Breeding for High Biomass Yield in Spring Barley

Abstract

Breeding for high biomass has been proposed as a way to enhance yield in small grain. The objectives of this study were to evaluate 42 spring barley (Hordeum vulgare L.) genotypes for biomass production and related agronomic traits; to obtain heritability estimates for biomass, vegetative biomass, and grain yield; and to assess changes in biomass and related traits during six decades of barley breeding. Barley genotypes from seven breeding programs, and a set of 10 barley cultivars representing different eras, were evaluated at St. Paul and Crookston, MN in 1984 and 1985. The 42 barley genotypes differed significantly for 12 traits including grain yield, biomass, and vegetative biomass. Biomass ranged from 6.6 to 10.0 Mg ha−1 and vegetative biomass from 3.4 to 6.0 Mg ha−1. The semidwarf genotypes were 16.9% lower in vegetative biomass, but 3.3% higher in harvest index than the tall genotypes. Several genotypes appeared to be good sources of high vegetative biomass with H74140002 exceeding ‘Robust’, the commercial check, by 27%. Heritability on a trial mean basis was 0.75, 0.76, and 0.67 for biomass, vegetative biomass, and grain yield, respectively. Vegetative biomass showed significant positive correlations with grain yield, height, and visual score of vegetative biomass. In the 10‐cultivar set, representing the different eras, grain yield, harvest index, biomass, vegetative biomass, kernel weight, and days to maturity increased significantly over time, whereas height decreased. Biomass increased at a rate of 22.5 kg ha−1 yr−1; vegetative biomass and grain yield increased at rates of 6.8 and 15.7 kg ha−1 yr−1, respectively. It was postulated that enhancing vegetative biomass would lead to higher grain yield and, therefore, be worthy of a breeding effort. However, because of the cost of measuring vegetative biomass, indirect selection based on plant height and visual scoring of biomass was suggested.