Crop Legumes Grown in Jhum Fields and Home Gardens in Nagaland and Study of the Root Nodule Morphology

Surveys were conducted in five districts of Nagaland to collect crop legumes grown in Jhum fields and home gardens. Ten crop legumes, namely Canavalia gladiata (Jacq.) DC, Glycine max (L.) Merr, Lablab purpureus L., Mucuna prurita (L.) DC, Phaseolus lunatus L., Phaseolus vulgaris L., Psophocarpus tetragonolobus L., Vicia faba (L.) D.C, Vigna umbellata (Thunb.) Ohwi and H. Ohashi and Vigna unguiculata (L.) Walp were commonly cultivated. Vigna unguiculata and Vigna umbellata were the most popularly grown beans. Root nodule was observed in all nine crop legumes except for Vicia faba. The nodules were of the determinate type. Number of root nodules and nodule size varies with the species. Large nodules were found in Canavalia gladiata, Psophocarpus tetragonolobus, and Mucuna prurita with the mean size of 5.15 ± 0.617 mm, 4.93 ± 0.115 mm, and 4.83 ± 0.289 mm. The smallest was in Vigna umbellata, with 1.45 ± 0.610 mm. Root nodule endophytes belonging to Rhizobium sp. were isolated from three popular crop legumes, namely, V. umbellata, V. unguiculata, and P. vulgaris. The study underscores the importance of further research on the crop legume symbiotic association with native root nodulating bacteria (rhizobia) for crop productivity.