Genetic analysis of non-essential amino acid contents in rice (Oryza sativa L.) across environments.

Genetic main effects and genotype x environment (GE) interaction effects for 7 non-essential amino acids in milled rice were analyzed for two year data by using the genetic models based on mixed linear model approaches for quantitative traits of triploid endosperm. Nine cytoplasmic, male sterile lines as females and five restoring lines as males were introduced in a diallel cross in two environments. It was found that the content of non-essential amino acids including Asp, Ser, Glu, Gly and Tyr were mainly controlled by genetic main effects, whereas the content of Ala or Pro was mainly affected by GE effects. In genetic main effects, the cytoplasmic and maternal genetic effects were preponderant for all traits of non-essential amino acids, indicating that selection for improving these traits based on the maternal plant would be more effective than on seeds. The total narrow-sense heritabilities for non-essential amino acids were 70.9-85.9%. By predicating the genetic effects of parents, the total genetic effects from Xieqingzao, V20, Zuo 5 and Zhenshan 97 were mainly negative and these parents would decrease the content of most essential amino acids. Since parents of Zhenan 3, Yinchao 1, T49, 26715, 102 and 1391 had possessed a positive value of most total genetic effects, these parents could be chosen as optimal parents for increasing the content of most non-essential amino acids.