Genetic Diversity and Utility of castor (Ricinus communis L.) Germplasm Accessions Collected from Tamil Nadu

Abstract

Genetic diversity and utility of castor (Ricinus communis L.) germplasm accessions collected from Tamil Nadu T Manjunatha1*, C Lavanya1, AJ Prabhakaran2 and G Balakishan1 1-ICAR-Indian Institute of Oilseeds Research, Hyderabad, 2- ICAR-Sugarcane Breeding Institute, Coimbatore *Corresponding author Email Id: t.manjunatha@icar.gov.in Castor is an important non-edible oilseed crop and its oil is used in more than 250 industrial products like paints, varnishes, cosmetics, lubricants, medicines etc. India is the leading producer of castor seed with 1.92 MT (90% of the world’s production) from 0.82 m ha area (70% of world’s castor area) in the world with a highest productivity of 2300 kg/ha. India is the leading exporter of castor oil and its derivatives, earning foreign exchange to the tune of Rs. 6000-7000 crores annually. The utilization of castor germplasm has played an important role in developing short to medium duration high yielding varieties and hybrids resistant to biotic and abiotic stresses. Two hundred and nine castor germplasm accessions were collected, representing diverse agroecosystems of open fields, house backyards, shade/border plants in ginger cultivation and other crops, from nine districts of Tamil Nadu viz., Namakkal, Erode, Salem, Thanjavur, Madhurai, Theni, Karur, Tirupur and Nilgiris. These accessions were evaluated for their agromorphological traits in ARBD design. Agromorphological evaluation indicated a wide variation for stem colour, bloom, plant height, days to 50% flowering, length of primary spike, capsule size and test weight. Of the 209 accessions, 108 accessions were of zero bloom, 86 were triple bloom, 8 were single bloom and 19 accessions were of double bloom. Majority of single and triple bloom nature of the accessions indicated that there was no extensive intercrossing between zero and triple bloom types, though castor is a highly cross pollinated (mainly air) crop. Days to 50% flowering ranged between 50 and 80 days while their node number to primary spike ranged between 12 and 30 with a mean of 20 nodes. Plant height ranged between 54 and 230 cm with a mean of 151 cm. Among the yield traits, length of primary spike ranged between 26 cm and 77 cm with a mean of 45 cm and effective primary spike length ranged between 11 cm and 72 cm with a mean of 40 cm and spikes per plant ranged between 1 and 16 with a mean of 4. Test weight ranges from 20 g and 58 g with a mean of 37 g. FC-82 recorded longest spike length of 77 cm with a test weight of 46 g. Range and mean of agromorphological characters indicated that majority of the accessions were late flowering and perennial in nature. However some accessions like FC-07, FC-08, FC-13, FC-123 (a farmer’s variety), and FC-129 had desirable traits, which could be used in introgression and diversification of castor genepool.