Characterization of small bitter gourd germplasm collections from various agro-ecological zones of India

Abstract

Crop wild relatives can evolve into crop plants through conscious selection by a process known as domestication, usually involving an early hybridization event followed by selective breeding. M. charantia var. muricata Willd. (Chakrav.), commonly known as wild bitter gourd or small bitter gourd, is an annual monoecious climber, with fruit varying from spindle-rhomboid to discoid and globose shape. The present study aimed to characterize the available small bitter gourd germplasm for major leaf, flower, fruit, and seed characters to demarcate the true wild types from the semi-domesticates and large-fruited cultivated types using key morphological markers, and also to investigate the extent of domestication of the crop in India. The results indicated that, the fruit and seed characters can be considered reliable indicators to delineate the wild and semi-domesticates from large-fruited cultivated types, rather than leaf and floral characters. As a result of domestication, gene flow occurred between the wild and the cultivated types, leading to the development of variant populations of small bitter gourds, with remarkable variations favouring mostly fruit characters. Further, morphological field keys pertaining to leaves, flowers, fruits, and seeds were also developed to differentiate the wild types from the semi-domesticates and large-fruited cultivated types.