Cotton mutant and its application in breeding high-strength fiber land long-staple cotton

Abstract

The application discloses a cotton mutant and application thereof in cultivating high-strength fiber land long-staple cotton, and the cotton mutant is mutant tzy9115, the mutant tzy9115 is preserved in the China General Microbiological Culture Collection Center, and the preservation date is March 5, 2025, and the biological preservation number is CGMCC NO: 33497. The application utilizes the co-separation relationship between the multi-hair property of the land cotton mutant and fiber length, fiber specific strength and micronaire value, uses the multi-hair property as a morphological marker co-separating with the fiber quality property of the land cotton to realize directional improvement of the fiber quality properties such as fiber length, fiber specific strength and micronaire value, and thus high-strength fiber land long-staple cotton varieties are created.

Description

Technical Field

[0001] This invention relates to the field of cotton breeding technology, and in particular to a cotton mutant and its application in the cultivation of high-strength fiber upland long-staple cotton. Background Technology

[0002] Cotton is a vital economic crop worldwide, providing the textile industry with the most important natural fiber. Genetic improvement of yield and fiber quality is a crucial goal of cotton breeding globally. However, because yield and fiber quality are complex quantitative traits controlled by multiple genes, they are highly susceptible to environmental influences. Furthermore, the negative genetic correlation between cotton yield and fiber quality makes it difficult to break this adverse linkage using conventional breeding methods, resulting in a severe shortage of high-yielding and high-quality breakthrough cotton varieties in my country. Therefore, achieving synergistic improvement between high yield and high quality is a critical scientific problem that cotton breeding needs to address. While traditional breeding has made some progress in improving cotton yield and quality, it often struggles to achieve synergistic improvement between these two traits. Molecular breeding allows for direct selection of genotypes, effectively breaking the negative correlation between breeding traits and achieving synergistic improvement of multiple target traits. Currently, a large number of QTL loci associated with traits such as yield and fiber quality have been identified, laying the foundation for using molecular marker-assisted selection to synergistically improve cotton yield and quality. However, most of the QTLs associated with cotton fiber quality traits currently identified have low effects, and some markers are unstable in different genetic backgrounds and are easily affected by the genetic background. The number of molecular markers that can be applied to cotton fiber quality-assisted breeding is small, which has resulted in no reports of molecular markers being successfully applied to cotton fiber quality breeding.

[0003] Currently, traditional breeding techniques remain the main way to improve cotton fiber quality. The key to its success is how to break the unfavorable linkage to achieve gene optimization and recombination, thereby achieving synergistic improvement of yield and quality. The main methods currently used for cotton fiber quality breeding include: (1) selection breeding, which has a low probability of selecting superior individuals, making it difficult to achieve significant breakthroughs in yield and fiber quality improvement, and even more difficult to overcome and break the negative correlation between yield and fiber quality; (2) intervarietal hybridization breeding, which has the disadvantages of having few hybridization times, difficulty in breaking the negative correlation between yield and fiber quality, being unfavorable for the accumulation and recombination of beneficial genes, and difficulty in selecting varieties with a high degree of aggregation of high yield and excellent fiber quality; although methods such as improved cross-crossing based on multiple hybridizations, improved backcrossing based on multiple parental backcrosses, split mating selection based on the mutual hybridization of extreme individuals of hybrid segregation offspring, and cyclic selection based on continuous hybridization selection of superior individuals of hybrid offspring have been derived from this method, these methods still have the disadvantages of low selection efficiency of fiber quality traits and long breeding cycles during the breeding process; (3) distant hybridization breeding, which utilizes Using cotton species such as sea island cotton and wild cotton to improve the fiber quality, resistance and adaptability of upland cotton varieties is very effective. However, this method has drawbacks such as reproductive isolation of distant hybridization, sterility of hybrid offspring and reduced yield. (4) Utilization of heterosis: This method uses interspecific and intervarietal hybridization of cotton to improve cotton yield and fiber quality. However, since the range and degree of heterosis shown by hybrids of different parent combinations of cotton are often different, and the offspring of land and sea hybrids still have drawbacks such as sterility and reduced yield, this method has disadvantages such as long breeding years and limited yield potential. (5) Gradual breeding method: This method uses multiple types of parents to cross one after another and gradually and synergistically improve cotton yield and fiber quality to cultivate high-quality and high-yield new cotton varieties. Although this method is conducive to promoting the accumulation of excellent genes and the aggregation of excellent traits through multiple parent selection and hybridization, it still has drawbacks such as low selection efficiency and long breeding cycle in the selection of fiber quality traits. Based on the above analysis, it can be considered that the key to overcoming the current defects in fiber quality breeding is to obtain markers (morphological markers or molecular markers) that co-segregate with the fiber quality traits of upland cotton, and that the phenotypes associated with these markers have the characteristics of quality trait inheritance, which can be stably inherited in different genetic backgrounds. This would enable marker-assisted selection of fiber quality traits, thereby breaking the technical bottleneck of the negative genetic correlation between yield and fiber quality in fiber quality breeding, and overcoming the current drawbacks of low selection efficiency and long breeding cycle in fiber quality breeding.

[0004] Excessive pubescence is a prominent morphological feature of plants and can regulate their insect resistance. Pubescent cotton exhibits a certain degree of resistance to pests such as aphids, leafhoppers, planthoppers, pink bollworms, and cotton bollworms. The location, length, and density of pubescence growth all influence insect feeding and oviposition. Cotton pubescence is mainly distributed on the surface of cotton leaves and stems, and structurally similar to cotton fibers, it is also a type of single-celled trichome with one or more branches. Studies by Du Xiongming et al. have shown that cotton varieties in tropical regions have densely pubescent plants, while in subtropical cotton varieties, the amount of pubescence varies with latitude; the lower the latitude, the more pubescent the plant, and the higher the latitude, the less pubescent the plant. The aphid resistance of pubescence depends not only on the density of pubescence on leaves and stems but also, and more importantly, on the density and distribution of pubescence on the underside of the central leaves and young leaves. Because aphids prefer to feed on the tender parts of the underside of the heart leaves and along the sides of the midrib at the leaf base, and the distribution of pubescence on the leaves of hairy cotton is basically consistent with the feeding sites of aphids, the distribution of pubescence successfully prevents aphids from laying eggs and larvae from feeding on these areas. Therefore, the density and length of pubescence on cotton leaves and stems are closely related to insect resistance. Studies by Li Youzhong et al. have shown that the pubescent mutant of cotton has lower fiber length, first node height, plant height, first node position, and boll number than other varieties, indicating a certain relationship between the amount of pubescence in cotton and traits such as fiber length, boll number, and first node position. However, the relationship between cotton pubescence and other fiber quality indicators such as fiber length, specific strength, and micronaire value has not yet been reported.

[0005] Existing studies have shown that the pubescent trait in cotton is related to traits such as cotton insect resistance, fiber length, boll number, and first node position. However, current research has not clarified the correlation between the pubescent trait in cotton and fiber quality traits, nor has it resolved whether the pubescent trait can be used as a morphological marker for marker-assisted selection of fiber quality traits. Summary of the Invention

[0006] The purpose of this invention is to provide a cotton mutant and its application in the breeding of high-strength fiber upland long-staple cotton. Utilizing the co-segregation relationship between the pubescent trait of the upland cotton mutant and fiber length, fiber specific strength, and micronaire value, the pubescent trait is used as a morphological marker co-segregating with upland cotton fiber quality traits to achieve targeted improvement of fiber length, fiber specific strength, and micronaire value, thereby realizing the creation of high-strength fiber upland long-staple cotton varieties.

[0007] This invention enables marker-assisted selection of fiber quality traits in upland cotton based on morphological markers, which greatly improves the selection efficiency of traits, overcomes the technical bottleneck of the genetic negative correlation between yield and fiber quality in fiber quality breeding, and solves the problems of low selection efficiency and long breeding cycle in current cotton fiber quality breeding.

[0008] Specifically, the technical solution adopted in this invention is as follows:

[0009] A cotton mutant, tzy9115, has been deposited at the China General Microbiological Culture Collection Center (CGMCC) on March 5, 2025, with the accession number CGMCC NO: 33497.

[0010] This cotton mutant can be used to breed high-strength fiber upland long-staple cotton, including the following steps:

[0011] (1) Using a high-quality variety among the existing promoted varieties as the female parent and the mutant tzy9115 as the male parent, a hybrid combination is prepared. The F1 seeds of the hybrid combination are self-pollinated to obtain F2 seeds, or the F2 generation seeds are further self-pollinated to obtain F2 seeds. 5-8 High-generation seeds;

[0012] (2) F2 seed or F 5-8 High-generation seeds were planted in the field, and the characteristics of single-plant pubescence, flowering time, number of fruiting branches per plant, number of bolls per plant, boll weight, and lint percentage were investigated at different growth stages. At harvest, high-yielding, pubescent plants were selected for fiber quality tests. Based on the test results, plants with fiber length >33mm and specific strength >35cN·tex were selected. -1 High-yielding individual plants with a micronaire value of 3.7 to 4.5.

[0013] The high-quality varieties require a fiber length >32mm and a specific strength >32cN·tex. -1 .

[0014] The fiber quality characteristics include the average length of the upper half of the fiber, the fiber uniformity index, the breaking strength, the micronaire value, and the fiber elongation.

[0015] Compared with the prior art, the outstanding effect of the present invention is as follows:

[0016] (1) This invention utilizes multi-hair morphological markers co-segregated with upland cotton fiber quality traits to achieve marker-assisted selection of traits such as fiber length, fiber specific strength, and micronaire value in upland cotton. Furthermore, the multi-hair trait of this invention conforms to the genetic characteristics of quality traits controlled by two pairs of genes. Compared with traditional breeding, this invention can increase the selection efficiency of traits by more than 16 times.

[0017] (2) This invention achieves targeted improvement of fiber quality traits in upland cotton varieties, increasing fiber length by more than 1 mm and fiber specific strength by 2 cN·tex in existing upland cotton varieties. -1 The above values ​​indicate a decrease in the micronaire value of 0.7 or more.

[0018] (3) This invention can directionally produce fibers with a length greater than 33 mm and a fiber specific strength greater than 35 cN·tex. -1 High-strength long-staple cotton material with micronaire value of 3.7 to 4.5.

[0019] (4) This invention helps to solve the technical bottleneck of the genetic negative correlation between yield and fiber quality in the current cotton fiber quality breeding, rapidly improve the fiber quality of existing cotton varieties in my country, and promote the improvement of quality and efficiency of cotton production in my country.

[0020] The cotton mutant of the present invention and its application in cultivating high-strength fiber upland long-staple cotton will be further explained below with reference to the accompanying drawings and specific embodiments.

[0021] Biological Preservation Instructions

[0022] The cotton mutant tzy9115, classified as upland cotton (Gossypium hirsutum L), is deposited at the China General Microbiological Culture Collection Center (CGMCC), located at the Institute of Microbiology, Chinese Academy of Sciences, No. 1 Beichen West Road, Chaoyang District, Beijing. The deposit date is March 5, 2025, and the accession number is CGMCC NO: 33497. Attached Figure Description

[0023] Figures 1-5 Phenotypic images of the top true leaves of the hairy mutant and its homologous hairless line are shown. Figure 1 Day 1: The top true leaves of the hairy mutant (left) and its homologous hairless line (right) are spread out. Figure 2 The top true leaves of the hairy mutant (left) and its homologous hairless line (right) are spread out on day 2. Figure 3 The top true leaves of the hairy mutant (left) and its homologous hairless line (right) are spread out on day 3. Figure 4 The top true leaves of the hairy mutant (left) and its homologous hairless line (right) are spread out on day 4. Figure 5 The top true leaves of the hairy mutant (left) and its homologous hairless line (right) are spread out on day 6.

[0024] Figure 6 These represent three phenotypic traits in the F2 population. From left to right, they are: trichomes (mutant tzy9115 phenotype), intermediate trichomes (hybrid F1 phenotype), and trichomes (ZY9115 phenotype). Detailed Implementation

[0025] The application of a cotton mutant in the cultivation of high-strength fiber upland long-staple cotton includes the following steps:

[0026] (1) Seeds of the superior upland cotton germplasm Zhongyuan 9115 were obtained from the cotton germplasm resource mid-term bank and the seeds were continuously self-pollinated.

[0027] (2) Seeds from continuous self-pollination were planted in areas severely affected by Verticillium wilt in Xinjiang. Phenotypic identification was performed, and a mutant with significantly more hairs on its leaves and stems was obtained and named tzy9115.

[0028] (3) The mutant tzy9115 was planted in the field for self-pollination and phenotypic identification. Furthermore, the homogeneous glabrous line ZY9115 was isolated from the tzy9115 population. The phenotypes of the mutant tzy9115 and the homogeneous glabrous line ZY9115 at different growth stages are as follows: Figure 1-5 As shown.

[0029] (4) The homogeneous hairless line ZY9115 was used as the female parent and the mutant tzy9115 was used as the male parent to obtain hybrid F1. The hybrid F1 was self-crossed to obtain F2 population. The hybrid F1, F2 population and the seeds of their parents were planted in the field. The characteristics of plant surface hair, flowering time, number of fruit branches per plant and number of bolls per plant were investigated at different growth stages, and boll weight and lint percentage were calculated. At harvest, the fiber quality characteristics of each plant were tested, including the average length of the upper half of the fiber, fiber uniformity index, breaking strength, micronaire value and fiber elongation.

[0030] (5) Based on the phenotypic survey results of the F1 and F2 hybrid populations and their parents, a genetic analysis was conducted on the pubescence trait of the mutants. The phenotypic survey showed that the pubescence phenotype of the F1 hybrids was intermediate between that of the parents, while the F2 population segregated into three types: abundant pubescence (mutant tzy9115 phenotype), intermediate pubescence (hybrid F1 phenotype), and no pubescence (homogeneous pubescent line ZY9115 phenotype), such as... Figure 6 As shown, the inheritance of the pubescence trait conforms to the characteristics of qualitative trait inheritance controlled by incompletely dominant genes. The chi-square test shows that the segregation ratio of the pubescence trait in the F2 population conforms to the Mendelian segregation ratio of traits controlled by two pairs of genes. The results of the chi-square test are shown in Table 1. The results indicate that the pubescence trait of the mutant of this invention is controlled by two pairs of incompletely dominant genes, belonging to qualitative trait inheritance.

[0031] Table 1 Genetic analysis of the pubescence trait in mutants

[0032]

[0033] Note: The chi-square test meets the significance level of 0.05 (the critical value of the chi-square test at the 0.05 level is 5.991 when the degrees of freedom are 2).

[0034] (6) Analysis of variance was performed on the flowering time, number of fruiting branches per plant, number of bolls per plant, boll weight, lint percentage, and fiber quality (including average length of the upper half of the fiber, fiber uniformity index, breaking strength, micronaire value, and fiber elongation) of the F2 population and its parents' hairy, intermediate, and hairless plants. The results of the analysis of variance for the mutant tzy9115 and the homogeneous hairless line ZY9115 are shown in Table 2. The results showed that the mutant was significantly inferior to the homogeneous hairless line in terms of flowering time, number of fruiting branches per plant, number of bolls per plant, average length of the upper half of the fiber, and breaking strength. Specifically, the flowering time was shortened by an average of 3.74 days, the number of fruiting branches per plant decreased by an average of 1.73, the number of bolls per plant decreased by an average of 3.38, the average length of the upper half of the fiber decreased by an average of 2.23 mm, and the breaking strength decreased by an average of 3.73 cN·tex. -1 This indicates that the mutant has better precocity, while the homogeneous hairless line has higher yield and fiber quality.

[0035] The results of the analysis of variance for the F2 population are shown in Tables 3 and 4. The results indicate that the hairless plants in the F2 population were significantly superior to the hairy plants in traits such as the number of fruiting branches per plant, the number of bolls per plant, the average length of the upper half of the fiber, the breaking strength, and the micronaire value. Specifically, the number of fruiting branches per plant increased by an average of 0.47, the number of bolls per plant increased by an average of 1.5, the average length of the upper half of the fiber increased by an average of 3.02 mm, and the breaking strength increased by an average of 4.06 cN·tex. -1 The micronaire value decreased by an average of 1.12, indicating that selecting hairless plants in the F2 segregating population can yield cotton with significantly improved yield traits such as the number of fruiting branches and bolls per plant, as well as significantly improved fiber quality indicators such as the average length of the upper half of the fiber, breaking strength, and fiber fineness (micronaire value). This achieves a certain degree of coordinated improvement in yield and quality. On the other hand, since the hairy trait is controlled by two pairs of genes, the segregation ratio of hairy plants, intermediate hairy plants, and hairless plants in the F2 segregating population is 1:14:1 (Table 1). Therefore, only 1 / 16 of the hairless plants need to be selected to obtain cotton plants with improved yield and fiber quality at the same time, thereby increasing the trait selection efficiency by 16 times.

[0036] Table 2. Analysis of variance of traits between mutant tzy9115 and homogeneous hairless line ZY9115

[0037]

[0038] Note: * indicates significance at the P=0.05 level, and ** indicates significance at the P=0.01 level.

[0039] Table 3. Analysis of variance of yield-related phenotypic patterns in the F2 population of mutant tzy9115 × homogeneous hairless line ZY9115.

[0040]

[0041] Note: * indicates significance at the P=0.05 level, and ** indicates significance at the P=0.01 level.

[0042] Table 4. Analysis of variance of quality-related phenotypic patterns in the F2 population of mutant tzy9115 × homogeneous hairless line ZY9115.

[0043]

[0044]

[0045] Note: * indicates significance at the P=0.05 level, and ** indicates significance at the P=0.01 level.

[0046] (7) In order to further verify whether the pubescent trait can be used as a morphological marker for breeding selection of fiber quality traits, hybrid combinations were prepared by using the cotton varieties Zhongmian Institute 113, Zhongmian Institute 425 and Zhongmian EB001, which are widely used in production, as the female parent and the mutant tzy9115 as the male parent. The F1 seeds of each hybrid combination were self-crossed to obtain F2 seeds. The F2 generation seeds of each hybrid combination were planted in the field. The F2 generation plants of each hybrid combination were randomly selected. For the F2 generation plants of each hybrid combination and the pubescent plants, intermediate type and non-pubescent plants of their parents, the following traits were analyzed: flowering time, number of fruit branches per plant, number of bolls per plant, boll weight, lint percentage and fiber quality (including average length of the upper half of the fiber, fiber uniformity index, breaking strength, micronaire value and fiber elongation).

[0047] The results of variance analysis of the Zhongmian EB001×tzy9115 combination and its parents are shown in Tables 5, 6, and 7. The results showed that there were no differences between Zhongmian EB001 and the mutant in traits such as flowering time, boll weight, fiber length, specific strength, and micronaire value. However, the number of fruiting branches per plant, number of bolls per plant, lint percentage, and fiber uniformity of Zhongmian EB001 were significantly higher than those of the mutant (Table 5). In the F2 population of Zhongmian EB001×tzy9115, there were no differences between hairy and hairless plants in traits such as flowering time, number of fruiting branches per plant, number of bolls per plant, boll weight, and lint percentage (Table 6). However, hairless plants showed significantly higher fiber quality traits than hairy plants in fiber length, uniformity, specific strength, micronaire value, and elongation. Furthermore, the fiber length of hairless plants was 1.82 mm longer and the specific strength was 2.76 cN·tex higher than that of the parent Zhongmian EB001. -1 The micronaire value was 0.16 lower than that of the parent (Table 7), indicating that selecting hairless materials from the F2 population can significantly improve fiber quality, thus achieving targeted improvement of fiber quality of Zhongmian EB001.

[0048] Table 5. Analysis of variance of traits between mutant tzy9115 and Zhongmian EB001

[0049]

[0050]

[0051] Note: * indicates significance at the P=0.05 level, and ** indicates significance at the P=0.01 level.

[0052] Table 6. Analysis of variance of yield-related traits in the F2 population of cotton EB001×tzy9115.

[0053]

[0054] Table 7. Analysis of variance of fiber quality-related traits in the F2 population of cotton EB001×tzy9115.

[0055]

[0056] Note: * indicates significance at the P=0.05 level, and ** indicates significance at the P=0.01 level.

[0057] The results of variance analysis of the Zhongmian Institute 425 × tzy9115 hybrid and its parents are shown in Tables 8, 9, and 10. The results indicate that there are no differences between Zhongmian Institute 425 and the mutant in traits such as flowering time, boll weight, fiber length, and specific strength. However, the micronaire value, number of fruiting branches per plant, number of bolls per plant, lint percentage, fiber uniformity, and elongation of Zhongmian Institute 425 are significantly higher than those of the mutant (Table 8). The F2 population of Zhongmian Institute 425 × tzy9115... There were no differences between hairy and hairless plants in yield-related traits such as the number of fruiting branches per plant, the number of bolls per plant, boll weight, and lint percentage (Table 9). However, hairless plants had higher fiber length, uniformity, specific strength, and elongation than hairy plants, while the micronaire value of hairless plants was lower than that of hairy plants (Table 10). Specifically, the fiber length of hairless plants was 0.22 mm longer than that of the parent Zhongmian 425, and the specific strength was 2.51 cN·tex higher than that of the parent Zhongmian 425. -1 The micronaire value was 0.37 lower than that of the parent, indicating that selecting hairless materials from the F2 population can yield materials with better fiber quality than the parent, Zhongmian Institute 425, thus achieving targeted improvement of the fiber quality of Zhongmian Institute 425.

[0058] Table 8. Analysis of variance of traits between mutant tzy9115 and Zhongmian Institute 425

[0059]

[0060] Note: * indicates significance at the P=0.05 level, and ** indicates significance at the P=0.01 level.

[0061] Table 9. Analysis of variance of yield-related traits in the F2 population of the 425×tzy9115 cotton research institute.

[0062]

[0063]

[0064] Note: * indicates significance at the P=0.05 level, and ** indicates significance at the P=0.01 level.

[0065] Table 10. Analysis of variance of fiber quality-related traits in the F2 population of the 425×tzy9115 group from the China Cotton Research Institute.

[0066]

[0067] The results of variance analysis of the Zhongmian Institute 113×tzy9115 combination and its parents are shown in Tables 11, 12 and 13. The results showed that there were no significant differences between Zhongmian Institute 113 and the mutant in traits such as flowering time, number of fruiting branches, boll weight, and micronaire value. However, the number of bolls per plant, lint percentage, fiber length, fiber uniformity, specific strength and elongation of Zhongmian Institute 113 were significantly higher than those of the mutant (Table 11). In the F2 population of Zhongmian Institute 113×tzy9115, there were no differences between hairy and hairless plants in traits such as flowering time, number of fruiting branches, boll weight and lint percentage (Table 12). However, the fiber length, specific strength and elongation of hairless plants were higher than those of hairy plants, while the micronaire value of hairless plants was lower than that of hairy plants (Table 13). Among them, the fiber length of the hairless plants in the F2 population was 0.52 mm longer than that of the parent Zhongmian 113, and the specific strength was 2.29 cN·tex higher than that of the parent Zhongmian 113. -1 The micronaire value was 0.76 lower than that of the parent, indicating that selecting hairless materials from the F2 population can yield materials with better fiber quality than the parent, Zhongmian Institute 113, thus achieving targeted improvement of the fiber quality of Zhongmian Institute 113.

[0068] Table 11. Analysis of variance of traits between mutant tzy9115 and Zhongmian Institute 113

[0069]

[0070]

[0071] Note: * indicates significance at the P=0.05 level, and ** indicates significance at the P=0.01 level.

[0072] Table 12. Analysis of variance of yield-related traits in the F2 population of the 113×tzy9115 cotton research institute.

[0073]

[0074] Table 13. Analysis of variance of fiber quality-related traits in the F2 population of the 113×tzy9115 group from the China Cotton Research Institute.

[0075]

[0076] Note: * indicates significance at the P=0.05 level, and ** indicates significance at the P=0.01 level.

[0077] (8) In order to further verify the selection effect of the pubescent trait as a morphological marker on the fiber quality traits of the high-generation segregating population of the hybrid combination, hybrid combinations were prepared by using the cotton varieties Lumian 2632, Xinluzao 61, Zhongmian Institute 19, Zhongmian Institute 12, Zhongmian Institute 35 and Lumian 238, which are widely used in production, as the female parent and the mutant tzy9115 as the male parent. The F1 seeds of each hybrid combination were self-pollinated to obtain F2 seeds. The F2 generation seeds of each hybrid combination were continuously self-pollinated to obtain F5 generation seeds. The F5 generation seeds were planted in the field, and the F5 generation plants of each hybrid combination were randomly selected. For the pubescent plants, intermediate type and non-pubescent plants in the F5 generation of each hybrid combination, the variance analysis of traits such as boll weight, lint percentage and fiber quality (including the average length of the upper half of the fiber, fiber uniformity index, breaking strength, micronaire value and fiber elongation) was carried out.

[0078] The results of the variance analysis of the F5 generation plants of the Lumian 2632×tzy9115 combination are shown in Table 14. The results show that the fiber length, uniformity, specific strength and elongation of the hairless plants in the F5 generation population of the Lumian 2632×tzy9115 combination are significantly higher than those of the hairy plants, while the micronaire value of the hairless plants is significantly lower than that of the hairy plants (Table 14). This indicates that selecting hairless plants in the F5 generation population can significantly improve fiber quality.

[0079] Table 14. Analysis of variance of F5 generation plants of the Lumian 2632×tzy9115 combination.

[0080]

[0081] Note: * indicates significance at the P=0.05 level, and ** indicates significance at the P=0.01 level.

[0082] The results of the ANOVA of the F5 generation of Xinluzao 61×tzy9115 are shown in Table 15. The results show that the fiber length, uniformity, specific strength and elongation of the glabrous plants in the F5 generation population of Xinluzao 61×tzy9115 are significantly higher than those of the hairy plants, while the micronaire value of the glabrous plants is significantly lower than that of the hairy plants (Table 15). This indicates that selecting glabrous plants in the F5 generation population can significantly improve fiber quality.

[0083] Table 15. Analysis of variance of F5 generation plants from the combination of Xinluzao 61×tzy9115

[0084]

[0085]

[0086] Note: * indicates significance at the P=0.05 level, and ** indicates significance at the P=0.01 level.

[0087] The variance analysis results of F5 generation plants of other hybrid combinations such as Zhongmian Institute 12×tzy9115, Zhongmian Institute 19×tzy9115, Zhongmian Institute 35×tzy9115 and Lumian 238×tzy9115 are shown in Table 16. The results show that the fiber length, uniformity, specific strength and elongation of hairless plants in the F5 generation population of different combinations are higher than those of hairy plants, while the micronaire value of hairless plants is lower than that of hairy plants (Table 16). This indicates that selecting hairless plants in the F5 generation population can significantly improve fiber quality.

[0088] Table 16. Analysis of variance of F5 generation plants from different hybridization combinations

[0089]

[0090]

[0091] (9) Based on the above analysis, a method for creating high-strength fiber upland long-staple cotton is proposed, specifically: using high-quality varieties among the existing promoted varieties (fiber length > 32 mm, specific strength > 32 cN·tex) -1 Using a female parent (such as Zhongmian 113) and a mutant tzy9115 as the male parent, a hybrid combination is prepared. The F1 seeds of the hybrid combination are self-crossed to obtain F2 seeds, or the F2 seeds are further self-crossed to obtain F2 seeds. 5-8 Equal to higher generation seeds, F2 seeds or F 5-8High-generation seeds were planted in the field, and traits such as pubescence, flowering time, number of fruiting branches per plant, number of bolls per plant, boll weight, and lint percentage were investigated at different growth stages. At harvest, high-yielding, pubescent plants were selected for testing fiber quality traits (including average length of the upper half of the fiber, fiber uniformity index, breaking strength, micronaire value, and fiber elongation). Based on the test results, plants with fiber length > 33 mm and fiber strength > 35 cN·tex were selected. -1 High-yielding single plants with micronaire values ​​of 3.7 to 4.5 have achieved the targeted creation of high-strength fiber upland long-staple cotton.

[0092] Using the high-strength fiber upland long-staple cotton creation technology of this invention, fibers with a length >33mm and a specific strength >35cN·tex were screened from the offspring of the 113×tzy9115 hybrid combination of the China Cotton Research Institute. -1 Four high-yielding single plants with micronaire values ​​of 3.7 to 4.5 (namely, numbers 23, 42, 85, and 121) are shown in Table 17.

[0093] Table 17 shows the high-strength upland long-staple cotton selected from the offspring of the 113×tzy9115 hybrid combination from the China Cotton Research Institute.

[0094]

[0095] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. The application of a cotton mutant in the cultivation of high-strength fiber upland long-staple cotton, characterized in that: The cotton mutant is a mutant. tzy9115 It is deposited at the China General Microbiological Culture Collection Center (CGMCC) on March 5, 2025, with the biological accession number CGMCC NO: 33497; Using high-quality varieties from existing promoted varieties as the female parent and mutants tzy9115 To obtain F2 seeds, either create a hybrid combination with the male parent, self-pollinate the F1 seeds of the hybrid combination, or continue self-pollinating the F2 seeds to obtain F2 seeds. 5-8 High-generation seeds; F2 seed or F 5-8 High-generation seeds were planted in the field, and the characteristics of single-plant pubescence, flowering time, number of fruiting branches per plant, number of bolls per plant, boll weight, and lint percentage were investigated at different growth stages. At harvest, high-yielding, pubescent plants were selected for fiber quality tests. Based on the test results, plants with fiber length > 33 mm and specific strength > 35 cN•tex were selected. -1 High-yielding individual plants with a micronaire value of 3.7 to 4.

5.

2. The application of the cotton mutant according to claim 1 in the cultivation of high-strength fiber upland long-staple cotton, characterized in that: The premium varieties require a fiber length >32 mm and a specific strength >32 cN•tex. -1 .

3. The application of the cotton mutant according to claim 2 in the cultivation of high-strength fiber upland long-staple cotton, characterized in that: The fiber quality characteristics include the average length of the upper half of the fiber, the fiber uniformity index, the breaking strength, the micronaire value, and the fiber elongation.

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