Internal Transcribed Spacer (ITS) regions: A powerful tool for analysis of the diversity of wheat genotypes

Wheat is a widely cultivated crop and it is one of the major food sources worldwide. Among the various tools used to study diversity of wheat species, the internal transcribed spacer (ITS) assessment emerges to be the more appropriate approach. In the present study, we evaluated 15 genotypes of Iranian wheat cultivars (wild, native, and breed) using ITS gene sequences. Similarity matrices and dendrogram of phylogenic relationship were constructed using Mega ver6 software. We report the major nucleotide changes in the same position between diploid and hexaploid species. dN/dS ratio for diploid, tetraploid, and hexaploid species indicated a pure selection in the examined gene, with no key changes in the genes, and 91% ITS diversity within individual wheat was evident. The results suggest that as evolution moves forward, nucleotide changes are reduced so that only a few changes in nucleotides occur. ITS marker can distinguish different wheat genotypes at the genomic level and thus prove to be the most appropriate assessment tool for analyzing inter and intra-species relationships.

Plant Growth Promotion and Root Colonization by EPS Producing Enterobacter sp. RZS5 under Heavy Metal Contaminated Soil.

The heavy metal resistant bacterium isolated from field soil and identified as Enterobacter sp. RZS5 tolerates a high concentration (100-2000 mM) of various heavy metal ions such as Mn2+, Ni2+, Zn2+, Cu2+, CO2+ and Fe2+ when grown in such environment and produces exopolysaccharides (EPS). Here, we have demonstrated EPS production by Enterobacter sp. RZS5 during 60 h of growth in yeast extract mannitol broth (YEMB). The yield increased by two fold after the addition of 60 M of Ca2+; 50 M of Fe2+ and 60 M of Mg2+ ions in YEMB, and the optimization of physico-chemical parameters. EPS was extracted with 30% (v/v) of isopropanol as against the commonly used 50% (v/v) isopropanol method. EPS-rich broth promoted seed germination, shoot height, root length, number of leaves and chlorophyll content of wheat (Triticum aestivum) and peanut (Arachis hypogaea) seeds. The higher colony-forming unit of Enterobacter sp. in soil inoculated with EPS rich broth of Enterobacter sp. indicated the root colonizing potential and rhizosphere competence of the isolate. The FTIR spectra of the EPS extract confirmed the presence of the functional group characteristics of EPS known to exhibit a high binding affinity towards certain metal ions. This overall growth and vigour in plants along with the effective root colonization, reflected the potential of the isolate as an efficient bio-inoculant in bioremediation.

Production of biocontrol traits by banana field fluorescent Pseudomonads and comparison with chemical fungicide.

Pseudomonas aeruginosa isolated from banana field rhizosphere produced different antifungal metabolites like bactriocin, hydrogen cyanide and siderophore. Bacteriocinogenic, siderophoregenic, and HCN rich broth of isolate inhibited the growth of phytopathogen like Aspergilus niger, Aspergilus flavus, Fusarium oxysporum and Alternaria alternata. The isolate exhibited more antifungal activity and comparatively low MIC vis-a-vis commonly used copper based systemic chemical fungicide;bil cop.

Poly--hydroxybutyrate production by Pseudomonas sp. RZS 1 under aerobic and semi-aerobic condition.

Pseudomonas sp. RZS1 was isolated from distillery effluent and identified based on phenotypic characters and 16s rRNA sequencing. It accumulated optimum amount (703.79 g/mg of biomass) of poly--hydroxybutyrate (PHB) under aerobic process of fermentation and 75 g/mg of biomass under the anaerobic process of fermentation. Aerobic fermentation yielded 9.3-fold more PHB than semi-aerobic fermentation. Acetone alcohol method proved to be the best suitable recovery method as it gave 703.79 g PHB per mg of biomass with a percentage recovery yield of 70.37. It started to accumulate PHB at the end of lag phase (from 6 h of incubation). Optimum amount of PHB (20 g/ml) was reported during early stationary phase (30 h of incubation). Extracted PHB showed two peaks, minor one at 248 nm and major one at 365 nm. IR spectra revealed the presence of functional groups characteristics of PHB.

Solid state cultivation of Curvularia lunata for transformation of rifamycin B to S.

Biotransformation of rifamycin B to rifamycin S using two strains of C. lunata namely NCIM 716 and NMU grown on various solid substrates viz., grass, paper, jowar/wheat straw, bran and bagasse was studied. Almost complete biotransformation efficiency of rifamycin B at 0. 06 mM concentration was observed within 24 hr. Among these two strains, C. lunata NMU showed 90% of biotransformation and higher rate of cellulose utilization on solid substrates vis-à-vis reference strain. Cellulase activity of both strains was also studied for exoglucanase, endoglucanase and beta-glucosidase. Column bioreactor studies with bagasse revealed further improvement in biotransformation efficiency of C. lunata NMU.