用棉花显性光子突变体N_1与陆地棉遗传标准系TM-1、海岛棉品种新海7号和海7124杂交,共配制3个F_2分离群体和1个BC_1群体;用隐性光子突变体n_2与TM-1、海岛棉品种新海7号和军海1号杂交,共配制3个F_2分离群体和2个BC_1群体。遗传分析结果表明:显性光子突变体N_1和隐性光子突变体n_2与正常海岛棉、陆地棉品种(系)在光子性状上均存在1对基因的差异,符合单基因遗传模式。用SSR分子标记对显性光子基因N_1进行定位,结果显示,N_1位于染色体A12(Chr.12)上,与目的基因最近的标记是BNL1679,遗传距离为1.9 cM。用SSR分子标记对隐性光子基因n_2进行定位,结果表明:在海×陆种间群体中,n_2基因位于染色体A12上,与n_2基因最近的分子标记是BNL1679,遗传距离为2.7 cM,而在陆×陆种内群体中,n_2基因则位于染色体D12(Chr.26)上。根据遗传分析和分子定位结果,推测隐性光子性状在异源四倍体棉花中可能在部分同源染色体上存在重复基因,导致隐性光子基因n_2在不同类型的分离群体中定位在不同的部分同源染色体上。
In the research described in this paper,the dominant fuzzless mutant N_1(N_1FLM) and recessive fuzzless mutant (n_2FLM) were crossed with several wild fuzz parents,including Gossypium hirsutum L.and Gossypium barbadense L.,six F_2 generations from crosses N_1FLM×TM-1,N_1FLM×Xinhai7(XH7),N_1FLM×Hai7124(H7124),n_2FLM×TM-1,n_2FLM×XH7 and n_2FLM×Junhai1(JH1),and three BC_1 from crosses n_2FLM×TM-1,N_1FLM×H7124 and n_2FLM×JH1 were conducted.Genetic analysis showed both N_1 and n_2 FLMs fit a simple gene inheritance model in both interspecific and intraspecific crosses.Molecular tagging revealed that N_1 was mapped on A12(Chr.12),and the nearest marker was BNL1679,at a distance of 1.9 cM.However, n_2 was mapped not only on A12 in the G.hirsutum×G.barbadense interspecific mapping population,the closest marker to n_2 was BNL1679,at a distance of 2.7 cM,but also on D12(Chr.26) in the intraspecific mapping population in G.hirsutum.Given these genetic analysis and molecular tagging data,a duplicate inheritance of the recessive fuzzless trait in allotetraploid cotton was assumed. This inheritance mode would explain the variable mapping results reported in previous studies of n_2 FLM in cotton.