Adaptation of chickpea genotypes to the Mediterranean basin

Chickpea (Cicer arietinum L.), the third most important pulse crop in the world, is a spring crop in the Mediterranean traditional agricultural systems. It is sown during March-April and is extremely affected by long periods of drought during the reproductive phase. As a consequence, there is a need to develop chickpea germplasm with resistance to abiotic stresses mainly drought. . Chickpea requires around 150 days from sowing to maturity, although the duration of the development is water and temperature dependent. Chickpea can be cultivated in the range of mean daily air temperatures of 20-30ºC, but high temperatures can limit production seriously. Similarly, chickpea yield may decrease substantially with increased frequency of drought. The present investigation was carried out to study stability for seed yield and its components in 15 genetically diverse genotypes (13 from ICARDA, Syria and 2 from INIAV, Elvas, Portugal) of chickpea, using a randomized complete block design. Trials were conducted during three years under rainfed conditions in Portugal and Syria, using a late sowing date to naturally expose the plants to drought and heat stress. The accumulated results indicated a high variability in the yield response among genotypes and regions. Genotype × environment interaction (GxE) was observed in all experiments. Cross-over GxE interaction between top-yielding and low yielding cultivars occurred across the environments. Data showed higher yield potential in Portugal than in Syria due to higher and more adequate distribution of rainfall. In general, genotypes that fasten their development cycle showed higher grain yield, especially in dry years. G×E interaction analyses were calculated by regressing genotype means against a site index, the mean yield or the mean site effect (Finlay and Wilkinson, 1963). The analysis of results for the three years and across two sites showed four groups of genotypes: 1) genotypes with high adaptation to distinct environments; 2) genotypes adapted to favourable conditions, but with bad performance under adverse conditions; 3); genotypes with very good adaptation for poor environments and 4) genotypes with no adaptation (worst situation). The genotypes ILC 3182 and FLIP03-145C stand out by their high yield in the two regions and three years, including water stress conditions