Intestinal lactic acid bacteria (LAB) for humans are closely associated to the host’s health because the presenceof LAB is an important bio-defense factor in preventing colonization and subsequent proliferation of pathogenic bacteria inthe intestine. Some probiotics such as Lactobacillus species can intoxication of carcinogens including chemical mutagens.The purpose of this study was to compare the ability of antimutagenesity among 24 strains of LAB isolated from infantfeces, yogurt and kimchi etc. The antimutagenic effects of protein fractions extracted from the cells of 24 LAB strains wereinvestigated using mutagens as 4-nitroquinoline-N'-oxide in Ames test (Salmonella Typhimurium TA 100). In the Amestest, dose-dependent activity was exhibited significantly against 4NQO. Three strains of Lactobacillus showed the highestanti-4NQO activitiy (62.1%) among the tested strains of LAB.

Meedon rice varieties are important for local adaptability, grain quality and market availability, and have been grown in Myanmar for centuries. Because of temporal variability and spatial heterogeneity, Meedon rice varieties in rainfed lowland areas may be diverse. However, information on diversity of Meedon rice germplasm is limited. This study was carried out to assess genetic diversity and to analyze population structure of Meedon rice germplasm conserved in Myanmar Seed Bank using SSR markers. For assessing genetic diversity, 154 accessions of Meedon rice germplasm were analyzed with nine SSR markers. A total of 86 alleles were detected with an average of 9.6 alleles per locus. All the loci were found to be polymorphic, and there were considerable genetic variation among accessions with mean values of expected heterozygosity (HE) = 0.5774 and polymorphic information content (PIC) = 0.5496. High frequency of rare alleles was identified, among which 35 unique (accession-specific) alleles were observed. Based on cluster analysis, rice accessions were mainly clustered into two groups, and as a result of model-based analysis, two distinct genetic populations and an admixture were classified. This result indicated that SSR markers have proved to be useful markers for detecting genetic diversity in Meedon rice, and the occurrence of a considerably high number of rare and unique alleles in the germplasm indicates their potentiality as a reservoir of rare genotypes for use. Unique alleles are also important because they may be diagnostic of a particular type of genotype for identification.

The chloroplast (cp) is an organelle with its own genome encoding a number of cp-specific components. The membrane-bound organelles are mainly involved in the photosynthetic conversion of atmospheric CO2 into carbohydrates in which light energy is stored as chemical energy. Resequencing technology via next-generation sequencing has recently been successfully applied which results the field of cp genome characterization is growing fast. Here, we report the complete sequence of the chloroplast genome of Capsicum frutescens, a species of chili pepper. The total length of the genome is 156,817 bp, and the overall GC content is 37.7%. A pair of 51,584-bp inverted repeats (IRs) is separated by a small (17,853 bp) and a large (87,380 bp) single-copy region. The C. frutescens chloroplast genome encodes 103 unique genes, including 79 protein-coding genes, 20 tRNA genes, and four rRNA genes. Of these, 19 genes are duplicated in the IRs and 18 genes contain one or two introns. Comparative analysis with reference cp genome revealed 125 simple sequence repeat (SSR) motif and 34 variants, mostly located in the non-coding regions. These microsatellite markers will facilitate the studies of genetic diversity, population genetic structure, and sustainable conservation for C. frutescens.

Potato virus Y (PVY) and potato leafroll virus (PLRV) are among the most damaging potato viruses and prevalent in most potato growing areas. In this study, cryopreservation was used to eradicate PVY and PLRV using two cryogenic methods. Potato shoot tips proliferated in vitro were cryopreserved through droplet-vitrification and encapsulation-vitrification using plant vitrification solution 2 (PVS2; 30% glycerol + 15% dimethyl sulfoxide + 15.0% ethylene glycol + 13.7% sucrose) and modified PVS2. Both cryogenic procedures produced similar rates of survival and regrowth, which were lower than those from shoot tip culture alone. The health status of plantlets regenerated from shoot tip culture alone and cryopreservation was checked by reverse transcription-polymerase chain reaction. The frequency of virus-free plants regenerated directly from highly proliferating shoot tips reached 42.3% and 48.6% for PVY and PLRV, respectively. In comparison, the frequency of PVY and PLRV eradication after cryopreservation was 91.3~99.7% following shoot-tip culture. The highest cryopreserved shoot tip regeneration rate was observed when shoot tips were 1.0~1.5 mm in length, but virus eradication rates were very similar (96.4~99.7%), regardless of shoot tip size. This efficient cryotherapy protocol developed to eliminate viruses can also be used to prepare potato material for safe long-term preservation and the production of virus-free plants.