Khanduri, Dr. V.P.Sukumaran, Arun2016-11-232016-11-232016-06http://krishikosh.egranth.ac.in/handle/1/87245Cornus capitata is a medium sized semi evergreen or sub deciduous tree native to East Asian and Montane Himalaya. It is a mass bloomer and popularly used as an avenue tree. The studies in relation to reproductive biology conducted at Ranichuari (Tehri Garhwal, Uttarakhand, India) exhibited that the reproduction in Cornus capitata is a continues cycle. Floral morphology studies showed that tree producing ball shaped cymose inflorescence consist of an average number of 67.6 ± 2.05 flowers per ball. One complete reproductive period last up to 16-17 months from flower bud initiation to fruit maturity. The flowers opened around 341 ± 1.87 days after the ball initiation. The time of maximum anthesis was between 08:00 to 10:00 h of the day. An inflorescence ball took 14-15 days for complete blooming. The total pollen production within a tree recorded between 4.0×107to 9.3× 107. However pollen production and number of inflorescence varied significantly among trees. Stigma remained receptive up to 2-3 days after anther dehiscence. Pollen ovule ratio was 632.8 ± 6.57 to 712 ± 10.58. The mean pollen viability was 68.28 ± 1.25%. To effectively assess in-vitro pollen viability in Cornus capitata, an optimised germination medium NAA 150ppm (Naphthalene Acetic Acid) was developed.The maximum germination observed in NAA was 42.97%. Anthophora bees and trips were observed as the main pollinators. The result of breeding system showed fruit setting 100% and 92% in open pollination and self pollination respectively. Results from the assessment of self compatibility reported that the seed ovule ratio of autogamous flower is 55% and natural pollination was 36%. The pollen ovule ratio result suggests that breeding system of Cornus capitata coming under the class facultative xenogamy. Seed set per fruit was observed more in fruit formed through autogamous self pollinations. Limited seed set within fruit imply that high amount of ovule abortion existing in inflorescence ball. Seed germination test under in –vitro showed that the seed germinated only in quality seed derived from open pollination which supporting xenogamy in Cornus capitata. Detailed studies on reproductive biology conclude that the species is supporting autogamy, geitonogamy and xenogamy. Information on timing of floral anthesis, pollen viability and floral characteristics will be helpful for initiation of controlled crossing programmes. The current findings in Cornus capitata will be useful for formulating effective forest management plan and initiating various tree improvement programmes in future.enThesis