Revealing the hybrid zone and genetic polymorphisms of genetic sub-populations within Pseudo-nitzschia pungens (Bacillariophyceae)

Abstract

Genetic sub-populations of cosmopolitan marine diatom Pseudo-nitzschia pungens might have distinct habitats, however, it is still unrevealed because of technical difficulties and lack of evidences in nature. We employed the 137 number of genetic information of P. pungens and its sampling data originated from the West Pacific area, and used field application of qPCR assay. Only two genotypes, clade I and III, were identified in the West Pacific area. Clade I was distributed from 39 to 32.3 °N, and clade III were from 1.4 to 34.4 °N. The estimated habitat temperature for the clade I and clade III ranges were 8.1 - 26.9 °C and 24.2 - 31.2 °C, respectively. The offspring strains showed recombinant sequences types, and the high ratios of single nucleotide polymorphism in its ITS2 region. The hybrid zone and genetic polymorphism phenomenon should contribute to maintain the genetic diversity and to produce the new genotypes within this species.