Phenological traits and molecular markers established genetic relationship and population structure in jute (Corchorus species) populations collected from Southern India

Wild species of genus Corchorus are valuable resource for improving fibre quality, stress tolerance and nutritional attributes in cultivated species. In the present study a total of 120 accessions of 7 Corchorus species (6 wild species and one cultivated species i.e. Corchorus olitorius) naturalized in Southern India studied for habitat distribution, species richness, variability, genetic diversity and population structure. For these study, agro-morphological traits (leaf blade length, leaf blade width, petiole length, plant height, stem basal diameter, green weight, dry stem weight and dry fibre weight), Inter Simple Sequence Repeat (ISSR) and Sequence Related Amplified Polymorphism (SRAP) markers were employed. These species are found frequently but unevenly distributed along geographical boundaries in the region. C. aestuans was the most frequently distributed species followed by C. trilocularis, C. olitorius, C. tridens, C. urticifolius, C. fascicularis and C. pseudo-olitorius. Naturalized habitats represented arid to humid agro-climatic zones. Altitude emerged the key determinant influencing species differential spatial distribution in the region. The multispecies population revealed broad spectrum phenotypic coefficient of variation (PCV) for important agro-morphological traits including green weight (PCV = 50.40%) and dry fibre weight (PCV = 97.16%). The highest genetic diversity in the population was exhibited by ISSR having high Shannon’s Information index (SI = 0.384) and expected heterozygosity (He = 0.255). But, the highest intra-species variance was recorded by SRAP (86%) markers. Nevertheless, SRAP marker estimated higher gene flow in the population (3.702). Both the markers together positively correlated with the geographical distances of naturalized habitats. Based on genetic similarity among wild species C. urticifolius is suggested to be the closest extant relative of cultivated species of jute (C. olitorius).