Studies on variability of mungbean yellow mosaic virus isolates of mungbean and ecofriendly management of disease
| dc.contributor.advisor | Dr. Ashok Mishra | |
| dc.contributor.author | PRIYA JOHN | |
| dc.date.accessioned | 2017-12-27T09:02:07Z | |
| dc.date.available | 2017-12-27T09:02:07Z | |
| dc.date.issued | 2005 | |
| dc.description.abstract | Amidst the din of biodiversity within begomoviruses, a quantum leap in the occurrence of yellow mosaic disease (YMD) in pulses was realized. Gujarat is not an exception to this plague, especially Mungbean yellow mosaic virus (MYMV) crippling Vigna radiata, have attracted considerable attention. Vigna belongs to the family: Leguminosae; subfamily: Papilionoidae; tribe: Phaseoleae; subtribe: Phaseolinae. Mungbean repletes excellent nutritional qualities. Inquisitive about the natural variability of MYMV, the study was divided into two parts, the first part included the collection and characterization of natural variants of MYMV from Anand followed by the second part which comprised DNA hybridization based investigations of the biodiversity among MYMV isolates from different areas of Gujarat. Concomitant repertoire of specific variants showing symptoms of yellow mosaic, was carried out from diverse areas of Gujarat including Anand, Navsari, Ahmedabad, Sardarkrushinagar, Himmatnagar and Rajkot. Nomenclature of Anand isolates understudy was done according to their original host and place of collection. So the mungbean isolates from Anand were named as mb-AND1, mb-AND2, mb-AND3 and mb-AND4. In a case-by-case basis evaluation of Anand isolates, mb-AND1 was commendably selected for major studies. Isolate mb-AND1 has the potential to infect mungbean cultivars (K 851, GM-2-12-24 and GM-02-01), French bean, mothbean, dolichos, soybean and cowpea but not blackgram and pigeonpea by whitefly-mediated transmission, which makes it distantly distinct from other, reported MYMV from India. Transmission by graft and not by sap, distant it from MYMV of Thailand and West Malaysia. The induction of yellow mosaic symptoms, changes in micronutrient level and reduction in yield are complementary mode effects of MYMV including mb-AND1. Polymerase chain reaction (PCR) was carried out by using Mungbean yellow mosaic India virus (MYMIV) primers. Amplification was seen only with DNA extracted from mungbean, soybean and cowpea and the amplicon product of 1.8 kb was obtained in the case of mungbean (mb-AND3), soybean (mb-AND1) and cowpea (mb-AND1 and mb-AND2) samples, that represents left half of DNA A with AC abut and Rep C2 primers. A 750 bp amplicon representing right half of DNA A was obtained with CPV1 and AC abut primers in mungbean (mb-AND4) samples. PCR amplification with abutting primers could not be achieved at all. Consequently, the viral replicative forms, identified to represent double stranded super coiled form by analogy with the profile of other begomoviruses, were obtained in mb-AND1 (mungbean), mb-AND1 (cowpea) and mb-AND1 (mothbean) by cesium chloride (CsCl2) density gradient centrifugation and confirmed by Southern hybridization. Radiolabelled probes prepared from PCR amplified DNA A fragment coding for coat protein (CP) of MYMIV were used. mb-AND1 (cowpea) responded appreciably as the concentration of viral replicative forms were predominantly high. Cowpea (mb-AND1) fractions were pooled together and was taken for cloning in pUC 18 DNA at Kpn I and Bam HI loci followed by digestion with Bgl I. Southern hybridization using probe of CP and movement protein (MP) gene of MYMIV, restriction analysis and PCR amplification revealed clones pCGK 25 and pCGB 31 representing DNA A and DNA B. Sequencing of these clones was carried out in an automated DNA sequencer (Microsynth GmbH, Sequencing Group, Schutzenstrasse 15 PostFach, CH-9436 Balgach, Switzerland; sequencing@microsynth.ch & ABI Prism, Perkin Elmer and University of Delhi, South campus, New Delhi) and it was designated in the light of guidelines comprehended by the study group on Geminiviridae, International Committee on Taxonomy of Viruses (ICTV) as Mungbean yellow mosaic India virus-cowpea (Gujarat) {MYMIV-Cp (Guj)} which harnesses more than 89 % identity with MYMIV. These sequences are available in nucleotide sequence data libraries-DNA Data Bank of Japan (DDJB), European Molecular Biology Laboratory (EMBL) and GenBank databases, USA, under accession numbers AY937195 (DNA A) and AY937196 (DNA B) respectively. The genome structure of MYMIV-Cp (Guj) embodies two virion sense genes, AV2 and AV1 in DNA A and one BV1 in DNA B and complementary sense genes are AC1, AC2, AC3 and AC4 in DNA A and BC1 in DNA B. Comparative nucleotide sequence analysis evidenced the alignment of MYMIV-Cp (Guj) within the MYMIV cluster. Koch’s postulates of the cloned DNA components of mb-AND1 (cowpea) were proved by sprouted seed method of agroinoculation on mungean cv. K 851. The explored host range was confined to mungbean (GM-2-12-24 and Delhi local), French bean and blackgram, but no symptom induction was seen in mungbean (GM-9907, GM-9908, GM-9922 and GM-02-01), cowpea and Nicotiana benthamiana. DNA A alone of MYMIV-Cp (Guj) did not impassion any symptom on all the tested plant species. Pseudorecombination of the MYMIV-Cp (Guj) DNA A and MYMIViii Cp (Del) DNA B elucidated the importance of DNA B in symptom development by agroinoculation as the resistance of above-mentioned mungbean cultivars was overcome by the artificial recombination. Lack of variability was found between the full length [mb-AND1=MYMIV-Cp (Guj)] and the viral fragments cloned and sequenced from the Anand isolates of MYMV (mb-AND2, mb-AND3 and mb-AND4), which indicated that isolates from Anand may be considered as a single population of MYMIV-Cp (Guj). The accession numbers for cowpea (mb-AND2) 1.8 kb (L), mungbean (mb-AND3) 1.8 (L) and mungbean (mb-AND4) 750 (R) are AY937197, AY937198 and AY937199 respectively. However, differentiation of natural variants of MYMV isolates of mungbean in Gujarat could be detected by employing MYMIV-Cp (Guj) as probe in DNA-DNA hybridization and they could be classified into three groups (i) Strong hybridization to DNA A and B {mungbean (Anand), soybean (Navsari and Rajkot)}; (ii) Weak hybridization to DNA A and B {mungbean (Himmatnagar, Navsari and Ahmedabad), cowpea (Ahmedabad)}; (iii) Weak hybridization to DNA A alone {mungbean (Sardarkrushinagar), dolichos (Anand)}. It clearly revealed that the MYMV isolate of mungbean from Sardarkrushinagar is having genomic variation in DNA B component as compared to MYMIV-Cp (Guj). Satellite DNA β (1.3 kb) was found to be associated with begomovirus infected leguminous and non-leguminous hosts (dot blot positive with DNA A probe of Indian cassava mosaic virus) in Anand, whose role is yet to be understood. The botanicals possessing antiviral principles, Clerodendrum inerme and Boerhaavia diffusa inhibited yellow mosaic disease induced by isolate mb-AND1 upto 93.33 % (co-inoculation) and 86.67 % (pre-inoculation) respectively, implicating the role of botanicals as an effective and efficient ecofriendly measure to manage this vexed problem. Maximum disease inhibition (60.00 %) was shown in aureofungin (50 ppm) treated plants in the co-inoculation strategy. | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/5810038192 | |
| dc.keywords | variability, mungbean, yellow mosaic virus isolates, ecofriendly, management, disease | en_US |
| dc.language.iso | en | en_US |
| dc.publisher | AAU, Anand | en_US |
| dc.research.problem | Studies on variability of mungbean yellow mosaic virus isolates of mungbean and ecofriendly management of disease | en_US |
| dc.sub | Plant Pathology | en_US |
| dc.subject | agriculture, plant pathology | en_US |
| dc.subject | study | en_US |
| dc.theme | mungbean yellow mosaic virus isolates | en_US |
| dc.these.type | Ph.D | en_US |
| dc.title | Studies on variability of mungbean yellow mosaic virus isolates of mungbean and ecofriendly management of disease | en_US |
| dc.type | Thesis | en_US |