Effect of genotype×environment interaction on heterosis for lodging resistance of the culm in rice
LIANG Kang jing, WANG Xue ren, ZHANG Qin qi, CHEN Zhi xiong (College of Crop Science, Fujian Agricultural University, Fuzhou, Fujian 350002, China)
Genetic studies were conducted on heterosis for lodging resistance of the culm in rice (Oryza sativa L.), by using genetic models including genetic effects and genotype×environment(GE) interaction for additive dominant additive×additive epistasis. The results indicated that heterosis for lodging resistance of the culm in five traits, such as culm length (CL), culm thickness (CT),breaking strength of the based culm with leaf sheaths (BSBCLS),culm type index (CTI) and resistant index to lodging (RIL) were affected by genotype and environmental factors (i.e year). Slight positive heterosis over mid parents based on population mean (H MP ) and negative heterobeltiosis based on population means (H BP ) were observed in CT, because of its insensitivity to environment, The expression extents and directions of heterosis were influenced by GE interaction in CTI and RIL. However, the same direction positive GE interaction effects were also observed in CL and BSBCLS on different environments. It implied that the heterosis could be enhanced by improving environmental conditions.