Identification and Characterization of Simple Sequence Repeats (SSR) Markers Associated with Downy Mildew Resistance Locus “<i>RPV1</i>” in Grapes

The cultivation of grapes is severely impacted by the emergence of downy mildew (DM) disease which negatively affects quality and yield possibly resulting in heavy losses. Due to certain shortcomings in the usage of fungicides and the development of new cultivars by plant breeding, marker assisted selection (MAS) will be an efficient alternative method to introduce desired genes into the cultivated varieties in a short time period. The Simple sequence repeats (SSR) markers seem to be the most popular genetic marker of choice for MAS. In the present study, we identified 14 new SSR markers in RPV1 locus that are associated with downy mildew resistance in grapes. The characterization of the identified markers was carried out on the basis of various parameters such as types of repeat motifs, number of repeats, different classes and structure of microsatellites. Additionally, SSR genotyping in 56 different grape accessions was done to determine the susceptibility or resistance of these accessions to DM.

Regeneration and Genetic Fidelity Analysis of <i>Chlorophytum borivilianum</i>Using Flower Stalk as Explant Source

Chlorophytum borivilianum is a critically endangered plant well known for its medicinal properties for diabetes mellitus, diarrhea, arthritis, sterility, and erectile dysfunction, etc. Due to low viability and long dormancy of seeds, in vitro regeneration is required for large scale cultivation of this plant. In the present study, direct plant regeneration was optimized using flower stalk as explant. Nodal segments of flower stalk were sterilized and kept for direct regeneration on different combinations of BAP and KIN supplemented media. The highest, 15.27 ± 1.14 number of shoots were produced on medium containing BAP (2 mg/L) per nodal segment. The multiple shoot clumps regenerated from flower stalk were separated carefully and kept on rooting media. A maximum of 16.87 ± 1.53 roots per plant was observed in MS media having 0.5 mg/L of NAA. The rooted plantlets were shifted into the pot containing soilrite for hardening and acclimatization. The genetic stability of hardened plants was confirmed by start codon targeted, and inter simple sequence repeats molecular markers. All the 18 randomly selected plantlets showed similar genetic homogeneity to the mother plant. It is the first report on in vitro regeneration along with the genetic fidelity analysis of the regenerated plantlets from flower Stalk of C. borivilianum. As the standardized method of regeneration and mass multiplication is quite efficient and genetically stable, the protocol will be useful for the large-scale production of C. borivilianum to meet the market demand.

Bioremediation of malathion in soil by mixed Bacillus culture

Degradation of a pesticide, malathion, in soil by Bacillus sp has been reported during current study. A simple and highly sensitive reverse phase HPLC-UV (High pressure liquid chromatography-Ultraviolet) method was used for determination of malathion degradation in soil. The bioremediation of was performed in malathion contaminated sterile and nonsterile soil and it was found that 84.81% and 74.11% of malaoxon, respectively, from malathion concentration of 1.5% kg-1 soil was degraded by strain PU after 7 days. Similarly, 63.31% and 57.14% of malaoxon in sterile and nonsterile soil respectively, from malathion concentration of 1.5% kg-1 soil was degraded by strain KB2 after 7 days. Bioremediation of malathion in soil using strain KB1 have already discussed in the previous study (Singh et al., 2012). Regardless of soil sterilization, incorporation of bacterial strain in malathion containing soil resulted in higher level of degradation of malathion. Bioremediation of malathion in soil was maximum for mixed culture of all three strains.

Microplastics in soil: Impacts and microbial diversity and degradation

Microplastics(MPs) are plastic particles less than 5 mm in size that have become a major environmental pollutant due to their ubiquitous and persistent nature. Microplastic contamination of the aquatic environment has received the most attention so far, whereas the current understanding of MP prevalence and its impacts in the terrestrial environment is largely limited. The MP contamination of soil can cause bioaccumulation and toxicity in terrestrial animals and plants, which can consequently affect human health. This review is aimed towards combining the available information on the occurrence, sources, and effects of MPs on the different aspects of the terrestrial environment and to highlight the limitations in our knowledge regarding the nature and impacts of MPs in soil. The review also highlights microbial degradation of MPs as an advancing research area, with numerous microorganisms being identified as capable of efficiently degrading this persistent contaminant.