Sustainable Production of Groundnut (Arachis hypogaea L.) Through Screening and Selection of Soil Salinity-Tolerant Genotypes

Abstract

Crop plants that are tolerant to soil salinity are needed for a sustainable food production in areas where there is salt build-up caused by irrigation practices. Ten groundnut (Arachis hypogaea L.) genotypes (ICGY-6M-5236, ICG-IS-11687, ICGY-5M-4746, ICG-IS-6646, ICG-IS- 3584, ICG49-85A, UGA-7-M, RRB12, RMP91 and RMP12) were screened in laboratory and field studies to identify those tolerant to soil salinity. Plants were irrigated with 0 (control), 25, 50, 100, 150 and 200mM NaCl solution, prepared artificially from table salt. Germination rate and percentage germination decreased with increasing salinity. RRB12, RMP91 and RMP12 did not germinate up to 200mM while others germinated with low percentages. Agronomic characters were significantly reduced by salinity above 50mM NaCl. Biomass and growth decreased with increasing salinity. Mortality of 25-40% was caused at 150mM but only ICGY-5M-4746 and ICG-IS-6646 did survive at 200mM with 52.17 and 55.16%, respectively. Plants irrigated with saline water had lower yield than the control. However, ICGY-5M-4746 did not produce pods at 200mM while ICG-IS-6646 produced pods without seeds at maturity. There was a large variation in germination, plant survival and yield among the genotypes. ICGY-5M-4746, ICG-IS-6646 and ICG-IS-3584 with high survival and yield under high salinity were identified as salt tolerant genotypes and recommended for planting in soil with salinity below 200mM NaCl. The traits from the salt tolerant genotypes could be a source for developing salt tolerant variants for improvement in groundnut production.