Effect of biofilm PGPRs in alleviation of terminal growth stage water shortage on wheat's component yield and root

Biofilmed bacteria that possess growth promoting properties can help crops such as wheat to survive in water stress conditions. In this regard, a factorial experiment with randomized complete block design (RCBD) was carried out to evaluate the effects of biofilm bacteria on yield and its components of wheat in rain-fed condition. Factors were including biofilmed bacterial isolates (including no bacteria, and isolates 16-1, 38-2 and 1-54), different wheat varieties (Kohdasht and Chamran), and water application (applying 20, 50, and 80 % of available water content) which were applied in 3 replications in research greenhouse of university of Maragheh. Studied isolates were selected among 120 biofilm isolates which were isolated from Graminae’s roots resistant to drought in the Hashtrood region. Results revealed that bacteria had positive effects on yield component of wheat in all applied water conditions. Bacteria’s application also prevented the deduction in some of yield components which usually occurs due to water stress condition. However, the results revealed that the effects of bacterial application were higher in Chamran variety compared to Kohdasht variety. Root’s wet and dry weights, root’s tissues density, water holding percentage of root and root/shoot ratio were affected by water stress condition. Bacterial inoculation decreased root’s wet and dry weights and tissues density. In contrast, Bacterial inoculation considerably increased water holding percentage. In general, the results suggest that biofilmed bacteria are suitable to deduct the effects of drought stresses.