Marker-assisted Selection On The Length Of Fiber Of Cotton And The Exploitation Of New Markers

The cotton yield and fiber character are quantity traits,controlled by multiply genes, effected by environment. Cotton yield traits are negatively related with fiber length, the improvement of cotton fiber is slowly by conventional breeding.We should search some markers, such as concatenated with QTL of yield,fiber character,and so on, by the technology of molecular marker,doing some assisted-selection by marker to the fiber character and yiled, enhancing the selecting ratio ,step on the juice the course of breeding.In this experimentation,we study on the F2 population of hybridization between sea island cotton SuK202 and upland cotton Fuyide998, making foreground selecting through amplifying the individuals of population by SSR primers selected QTLs sites which relates with fiber length,meanwhile,selecting genetic background by SRAP primers selected.Selecting individuals possessing target gene according to field record and the result of testing fiber.To increase the numbers of microsatellites available for use in constructing a genetic map, and apply them in improving the quality of fiber in cotton, we studied also the development and use of a new marker EST-SSR in the article. The main results as follows:1. Selecting foreground between 282 individuals of the population using 10 pairs markers of 5 QTLs sites which relates with fiber length.Finally, we filtrated 132 individuals which possessing targed gene.2.We selected 62 pairs of primers possessing alelle from 88 random compounding of SRAP standard primers.We integrated the population used 20 pairs of them which possesing abundant strips.Recorded the markers'datas of the amplified result by ABH,and gained 5640 datas of marker type; filtrated out 197 individuals which possessing the genetic background of Fuyide998.3. Synthesizing foreground selecting and background, figured out 31 individuals which possessing the genetic background of Fuyide998 and targed gene. Counting the recovering ratio of genetic background according formula as: G(g)=[L+X(g)]/(2L)=1/2+(1/2)[X(g)/L], figuring out their RRGB, integrating the filed record and the result of fiber testing, filtrated out 8 individuals which possessing genetic background of Fuyide998 and fiber length gene.4. Designed 107 pairs of EST-SSR primers after getting rid of redundancy.86.9% of them could be amplified strips,51.4% of them could be amplified amelle between sea island cotton and upland cotton.The proportion of repetition for two to six nucletide are 32%,53.6%,7.3%,2.0%,5.1% among upland cotton EST-SSR; and they are 17.1%;36.6%;4.6%,5.0%,36.8% among sea island cotton EST-SSR. 5.Analysing the genetic diversity to 12 cotton varieties using the marker technology of EST-SSR,the result as follows: Junmian1, Xinluzhong15, Xinluzao7, 108-fu, KK1543, Jinmian10,Xinluzao13 and Zhongmian35 were assembled together becouse of the similar genetic background;SuK202 and K222 cited from Soviet Union were assembled together becouse of the same genetic background;Xinhai16 and C6015 were assembled together becouse they were all sea island cotton though they from different countries.