|
|
:
|
In the past, grain yield achievements during breeding have been mainly related to increasing the harvest index. However, future breeding efforts should focus on enhancing biomass production. Improving biomass depends on several factors which one of the most important is increasing radiation use efficiency. In the present study, sixteen bread wheat genotypes included Falat, Bamdad, Sepehr, Danesh, Jalal, Amin, Torabi, Talaei, Parsi, Sirvan, Shiraz, Marvdasht, Ghods, Mahdavi, Azadi, and Niknejad were evaluated in a randomized complete block design with three replications. Wheat varieties was sown in 2.4*10-meter plots during 2021–2023. Biomass dry weight was measured at key growth stages: stem elongation, spike emergence, flowering, and grain filling. Absorbed photosynthetic active radiation (PAR) was measured before each sampling using a linear PAR ceptometer, and then RUE was calculated for each developmental stage. Agronomic traits, including days to maturity, plant height, grain yield, yield components (spikes per m², grains per spike, thousand-grain weight), and harvest index, were recorded. Results showed that biomass and radiation use efficiency were influenced by wheat varieties only at the flowering growth stage. The Bamdad cultivar had the highest biomass (1596.80 gr/ m2 in average), and the highest radiation use efficiency (1.22 gr/Mj) at flowering stage. The results of this study showed that biomass and radiation use efficiency were not systematically modified by breeding in 43-year historical series of wheat cultivars.
|