Association between adaptation type and changes in the yield components of barley (Hordeum vulgare L.) varieties influenced by vernalization and daylength

Abstract

Changes in the yield components of 35 barley varieties, which formed eight adaptation groups, were studied as a function of daylength and vernalization treatment under controlled conditions. Changes in the daylength had a significant effect on the yield components in the majority of adaptation groups, though the extent and direction of these changes varied. In spring barley groups there was an increase in plant height, number of reproductive tillers and in the thousand kernel weight, while the number of spikelets, the grain number of the main spike and the grain yield decreased as the daylength became shorter. Among the winter barley varieties, changes in daylength had a significant influence on yield components only in those groups, which were sensitive to long and/or short days. The groups sensitive to long days produced higher grain yields under long-day conditions than the insensitive group. Under short days the grain yield of groups sensitive to short days declined to a greater extent than that of the insensitive group. The effect of vernalization on the yield components depended strongly on the vernalization requirements of winter barleys. Most of the yield components of winter barleys with the highest vernalization responses were significantly influenced, with the exception of the grain number in the main spike. Changes in yield components showed specific patterns between these eight groups well corresponding to the different adaptation types determined by their heading date characteristics.