A bacterium was isolated from feces of Allomyrina dichotoma larva that feeds on well-rotted sawdust of woods. The isolate was identified as a Gram-positive and spore-forming stain. We named the isolate as Bacillus amyloliquefaciens on the basis of morphological and biochemical properties as well as 16S rRNA gene sequences. The culture of bacteria beneficially increased root and shoot growth of tomato, pepper and cucumber plants compared to the distilled water control. In addition, the bacterial culture strongly inhibited the mycelial growth of several fungal phytopathogens. The drop collapse assay with this culture showed a surfactant activity that is a major indicator for the selection of biocontrol agent. Also, a bacterium has ability of wastewater treatment. These data demonstrate the potential application of B. amyloliquefaciens as a biocontrol agent.

The genetic diversity among the genus Viola was evaluated using the random amplified polymorphic DNA (RAPD) method. A total of 142 distinct amplification fragments by 18 random primers were scored to perform the cluster analysis with UPGMA. Viola species from the subsection Patellares were clustered into group I to IV. The groups from I to IV were consistent with its morphological taxonomy, series Pinnatae, Chinensis, Variegatae, and Patellares in the subsection Patellares, respectively. Even though V. albida and V. albida var. takahasii were classified in Chinensis, they were assigned into group I. The cluster analysis separated other subsections from Patellares in the section Nomimium. Interestingly, V. verecunda and V. grypoceras in subsections Biobatae and Trigonocarpae, respectively, were clustered into group C with a high similarity coefficient. Therefore, RAPD analysis can be used for providing an alternative classification system to identify genotypes and morphological characters of Viola species.