Abstract:

Growth and development of plants are adversely affected by drought, extreme temperatures (high temperatures or heat and low temperatures or cold), and nutritional imbalance including salinity, deficiency and toxicity of nutrients, and the concerned stresses result in low and instable yield as well as seed quality. Resistant varieties for these stresses can be improved by either (1) direct or (2) indirect breeding approaches. Mutagenesis for resistance to abiotic stresses is a well-known effective and efficient breeding approach in order to create new desirable genetic variability, as the use of the traditional breeding methods have narrowed genetic variability in the cultivated crop species over a long period. This chapter deals with (1) mutagenesis for resistance to abiotic stresses, and (2) achievements on resistance to drought, heat, cold, salinity and iron (Fe) deficiency chlorosis in the cultivated chickpea (Cicer arietinum L.) and its progenitor (Cicer reticulatum Ladiz.). About 500 seeds per dose each genotype of 10 accessions of Cicer species including three ‘kabuli’, four ‘desi’ chickpeas and one accession of Cicer bijugum K.H. Rech. and two accessions of C. reticulatum Ladiz. were irradiated with 200, 300 and 400 Gy gamma rays from a 60Co source. Mutant lines were screened for resistance to drought and heat, salinity and Fe-deficiency chlorosis, as well as tolerance to cold. Some of the mutants were not only resistant to the concerned abiotic stresses, but also had improved resistance to some other biotic stresses such as Ascochyta blight (Ascochyta rabiei (Pass.) Labr.) and leaf miner (Liriomyza ciceri Rond.). These mutants will be used (1) either directly in the target environments as commercial varieties, or (2) indirectly in breeding programmes as useful parents. Also, some previous unknown and known gene(s) were induced by gamma rays, and they can be used for gene mapping in Cicer species.