DIVERSITY IN INDIAN SESAME COLLECTION AND STRATIFICATION OF GERMPLASMACCESSIONS IN DIFFERENT DIVERSITY GROUPS

Sesame (Sesamum indicum L.) is one of the ancient oil crops, grown in India since over 5,000 years ago. Diversity in the Indian sesame colle ction (3,129 accessions), representing all eco-geographical regions, f or a range of morphological and agronomic characters was studied. Wide variation in plant habit (plant height and branching pattern), pubesc ence of various plant parts (stem, leaf, corolla and capsule), flower colour and number of flowers per leaf axil, capsule characteristics (s hape, size, number in the axil of a leaf and number of locules in a ca psule), number of capsules per plant, number of seeds per capsule, mea n seed weight, and yield per plant was recorded. A detailed multivaria te analysis was performed on a set of 100 selected accessions represen ting different agro-ecological zones. The accessions were classified i nto 7 discrete clusters. The principal components analysis described t he spatial relationship among the entities and confirmed groupings obt ained through clustering. Based on the clustering pattern of 100 acces sions, the entire collection was allocated to different clusters. Repr esentation of various zones in 7 clusters gives us the opportunity to form distinct diversity groups making combined use of passport and cha racterisation data. These diversity groups would subsequently be used for sampling the accessions for building up a core collection of sesam e, a project already operative at the NBPGR.