Variation Analysis of Yield Traits of Dian-type keng Hybrid Rice Maintainers Lines under Different Environmental Conditions

PurposesTo study the traits variation of Dian-type keng hybrid rice maintainer lines under different environmental conditions, providing the basis for breeding the new keng hybrid combination with wide adaptability.

MethodA total of 220 Dian-type keng hybrid rice maintainer lines were planted in greenhouse and tested field, respectively, which with obvious differences of temperature and humidity. Ten yield traits including panicle number, filled grain number, and thousand-grain weight, etc., were measured; the data were analyzed by methods of significance test of difference, correlation test and clustering analysis.

ResultsExcept panicle length and numbers of primary branch per panicle, the other eight traits showed significant difference between the two different planting conditions. Especially, under high temperature and humidity condition, all maintainer plants showed extremely significantly higher plant height and less panicles, the variation range of traits among materials was increased, and the degree of dispersion was higher. Correlation analysis showed that the yield per plant was highest correlated with panicles and the filled grains per panicle, both in two planting environmental condition, but there was no significant correlation between panicles and other eight traits. Based on clustering analysis, all 220 maintainer lines were divided into four groups, which accounted for 14.5%, 38.1%, 27.3% and 20.1% of the total materials, respectively. Maintainers in group Ⅰ and Ⅱ had well performs, but those maintainer lines were sensitive to high temperature condition, the rice plants performed significantly higher height, less panicle, and significantly lower yield in high temperature and humidity condition. Maintainers in group Ⅲ and Ⅳ had lower yield, however, the variation of traits was relatively small in different environments, and the traits of group III were the most stable.

ConclusionUnder higher temperature and humidity conditon, maintainer lines of Dian-type keng hybrid rice varied vigorously, which resulted in higher plant height, decreased panicles, less thousand-grain weight and lower yield, but the panicle length and primary branches were less affected. In the keng hybrid rice breeding, panicles and filled grains per panicle were the two important traits correlated to higher yield improvement.