Opportunities for wheat cultivars with superior straw quality traits targeting the semi-arid tropics

Abstract

Fifty wheat lines targeting semi-arid locations in India and Bangladesh were investigated for grain and straw yield and straw fodder quality traits for two consecutive years at two locations in India and one in Bangladesh. Fodder traits investigated were nitrogen (N), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), in vitro organic matter digestibility (IVOMD), and metabolizable energy content (ME). Highly significant (P < 0.0001) differences among lines were observed for all the traits, but location and year generally had greater effects than line. There were no significant relationships between straw yield and straw fodder quality traits. However, inverse associations (P = 0.17) were observed between straw N and grain yield and between straw ADF and straw yield. Variations among fodder quality within a location were slightly higher than when averaged across locations. For example, ADF, a trait significantly inversely correlated with price differences in wheat straw trading, ranged from 49 to 50.8% across locations whereas it ranged from 44.8 to 47.8% and from 47.2 to 49.6% at the two India sites and from 53.9 to 55.9% at the Bangladesh site. Moderate broad sense (h2) heritabilities were observed for ADF (h2 = 0.31) and ADL (h2 = 0.34), whereas h2 for other fodder traits were very low. Extrapolation of mean differences among lines in straw fodder quality traits across locations and years suggests that the best lines could meet the highest quality criteria observed in wheat straw trading with price premiums of 10–17% depending on whether the trading occurred in a rural or an urban area, respectively.