Phylogenetic analysis of coat protein gene of CYDV-RPV strain from Wheat

Background: Keeping in view the potential damage caused by viruses to production of different crops and possible ‘directed damages’ by manipulated viral attack in/across border collectively make phylogenetic analysis of any attacking viral specie important. Cereal yellow dwarf viruses (CYDV) are highly important viruses in wheat causing significant yield loss.Methods: Double antibody sandwich ELISA and reverse transcription polymerase chain reaction (RT-PCR) was used to detect and confirm the polerovirus i.e. CYDV-rhopalosiphum padi virus (RPV), and unassigned viruses (SGV, RMV) in Punjab and NWFP provinces. The PCR products were inserted into a pGEM®-T easy vector, which then transformed in JM-107 cells of Escherichia coli. Recombinant plasmids were sequenced. Nucleotide and predicted amino acid sequences were aligned, analyzed and compared with other RPV isolates of the family. The nucleotide sequence data were used to make a phylogenetic tree.Results: Sequencing of 600 bp of coat protein gene confirmed the presence of CYDV-RPV strain. Pakistani isolate has close phylogenetic relationship with RPV-Mexcio and RPV-Yolo (USA). They had 99.95% similarity with RPV-Pakistan. The RPV-Aus, RPV-IR, and RPV-Cal (USA) had 99.94% identities with RPV-Pakistan.Conclusion: This work led to a conclusion that there is very low genetic diversity in RPV-Pakistan. Now it is in our future interest to clarify the identity of RPV-PK with more sequencing. The current study may help scientists to formulate appropriate management strategies against CYDV-RPV

Molecular confirmation of Bdv2 gene in wheat germplasm and its field based assessment for resistance against barely yellow dwarf viruses

Background: Barley yellow dwarf in wheat is an important viral disease among wheat cultivating areas of the world. It is gradually progressing as a major threat to wheat crop in Pakistan due to availability of favorable environmental conditions. The use of resistant cultivar is environmentally safest method for disease control so, it is necessary to develop resistant cultivars before epidemic outbreaks.Methods: The most commonly used wheat variety Inqilab91 was crossed with BYDV / CYDVresistant variety TC14. F1 generation obtained from the P1 cross was then allowed to self-cross. 61 plants were selected from F2 generation onTHE BASIS OF disease tolerance or susceptibility and only tolerant plants were included for further experiments in the study. The presence of BDV2 among F2 generation was confirmed by sequence characterized amplified region (SCAR) markers in 6 (91, 96, 110, 119, 121 and 131) out of 61 genotypes which were then backcrossed with recurrent parent. Advance analysis regarding the presence of resistance source among the selected F2 generation was carried out using ELISA. Moreover, appearance of symptoms, agronomic values for different parameters, green house and field responses were also kept under consideration to characterize and confirm the presence of BDV2 among plants.Results: Results indicated that majority of F2 segregating population showed less yellowing, low viral titer and good agronomic values. ELISA value, glasshouse and field analysis showed that seven genotypes (30, 81, 89, 91,101,110 and 121) were resistant, and twenty-four genotypes were found moderately resistant. Tolerance was detected in genotypes 31, 47, 48, 50, 52, 56, 57, 60, 61, 94, 103, 106, 113, 115, 127, 140 and 413.Conclusion: Wheat lines containing Bdv2 genes showed resistance in both field and glasshouse. These wheat germplasm could be used as a source of resistance in CDRP-NARC for the further development of resistant wheat varieties against BYDV / CYDV

Molecular confirmation of Bdv2 gene in wheat germplasm and its field based assessment for resistance against barely yellow dwarf viruses

Background: Barley yellow dwarf in wheat is an important viral disease among wheat cultivating areas of the world. It is gradually progressing as a major threat to wheat crop in Pakistan due to availability of favorable environmental conditions. The use of resistant cultivar is environmentally safest method for disease control so, it is necessary to develop resistant cultivars before epidemic outbreaks. Methods: The most commonly used wheat variety Inqilab91 was crossed with BYDV / CYDV resistant variety TC14. F1 generation obtained from the P1 cross was then allowed to self-cross. 61 plants were selected from F2 generation on the basis of disease tolerance or susceptibility and only tolerant plants were included for further experiments in the study. The presence of BDV2 among F2 generation was confirmed by sequence characterized amplified region (SCAR) markers in 6 (91, 96, 110, 119, 121 and 131) out of 61 genotypes which were then backcrossed with recurrent parent. Advance analysis regarding the presence of resistance source among the selected F2 generation was carried out using ELISA. Moreover, appearance of symptoms, agronomic values for different parameters, green house and field responses were also kept under consideration to characterize and confirm the presence of BDV2 among plants. Results: Results indicated that majority of F2 segregating population showed less yellowing, low viral titer and good agronomic values. ELISA value, glasshouse and field analysis showed that seven genotypes (30, 81, 89, 91,101,110 and 121) were resistant, and twenty-four genotypes were found moderately resistant. Tolerance was detected in genotypes 31, 47, 48, 50, 52, 56, 57, 60, 61, 94, 103, 106, 113, 115, 127, 140 and 413. Conclusion: Wheat lines containing Bdv2 genes showed resistance in both field and glasshouse. These wheat germplasm could be used as a source of resistance in CDRP-NARC for the further development of resistant wheat varieties against BYDV / CYDV