Assessment of meat quality defect genes in indigenous pigs of Bareilly region

This investigation was undertaken to assess the population of indigenous (Bareilly local) pigs for meat quality genes (RYR1, PRKAG3, HFABP, MYF-5, and MC4R). The results showed that indigenous pigs were monomorphic at RYR1locus (100% NN genotype), HFABP locus (100% HH genotype), and MYF-5 locus (100% DD genotype). Homozygote RR and heterozygote QR genotypes were observed at PRKAG3 (c.599 G>A) SNP locus with 89 and 11% frequency. The frequency of wild (R) and mutant (Q) allele at the said locus was 95 and 5%. The MC4R SNP had three genotypes; homozygote AA with 5% frequency, heterozygote AG with 53% frequency, and homozygote GG with 42% frequency. Corresponding frequency of A and G allele was 32 and 68%, respectively. Monomorphic status at RYR1locus for NN genotype, HFABP locus for HH genotype, and MYF-5 locus for DD genotype indicated that favorable genes for quality pork production have been fixed in the population. The higher frequency of RR genotype (89%) at PRKAG3 and GG genotype (42%) at MC4R locus further explained the existence of favorable genotypes in indigenous pigs.

     

Diverse RNA viruses in a parasitic flowering plant (spruce dwarf mistletoe) revealed through RNA-seq data mining

Journal of General Plant Pathology - Spruce dwarf mistletoe (Arceuthobium sichuanense) is an important vascular parasite of spruce. In this study of the virome of A. sichuanense parasitizing Picea...     

Identification of ‘Ca. Phytoplasma asteris’, banana bunchy top virus and banana streak MY virus associated with Champa and Sabri banana cultivars in Tripura,a North Eastern state of India

European Journal of Plant Pathology - Symptoms of bunchy top, little leaf, leaf chlorosis with chlorotic streaks, leaf necrosis and stunted growth were noticed in two banana cultivars, Champa and...     

Sequence and evolutionary analysis of ribosomal DNA from Huanglongbing (HLB) isolates of Western India

Citrus greening (Huanglongbing, HLB) is a widespread and economically important citrus disease all over the world. The disease is caused by a phloem-limited fastidious gram negative bacterium, “Candidatus Liberibacter spp.” which belongs to the alpha-proteobacteria group classified on the basis of its 16SrDNA sequence. Although the pathogen has been classified under three distinct groups, viz. Asian, African and American isolates, nothing is known about the status and the molecular variabilities among the Indian HLB isolates collected from different citrus cultivars grown in India. Five different HLB isolates showing variable symptoms based on their severity of infection on different citrus, viz. Mosambi, Rangpur lime, Cleopatra mandarin, acid lime and rough lemon, were studied by PCR amplification, sequence and evolutionary analysis of their 16S and 16S/23S rDNA intergenic regions. Analysis of the 16S/23S rDNA intergenic region separated all five Indian isolates from existing African isolates but failed to differentiate among Asian, American and Indian isolates. However, further analysis of complete 16S rDNA clearly indicated that Indian isolates fall within the Asian HLB group. Overall, our results suggest that all the five Indian HLB isolates taken for the current analysis belong to the Candidatus Liberibacter asiaticus strain, which showed distinct sequence variabilities and produced noticeable symptoms on the citrus trees. These results provide a robust framework for understanding how differences in pathogenicity among various HLB isolates may be related to evolutionary history.     

<Emphasis Type="Italic">Indian citrus ringspot virus:</Emphasis> localization of virus in seed tissues and evidence for lack of seed transmission

Indian citrus ringspot disease is an important viral disease in kinnow mandarin orchards where disease incidence up to 100% has been recorded. The disease is caused by Indian citrus ringspot virus (ICRSV), a positive sense flexuous RNA virus. The transmission of ICRSV is generally through budwood. Association of ICRSV with pollens of naturally infected flowers from cv. ‘Kinnow’ mandarins has been shown previously and this study demonstrates the presence of ICRSV in seed tissues. DAC-ELISA revealed the presence of virus in seed coats but not in embryo and endosperm of seeds collected from the fruits of ICRSV-infected Kinnow plants. Of the infected seed coats, 18% were found to harbor the virus. The seedlings in the grow-out test did not show any symptom for 2 years and the virus could not be detected in seedlings by DAC-ELISA and RT-PCR. The present study indicated that ICRSV could be localized in the testa of seeds but its transmission to progeny was not observed.     

Molecular characterization of Citrus yellow mosaic badnavirus (CMBV) isolates revealed the presence of two distinct strains infecting citrus in India

Citrus yellow mosaic badnavirus (CMBV) is a non-enveloped, bacilliform DNA virus and the etiologic agent of yellow mosaic disease of citrus in India. The disease was initially reported from the southern parts of India and has now spread to other parts of the country. It is a serious disease of sweet orange (Citrus sinensis) in southern India, where it causes significant yield losses. During a recent survey of citrus groves in the Nagpur region, central India, characteristic mosaic symptoms were observed in mandarin orange (Citrus reticulata) and sweet orange. Virus transmission studies, electron microscopy, PCR amplification and sequencing of cloned PCR products from samples showing mosaic symptoms confirmed the presence of a badnavirus. The CMBV–Nagpur isolate could be transmitted to the Rangpur lime (C. limonia) and acid lime (Citrus aurantifolia) by graft inoculation. Sequence analysis of a segment of ORF-III region and intergenic region (IR) of the viral genome revealed that CMBV–Nagpur isolate formed a distinct clade along with some previously reported isolates that are known to infect acid lime and Rangpur lime. CMBV isolates that infect citrus species other than the acid lime and Rangpur lime formed a second clade. Based on the transmission studies and phylogenetic analyses, it was concluded that at least two strains of CMBV exist in India currently.     

<Emphasis Type="Italic">Citrus exocortis viroid</Emphasis> transmission through commercially-distributed seeds of <Emphasis Type="Italic">Impatiens</Emphasis> and <Emphasis Type="Italic">Verbena</Emphasis> plants

Surveys of Impatiens and Verbena species in local nurseries in Fredericton, Canada and Verbena species in New Delhi, India showed widespread infection of Citrus exocortis viroid (CEVd) in vegetatively-propagated and seed-grown plants. To determine viroid seed transmission, samples of eight varieties of Impatiens and 11 varieties of Verbena were obtained from four commercial sources. All 19 samples collected contained viroid infection irrespective of variety. The presence of viroid in non-germinated seed was 21%, while the transmission rate in seedlings was 66% in Impatiens walleriana in 2006. Following 2 years of seed storage, the respective figures were 6% and 26%. Similarly, in Verbena x hybrida the presence of viroid in seed was 13% in 2006 with a seed-transmission rate in seedlings of 28%, while the respective figures after 2 years of storage were 5% and 45%.     

Identification of sugarcane grassy shoot-associated phytoplasma and one of its putative vectors in India

During a survey of sugarcane fields at the Sugarcane Research Institute, Shahjahanpur, Uttar Pradesh, India, in August–September 2012, 6% to 28% incidence of sugarcane grassy shoot disease was observed in different fields of sugarcane variety CoS 7250. The association of phytoplasma with symptomatic sugarcane was confirmed by direct and nested PCR amplification of phytoplasma ribosomal gene. Four different delphacid leafhopper species, viz. Cofana unimaculata Signoret, Exitianus indicus (Distant), Sogatella kolophon Kirkaldy and Hishimonus phycitis (Dist.) were the prevalent feeding species of the Auchenorrhyncha fauna in the symptomatic sugarcane fields. Out of these four leafhopper species, only E. indicus tested positive for phytoplasma presence. Phylogenetic analysis suggested that the phytoplasmas from sugarcane and E. indicus in the present study were members of 16Sr XI. The confirmation of association of sugarcane grassy shoot phytoplasma in E. indicus population is important to understand the secondary spread of this phytoplasma in sugarcane plants.