Relationship between SSR‐based Genetic Distance and Cotton F2 Hybrid Performance for Lint Yield and Fiber Properties

Abstract

ABSTRACTAnalysis of relationships between genetic distance and hybrid performance may promote utilization of exotic germplasm in hybrid production. This study was designed to determine the relationship between SSR‐based genetic distance (GD) and F2 hybrid performance in cotton (Gossypium hirsutum L.). Forty‐eight F2 hybrids derived from crosses between four elite germplasm (EL) lines and 12 exotic germplasm lines, that is, six Species Polycross (SP) germplasm lines and six John Cotton (JC) germplasm lines, were evaluated in four environments during 2008 and 2009. One hundred and fourteen primer pairs amplified 284 polymorphic fragments among the 16 parental lines. Parents divided into three groups in a dendrogram of UPGMA clusters based on pair‐wise GD among parents. The correlations between the GD and F2 performance were significant for some fiber properties, but low with the highest r value in fineness (r = –0.43). The highest correlation between GD and mid‐parent heterosis was −0.43 for short fiber content. Population differentiation (P < 0.001) was identified between the JC and EL germplasm, but not between the SP and EL germplasm. Moderate correlations with r values ranging from −0.42 to 0.62 were detected between GD and fiber properties in the JC‐derived F2 hybrids. The results suggest that prediction of F2 performance by GD may be effective when crosses are made between parents from genetically differentiated groups in cotton germplasm.