Stay-green character and its contribution in Brazilian wheats

摘要

The stay-green character has been related to greater stress tolerance and yield through longer activity of the photosynthetic apparatus. Association of this character with grain yield may be linked to a network of features other than the grain mass. This study aimed to shed light on the actual contribution of stay-green character in Brazilian wheats and the associations between grain yield components in different environmental conditions. The experiment was conducted in a randomized block design with three replications in the years 2003, 2004 and 2005. Sibling lines with and without the stay-green character were evaluated analyzing the phenotypic correlation and path analysis separately by year and maturity group. Under favorable growing conditions, the contribution of stay-green character in wheat is obtained by the increased ear fertility and number of grains. In a more restrictive scenario, it favors an increase in grain mass by longer filling time at the end of the cycle.