Indirect Selection for Grain Yield of Barley in Harsh Mediterranean Environments

Abstract

Selection for yield of barley (Hordeum vulgare L.) in unfavorable Mediterranean environments will be more efficient if plant traits can be identified that are related to yield under stress. The aim of this study was to assess whether, in fall-sown barley, plant traits measuredin favorable environments can be used as criteria for indirect selection for grain yield in unfavorable environments. Thirty-six two-row barley genotypes were grown in 15 Mediterranean environments. The plant traits measured were plant ideotype in winter (WPI, a principal component of winter growth habit, winter plant color, and cold tolerance) and heading date. Values were averaged across three favorable environments. Winter type barley had high values for WPI; spring type barley had low values. Grain yield under favorable and unfavorable conditions was represented by average standardized yields in six high-yielding (HY) and five low-yielding (LY) environments, respectively. In LY environments, a high value for WPI and early heading had a significantly positive effect on yield. A high value for WPI tended to result in late heading, however. In HY environments, a high value for WPI had a weakly negative effect on yield; heading date had no effect. Both WPI and heading date had a significant effect on yield response. Selection in HY environments for WPI and heading date together can be an efficient method of selection for yield of barley under stress, especially in early generations, when yield trials are difficult to conduct.