Role of Provenance Trials in the Study of Population Differentiation

Wide distribution of many Linnean species across climatic, edaphic and biotic barriers may be either due to a wide ecological amplitude of the species as such, or to the presence of a number of distinct local populations, well adapted to the respective ecoclimates. These populations may show continuous variation along an envirormental gradient (ecocline) or discontinuous variation (ecotypes). The morphological or physiological adaptive characters are genetically fixed. Although a number of genecological techniques have been developed in the recent past, to differentiate such ecologic populations, the provenance trial technique has gained much importance. In the present communication the technique as well as some important results obtained through its use, both within and outside India, have been briefly discussed.