Composite initiator for improving germination rate of teasel seeds and application of composite initiator

Abstract

The invention provides a composite initiator for improving the germination rate of teasel seeds and application of the composite initiator, and belongs to the technical field of plant seeds. The composite initiator disclosed by the invention is prepared from gibberellin GA3, polyethylene glycol 6000 and CaCl2. Experiments show that various germination indexes of the single initiator PEG6000 and CaCl2 are superior to those of GA3, different proportions of the composite initiator have obvious influence on the germination indexes, the germination rate of seeds treated by the composite initiator provided by the invention is the highest, and the initiation effect on the length of the overground part of teasel and the weight of a single plant is superior to that of the single initiator. According to the method, the germination rate of the teasel seeds can be increased, meanwhile, the growth of teasel seedlings can be effectively promoted, and the seedling strengthening effect is achieved.

Description

Technical Field

[0001] This invention relates to the field of plant seed treatment technology, and in particular to a compound initiator for improving the germination rate of Dipsacus asper seeds and its application. Background Technology

[0002] Sichuan Dipsacus ( Rough teasel *Dipsacus asper* (Walnutia ex Henry) is a plant belonging to the genus *Dipsacus* in the family Dipsacaceae. Its rhizome is used medicinally, possessing properties that tonify the liver and kidneys, strengthen tendons and bones, heal fractures, and stop metrorrhagia. *Dipsacus asper* is primarily propagated by seed. However, due to the dormancy characteristic of its seeds and their low germination rate, it cannot meet the demands of standardized, large-scale cultivation. With the increasing artificial cultivation of *Dipsacus asper*, achieving high germination rates and uniformity are urgent problems that need to be addressed in its cultivation.

[0003] Seed priming techniques can increase seed vigor and the activity of related enzymes within the seed, thereby improving seed germination traits. Previous studies have reported that appropriate concentrations of gibberellin treatment have a good promoting effect on the germination of *Dipsacus asper* seeds, but there are no reports, either domestically or internationally, on the effects of different priming agents or mixed priming agents on *Dipsacus asper*.

[0004] This study investigated the effects of different types and concentrations of seed soaking initiation treatments on the germination, seedling growth, and physiological characteristics of Dipsacus asperoides seeds. The aim was to screen suitable initiators and their combinations to improve the germination rate and uniformity of Dipsacus asperoides seeds, and to provide technical support for the standardized and large-scale cultivation of Dipsacus asperoides. Summary of the Invention

[0005] The purpose of this invention is to provide an initiator and its combination that improves the germination rate and uniformity of Dipsacus asper seeds.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a composite initiator for improving the germination rate of Dipsacus asper seeds, which is composed of gibberellin GA3, polyethylene glycol 6000 and CaCl2.

[0007] Preferably, the composite initiator is composed of: 100 mg / L GA3 + 10~40% (w / v) PEG6000 + 0.5~1% (w / v) CaCl2.

[0008] The present invention also provides the application of the composite initiator in improving seed germination rate, promoting seedling growth and enhancing seedling quality.

[0009] Furthermore, the method for treating seeds using the composite initiator is as follows: immerse the seeds in the composite initiator, treat them in the dark at 18~22℃ for 8~24 hours, rinse, and dry them at 25~28℃.

[0010] This invention utilizes different types of initiators and their combinations to treat *Dipsacus asper* seeds. Results showed that single initiators PEG6000 and CaCl2 exhibited better germination indicators than GA3. Different ratios of the compound initiator significantly affected germination indicators, with the highest germination rate observed in the treatment with the compound initiator 100 mg / L GA3 + 20% PEG6000 + 1% CaCl2. Regarding seedling growth, the compound initiator was more effective than single initiators in inducing the length of the aboveground parts and the weight of individual plants. PEG6000 was more effective than other treatments in inducing the length of the underground parts. The physiological activity indicators of seedlings treated with GA3 were lower than other treatment groups, while the physiological activity indicators of seedlings treated with the compound initiator 100 mg / L GA3 + 10% PEG6000 + 1% CaCl2 were higher than other treatment groups. Finally, the principal component analysis results showed that the treatment with the composite initiator 100 mg / L GA3 + 10% PEG6000 + 1% CaCl2 had the best effect, indicating that the present invention can not only improve the germination rate of Dipsacus asper seeds, but also effectively promote the growth of Dipsacus asper seedlings, enhance the quality of seedlings, and achieve the effect of strong seedlings. Detailed Implementation

[0011] In the invention, Sichuan fructose ( Rough teasel Seeds for Wall. ex Henry were provided by the Sichuan Academy of Traditional Chinese Medicine. GA3 was purchased from Shanghai McLean Biochemical Technology Co., Ltd. The ELISA test kit was purchased from Jiangsu Enzyme Immunoassay Co., Ltd. PEG6000 (analytical grade) was purchased from Chengdu Kelong Chemical Co., Ltd. CaCl2 (analytical grade) was purchased from Chengdu Changlian Chemical Reagent Co., Ltd.

[0012] Microsoft Excel and DPS software were used to perform analyses such as mean, variance, significance, and membership function values.

[0013] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0014] Example 1: Effects of different initiators and their combinations on the germination of Dipsacus asper seeds

[0015] Single initiator: Three concentration gradients were set for GA3 (T1: 50 mg / L, T2: 100 mg / L, T3: 200 mg / L); PEG6000 is set with three concentration gradients (T4: 10%, T5: 20%, T6: 40%). Three concentration gradients were set for CaCl2 (T7: 0.5%, T8: 1%, T9: 2%); Prepare the above-mentioned initiator, ensuring it completely submerges the seeds, and treat them in the dark at 20°C for 24 hours.

[0016] Composite initiator; T10: 50 mg / L GA3 +10% PEG6000+0.5% CaCl2; T11: 100 mg / L GA3 +20% PEG6000+1% CaCl2; T12: 200 mg / L GA3 +40% PEG6000+2% CaCl2; T13: 50 mg / L GA3 +20% PEG6000+2% CaCl2; T14: 200 mg / L GA3 +20% PEG6000+0.5% CaCl2; T15: 100 mg / L GA3 +10% PEG6000+1% CaCl2; T16: 100 mg / L GA3 +40% PEG6000+1% CaCl2; Each sample was treated with the above-mentioned composite initiator for 8 h under dark conditions at 20°C.

[0017] T17: Water treated for 24 hours as control 1 (CK1); T18: No treatment was given as control 2 (CK2).

[0018] Each treatment was repeated 3 times. After initiation, the seed surface was rinsed with distilled water for 30 seconds, the moisture on the seed surface was absorbed with absorbent paper, and the seeds were allowed to air dry naturally at room temperature (25℃).

[0019] The seeds were evenly arranged in 9 cm petri dishes lined with double-layered filter paper and germination was carried out at a constant temperature of 20℃. The number of germinated seeds was observed and recorded daily. Germination potential was calculated after 7 days and germination was completed after 15 days. The germination rate was calculated based on the length of the seed from the first white sprout.

[0020] Seed germination potential = (1)

[0021] Seed germination rate = (2)

[0022] Germination Index (GI) = (3)

[0023] Vitality Index (VI) = (4)

[0024] Where Gt is the number of germinated seeds on day td, Dt is the corresponding number of germination days, and S is the fresh weight of Dipsacus asper seedlings (day 15). S can be obtained by first absorbing the surface moisture of the seedlings with clean filter paper and then weighing them with an analytical balance.

[0025] Table 1. Effects of initiators on germination indices of Dipsacus asper seeds.

[0026] Note: Lowercase letters in the same column indicate differences between treatments. P <0.05 is significant. (The same applies below.)

[0027] Table 1 shows that different initiator treatments significantly affected the germination indices of Dipsacus asperoides seeds. The germination rates of treatments T4, T9, T11, and T15, the germination potential of treatments T7, T8, and T17, the germination indices of treatments T4, T7, T8, T9, T11, T15, and T17, and the vigor indices of treatments T4, T9, and T11 were all significantly higher than those of CK2.

[0028] In terms of initiator types, PEG6000 and CaCl2 outperformed GA3 in various germination indicators. However, under specific ratios, PEG6000 and CaCl2, as single initiators, showed better germination effects than certain combinations of compound initiators. Different ratios of compound initiators significantly affected germination indicators; the T11: 100 mg / L GA3 + 20% PEG6000 + 1% CaCl2 compound initiator combination produced the highest seed germination rate.

[0029] Example 2: Effects of different initiators and their combinations on the growth of Dipsacus asper seedlings

[0030] The maximum leaf area, longest root length, and fresh weight of *Dipsacus asper* seedlings in each group (same as in Example 1) were measured. The contents of malondialdehyde (MDA), proline (Pro), soluble protein, and chlorophyll in *Dipsacus asper* seedlings under different priming treatments were measured according to the kit instructions (Jiangsu Enzyme Immunoassay Co., Ltd.).

[0031] Table 2 Effects of initiators on the growth of Dipsacus asper seedlings

[0032] Table 2 shows that different initiator treatments significantly affected the growth of *Dipsacus asper* seedlings. The aboveground part length of treatments T10, T12, T13, T14, and T15, and the fresh weight per plant of treatments T9, T10, T11, T12, T13, and T14 were significantly higher than other treatments. The underground part length of treatments T4, T5, T6, T7, T9, and T13 was higher than the control, but the difference was not significant. In terms of initiator type, the compound initiator was more effective than the single initiator in initiating the aboveground part length and weight of *Dipsacus asper*, while PEG6000 was more effective than other treatments in initiating the underground part length.

[0033] Table 3 Effects of initiators on the physiological activity of Dipsacus asper seedlings

[0034] Table 3 shows that different initiator treatments significantly affected the physiological activity of *Dipsacus asper* seedlings. The MDA content of treatments T15 and T16, the Pro content of treatments T5, T15, and T16, the soluble protein content of treatments T9 and T15, and the chlorophyll content of treatments T15 and T16 were all significantly higher than other treatments. Regarding the type of initiator, the physiological activity indicators of seedlings treated with GA3 were lower than those of other treatment groups. The physiological activity indicators of seedlings treated with T15 (100 mg / L GA3 + 10% PEG6000 + 1% CaCl2) were higher than those of other treatment groups.

[0035] Example 3: Principal Component Analysis and Comprehensive Evaluation

[0036] Principal component analysis was used to comprehensively evaluate 11 indicators, including germination rate, germination potential, germination index, vigor index, aboveground length, underground length, fresh weight per plant, MDA content, Pro content, and soluble protein content.

[0037] Table 4. Eigenvalues ​​and eigenvectors of each principal component

[0038] As shown in Table 4, a total of three principal components were extracted, with eigenvalues ​​of 5.271, 2.913, and 1.611, respectively, and variance contribution rates of 47.914%, 26.480%, and 14.642%, respectively. The cumulative contribution rate reached 89.036%, indicating that these three principal components can explain most of the original information of all indicators.

[0039] Table 5 Principal Component Scores and Rankings

[0040] The original 11 indicators are designated as X1 to X11, and the standardized data are ZX1 to ZX11. The scores of the three principal components, PC1, PC2, and PC3, are calculated based on the principal component loading matrix using the following functional expressions: F1=0.42ZX1+0.41ZX2+0.42ZX3+0.42ZX4-0.23ZX5-0.24ZX6-0.06XZ7+0.33ZX8+0.3 9ZX9+0.31ZX10+0.37ZX11; F2=-0.32ZX1-0.30ZX2-0.33ZX3-0.33ZX4+0.48ZX5-0.5 The formula is: 2ZX6 - 0.10ZX7 + 0.50ZX8 + 0.36ZX9 + 0.50ZX10 + 0.43ZX11; F3 = -0.13ZX1 + 0.02ZX2 - 0.13ZX3 + 0.35ZX4 + 0.63ZX5 + 0.48ZX6 + 0.79ZX7 - 0.27ZX8 + 0.14ZX9 + 0.19ZX10 - 0.17ZX11. Based on the contribution rate of each principal component, the weights of principal components F1, F2, and F3 are calculated to be 53.81%, 29.74%, and 16.45%, respectively. Therefore, the function expression for the overall score is: F = 53.81%F1 + 29.74%F2 + 16.45%F3.

[0041] As shown in Table 5, the overall ranking of each initiation treatment is T15 > T9 > T16 > T8 > T4 > T11 > T13 > T7 > T5 > T18 > T17 > T10 > T6 > T14 > T12 > T2 > T3 > T1. Among them, the composite initiator T15 treatment has the highest overall score, followed by the single initiator T9 treatment, with a difference of only 2.46 points. The single initiator GA3 has the lowest overall score.

[0042] This invention employs three single initiators and their combinations to induce germination in *Dipsacus asper* seeds. Results showed that the seed germination rate was highest with the combination of T11 (100 mg / L GA3 + 20% PEG6000 + 1% CaCl2), and the physiological activity indicators of seedlings treated with T15 (100 mg / L GA3 + 10% PEG6000 + 1% CaCl2) were higher than those of other treatment groups. Furthermore, principal component analysis and comprehensive evaluation revealed that the optimal combination of T15 (100 mg / L GA3 + 10% PEG6000 + 1% CaCl2) effectively promoted seedling growth and enhanced seedling quality while maintaining a high germination rate.

[0043] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A compound initiator for improving the germination rate of Dipsacus asper seeds, characterized in that, The composite initiator is composed of gibberellin GA3, polyethylene glycol 6000 and CaCl2.

2. The composite initiator as described in claim 1, characterized in that, The composition of the composite initiator is: 100 mg / L GA3 + 10~40% (w / v) PEG6000 + 0.5~1% (w / v) CaCl2.

3. The application of the composite initiator according to claim 1 or 2 in improving seed germination rate, promoting seedling growth and enhancing seedling quality.

4. The application as described in claim 3, characterized in that, The method for treating seeds using the composite initiator is as follows: immerse the seeds in the composite initiator, treat them in the dark at 18~22℃ for 8~24 hours, rinse, and dry at 25~28℃.

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