Effect of Water Deficit Stress on Seed Composition, Seed Germination and Seedling Growth in German Chamomile

In order to evaluate germination, seedling growth and seed composition of German chamomile produced at different irrigation regimes (Irrigation at 30, 60, 90, and 120mm evaporation from pan class A) a randomized complete block design with six replications was conducted in 2009-2010 at the Research Station of Faculty of Agriculture, Urmia University, Urmia-Iran. Results showed that the significant effect of irrigation on percentage, rate and index of germination, and however nitrogen and phosphorus content, and percent and yield of seed protein, but non significant effect of irrigation on time to 50% germination, root length, shoot length, seedling length, root/shoot length ratio, potassium content and seed yield. The highest germination percent (90%), rate (8.2% d-1) and index (8.5) belonged to irrigation after 60 mm evaporation from pan and the lowest germination percent (48%), rate (4.4% d-1) and index (4.8) belonged to irrigation after 120 mm evaporation. However the highest (3.43 and 21.44%) and lowest (3 and 18.74%) nitrogen and protein content were obtained from irrigation after 120 and 30 mm evaporation, respectively. The changes in protein yield were the same with protein percentage because of non significant effect of irrigation on seed yield. Thus the strongest water stress was the optimum regime for producing seed yield because of minimum water use. Concerning with phosphorus, the highest (8.08%) and lowest (6.56%) amounts were occurred at irrigation after 60 and 120 mm evaporation from pan. The binomial regression between irrigation and germination percent, rate, and index, nitrogen, phosphorus and protein percentage emphasized to results of ANOVA. Non significant correlations between content of phosphorus and germination, and potassium and germination, and however between seedling growth and nitrogen, phosphorus and potassium reserve of seed emphasized to independence of germination and seedling growth from these reserves. However, correlation between nitrogen content of seeds and germination was significant and negative.