Study of photosynthesis, leaf water exchange and yield of field grown common winter wheat varieties under dry prone conditions.

Field experiment was conducted with six common winter wheat varieties in IPGR, Sadovo during 2020-2021 vegetation period. The gas exchange, relative chlorophyll content, canopy temperature depression, morphometry and leaf water exchange of the flag leaves were measured. After harvest the yield components were determinated. The main objective of this study was to determine the effect of water stress on response of photosynthetic activity, water exchange and yield in common winter wheat varieties. The better photosynthetic activity, presented by the parameters photosynthetic assimilation rate (A), intercellular (sub-stomatal) CO2 concentration (Ci) and stomatal conductance (Gs) during grain filling stage was reported for the varieties Sashez, Nadita and Yailzla compared to a standard Sadovo 1. The highest values of the morphometric parameters fresh weight, dry weight and relative chlorophyll content of flag leaves were expressed at the varieties Nadita Ð, Enola. From the analysis of the results for photosynthetic activity, leaf morphometry and water exchange, the most tolerant reaction to dry prone conditions can be determined in variety Nadita. The highest average yield was estimated for the varieties Avenue, Nadita and Enola. It was determinated the more intense physiological activity correlate with better yield in the varieties Nadita, Enola and Yailzla. [ABSTRACT FROM AUTHOR]