Effect of putrescine on yield and some physiological parameters of wheat in response to water deficit stress

Drought stress is one of the most important environmental factors involved in the growth and yield of wheat reduction and causes many damages by disrupting morphological and physiological processes. On the other hand, putrescine as a growth stimulant with antioxidant properties in the plants can inhibit the destructive effects of dehydration stress. For this purpose, a factorial experiment based on a completely randomized design with three replications was carried out in the greenhouse of the Faculty of Agriculture, University of Mohaghegh Ardabili. Factors included water deficit stress (control, 85% and 65% of field capacity), wheat cultivars (Kuhdasht, Zagros, Gonbad and lines 23, 24, 25, 27, 28, 39 and 40) and putrescine (non-application, 0.088 and 0.176 g / L-1). Putrescine foliar application was performed in the three-leaf stage of the plant and dehydration stress was applied one day later for one week. Mean comparisons showed that dehydration stress decreased leaf chlorophyll index, F0, Fm, Fv / Fm, stem length and grain yield (grain number and grain weight) in some studied genotypes. The combination of 0.088 g / L-1 putrescine and drought stress improved the chlorophyll index (28.16%) and the amount of photosystem two (10.54%) compared to the control conditions. Also, the dendrogram obtained from cluster analysis placed the studied genotypes under dehydration stress and putrescine foliar application in three groups. In general, foliar feeding of 0.088 g / L-1 putrescine is more effective and recommended for the photosynthetic system improvement and tolerance of wheat plant to dehydration stress. Among the studied genotypes, Koohdasht, Zagros and Line 27 were more tolerant to dehydration stress due to putrescine-enhanced photosynthetic system and improved grain yield.