AGRICULTURAL RESEARCH COMMUNICATION CENTRE www.arccjournals.com LR-4055 [1-7] *Corresponding author’s e-mail: maru7806@gmail.com 1 ICAR-Central Research Institute for Jute and Allied Fibres, Kolkata-700 120, Barrackpore, India 2 ICAR- NBPGR Regional Station, Ranchi, Jharkhand-834 010, India. 3 ICAR- Directorate of Rapeseed-Mustard Research, Bharatpur, Rajasthan-321 303, India. Legume Research, Print ISSN:0250-5371 / Online ISSN:0976-0571 DIVA-GIS based insight into geographical distribution and diversity spectrum of Indian sunnhemp (Crotalaria juncea L.) accessions suitable for diversified applications R.T. Maruthi* 1 , A.A. Kumar 1 , S.B. Choudhary 2 , H.K. Sharma 3 and Jiban Mitra 1 Crop Improvement Division, ICAR-Central Research Institute for Jute and Allied Fibres, Kolkata-700 120, West Bengal, India. Received: 23-06-2018 Accepted: 11-03-2019 DOI: 10.18805/LR-4055 ABSTRACT Commercial prospects of sunnhemp inspired present study to understand geographical distribution pattern(s) and to scale agro-morphological diversity spectrum of forty-four sunnhemp accessions naturalized across diverse habitats of India. Field experiment revealed broad spectrum diversity for all the 11 agro-morphological traits. Wider range of plant height (110.50 to 173.17 cm), number of pods per plant (35.33 to 143.00), seeds per pod (6.33-15.17g) and seed yield per plant (8.27-29.43g) highlighted the adequacy of present genetic resources to improve sunnhemp for diversified applications. Principal component analysis of the agro-morphological characters identified the first PC with 1109.6 eigen value explaining 61.70% of total variation followed by PC-II (22.9%) and PC-III (11.1%). In PC-I significant contribution was made by traits like NLP, NPP and PH. Agglomerative hierarchical cluster analysis grouped all accessions into four distinct seed producing clusters irrespective of their origin. Cluster wise mean values suggested that cluster-II is the best with outstanding trait values for majority of traits. DIVA-GIS based analysis identified accessions from Rajasthan, Western Gujarat and Jharkhand with high diversity index for number of leaves/plant. But, accessions from North West Jharkhand and Maharashtra with highest diversity index for seed yield/plant. Key words: Agro-morphological traits, Cluster analysis, Cover crop, Crotolaria juncea L., DIVA-GIS. INTRODUCTION Sunnhemp (Crotalaria juncea L.) is one of the earliest (400B.C.) domesticated crops valued for its multipurpose applications. In India, being the most distinctly named fibre crop (Sarkar et al., 2015), this species earned several locale names including Indian hemp, Madras hemp, brown hemp, Tropic sun etc. Stem bark of the plant produces phloem fibre commercially valued for durability, lighter colour and resistant to moisture, mildew, and micro- organisms (Maiti et al., 2010). The fibre found even better than jute (Corchorus olitorius) for durability and scored better fibre length (3.79 vs. 2.62 mm ) and width (24.3 vs. 19.7 μm) over kenaf (Hibiscus cannabinus) (Cunningham et al ., 1978). As a result its commercial prospects in traditional industries like preparation of cordage, fishing nets, tatpatti, ropes, twines, canvas and floor mats have not only consolidated over the years but also expanded to new horizons like manufacturing of pulp, paper, newsprint and specialty papers. In addition, the species traditionally valued as a green manure crop and often grown in rotation with several different crop species across tropical and subtropical regions (Linares et al., 2007; Tripathi et al., 2013). With rapidly establishing canopy the crop found effective competitor of common field weeds besides producing 5.9 to 7.6 t ha -1 of biomass within 12 to 14 weeks and fix 120 to 144 kg ha -1 nitrogen over 9 to14 weeks (Balkcom and Reeves, 2005; Bhardwaj et al., 2005). Further, the species is an outstanding soil organic matter augmenter and carbon sequester. Its potentiality to suppress plant pathogenic nematodes like root knot nematode populations, encourage its use as an alternative to nematicides (Pradhan et al., 2001; Wang et al., 2001). Despite such a broad spectrum commercial prospects and emerging opportunities, area under sunnhemp cultivation is stagnated. In 2014-15, the crop occupied an area of 11.6 thousand hectares that produces 46.8 thousand bales of fibre (1 bale = 180 kg) with a national productivity of 7.3 q ha -1 (DAC&FW, 2017). With the growing carbon footprints of developmental initiatives in the post industrialization era and input intensive farming practices during post green revolution, interests in the crop further