Evaluation of trend changes genetic in grain yield and characteristics associated with yield in facultative and winter bread wheat varieties in during past 50 years in Iran.

To estimate genetic progress and the variation in grain yield and characteristics associated with yield in facultative and winter bread wheat varieties in during past 50 years in Iran in 15 wheat (Triticum aestivum L.) cultivars with facultative and winter growth habit released in Iran between the 1930 and 2010, a field experiment was conducted using randomized complete block design with three replications at the Seed and Plant Improvement Institute’s Research Field Station in Karaj, during the 2010-2011 crop cycle. The results indicated that Navid cultivar with yield of 5.13 ton/ha and the Shah-pasand cultivar with 2.06 ton/ha had the highest and lowest yields. Performance of emulsion carbohydrates peduncle and internode under peduncle with annual changes was increased up to 0.349 and 0.107 ml gr/gr annually. Trend of temporal variation in the traits measured revealed that yield components including number of seed per spike, harvest index have increased in more recent released cultivars, however, thousand grain weight, Days of heading and Height has decreased, in comparison with the older cultivars.