% respectively; for Ganwanxian No. 30, single spraying of 28-homobrassinolide and gibberellin GA 4+7 The spraying of the two-component mixed compound agent significantly increased the seed setting rate, 1000-grain weight and yield of the two conventional rice varieties, with the yield increased by 12.96%, 3.71% and 20.32% respectively. Although the exogenous spraying of the single-component preparation and the two-component mixed compound agent significantly increased the seed setting rate, 1000-grain weight and yield per plant of the two conventional rice varieties, the spraying of the 28-homobrassinolide and gibberellin GA 4+7 The combination of the two ingredients is the best.

[0025] Table 1 Effects of spraying single and compound agents on conventional rice yield components

[0026]

[0027] Note: Treatment groups 1, 2 and 3 were sprayed with 28-homobrassinolide and gibberellin GA respectively. 4+7 Single preparation and two-component mixed preparation; different letters in the same column of each variety indicate significant differences (P<0.05).

[0028] Example 2: Application of compound agent in hybrid rice varieties Jiafengyou 2 and Weiliangyou 8612

[0029] (1) Two hybrid rice varieties, Jiafengyou 2 and Weiliangyou 8612, were selected for field trials at the experimental field of Jiangxi Agricultural University. The sowing dates were adjusted to allow the two rice varieties to be exposed to naturally high temperatures during the flowering and grain filling stages. Jiafengyou 2 was sown on April 10, transplanted on May 5, and heading on July 25; Weiliangyou 8612 was sown on April 20, transplanted on May 15, and heading on July 22.

[0030] (2) 28-homobrassinolide and gibberellin GA 4+7 A single-component preparation and a two-component compound preparation were prepared with final concentrations of 0.03 mg / L and 1.5 mg / L, respectively. 0.1% by volume of Tween 20 was added to the single-component preparation and the two-component compound preparation, and the mixtures were mixed and set aside.

[0031] (3) Use a sprayer to evenly spray the prepared single-component preparation and the two-component mixed preparation on the surface of the aboveground organs of Jiafengyou No. 2 and Weiliangyou 8612 plants one week before heading and at the full heading stage, avoiding the rainy days and the noon time on sunny days. The dosage of the compound preparation is 30L / mu.

[0032] (4) After the rice is mature and harvested, the yield and yield components of the two hybrid rice varieties are statistically analyzed. The yield components include the number of effective panicles, the number of grains per panicle, the fruit set rate and the thousand-grain weight.

[0033] The test results are shown in Table 2 and Appendix Figure 2 As shown, for Jiafengyou 2, a single spray of 28-homobrassinolide and gibberellin GA 4+7 The spraying of the two-ingredient compound agent significantly increased the fruit setting rate, 1000-grain weight and yield, with the yield increasing by 7.27%, 4.64% and 12.81% respectively. For Weiliangyou 8612, spraying 28-homobrassinolide and gibberellin GA alone increased the fruit setting rate, 1000-grain weight and yield significantly, with the yield increasing by 7.27%, 4.64% and 12.81% respectively. 4+7 The spraying of the single-component preparation and the two-component mixture can significantly increase the seed setting rate, 1000-grain weight and yield of the two hybrid rice varieties, with the yield increased by 9.60%, 4.21% and 15.68% respectively. Although the exogenous spraying of the single-component preparation and the two-component mixture can significantly increase the seed setting rate, 1000-grain weight and yield per plant of the two hybrid rice varieties, the combination of 28-homobrassinolide and gibberellin GA can significantly increase the seed setting rate, 1000-grain weight and yield per plant of the two hybrid rice varieties. 4+7 The combination of the two ingredients is the best.

[0034] Table 2 Effects of spraying single and compound agents on hybrid rice yield components

[0035]

[0036] Note: Treatment groups 1, 2 and 3 were sprayed with 28-homobrassinolide and gibberellin GA respectively. 4+7Single preparation and two-component mixed preparation; different letters in the same column of each variety indicate significant differences (P<0.05).

[0037] The results of the above examples show and confirm that, when the rice is sprayed with 0.03 mg / L 28-homobrassinolide and 1.5 mg / L gibberellin GA one week before heading and at the full heading stage, the rice 4+7 A compound (containing 0.1% by volume of Tween 20) significantly enhances rice's ability to withstand high-temperature heat damage during the flowering and grain-filling stages, effectively increasing seed set and 1000-grain weight, thereby boosting rice yield. This compound has broad application value and can be used in rice-growing areas where high-temperature heat damage is frequent during the flowering and grain-filling stages.

Claims

1. A compound agent for improving the resistance of rice to high temperature heat damage during the flowering and filling period, characterized in that: The active ingredients of the compound include 28-homobrassinolide and gibberellin GA 4+7 .

2. The compound agent for improving the resistance of rice to high temperature heat damage during flowering and filling period according to claim 1, characterized in that: The concentration of the compound 28-homobrassinolide is 0.03 mg / L, and gibberellin GA 4+7 The concentration is 1.5mg / L.

3. The compound agent for improving the resistance of rice to high temperature heat damage during flowering and filling period according to claim 1 or 2, characterized in that: The compounding agent also includes 0.1% by volume of Tween 20.

4. The use of the compound agent for improving the resistance of rice to high temperature heat damage during flowering and filling period as claimed in any one of claims 1 to 3, characterized in that: Spraying the compound agent evenly on the surface of rice plants one week before heading and at the heading stage can effectively reduce the damage of high temperature heat damage to rice during the flowering and filling stages, which is beneficial to increase rice yield.

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