Les champignons endophytes d'algues marines: Etude in vivo sur la culture du blé dur et perspectives à la tolérance au stress salin.

Abstract

Endophytic fungi are used as an alternative to stimulate plant growth under salt stress. The tolerance of durum wheat (variety SIMETO) to salt stress at different NaCl concentrations (0, 50, 100, 150 and 200mM) was studied after inoculation of the endophyte (AY1S) on the seeds. The tolerance of 35-day-old wheat plants, grown in a growth chamber under pots, was assessed by analysing emergence rate, growth, relative water content, photosynthetic pigments, as well as proline and MDA (malondialdehyde) levels. The results indicate that increasing salinity levels has no negative effect on the growth, physiological and biochemical characteristics of durum wheat. Emergence rates, number of roots and leaves, carotenoids and MDA are comparable to the control. The same is true for chlorophyll b at high NaCl concentrations (150 and 200mM). However, leaf height and leaf area were negatively affected. This symbiotic association showed an increase in chlorophyll a at 200mM and remarkable levels of proline at 150 and 200mM NaCl. These results demonstrate the halotolerant effect of AY1S in attenuating the deleterious effects of NaCl on durum wheat plants.