Combining Ability and Heritability Analysis Provide Insights into Variability for Multiple Agronomic Traits in Two-Line Hybrid Black Rice

Abstract

To analyze the combining ability and heritability of the main agronomic traits in black rice parents, and thus provide a theoretical basis for parent seed selection of two-line hybrid black rice and screening of superiority combinations. The combining ability and heritability of eight main agronomic traits were analyzed by 6×5 incomplete diallel cross (NCII) model through 6 sterile lines and 5 restorer lines. The results showed a significant difference in combining ability variance of the studied agronomic traits. The seed setting rate is mainly controlled by special combining ability of the combination. The effective panicle number is mainly controlled by general combining ability of the parents. The other agronomic traits are controlled by special combining ability of the combination together with general combining ability of the parents. From big to small, the narrow heritability is in the order of plant height, thousand seed weight, panicle length, spikelets per panicle, filled spikelets per panicle, yield per plant, effective panicle and seed setting rate. Multiple agronomic traits in two-line sterile line D18S, D40S and restorer line R401 of black rice have high effect value in terms of general combining ability and special combining ability, and the application prospect is bright.