Correlation and combining ability of main chemical components in sorghum stems and leaves using cytoplasmic male sterile lines for improving biomass feedstocks

Abstract

A better understanding of the genetic basis that governs the inheritance of biomass quality traits may help to improve sorghum (Sorghum bicolor [L.] Moench) varieties for energy purposes. Here, combining ability studies were conducted using three restorer lines (male) and 60 cytoplasmic male sterile (CMS) lines (female), at two locations in China, during 2017 and 2018. Both entries and environments (i.e., site) significantly affected concentrations of soluble sugar, cellulose, hemicellulose, lignin, and ash of sorghum, in both stems and leaves. The coefficient of variation level was higher in stems than leaves for each chemical component investigated. The broad-sense and narrow-sense heritability indicated the predominance of an additive gene effect upon chemical components occurring in stems and leaves. This investigation is the first report to evaluate the combining ability effects on soluble sugar, cellulose, hemicellulose, lignin, and ash in stems and leaves of sorghum plants. Sorghum exhibited either significantly negative or positive general combining ability (GCA) effect for all chemical components in stems and leaves. Highly significant negative correlations were found between the GCA effect on soluble sugar and that on cellulose, hemicellulose, and lignin. Significant positive correlations were found among GCA effects of cellulose, hemicellulose, and lignin. The GCA effect on ash was significantly negatively correlated with that on soluble sugar but positively so with that on hemicellulose in stems, whereas it had significant negative correlations with that on soluble sugar, cellulose, and hemicellulose in leaves. Based on these findings, 11 and 6 female lines were selected for further development of biomass sorghum hybrids and sweet sorghum hybrids, respectively.