Effect of terminal drought stress on the germination and growth potential wheat cultivars seeds

Abstract

In order to study the germination and growth potentials of seeds of bread wheat cultivars produced under terminal drought stress condition, seeds for five cultivars namely Sabalan, Rasad, Azar-2, Sardari and Zaare’ produced both under terminal drought stress and normal irrigation conditions were subjected to a factorial experiment in the form of Randomized Complete Blocks (RCB) design with three replications. The first factor of the experiment included the type of seed production (rainfed and irrigated), the second factor included drought condition using Polyethylene Glycol 6000 (0 mp , -3 mp , -6 mp levels), whereas the third factor included cultivars. In addition, traits such as germination within 10 days (using Al-Mudaris method, 1998), germination after 10 days, wet weight and germination percentage were measured during the experiment. Furthermore, during in vitro germination experiment indices such as coefficient of velocity of germination (CVG), germination rate index (GRI), final germination percentage (FGP), germination index (GI), mean germination time (MGT), germination stress index (GSI) and seedling traits were measured. Samples subjected to -6mp level of drought stress ceased growth at germination stage, while the remaining samples grew into stem stage. Results from the experiment showed that stress applied by polyethylene glycol 6000 had impact on traits such as coleoptile length, shoot length, shoot weight, germination percentage and germination rate index at 1% probability level. Likewise, types of seed production had impact on germination percentage, GRI, GI, and GSI. Finally, all the cultivars differed for the abovementioned traits except for shoot weight and GSI.