Working group session:
Structural Genomics
Presentation type:
oral
Authors:
Shi, Yuzhen ; Zhang, Jinfeng ; Li, Wentan; Ge, Ruihua ; Li, Junwen; Li, Aiguo; Liang, Yan ; Jia, Yujuan ; Li, Junzhi ; Liu, Guangping; Zhang, Baocai ; Liu, Aiying ; Gong, Juwu ; Shang, Haihong ; Wang, Tao ; Gong, Wankui; Yuan, Youlu
Presenter:
Yuan, Youlu
Correspondent:
Yuan, Youlu
Abstract:
In order to introgress elite QTL alleles of G. barbadense L. for fiber yield and quality into G. hirsutum L. and enlarge the genetic base of G. hirsutum and provide more new germplasm resources for the Upland variety development, the commercial G. hirsutum variety ‘Zhongmiansuo36’ and G. barbadense ‘Hai 1’ were respectively used as recurrent and donor parent to produce backcross populations for construction of genetic linkage map based simple sequence repeat, including BC1F1, BC1S1 and BC2F1, BC5F3,BC5F3:4,BC5F3:5 ,QTL analysis of yield-related trait and fiber quality on three phenotypic data sets were proceeded by the Composite Interval Mapping method. Genetic basis can be widened for excellent gene from Sea Island cotton into Upland cotton, and there will be more abundant resource materials for the improvement of cotton varieties.
A total of 21973 pairs of SSR primer were used to screen polymorphism among the parents Zhongmiansuo36, Hai 1 and their F1 progeny, which resulted into 2148 pairs of polymorphic primer with the special band for Hai 1, and all of them were used to screen the BC1F1 population. Linkage test indicated 2280 polymorphic locus could be mapped on the 26 cotton chromosomes, respectively and covered a total genetic distance of 5088.28cM. The number of the markers per linkage group was 87.69, which spanned 195.70cM of the cotton genome. And the average distance of the neighboring markers were 2.23cM.
Most of QTLs for fiber quality and yield-related traits, including fiber length, strength, micronaire, elongation ratio, uniformity and lint percentage, boll weight and seed index, were mapped among the three generations (BC1F1, BC1S1 and BC2F1) using CIM. The QTLs for lint percentage and fiber length could be detected in the three generations.
BC5F3 individuals with superior fiber quality were selected to evaluate the phenotypic traits related to yield and fiber quality in BC5F3:4 and BC5F3:5 line populations. Total of 408 BC5F3 individuals were detected by 210 pairs of SSR markers selected from 12 linkage groups for identifying the donor chromosome fragments and QTLs for fiber yield and quality related traits, which lays the foundation for further QTL fine mapping and molecular-assisted breeding. Total of 41 QTL controlled fiber quality traits were detected, and a single QTL could explain from 2.50% to 7.31% of phenotypic variance. Total of 50 QTL controlled fiber yield-related traits were identified, and a single QTL could explain from 2.50% to 6.15% of phenotypic variance. A total of 27 QTL could be detected in two or more puoulations and environments. six QTL (one for fiber length and seed index, and two for boll weight and lint percent) could be detected in four populations or environments. These QTL detected in different populations and environments could be used for molecular assistant breeding.
Key words: Cotton, advanced backcross, chromosome segment substitution lines, SSR, genetic linkage map, QTL