Plant growth-promoting bacteria that are also capable of suppressing plant pathogenic fungi play an important role in sustainable agriculture. There is a critical need for conducting research to discover, characterize and evaluate the efficacy of new strains of such bacteria in controlling highly aggressive plant pathogens. In this study, we isolated endophytic bacteria from medicinal plants of Bangladesh and evaluated their antagonistic capacity against an important phytopathogenic fungus Sclerotinia sclerotiorum. Growth-promoting effects of those isolates on cucumber and rice seedlings were also assessed. Among 16 morphologically distinct isolates, BDR-2, BRtL-2 and BCL-1 significantly inhibited the growth of S. sclerotiorum through induction of characteristic morphological alterations in hyphae and reduction of mycelial dry weight. When cucumber and rice seeds were treated with these endophytic bacteria, seven isolates (BCL-1, BDL-1, BRtL-2, BRtL-3, BDR-1, BDR-2 and BBoS-1) enhanced seed germination, seedling vigor, seedling growth and number of roots per plant at a varying level compared to untreated controls. All isolates produced high levels of indole-3-acetic acid (6 to 63 μg/mL) in vitro. Two most potential isolates, BDR-2 and BRtL-2, were identified as Bacillus amyloliquefaciens and B. subtilis, respectively, based on the 16S rRNA gene sequencing. These results suggest that endophytic Bacillus species from native medicinal plants have great potential for being used as natural plant growth promoter and biopesticides in sustainable crop production.

The present investigation consists of 47 rice genotypes and the experiment was conducted during Aus season, 2016 in Randomized Block Design with three replications. The data were recorded for 13 quantitative characters to study genetic variability, heritability, genetic advance, correlation coefficient analysis and path analysis. Analysis of variance among 47 genotypes showed a significant difference for all characters studied. The highest genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were observed for grain yield followed by the number of effective tillers, the number of filled grains per panicle and 1000 grain weight indicating that these characters could be used in selection for the crop improvement program. High estimates of heritability was observed for grain yield, grain length, plant height, number of filled grain per panicle, 1000 grain weight and days to 50% flowering. High genetic advance was observed for the number of filled grains per panicle and plant height, indicating predominance of additive gene effects and possibilities of effective selection for the improvement of these traits. Grain yield showed positive association with number of effective tiller and number of filled grain per panicle at genotypic in conjunction with phenotypic level. Days to maturity possessed the highest positive direct effect and significant indirect correlation with yield. The Agriculturists 2020; 18(1) 01-09