Comparative Salinity Responses among Pigeonpea Genotypes and Their Wild Relatives

Abstract

Soil salinity can be a major constraint to pigeonpea (Cajanus cajan (L.) Millsp.) in the regions where it is predominantly grown. This study was conducted to assess the extent of genetic variation for salinity tolerance in the germplasm of pigeonpea and its wild relatives. Solution culture experiments in a greenhouse and controlled environment chamber were conducted to screen a range of cultivated pigeonpea genotypes for ability to germinate and grow up to 60 d under saline conditions. Several wild relatives of pigeonpea were screened for salinity response in a sand culture system in a greenhouse. Among cultivated pigeonpea genotypes, ICPL 227 was one of the most tolerant and HY 3C one of the most sensitive genotypes tested. None of the pigeonpea genotypes tested were able to survive beyond 30 d at 8 dS nr 1 or higher salinity levels. The extent of variation in salinity response among cultivated pigeonpea genotypes appeared too limited to warrant genetic enhancement of salinity tolerance. Among the wild relatives of pigeonpea, various species of Atylosia, Rynchosia, and Dunbaria showed a wide range of variation in their salinity tolerance (critical levels from 4 to 12 dS nr 1): A. albicans (W. & A.) Benth., and A. platycarpa could grow in a sand culture system at 12 dS nr 1 and Rynchosia albiflora could not tolerate salinity levels above 4 dS nr 1. These results suggest that using wild relatives for genetic improvement may increase salinity tolerance of pigeonpea.

Genetic Variability of Pigeonpea (Cajanus cajan (L.) Millsp.) for Water Logging and Salinity Tolerance under in vitro and in vivo Conditions

“…The genotypes which were found highly tolerant or tolerant and highly sensitive in both in vitro and in vivo conditions under water logging and saline conditions can be used for developing appropriate populations for genetic studies. Subarao et al [6] studied comparative salinity tolerance among pigeonpea genotypes and their wild relatives. A large genetic variation was also observed earlier in cultivated and wild species of pigeonpea, especially C. scarabaeoides, for salinity tolerance [5].…”

“…These abiotic stresses adversely affect its productivity causing severe yield losses [1,2]. Pigeonpea is reported to be highly sensitive to water logging [3,4] and salinity [5,6]. Water logging and salinity stresses are important yield constraints in pigeonpea as water logging blocks oxygen supply to roots which hampers root permeability [7] and salinity impairs seed germination, reduces nodule formation, retards plant development and finally reduces crop yield [8].…”

Screening of salt-tolerant genotypes ofBrassica junceabased on photosynthetic attributes

“…These are very sensitive to salt levels and soil drought status, experiencing water deficit due to osmotic stress possibly coupled with biochemical perturbations induced by the influx of sodium ions. Some of the leguminous plants like faba bean (Abdel Ghaffar et al 1982), chickpea (Lauchli 1984), tepary bean (Coons and Pratt 1988), pigeon pea (Subbarao and Johansen 1991) and common bean (MorenoLimo´n et al 2000) have been reported to show salt tolerance. However, the reports on the salt tolerance in mustard genotypes are meager.…”

Morphological changes and antioxidant defence systems in soybean genotypes as affected by salt stress

“…These are very sensitive to salt levels and soil drought status, experiencing water deficit due to osmotic stress possibly coupled with biochemical perturbations induced by the influx of sodium ions. Some of the leguminous plants, like faba bean (Abdel-Ghaffar et al 1982), chickpea (Lauchli 1984), tepary bean (Coons and Pratt 1988), pigeon pea (Subbarao and Johansen 1991) and common bean (Moreno-Limon et al 2000) have been reported to show salt tolerance. However, reports on the salt tolerance in soybean genotypes are meagre.…”