18 rhizobacteria were isolated from various rhizospheric soils in Mandalay region, Myanmar and some of their biochemical characteristics were studied. Among them, 4 isolates belonged to Bacillus spp. and another 5 strains were recognized as Serratia spp. All 18 isolates were screened for indole-3-acetic acid (IAA) production and quantitative determination of IAA was done for all strains by UV-Vis spectrophotometer with 2 days interval during 10 days incubation. All isolates had different optimum IAA production periods and strain R1 was the best IAA producer strain with 121.1 ppm. It was observed that Bacillus spp. produced IAA ranging from 53.1 ppm to 71.1 ppm optimally and Serratia spp. were regarded as poor IAA producers. Among these 18 strains, the best four IAA producers (R1, R3, R5, R8) were selected for further study on maize plant and their activities of nitrogen fixation were also detected by plate screening method. Seed germination rate was studied with eight types of treatment and the treatments with isolates did not show significant effects on seed germination rate. At 20 th day after sowing, dry root weight and fresh root weight, root length, number of adventitious roots, dry shoot weight and fresh shoot weight and shoot height were analyzed. In pot trial experiment, treatment R1 significantly increased the fresh shoot weight, shoot height and dry shoot weight whereas treatment R3 significantly increased fresh root weight, root length, dry root weight and number of adventitious roots and all treatments with bacterial isolates showed plant growth promotion than the control systems.

Consumer preferences are greatly influenced by eating and cooking qualities of rice grains, along with the economic value of a specific rice variety. This study was to evaluate ten rice varieties including the check variety IR64 on their physicochemical, cooking and eating qualities as well as to identify their genetic diversity using SSR markers. Most rice varieties are medium-grain types based on length-breadth ratio, whereas the famous Myanmar rice variety, Paw San Bay Kyar, (PSBK) is bold. PSBK showed the best cooking and eating quality traits with intermediate amylose content (AC), intermediate gelatinization temperature (GT), soft gel consistency (GC), and the highest elongation ratio among the studied rice varieties. Seventeen SSR markers linked with cooking and eating traits were used to assess the extent of polymorphism and genetic variation among ten rice varieties. There were 49 alleles in total, with an average of 2.88 alleles per locus. RM592 had the maximum number of alleles. The average PIC value ranged from 0.22 (RM540) to 0.77 (RM592). Cluster analysis with UPGMA method based on Jaccard’s similarity coefficient divided ten rice varieties into two main groups and four sub-clusters. In multiple regression analysis, RM190 and Wx primers were discovered to be significantly associated with AC, GC and GT of cooking and eating quality traits. This study could contribute to the choice of rice varieties with superior cooking and eating qualities for rice breeding programs by implementing physicochemical characteristics and molecular analysis.

There is vast genetic diversity of Myanmar Mangoes. This study mainly focused on indigenous thirteen different mango landraces cultivated in central area of Myanmar, Kyauk-se District and their fruit characteristics by 18 descriptors together with genetic relationship among them by 12 SSR markers. Based on the morpho-physical characters, a wide variation among accessions was found. Genetic characterization of thirteen mango genotypes resulted in the detection of 302 scorable polymorphic bands with an average of 4.33 alleles per locus and an average polymorphism information content (PIC) of 0.7. All the genotypes were grouped into two major clusters by UPGMA cluster analysis and a genetic similarity was observed in a range of 61~85%. This study may somehow contribute insights into the identification of regional mango diversity in Myanmar and would be useful for future mango breeding program.