Temporal variation in phenological characteristics, grain yield, and yield components of spring bread wheat (Triticum aestivum L.) cultivars released in Iran between ۱۹۵۲ and ۲۰۰۹

To estimate genetic progress and the variation in agronomic characteristics and phenology in ۱۵ bread wheat (Triticum aestivum L.) cultivars released in Iran between ۱۹۵۲ and ۲۰۰۹, a field experiment was conducted at the Seed and Plant Improvement Institute’s Research Field Station in Karaj, Iran, in the ۲۰۰۹-۲۰۱۰ and ۲۰۱۰-۲۰۱۱ growing seasons. Temporal variation trends of the measured traits revealed that grain yield and related traits have increased in more recently released cultivars, though thousand-grain weight has changed only slightly compared with older cultivars released during ۱۹۵۲-۲۰۰۹. Number of days to heading and to anthesis did not change in modern cultivars, but grain-filling period and days to physiological maturity did increase. Grain number spike-۱ and rate of grain growth increased but plant height decreased in more recently released cultivars.

Keywords:

Anthesis , grain growth rate , physiological maturity , thousand-grain weight