RESUMO
BACKGROUND: The state of Manipur, North East India has distinct topology of hill and valley regions with vast agroclimatic variability, being considered as one of the centers of rice diversity. The indigenous Manipur black rice cultivars exhibit wide range of diversity in morphology, pericarp color, shape and size of grain, aroma, glutinous or non-glutinous features but remain less characterised. Many of these cultivars, such as those named Chakhao, are endowed with multiple health benefits due to high anthocyanins, and hold special importance for the local people. It is important to analyse the genetic diversity and population structure for this germplasm with unique allelic combinations to utilize in rice breeding programme. METHODS AND RESULTS: We characterized total soluble seed protein fractions to not only fingerprint the 45 indigenous black rice cultivars but assess their genetic relatedness. Cluster analyses generated mainly two groups, complemented by PCoA scatter plot ascertaining geographical distinction. The hill black rice were more diverse. The population structure analysis revealed seven subpopulations indicating high genetic variability. The 24 polymorphic bands were scored in the range of 127.8 to 10.3 kDa comprised of four protein fractions. Three polypeptide bands each were ascribed to known fractions of glutelins and prolamins, while one band each could be described for albumin and globulin fractions, besides other diagnostic bands. CONCLUSION: Some diverse cultivars were Amubi, Chedo Anal, Chipi Buh, Athebu, Poireton, BuPu Mui, Kotha Chahao II. These cultivars can be used in future black rice breeding programmes. This can further prevent genetic erosion and protect intellectual property rights.