GENETIC DIVERSITY OF Phytophthora spp. CAUSING LEAF AND STEM ROT DISEASE ON LOTUS (Nelumbo nucifera)

Abstract

Leaf and stem rot disease on lotus (Nelumbo nucifera) caused by Phytophthora spp. is one of the important diseases affecting the productivity and quality of lotus products. The objective of this research was to identify Phytophthora species causing leaf and stem rot disease on lotus. In this study, the fungi samples were determined based on morphological, biological characteritics and pathogenicity. The results showed that all 30 fungi strains belonged to genus Phytophthora and they induced typical symptoms of leaf and stem rot disease on lotus. The nucleotide sequences of ITS-rDNA region were determined and used for phylogenetic analysis. The results indicated that 30 strains divided three groups: group 1 including 12 strains testing that was belong to Phytophthora cinnamomi species; group 2 including 8 strains that was belong to Phytophthora cactorum species and group 3 including 10 strains testing that was belong to Phytophthora palmivora species. The results of this study will be the basis for further researchs to contribute to finding the effective methods to control leaf and stem rot disease on lotus.