The diversified genus of Clerodendrum with its complex evolutionary history leads to taxonomic mystification. Unlike traditional taxonomic methods, DNA barcoding could be a promising tool for the identification and conservation of Clerodendrum species. This study was attempted to develop an efficient barcode locus in Clerodendrum species of North East India. We evaluated four barcode candidates (ITS2, matK, rbcL, ycf1) and its combinations in different Clerodendrum species. The reliability of barcodes to distinguish the species were calculated using genetic pairwise distances, intra- and inter-specific diversity, barcode gap, and phylogenetic tree-based methods. The results exemplify that matK posse’s maximum number of variables and parsimony-informative sites (103/100), intra- (0.021 ± 0.001) and inter- (0.086 ± 0.005) specific divergences and species resolution rate (89.1%) followed by ITS2, ycf1, and rbcL. Among the combinatorial locus, ITS2 + matK showed the best species discrimination with distinctive barcode gaps. Therefore, we tentatively suggest that the combination of ITS2 + matK as core barcode for Clerodendrum and converted into quick response (QR) code. Hence, this finding indicates that DNA barcoding could provide consistent resources for species discrimination and resolve taxonomic controversies of the genus as well as set a preliminary assessment toward its biodiversity.
16 February 2012 in African Journal of Microbiology Research
Rise in human population always demands a rapid and sustainable increase in cereal production. As a result nitrogenous fertilizers were used constantly in excess, which resulted in a number of problems such as green house emissions (particularly N2O) and leaching to ground-water. Moreover they are expensive. So long term sustainability in agriculture can only be obtained with the use of low cost fertilizer which should also be ecologically safe. In this regard biological nitrogen fixation by microbes, that is, biofertilizer, plays an active role helping in better maintenance of crop nutrient as well as soil health.Azospirillum, an associative symbiotic nitrogen fixing bacterium has a higher nitrogen fixing potential in non-legumes in comparison to other nitrogen fixing bacterium, by the formation of para nodules. However further investigation is needed to find possible avenues for the exploitation of this bacterium. The current review emphasizes the central issues of Azospirillum and its application either alone or in combination with other plant growth promoting rhizobacteria for the benefit of the non leguminous crops. Key words: Azospirillum, non legumes, BNF, para-nodules, inoculation, rhizosphere.
An efficient protocol for in vitro micropropagation of Bambusa nutans Wall. ex. Munro has been described. Nodal explants obtained from 1½-year-old field-grown culms of B. nutans produced up to 7.0 multiple shoots per explant on Murashige and Skoog (MS) basal medium supplemented with 6- benzylaminopurine (BAP, 1.0 mg/L). Continuous shoot proliferation up to 11.33 shoots was achieved by sub-culturing shoot clumps (4 shoots/cluster) in BAP (0.5 mg/L) and 0.1 mg/l α-naphthalene acetic acid (NAA) fortified medium every 4 weeks. 85% rooting was recorded on 2.0 mg/L NAA supplemented medium after 30 to 35 days of culture period. Micropropagated plantlets of B. nutans showed 70% survivability during the hardening stage. After hardening, rooted plantlets were successfully transferred to the soil and exhibited 80% survivability and normal growth. Plantlets cultivated in field condition achieved 95% survivability. Seed explants were also used for in vitro culture establishment of B. nutans on different combination of MS medium. Key words: Bambusa nutans, micropropagation, nodal explants, seed explants.