Problems in Indian Forest Plant Breeding

At the outset of a programme of applied genetics to forestry in India, it is useful to estimate what can or cannot be expected out of it. The material for such plant breeding experiments exists in our forests, as well as in introduced exotics. Advantage should first be taken of self-pollinated species which already exist as 'pure-lines', e.g., among the Papilionaceae. The evolution of sex in higher plants ranges from hermaphroditism to complete sex differentiation and genetic programmes have to be appropriately adapted. The naturally cross-pollinating species which may also have minute flowers in clusters, with a high degree of flower-drop, offer the greatest complexity to the breeder. Provenance and individual plant collections at various arboreta comprise the foundation material. Gene-frequencies occurring in nature could be assessed even from the beginning, while segregating populations will reveal further ratios. Cytologically, there is a paucity of polyploid series among the tropical forest species. Artificial methods of inducing polyploidy or comutations need to be exploited. Vegetative propagation of species suited to it, offer an immediate means of increasing selected individuals which can be used in plantations and then in seed-orchards. Scions grafted on dwarfing-stock should be valuable for seed-orchards as well as to conduct selective pollinations. Portable tub-plants are suggested for easier location of plants for crossing. Suitable planthouses for climatic and physiological response-control are required to be evolved for India. 'Isolation' -planting could be utilized for self-pollination purpose, in inbreeding. Juvenility at flowering of various species should be determined to estimate the rate of reproductive cycles and intensity of breeding programmes. An inventoiy of 'mother-trees' for seed should be made all over the country for all species, and progenies raised from them and tested. Progenies of recorded 'giant-trees' should be raised to evaluate the genotype of these moribund old individuals. Among the important forest plant breeding problems of India are: Wattle (Acacia spp.) breeding, improvement of Tectona grandis, Pinus roxburghii, Santalum album, Prosopis spp., Casuarina spp., Hardwickia binata, Salmalia malabarica, Terminalia spp., aromatic grasses, medicinal plants and others yielding minor forest products.