Salt sensitivity of the vegetative and reproductive stages in chickpea (Cicer arietinum L.): Podding is a particularly sensitive stage

Abstract

Soil salinity is an increasing problem, including in regions of the world where chickpea is cultivated. Salt sensitivity of chickpea was evaluated at both the vegetative and reproductive phase. Root-zone salinity treatments of 0, 20, 40 and 60mM NaCl in aerated nutrient solution were applied to seedlings or to older plants at the time of flower bud initiation. Even the reputedly tolerant cultivar JG11 was sensitive to salinity. Plants exposed to 60mM NaCl since seedlings, died by 52 d without producing any pods; at 40mM NaCl plants died by 75 d with few pods formed; and at 20mM NaCl plants had 78–82% dry mass of controls, with slightly higher flower numbers but 33% less pods. Shoot Cl exceeded shoot Na by 2–5 times in both the vegetative and reproductive phase, and these ions also entered the flowers. Conversion of flowers into pods was sensitive to NaCl. Pollen from salinized plants was viable, but addition of 40mM NaCl to an in vitro medium severely reduced pollen germination and tube growth. Plants recovered when NaCl was removed at flower bud initiation, adding new vegetative growth and forming flowers, pods and seeds. Our results demonstrate that chickpea is sensitive to salinity at both the vegetative and reproductive phase, with pod formation being particularly sensitive. Thus, future evaluations of salt tolerance in chickpea need to be conducted at both the vegetative and reproductive stages