Effects of salt stress and mycorrhiza fungi on morpho-physiological characteristics of sweet corn

In order to investigate the interaction of mycorrhizal fungi and salinity on growth and physiological characteristics of sweet corn, a greenhouse experiment was conducted at College of Agriculture, Shiraz University, in 2014. The experimental design was factorial based on Completely Randomized Design in three replications. Treatments included salinity at four levels (0.4 (control), 4, 7, 10 dS m-1), and the fungi at three levels (no fungi (control), Glomus mosseae, Glomus intraradices). Results indicated that at flowering stage, with increasing salinity levels, leaf chlorophyll a, b and a+b content and carotenoid decreased at a rate of 18.9, 52.4, 33.1, and 34.5 respectively. Application of mycorrhiza under salinity, partially offset the negative impacts and increased tolerance of maize to NaCl by enhancing SOD and CAT activities, chlorophyll contents, carotenoid and K concentrations in leaves, plant height, leaf area, and total dry weight at flowering stage significantly, compared to control. The Na/K ratio at salinity level of 10 dS m-1 in treatments inoculated with GIN and GM fungi decreased by 39.69 and 40.45 percentage, respectively. Increases plant height, leaf area, total dry weight, concentrations of chlorophyll a, b, chlorophyll a+b and carotenoid and K, the activity of antioxidant enzymes compared with the control. Moreover, GIN type fungi had a greater advantage over GM and reduced the negative effects of salinity. Results indicated that application of mycorrhiza alleviated the adverse effect of salinity stress and improve the sweet corn dry weight up to 38 percentage at salinity level of 10 dS m-1