Somatic Embryogenesis in Rosewood and other Indian Tree Legumes

Abstract

Legumes are the most important among plants, and rank next to cereals. While extensive work has been done on cereals such as rice, wheat, corn, sorghum, and barley, important legumes like soybean and peanut have received comparatively less attention. Tree legumes have received even less attention, yet members of Leguminosae family show more promise for producing vast supplies of vegetable protein, fuel, fodder and timber. In the developing countries, cultivation of grain or tree legumes seems to be the quickest way to develop virgin lands. Leguminous species are found throughout the world, but the largest number of varieties grow in the tropics and subtropics (NRC, 1979). Of the thousands of known leguminous species, less than 20 are extensively used. The remaining species are little used and many of them are yet to be exploited. Many people are unaware that legumes encompass far more than herbaceous annual food crops, and they occur as vines, shrubs and trees. The significance of legumes for the energy crisis has been recognized by the international community. The most important task facing mankind today is to lessen the exploitation of non-renewable energy resources. For more than one-third of the world’s population, the real energy crisis (Anonymous, 1980) is a daily scramble to find wood for cooking. The western world has given little attention to the scarcity of firewood and most people in the developed countries have little idea of its importance: 90% people depend upon firewood as their main source of fuel and each year an average user burns anywhere from a fifth of a ton to a well over a ton. This is an enormous amount of fuel wood when multiplied by hundreds of millions of users, and 86% of this is consumed as fuel in the developing countries. Of this total at least half is used for cooking (Ayensu, 1980). To meet this enormous demand of fuel wood, large-scale plantations of fast growing fuel woods such as Acacia, Sesbania, Albizzia, Cassia, Prosopis, Pithecellobium, Parkinsonia and Leucaena, all leguminous trees has become a necessity. In the tropics, uncertain supplies and increasing costs of feed, fertilizer and food, coupled with projected population increases, are giving leguminous trees an important status that has not been previously realized. Leguminous trees are often among the first to colonize newly cleared land. Like other pioneer species, their advantages include rapid growth, adaptability to a wide range of soils, particularly nutrient deficient soils and marginal sites unsuited to food crops. They are also endowed with copious seed production at an early age, in all seasons and the ability to coppice.