Bio-diversity of plants




An American biologist, Edward O. Wilson, introduced the term “Biological diversity" or “Biodiversity" in comprehensive in late 80`s. The main and used by most scientists is the definition given in article 2, Convention of biological diversity, United Nations, i.e. “Biological diversity means the variability among living organisms from sources including interalia, terrestrial, marine and other aquatic ecosystems and the diversity within species between species and of ecosystem."

Biodiversity is an important criterion for the evolution of environment and symbiosis of society and economy as well. On the other hand, twelve mega biodiversity countries are all developing countries, namely : Mexico, Columbia, Ecuador, Brazil, Zaire, India, China and Madagascar. Therefore, it is important to study wild biodiversity and biodiversity through biotechnological tools as well.

In just about 2.4% of the geographical area, India harbors 11% of the world flora. It is estimated that as many a 5285 species of angiosperms belonging to 140 genera are endemic to India. However, this bio wealth is under unprecedented threat due to habit loss, fragmentation, over exploitation, invasion of exotics, pollution and climatic change. Species extinction is occurring at rates greater than natural rate, including the major phase of extinction in the past. According to Singh and Khurana(2002), about 25% of the higher plant species is expected to disappear in the next few decades and another 25% may be lost by the end of this century.

Reproductive biology plays an important rule in biodiversity conservation. Any conservation approach has to be based on an in-depth study of plant reproductive biology. This is because, the evolutionary success and survival of plants and angiosperms in particular is largely determined by the efficacy of their reproductive performance. Plants have evolved a wide range of reproductive performance. Plants have evolved a wide range of reproductive strategies to optimize their fitness. The investigations on reproductive biology of tree species require more time and effort as compared to herbaceous species. However, there are few studies that focus on the breeding systems at the individual species level.

Among the most colorful plants growing in the gardens, avenues and roadside are the species of family Bignoniaceeae, commonly called the biogens. The Bignoniaceeae are mostly tropical trees or shrubs comprising of 110-120 genera and 650-750 species, widely distributed in tropical and sub-tropical parts of the globe. According to Cornquist and Gentry there are about 100-120 genera and 800 species in the family.

These are mainly tropical or sometimes sub-tropical, best developed in tropical America. A few members may also be seen in the warm temperate zones of southern and northern hemisphere. The chief center of distribution is Brazil. Tabebuia, with about 100 species, may be the largest genus.


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