Effects of water deficit on chlorophyll content, relative water content and grain yield of six Croatian winter wheat genotypes

Drought is one of the major environmental factors that inhibits many metabolic processes and constrains plant growth and crop productivity. Croatia is part of Mediterranean Drought Group with late season drought stress during the grain filling in wheat. In order to evaluate water deficit on relative water content (RWC), chlorophyll content (Chl) and grain yield of six Croatian winter wheat genotypes, a factorial experiment based on randomized complete block design with three replications was conducted in 2009-2010. Factors were six winter wheat genotypes (Kaja, Divana, Karla, Kuna, Banica and ZGM 13) and two water regimes (control and water deficit occurred from anthesis to maturity). Physiological responses (RWC and Chl) were measured in late milk maturity (LMM) and in early waxy maturity (EWM). Grain yield, yield per spike and 1000 grain weight were measured after harvesting the plots at maturity. Results showed that genotypes Kuna and Banica had the highest Chl in LMM, and the genotype Karla had the highest Chl in EWM in both environments. The highest RWC was observed in the genotype Karla in LMM, and in the genotype Kuna in EWM in both environments. Genotypes Karla, Kuna and Banica are all high yielding genotypes, but Kuna and Banica had the biggest loss in yield in stress condition (17%, 15.9%). For this reason Karla, that is high yielding genotype, with high RWC, and high Chl, could be recommended for planting in regions with Mediterranean type of drought.