Breeding for increased water use efficiency in chickpea

Abstract

Water use efficiency (WUE) is a complex trait, hence secondary traits which are genetically associated with WUE and have a positive association with yield, easy to measure and have genetic variation can be used as breeding targets for high WUE. The aim of the present study was to discover the variation for water use efficiency and grain yield in different tillage and irrigation regimes; the basis of yield formation under water limited conditions and develop a chickpea ideotype. The field experiment was conducted at the Plant Breeding Institute, the University of Sydney in Narrabri, northwest New South Wales in Australia. A total of 36 entries were planted replicated twice under well-watered and water-stress conditions, and no-till and till regimes. Water use was monitored using a neutron probe moisture meter and water use efficiency calculated using the soil water balance method. Grain yield was higher under irrigation at 1722 kg/ha than rainfed conditions at 1478 kg/ha. No-till had 7.4% higher yield than the till regime. WUE was higher under no-till (5.02 kg/ha/mm) than under till (4.87 kg/ha/mm) and higher under irrigation (5.05 kg/ha/mm) than under rainfed conditions (4.84 kg/ha/mm). There was a strong association between grain yield and WUE under rainfed conditions, thus high yielding genotypes had high WUE. Sonali had the highest yield and WUE. Normalised difference vegetation index (NDVI) at early podding and late podding and chlorophyll content at late podding were useful marker traits in identifying genotypes with potentially high yield and high drought tolerance. Sonali, ICCV 96853 and PBA Slasher were identified as drought tolerant genotypes. The constructed chickpea ideotype had higher yields than the commercial varieties and had 76% resemblance to Sonali. By incorporating key target traits and targeting the right environment, chickpea yields can be sustained under soil water limited conditions.