POLLINATION ECOLOGY AND BREEDING SYSTEM IN DALBERGIA LATIFOLIA AND D. SISSOIDESK.R. Sasidharan, D. Thangamani, S. Prakash and K. Muraleekrishnan
Dalbergia latifolia and D.sissoides are very closely related and considered as two precious timber species of India; the former distributed in various parts of India, while the latter is restricted to the Western Ghats. D. latifolia is categorized as âVulnerableâ in the Red Data Book of IUCN. Both the species exhibited wide variation in the phenological features; D. latifolia flowered during August/ September and produced fruits from October onwards. In D. sissoides, flowering started in the second week of March and continued till the end of the month, for a very short period; the fruiting occurred in April. The flowers of both the species produced copious nectar having high sugar concentration and sticky pollen grains, which are adaptations for pollination by insects and birds. The tree species were found to be highly self incompatible and cross pollinated mainly by honey bees, butterflies and birds. The natural fruit setting recorded in D. latifolia was 5.24 percent and in D. sissoides the fruiting was 8 percent. Certain insect pests and flower feeding birds caused considerable damage to the flowers. The population of these tree species have been dwindling in the forest areas, due to various reasons and reproductive constraints could be one of those factors. In this context, there is urgent need for conserving the genetic resources of these species, both in-situ and ex-situ, for ensuring their survival.