Influence of F2-generated altitude on the panicle traits in rice segregating populations grown at low temperature condition

The genetic parameters of main panicle traits were analyzed in F2 populations planted at low temperature condition with 2200 m elevation, which populations generated at four different altitudes. The material female parent and male parent are Xiaohuagu and Nan34. The results showed that spikelet fertility and grain density were more sensitive characteristics, could be used as indicators of cold tolerance evaluation at booting stage. The average values of these both traits are increasing with the rising F2-generated altitude; however,the average values of panicle length and panicle node length in the F2 populations generated from middle elevation are significantly higher than in the F2 populations generated from lowest and highest elevation. In addition, the variation coefficient, broad heritability, genetic advance and genetic skewness of the panicle traits in F2 populations are significantly different with F2-generated altitudes. The results indicate that the F2-generated altitude variation had strong effects on panicle traits; the effect is especially obvious on spikelet fertility and grain density.