SCREENING FOR DROUGHT RESISTANCE IN SPRING CHICKPEA IN THE MEDITERRANEAN REGION

Even though chickpea (Cicer arietinum L.) is well adapted to growing o n stored soil moisture in drought-prone environments, drought is a maj or yield reducer in most chickpea-growing regions. Little progress has been made in breeding for improved performance under drought stress f or want of a reliable and repeatable method of screening for drought r esistance. Therefore, a study was initiated in 1990 to develop a scree ning technique and a rating scale to evaluate germplasm for drought re sistance. A spring date-of-planting experiment was conducted during sp ring from 1990 to 1992 at Tel Hayda (northern Syria) to see if the exp ression of genotypic differences in drought resistance should be accen tuated. Simultaneously, a rating scare was developed. Using the screen ing technique and rating scale, over 4000 germplasm lines were evaluat ed from 1992 to 1995. The resulting screening technique involves delay ed sowing by 3 weeks during spring at a relatively dry site (long-term average annual rainfall of 328 mm), preliminary evaluation of materia ls on a rating scale of 1-9 to discard susceptible lines, and final ev aluation of promising lines under stress (drought) and non-stress (sup plemental irrigation) conditions, selecting drought-resistant lines wh ich perform well under both conditions. In the 1-9 rating scale that w as developed: 1 = no yield reduction as compared to a non-stress contr ol and 9 = all plants dry without producing any seed. Using this techn ique, 19 lines out of 4165 lines screened were identified as drought r esistant, producing over 1 t ha(-1) seed yield under drought condition s while being able to yield over 2 t h(-1) under nonstress conditions. Resistant lines are being used by national programs in the Mediterran ean region and by ICARDA for developing drought-and disease-resistant, high-yielding cultivars.