The Effect of Reciprocal Cultivation in the Two Ecotypes of Vernonia patula (Dryand.) Merrill.

Abstract

Two ecotypes in Vernonia patula have been observed, viz., the erect type and the prostrate decumbent type. The erect type is an annual plant found in small colonies under shady habitats but the decumbent type is a common, perennial plant of open grasslands. Soil analyses reveal that the erect type occurs in base rich neutral soil whereas the decumbent type has base poor, sandy and acidic soil. Large numbers of morphological and physiological characters, such as initiation of early inflorescence, mode and magnitude of inflorescence, dry weight per plant show wide differences which have been observed at several occasions in different populations of the either type of Vernonia patula. Four months of cultivation of the either type of Vernonia patula, under reciprocal substratum and light conditions affect intensity of phenotypic expression of the genotype yet their differences are consistent, throughout the observations. Thus it appears that the two types of Vernonia patula investigated are ecotypes. The prostrate decumbent type of Vernonia patula has adapted to encounter hard compact dry soil, exposed to high illumination and temperature conditions and heavy to mild biotic operations, on the contrary, the erect type grows in neutral and base rich soil during favourable season of the year.