Screening for Drought Resistance in Spring Chickpea in the Mediterranean Region

Abstract

Even though chickpea (Cicer arietinum L.) is well adapted to growing on stored soil moisture in drought-prone environments, drought is a major yield reducer in most chickpea-growing regions. Little progress has been made in breeding for improved performance under drought stress for want of a reliable and repeatable method of screening for drought resistance. Therefore, a study was initiated in 1990 to develop a screening technique and a rating scale to evaluate germplasm for drought resistance. A spring date-of-planting experiment was conducted during spring from 1990 to 1992 at Tel Hayda (northern Syria) to see if the expression of genotypic differences in drought resistance should be accentuated. Simultaneously, a rating scare was developed. Using the screening technique and rating scale, over 4000 germplasm lines were evaluated from 1992 to 1995. The resulting screening technique involves delayed sowing by 3 weeks during spring at a relatively dry site (long-term average annual rainfall of 328 mm), preliminary evaluation of materials on a rating scale of 1-9 to discard susceptible lines, and final evaluation of promising lines under stress (drought) and non-stress (supplemental irrigation) conditions, selecting drought-resistant lines which perform well under both conditions. In the 1-9 rating scale that was developed: 1 = no yield reduction as compared to a non-stress control and 9 = all plants dry without producing any seed. Using this technique, 19 lines out of 4165 lines screened were identified as drought resistant, producing over 1 t ha(-1) seed yield under drought conditions while being able to yield over 2 t h(-1) under nonstress conditions. Resistant lines are being used by national programs in the Mediterranean region and by ICARDA for developing drought-and disease-resistant, high-yielding cultivars.