Effect of mycorrhiza fertilizer on physiological traits and economical yield of lettuce (Lactuca sativa L.) under water stress conditions

In order to investigate the effect of mycorrhiza biofertilizer on physiological traits, nutrient uptake and economic yield of lettuce under drought stress conditions, a split plot layout based on a randomized complete block design with three replications was conducted at University of Hormozgan.Experimental factors were included water stress levels as the main factor in three levels including irrigation of lettuce plants based on providing 50, 75 and 100% of RAW, equal to mild and moderate deficit irrigation and control respectively, and mycorrhiza fertilizer, it consists of three species of Glumos intraradices, G. mosseae and G. fasciculatum, at 0, 5, 10 and 20 g.m-2 as sub factor. The studied traits included physiological traits (chlorophyll a, b and total, maximum photosystem II efficiency (Fv/Fm) and catalase activity, relative leaf water content) leaf P and K content and economical yield of lettuce. The results of this study showed that water stress and mycorrhiza fertilizer significantly affected physiological traits of lettuce. With increasing in water stress level, leaf chlorophyll a, b and total content, maximum photosystem II efficiency (Fv/Fm), leaf relative water content, P and K content and overall economical yield of lettuce were decreased, While catalase activity was significantly increased under this condition. Application of mycorrhiza fertilizer under water stress conditions could improve physiological traits and nutrient content, so that in moderate water stress condition, application of 20 gm-2 of mycorrhiza fertilizer significantly increases the activity of catalase, Fv/Fm, chlorophyll a and total content, relative leaf water content compared with no fertilizer application.