Molecular authentication of green algae Caulerpa (Caulerpales, Chlorophyta) based on ITS and tufA genes from Andaman Islands, India

Abstract

Indigenous and non-indigenous invasive algal species introduction or prevalence is one of the major concerns to protect the native coastal environment. Globally, several studies have reported the effect of invasive alga Caulerpa on coral reefs. To establish the genetic variation between indigenous and non-indigenous invasive species, attempts have been made to develop molecular identification of Caulerpa algal species available at the Andaman Islands. In this study, 7 visually and morphologically different species belonging to the genus Caulerpa (Chlorophyta) were collected from the intertidal regions of South and Little Andaman Islands, India. The specimens were preliminarily identified based on the morphological characters and genetically mapped using ITS2 and chloroplast tufA gene markers. Six species of the Caulerpa viz. Caulerpa racemosa, C. racemosa var lamourouxii, C. racemosa var macrophysa, C. serrulata,C. fergusonii and C. microphysa were identified using ITS2 gene, and. C. mexicana var pluriseriata was identified using tufA gene. Two varieties, C. mexicana var. pluriseriata and C. racemosa var lamourouxii were found to be invasive to Indian waters. These were earlier reported in Red sea and in Phillipine waters in the pacific ocean. Further studies are needed to elucidate the genetic divergence of the Caulerpa species present in Andaman waters using different molecular markers.