Sampling strategies and screening of chickpea (Cicer arietinum L.) germplasm for salt tolerance

Abstract

Six hundred accessions of chickpea (Cicer arietinum L.) landraces and its wild relatives from 28 different countries, available at Australian Temperate and Field Crops Collection (ATFCC) were screened for tolerance to salt under greenhouse conditions using three sampling strategies; (1) random sampling of 200 accessions from different countries, (2) restricted random sampling of 200 accessions from geographical regions with salinity problems and high diversity (Middle East and West & South Asia) and (3) as for strategy 1 but with a reduced representation of accessions from the geographical regions used in strategy 2. Degree of salt tolerance was based on necrosis scores and shoot biomass reduction relative to unstressed controls at harvest after subjecting stressed plants to salt treatment from 21 to 42 days after sowing. There was a wide variation in salinity tolerance determined by both measures. For sampling strategies 1, 2 and 3 respectively; 24, 28 and 14% of accessions were salt tolerant. Accessions from the middle east and south Asian (regions with salinity problem, a long history of chickpea cultivation and high diversity) gave a higher probability (P < 0.01) of getting salt tolerant accessions.

Salt sensitivity in chickpea

“…2007). Symptoms of leaf necrosis, presumably related to the destruction of chlorophyll in leaf cells resulting from ion toxicity when Na + and/or Cl ‐ exceed tolerable levels in tissues, were reported by Maliro et al . (2008) and these authors showed that ‘visual scores’ of necrosis could be used as an index of resistance.…”

“…In both roots and nodules, ACC increased three-fold and ethylene doubled with exposure for 3 d to 10 dS m -1 of mixed salts (where the molar ratios of Na + , Ca 2+ and Mg 2+ were: Na + : Ca 2+ 1:1; Ca 2+ : Mg 2+ 1:3 and Cl -: SO4 2-7:3) (Kukreja et al 2005;Nandwal et al 2007). Symptoms of leaf necrosis, presumably related to the destruction of chlorophyll in leaf cells resulting from ion toxicity when Na + and/or Clexceed tolerable levels in tissues, were reported by Maliro et al (2008) and these authors showed that 'visual scores' of necrosis could be used as an index of resistance. The presence of salinity (up to 10 dS m -1 of mixed salt, see earlier discussion) induced an increase in hydrogen peroxide of 180% in chickpea (CSG-8962) roots and of lipid peroxidation by 170% (Kukreja et al 2005).…”

“…Other studies (Sinhgla & Garg 2005; Sohrabi, Heidari & Esmailpoor 2008), based on screening of few genotypes, support the findings of Dua & Sharma (1995). Germplasm from regions of the Middle East and South Asia, where there has been a history of soil salinity, revealed the most diversity for salinity resistance (Maliro et al . 2008).…”

“…2003; Serraj et al . 2004; Maliro et al . 2008) need further confirmation by evaluating these genotypes for seed yield under saline conditions.…”

Exploring genetic variation for salinity tolerance in chickpea using image-based phenotyping

“…22 , were also taken. Other traits measured included leaf sodium (Na + ) and potassium (K + ) ion content, plant height, yield and yield components including shoot biomass, seed number, total pod number, empty pod number, filled pod number and 100-seed weight.…”