QTL analysis of lodging and related traits in soybean.

Lodging is an important agronomical trait in soybean,which has obvious negative effect on yield,seed quality and mechanical harvesting efficiency.The 165 recombinant inbred lines(RIL) derived from a cross between Zhongdou 29 and Zhongdou 32 were used in two years,with the composite interval mapping(CIM) method to identify the QTLs associated with lodging,plant height,stem diameter,nodes on main stem,branch number,shoot weight,root weight and stem intension.On link-age groups A2,C1,C2,D1a,F,G,I,and L,25 and 19 QTLs for lodging and related traits were detected in 2006 and 2007,re-spectively,explaining 4.4–50.1% phenotypic variation.One QTL(qLD-15-1) of lodging and one QTL(qPH-15-2) of plant height on F linkage group were both detected in two years;one QTL of nodes on main stem and two QTLs of root weight were detected in two years on G,A2,and L linkage groups respectively.The positions of some QTLs of plant height,root weight,shoot weight,stem diameter,nodes on main stem and branch number were close to those of lodging,showing that the lodging resistance is asso-ciated with the characters in aerial part and underground portion,the results were consistent with the correlation analysis of phe-notypic traits,showing the correlation of these morphological traits in genetics.The QTLs of some traits had the same positions,but were not both detected in two years.