SSR Molecular Marker Location And Hormone Regulation Of Ligon Lintless Mutant In Cotton

The Ligon lintless( Li-1 ) is a monogenic, dominant cotton mutant with very short lint ,only 4~6mm in length, and curved leavies and distorted stems.Different kinds and concentration of plant growth substances were applied to the mutant plants of Ligon lintless and the medium of ovule culture.The contents of GA,IAA,ABA and ZR of treated ovules in the field and the callus of the different ovule c ulture were detected.This may reveal the hormone difference between fiber mutant and its wild type.Meanwhile, the 246 BC1 plants segregating from Li-1 crossed with genetic standard line TM-1was used as the mapping population for the SSR molecular marker location. The main results as followings:1. The hormone treatment for the mutant and wild type in the field indicated that the contens of IAA,GA,ABA,ZR in the ovules of mutant plants were less than that in the wild type. Especially, the contens of IAA in the ovules of mutant during the early fiber development stage was half of that in the wild type. Four hormones of IAA, GA, ABA, ZR in the ovules applied with IAA and the inhibitorof ABA than check plants. This implyed the hormone genes of IAA and ABA maybe change in the mutant plants, and IAA and ABA have the relationship with the fiber initiation and development.2. The hormone treatment of F, IAA, GA, ABA, BR in the ovule culture showed the contens of IAA, GA, ABA, ZR in the ovules of callus were higher than no treatment check in both of the mutant and wild type, and these hormone contents in the wild type were higher than that in the mutant.3. This experiment also showed the different salt concentration of SDS, SCD maybe cooperate with the hormone treatment to increase their endo-hormone contents to some extent.4. By the observation of modality between in wild type and mutant, there were little differences at 0 and 1 days postanthesis, and the first fiber initiation of them at 0 days postanthesis, but the fiber on the wild type was little longer than the mutant's at 3 days postanthesis. The second fiber iniation of them was at 5 days postanthesis.5. 28 pairs of polymorphism SSR primer with a polymorphism ratio of 0.7% between parents TM-1 and Ligon lintless were screened from 4,000 primers, and 23 polymorphism loci were detected in the BC1 population. A linkage map for the Ligon lintless mutant was constructed by Joinmap 3.0. The map spanned about 168 cM and covered 3.74% of cotton genome. The average distance of markers was 7.3 cM, and Li trait was location on chr.22.