棉花高品质纤维性状QTLs的分子标记筛选及其定位

Molecular Tagging and Mapping of QTLs for Super Quality Fiber Properties in Upland Cotton

利用 72 35、TM - 1亲本 (P1 、P2 ) ,以及 ( 72 35×TM - 1 )F1 、F2 (南京和美国 2个环境 )与F2 3(南京和海南 2个环境 )家系群体 ,根据F2 与F2 3的纤维品质性状表现 ,构建了纤维强度、细度与长度的极值DNA混合池 ,通过 2 2 1对SSR引物、1 840个RAPD引物对亲本和极值DNA混合池筛选 ,共得到了 1 3个多态性标记 ,其中 8个标记可能与高强有关 ,1个标记与低强有关 ;3个标记与麦克隆值有关 ;1个与绒长有关。进一步通过F2 分离群体检测 ,连锁分析表明与高强有关的 8个标记 ( 2个SSR标记和 6个RAPD标记 )紧密连锁 ,覆盖 1 5 .5cM。这一高强纤维的QTL ,4个环境中均以FSR1 933为最近 ,相距不超过 0 .6cM ,能解释 35 %的F2 变异 ,5 3.8%的F2 3的表型变异 ,是目前纤维强度单个QTL效应最大的 ,多个环境下稳定 ,可以直接用于标记辅助育种。单体测验表明 ,该在棉花的第 1 0染色体上。麦克隆值的一个主效QTL标记FMR1 60 3,在F2 中能解释 7.8%的变异 ,在F2 3中能解释 2 5 .4%的变异 ,同样表现环境稳定。纤维长度的一个标记FLR1 1 550 ,在 3个环境中预测到 ,最大能解释 9.5

A G. anomalum introgression line, 7235, characterized as super quality fiber properties, was used to identify molecular markers linked to fiber property QTLs. By use of (7235×TM 1)F 2 in Nanjing and College Station, USA, and (7235×TM 1)F 3 in Nanjing and Hainan. Bulked segregation analysis was employed to produce 3 pairs of mixed DNA pools for fiber strength, micronaire and fiber length according to individual value of (7235×TM 1)F 2 and F 23 . A total of 221 pairs of SSR primers, 1?840 arbitrary 10 mer oligonucleotide primers and 77 ISSR primers were used to screen polymorphism between two parents, and 3 pairs of bulked DNA pools. Fifteen markers amplified by thirteen primers were identified to be linked with fiber quality QTLs through DNA polymorphism surveying between the parents, and then paired bulked DNAs, and screening the individual plant of (7235×TM1)F 2. Linkage test indicated 15 markers could be mapped to three linkage groups. In the first linkage group, eight markers (two SSR and six RAPD markers) associated with fiber strength were tightly linked with 2.2 cM interval genetic distance on average, and located on chromosome 10 in cotton. Two major QTLs for fiber quality characters were identified. One for fiber strength could explain 35% of the phenotypic variation in F 2, and 53.8% in F 23 at Hainan, which has the greatest single QTL effect of fiber strength and could be identified in all four environments, and tightly linked to 6 RAPD markers and 2 SSR markers with genetic distance no more than 16 cM in chromosome10, in which FSRl 933 is the nearest with the distance no more than 0.6 cM. One QTL linked to FMR1 603 for Micronaire could explain 7.8% of the phenotypic variation in F 2, and 25.4% in F 23 at Hainan, and expressed in all four environments. One QTL linked to FLR1 1550 for fiber length could explain 9.5% of the phenotypic variation in F 23 at Hainan, very little in other environments. So they can be used in marker assisted selection in increasing fiber quality of commercial cultivars.