Viswanathan, T VMini, K SKAU2020-02-122020-02-121989http://krishikosh.egranth.ac.in/handle/1/5810142948PGInvestigations on karyomorphology, pollen sterility and seedset in Vetiveria zizanioides were undertaken using eleven cultivars of Vetiver, including North Indian type, South Indian type and one hybrid. The observations on plant morphology indicated no clearcut morphological features employable for exact identification of North Indian and South Indian types of Vetiver. The somatic chromosome number was observed constant in all cultivars ie. 2n = 20. However, the different cultivars differed cytologically with respect to chromosomal characters like size and shape, total chromatin content and meiotic configurations during different stages of division. Presence of meiotic abnormalities like bridges and laggards were observed in all cultivars with highest frequency in O D V - 4. This cultivar also showed high percentage of pollen sterility. A direct relationship between meiotic abnormalities and pollen sterility was noticed. Studies on seedset pattern of different cultivars revealed very low set, mostly nil upon selfing, while all the cultivars produced fairly high quantity of seeds upon open pollination.ennullThesis