Abstract
Variability and diversity of Emilia sonchifolia (L.) DC., an important medicinal plant species, in its natural habitats in Kerala were analyzed based on the observations on ten salient morphological characters recorded from thirty populations of the species distributed across Palakkad, Malappuram and Kozhikode districts of Kerala state, India. All the ten characters studied such as plant height, number of branches per plant, length of branches, number of leaves per plant, leaf length, leaf area, internodal length, number of inflorescences per plant, length of peduncle and fresh weight of plants showed statistically significant variations between the populations. The interrelationship between the characters and their association was also studied. Leaf length and leaf area showed significant positive correlation with three characters each. Number of branches per plant, number of leaves per plant, internodal length, number of inflorescences per plant and fresh plant weight showed significant positive correlation with two characters each. Plant height, length of branches and length of peduncle showed no significant positive correlation with any of the characters. By factor analysis three factors could be extracted and number of inflorescences per plant, number of branches per plant, number of leaves per plant and length of branches were found to be the lead characters. Highly significant variability with regard to morphological characters indicates the strong genetic base of the plant species in the field. However, care should be taken to conserve the gene pool of the species especially under the present conditions of environmental threats.
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