| Because of the increasingly population growth and the reduction of arable land, issues of food securtity becoming more and more serious, more attention were paied to solve this problem via scientific means. Breeding of high yield, nice quality and strong resistance rice varieties by modern molecular breeding technology, is a common goal of all the rice breeding scientists.Chromosome segment substitution lines as a permanent secondary mapping population though needing a long time to develop, with the advantages of more pure genetic background and less insertion segments of each lines in the CSSLs. It’s not only conducive to the mapping of QTL, but more conducive to collect the superior genes of rice in the process of molecular design breeding, then appropriate some technical means to breeding superior varieties of rice. And it’s will shorting the period of breeding.In this study, based on previous studies(Koshihikari/Guichao2chromosome segment substitution lines BC2F1generation), combined with marker-assisted selection and backcross to the recurrent parent4generations, to make the CSSLs——the whole genome chromosome segment substitution lines of Koshihikari/Guichao2of BC6F1——more perfect. Comparing with BC2F1generation, the number of lines in CSSLs BC6F1is more nearly doubled to achieve118; insert loci from BC2F1generation’s average each line28.5reduced to the average of each line11.7; target fragment as a single or double fragments of all the CSSLs increased, from BC2F1generation’s15to86; the genetic background response rate increased to96.44%from91.14%; coefficient of variation of the genetic background response rate reduced to0.019.The purification and refinement of the chromosome segment substitution lines of Koshihikar/Guichao is a long-term work. We backcross chosen for4generations on the base of BC2F1generation, to found the material foundation of QTL mapping even the design breeding with this CSSLs. |
PDF Full Text Request