Effect of drought-induced stress by PEG6000 on physiological and morphological traits of Lentil (Lens culinaris.) seed germination in order to selection of drought tolerant genotypes

Drought stress is one of the most important factors in arid and semiarid regions that lead to disorder in growth and development of plants especially at germination stage. Because of importance lentil, achieving genotype(s) that are capable of the drought stress at initiating growth stage is necessary. For this purpose, germination and plantlet growth of 49 genotypes were tested in drought stress conditions at four levels including 0 (control), -4, -8 and -12 Bar using PEG6000. This experiment was conducted at laboratory of Agronomy and Plant Breeding Department of University of Tehran in Karaj in 2016 as a factorial design in randomized complete block design (RCBD) with three replications. Traits that were studied including: germination percentage, germination rate, root length, shoot length, dry weight of roots and dry weight of shoots and allometry factor. Data were subjected to variance analysis and mean comparison. Results indicated that in most considered traits, effect of potential levels of genotypes and their interaction were significant. Result of simple correlation coefficient analysis indicated that germination percentage has the highest correlation with vigor germination (r=0.855) and speed germination (r=0.798). Factor analysis determined that two factors (germination and root traits) accounted 67% of the total variations among genotypes. In general, results represented that considerable genetic diversity was among genotypes. Regarding the studied traits, "6, 4 and 48" genotype had high tolerance to drought stress at germination stage, "34, 28” and “45" had low tolerance.