Working group session:
Functional Genomics
Presentation type:
poster
Authors:
Liu, Dexin; Zhang, Jian; Tang, Shiyi; Fang, Xiaomei; Zhang, Zhengsheng
Presenter:
Liu, Dexin; Zhang, Jian; Tang, Shiyi; Fang, Xiaomei
Correspondent:
Zhang, Zhengsheng
Abstract:
Fiber and leaf trichome are extremely-elongated single cells that initiate and develop on epidermal cells, and are likely to have common regulatory mechanisms. In our previous study, a major QTL affecting multiple fiber quality traits at T1 locus (trichome ) on chromosome 6 has been identified in a RIL population from a cross between high quality cultivar Yumian 1 and multiple dominant marker line T586. To fine-map the QTL at t1 locus, a 1440-individuals F2 population was developed from a cross between Yumian 1 and recombinant line RIL118 whose QTL region derived from T586 in 2010. Firstly, 104 markers on chromosome 6 were used to genotype 360 plants randomly selected from F2 population and a genetic map covering 146.3 cM was constructed, and QTL affecting fiber length, fiber uniformity, fiber micronaire and fiber strength was confirmed. T1 co-segregated with 10 markers, QTL affecting fiber quality traits covered 0.8 cM. Secondly, to fine map T1 and QTL affecting fiber quality traits, 380 new SSR primer pairs designed from the QTL corresponding region on chromosome 10 in G. raimondii genome, and 13 markers were obtained. Twenty-tree markers within the QTL region were used to genotype the 1440 plants and the saturated genetic map spanned 0.28 cM and T1 was flanked by SWU2518 and SWU2302. Based on fiber quality trait from the 1440 plants in 2010, the QTL identified explains 54.7%, 40.5%, 30.1% and 50.0% of the fiber length, micronaire, uniformity and strength phenotypic variation respectively. In 2011 and 2013, another 5535 F2-plants developed from (Yumian 1 × RIL118) were used to screen new recombinants in the QTL region, and thirty-five recombinants were obtained. However, T1 and QTL affecting fiber quality traits were still mapped in the same interval between SWU2518 and SWU2302. In G. raimondii genome, the QTL corresponding region covers about 2.7-Mb physical distance and contains 100 genes. The present study proves that QTL affecting fiber quality traits at T1 is stable and pleiotropic. However, the candidates for T1 and QTL affecting fiber quality traits need to study further.