f Journal of Spices and Aromatic Crops 9 (2) : 133-136 (2000) I, ! , Genetic variability and association analysis for yield and yield components in indigenous and exotic collections of vetiver (Vetiveria zizanioides (L.) Nash) R K Lal Central Institute of Medicinal and Aromatic Plants Lucknow - 226 015, India. Received 9 March 2000; Revised 20 June 2000; Accepted 5 August 2000. Abstract The variability in genetic parameters and their influence on growth and yield of vetiver (Vetiveria zizanioides) was studied in 45 indigenous and exotic collections. Considerable variability in morpho- metric traits was recorded in these collections. Strongly positive and significant correlations were found between plant height and root length and oil yield; root length and oil content; fresh root yield and dry root yield and oil yield; dry root yield and oil yield, and oil content and oil yield. Positive and significant associations were also observed between plant height and root width and fresh root yield; root length and root width. These traits may form a good selection criteria for improvement of essential oil yield in vetiver. Keywords: heritability, variability, vetiver, Vetiveria zizanioides. Introduction Vetiver (Vetiveria zizanioides (L.) Nash) (Poaceae) is a perennial, densely tufted grass, the roots of which are a source of khus (vetiver) oil which has considerable significance in the essential oil industry. Vetiver is a native of India and occurs widely in the Indian subcontinent, especially in parts of Uttar Pradesh, Rajasthan and peninsular India, particularly along river banks and marshy lands. In our research programme on improve- ment of vetiver, a large number of genetic stocks/ clones were assembled from different parts of India along with four exotic collections from Thailand, Ghana, Reunion Island and Indonesia with a view to study the genetic variability and to select promising lines suitable for high root and oil yields of better quality. In crop breeding programmes prior knowledge of various genetic parameters and their influence on growth and yield of crops is imperative. Therefore, the nature, amount and magnitude of genetic parameters and their influence on character associations for morpho-economic traits was studied in vetiver. Materials and methods A large number of clones/genetic stocks of vetiver were assembled at Central Institute of Medicinal and Aromatic Plants (CIMAP), Lueknow (India), from wild/cultivated sources from vari- ous places of India and abroad. Among the 120 germplasms/ collections available, 45 genetic stocks [Uttar Pradash (36), Rajasthan (1), Delhi (3), Kerala (3), Indonesia (1) and Reunion Island(I)] were used in this study. The collections were grown in a randomized block design repeated twice in a net plot size of 1.25 sqm, under normal fertility regime (80:40:40 kg N, P and K/ha). Each plot consisted of a single row of 2.5 m each 50 cm apart (total 5 plants in each row). The trials were undertaken at the Research Farm of CIMAP, Lueknow (India) (26'soN, 80S E and 120 m above MSL; annual rainfall 53.21 em). The plants were uprooted 18 months after planting for recording of observations. Morphometric data were recorded for nine eco- nomic traits, namely, plant height, tillers per plant, leaf width, leaf length, root length, root