Responses of wild Vigna species/sub-species to yellow mosaic disease viruses, detected by a PCR-based method

Forty-eight accessions of wild Vigna species/sub-species were grown to verify their reactions to yellow mosaic disease (YMD), under field conditions in New Delhi (India) during 2012 and 2013. Symptoms of YMD that developed on wild Vigna were similar to those observed on cultivated species. Symptomatic plants produced few flowers and pods with reduced seed size. The infection coefficient was in the range of 0–71%. The causal virus was identified by PCR using species-specific primers to detect all the four viruses responsible for YMD in pulse crops. All the YMD-affected wild Vigna species/sub-species accessions were infected by Mungbean yellow mosaic India virus (MYMIV), with positive amplification of the targeted DNA fragment, except one accession of V. hainiana (IC331450) which was infected with Mungbean yellow mosaic virus. This indicated that MYMIV is the predominant virus causing yellow mosaic in wild species/sub-species of Vigna at New Delhi. Eight accessions belonging to V. synthetic allotetraploid, V. umbellata, V. mungo var. mungo, V. trilobata, V. trinervia var. bourneae, V. radiata var. sublobata and V. dalzelliana were completely free from YMD and gave negative PCR results with primers specific to all the four viruses. This confirms resistance to YMD in these wild Vigna species

Genetic enhancement of okra [Abelmoschus esculentus (L.) Moench] germplasm through wide hybridization

IntroductionThe introgression of genetic material from one species to another through wide hybridization and repeated back-crossing, plays an important role in genetic modification and enriching the cultivated gene-pool with novel genetic variations. Okra (Abelmoschus esculentus [(L.) Moench)] is a popular vegetable crop with high dietary fibre and protein, rich in essential amino acids, lysine and tryptophan. The wild Abelmoschus genepool has many desirable traits like ornamental value, short internodal length, more number of productive branches, extended bearing, perennation tendency, reduced fruit length (more consumer preferred trait), high mucilage content (medicinal value), abiotic stress tolerances such as drought, high temperature and biotic stress resistances such as okra Yellow Vein Mosaic Virus (YVMV) and Enation Leaf Curl Virus (ELCV) diseases. The repeated use of elite breeding lines led to narrowing of the genetic base of the okra crop, one of the major factors attributed to breakdown of resistance/ tolerance to biotic stresses. YVMV and ELCV are the two major diseases, causing significant yield loss in okra. Hence, wide hybridization was attempted to transfer tolerance genes from wild species to the cultivated genepool to widen the genetic base.Material and methodsThe screening of germplasm of wild Abelmoschus species at hotspots led to the identification of tolerant species (Abelmoschus pungens var. mizoramensis, A. enbeepeegeearensis, A. caillei, A. tetraphyllus and A. angulosus var. grandiflorus), which were further used in a wide-hybridization programme to generate interspecific hybrids with the cultivated okra. Presence of pre- and post-zygotic barriers to interspecific geneflow, differences in ploidy levels and genotype specific variations in chromosome numbers led to varying degrees of sterility in F1 plants of interspecific crosses. This was overcome by doubling the chromosome number of interspecific hybrids by applying Colchicine at the seedling stage. The 113 cross derivatives generated comprising amphidiploids in the F1 generation (30), F3 (14), one each in F2 and F4 generations, back cross generation in BC1F2 (03), BC1F3 (25), and BC2F3 (02), crosses between amphidiploids (27), multi-cross combinations (07) and inter-specific cross (between A. sagittifolius × A. moschatus subsp. moschatus) selfed derivatives at F8 generation (03) were characterized in the present study. Besides they were advanced through selfing and backcrossing.Results and DiscussionThe amphidiploids were found to possess many desirable genes with a considerable magnitude of linkage drag. Majority of the wide cross derivatives had an intermediate fruit morphology and dominance of wild characters viz., hispid fruits, stem, leaves, tough fruit fibre, vigorous perennial growth habit and prolonged flowering and fruiting. The fruit morphology of three BC progenies exhibited a high morphological resemblance to the cultivated okra, confirming successful transfer of useful genes to the cultivated okra genepool. The detailed morphological characteristics of the various combinations of Abelmoschus amphidiploids and the genetic enhancement of the genepool achieved in this process is reported here

Synthesis, characterization and fabrication of solar cells making use of [Ru(dcbpy)(tptz)X]X (where X = CI-, SCN-, CN-) complexes

Dye-sensitized TiO2 solar cells were fabricated using tridentate ligand ruthenium(II) complexes, [Ru(dcbpy)( tptz)X]X (where dcbpy = 4,40-dicarboxy-2,20-bipyridine, tptz = 2,4,6-Tris(2-pyridyl)-s-triazine and X = Cl, SCN, CN) attached to sol–gel processed TiO2 electrodes. The ligand tptz functions as spectator ligand and dcbpy functions as the anchoring ligand with sufficient visible light absorption. The synthesized complexes were characterized before using them in solar cells. The functioning of the solar cells fabricated using different conducting glasses was monitored and the current–voltage characteristics were measured. The efficiencies of different cells were calculated and compared

Heterochromatin distribution and comparative karyo-morphological studies in Vigna umbellata Thunberg, 1969 and V. aconitifolia Jacquin, 1969 (Fabaceae) accessions

Chromosome studies along with heterochromatin distribution pattern analysis have been carried out in two domesticated species of Vigna Savi, 1824 which grow in contrasting geo-climatic conditions of India: Vigna umbellata Thunberg, 1969, a legume well acclimatized to subtropical hilly regions of North-east India and V. aconitifolia Jacquin, 1969, a species of arid and semi-arid regions in desert plains of Western India. Karyo-morphological studies in both species reveal 2n = 22 chromosomes without any evidence of numerical variation and the overall karyotype symmetry in chromosome morphology suggest that the diversification at intraspecific level in genus Vigna has occurred through structural alteration of chromosomes, rather than numerical changes. Heterochromatin distribution as revealed by fluorochrome binding pattern using CMA3 and DAPI, confirms the occurrence of relatively more GC content in V. aconitifolia as compared to V. umbellata. However, AT content was found to be comparatively higher in V. umbellata which perhaps play a role in species interrelationships

Direct conversion of solar radiation to electricity by fabricated solar cells using ruthenium polypyridyl complexes

In the present work, an attempt is made to synthesize few ligands and use them in the synthesis of mixed ligand ruthenium complexes, containing dicarboxy bipyridine as the other ligand. The synthesized ligands and complexes are characterized by various methods. The effectiveness of the synthesized dyes for the sensitization of nanocrystalline TiO2 films was determined by employing them in regenerative thin layer sandwich type solar cells. The solar cell parameters Isc, Voc, fill factor (ff), IPCE and cell efficiency were measured for the cells fabricated

Direct conversion of solar radiation to electricity by fabricated solar cells using ruthenium polypyridyl complexes

In the present work, an attempt is made to synthesize few ligands and use them in the synthesis of mixed ligand ruthenium complexes, containing dicarboxy bipyridine as the other ligand. The synthesized ligands and complexes are characterized by various methods. The effectiveness of the synthesized dyes for the sensitization of nanocrystalline TiO2 films was determined by employing them in regenerative thin layer sandwich type solar cells. The solar cell parameters Isc, Voc, fill factor (ff), IPCE and cell efficiency were measured for the cells fabricated.\u

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Not AvailableStudies over the decades highlighted the role of lipids in modulating inherent glycaemic response of rice, still much needed to elucidate how the chain length and saturation of fatty acid (FA) influence this. Hence in this study, we investigated the in vitro glycaemic response, starch-lipid complexing ability and resistant starch (RS) formation in three rice types [white rice (WR), black rice (BR) and red rice (RR)] cooked with four fats [ghee, coconut oil (CO), virgin coconut oil (VCO) and rice bran oil (RBO)], with three cooking conditions (‘before’, ‘during’ and ‘after’). Inherent glycaemic responsewas found least in RR (81.9%) and among the fats used, RBO rich in long chain unsaturated FA (72.6%) further reduced the least glycaemic response with maximum complexing ability and enriched RS content. Cooking conditions also resulted significant variation in the parameters studied, the most significant effect with complexing ability (28.67%) and RS (2.26%) observed when RBO added ‘during’ with RR. FTIR fingerprint within 950 to 1200 cm−1 region validated the complex interactions of amylose among FA, alcohols and acids present in the RBO. This is the first report proposing a ‘lipid induced resistance towards glycaemic response’ model highlighting the importance of FA type towards modulating the molecular configuration, complexing ability and RS-V formation.Not Availabl