Biological Characteristics And Genetic Analysis Of Tall Plant Mutant In Upland Cotton

Cotton is one of the important economic crops, and one of the main edible oil crops, but also an important material for textile industry, so the position of cotton in the national economy should not be underestimated. At present, the cottons’ harvesting method in our country mainly based on manual labor, with the rising price of cotton production, large amount of labor employment, and comparative benefit is lower than other crops, our country’s cotton planting area is facing shrinking plight. And the use of mechanized harvesting, the plant height and first branch height requirements are relatively higher. At present, about tall plant mutant cotton was less reported, and has not been applied to breeding. Therefore, the creation and discovery have very important significance. Based on the tall plant mutant lines with "Gaogan No.l" as experimental material, studied from the following aspects.Firstly, the plant height, internode length, height of the first fruiting branch and internode number in different growth stages of cotton were measured, which indicated that the height of the tall plant mutant was positively related with the first fruiting height and internode length, and no relation with internode number.Secondly, measuring endogenous hormone contents in seed embryo by enzyme-linked immunosorbent assay showed that, the contents of GA3 in Gaogan No.1 were respectively 1.39 times,2.21 times,2.37 times than those in the Hai 7124, N089, Xinluzao 16; the contents of IAA in Gaogan No.l were respectively 1.05 times,1.68 times,1.61 times than those in Hai 7124, N089, Xinluzao 16; the contents of ZR in Gaogan No.l were respectively 1.15times,2.79 times,2.77 times than those in Hai 7124, N089, Xinluzao 16, While the ABA contents were respectively 86.93%,76.05%,69.97% than those in Hai 7124, N089, Xinluzao 16. From the above results, it can be inferred, the rich of GA3, IAA, ZR are related with tall plant.Thirdly, cytological observation showed that the cells length of tall plant was 378.64μm, and the wild type was 263.81μm,both reached a very significant difference (P< 0.01), and there was no significant difference in cells number of vertical internodes between the mutant and the wild type. Therefore, a conclusion was deduced that causing tall plant was due to the increase of cell’s lengths in stem longitudinal sections.Lastly, Tall plant mutant "Gaogan No.l" from Gossypium hirsutum and "Xinluzao 16" with normal plant height were used as materials in this study. Its offspring F2 was used as mapping population. The number of tall plants in F2 was three times of normal plants. And the number of tall plants and normal plants were nearly equal in B2. Analysis the P1, P2, F1, F2, Bland B2 six generations of separation traits, we found that the tall mutation was controlled by a single dominant gene. Using 167 pairs of primers to locate, there were 34 pairs of primers had polymorphism, no primer was labeled with tall trait gene linkage at last.