Abstract
Understanding the wheat grain yield in terms of assimilation, remobilization and translocation the photosynthetic assimilates and the contribution of plant organs in grain filling is one of the future breeding necessary strategies. The aim of the present research to evaluate the indicators of photosynthetic assimilate remobilization of wheat cultivars that were released during the years 1991 to 2016. For this purpose, the experiment was conducted in the form of randomized complete block design in 3 replications during two crop years 2018–2019 and 2019–2020 in Shirvan Higher Education Complex Research Farm in North Khorasan, Iran. The results indicated the variability of photosynthetic assimilate remobilization potential from different organs among cultivars, and the relationship between the cultivars genetic diversity and the photosynthetic assimilate remobilization of different organs. Indeed, the greatest remobilization, contribution and efficiency of photosynthetic assimilate remobilization were observed in Ehsan, Karim and Gonbad cultivars. Also, the remobilization rate, contribution and efficiency of photosynthetic assimilate remobilization from flag leaf, peduncle and penultimate has increased during the last few decades in Iran during breeding activity. The results showed that the photosynthetic assimilate remobilization increased from the flag leaf and peduncle is about 8.7%, and 5% from penultimate per one year of release. The contribution of remobilization from different organs to grain yield was in the order of peduncle > penultimate > flag leaf. However, there were no significant differences in the photosynthetic assimilate remobilization efficiency between different organs and it was on average about 5% per one year of release.