Callogenesis in Cicer arietinum and identification of a genotype resistant to Ascochyta rabiei

Abstract

The chickpea (Cicer arietinum) is one of the leguminous species most appreciated by consumers in the Mediterranean basin, while being an important source of protein. Nevertheless, its crop yields are greatly limited by several biotic and abiotic stresses, the main one being Ascochyta rabiei, the causal agent of anthracnose. As traditional breeding methods have proved to be ineffective in controlling this pathogen, resorting to biotechnological methods is necessary. Therefore, in this study, the callogenic capacity of stem and leaflet explants from three genotypes of chickpea, namely ‘FLIP 84-92 C’, ‘ILC 32-97’, and ‘ILC 263’, cultured on Murashige and Skoog (MS) medium with different hormonal balances of auxins (indole-3-acetic acid [IAA] and 2,4-dichlorophenoxyacetic acid [2,4-D]) and cytokinin (kinetin), was determined. For all the genotypes, high percentages of callogenesis were recorded in the different explants grown on an MS medium with 2 mg of both IAA and kinetin. Then, a patho-system of Cicer arietinum calluses with Ascochyta rabiei was investigated, followed by a histological assessment of this interaction. The presence of the fruiting bodies of the pathogen was revealed in the calluses of the ‘ILC 32-97’ and ‘ILC 263’ genotypes. Notably, the latter showed a high sensitivity to the pathogen, as indicated by an abundance of pycnidia in its tissues. As for the ‘FLIP 84-92 C’ genotype, the histological sections showed a total absence of inter- and intracellular fruiting bodies of the pathogen in the callus tissues. Therefore, this genotype was considered as resistant to Ascochyta rabiei.