Molecular characterization of viruses infecting potato and vegetables in Iraq
General Material Designation
[Thesis]
First Statement of Responsibility
Sadeq Al-Kuwaiti, Nawres A.
Subsequent Statement of Responsibility
Seal, Susan ; Maruthi, Midatharahally
.PUBLICATION, DISTRIBUTION, ETC
Name of Publisher, Distributor, etc.
University of Greenwich
Date of Publication, Distribution, etc.
2013
DISSERTATION (THESIS) NOTE
Dissertation or thesis details and type of degree
Thesis (Ph.D.)
Text preceding or following the note
2013
SUMMARY OR ABSTRACT
Text of Note
Due to the lack of published molecular information concerning plant viruses from Iraq, this study was initiated to investigate the diversity of viruses infecting potato and vegetables in Iraq on a molecular basis. Based on the economic importance and incidence worldwide, eight virus genera were investigated in 175 potato and vegetable samples collected from fields in Baghdad, Anbar and Najaf provinces in Iraq. Using genus/family specific primers, published in the literature, polymerase chain reaction (PCR) and reverse transcription-polymerase chain reaction (RT-PCR) were performed to screen samples for potyviruses, begomoviruses, carlaviruses, tombusviruses, potexviruses, cucumoviruses, tobamoviruses and alfamoviruses. Circular DNA viruses were screened by rolling circle amplification (RCA). Products resulting from PCR/RT-PCR and RCA were cloned and sequenced and data obtained were used for sequence analyses. The above approach led to the first molecular characterisation of three potyviruses; Potato virus Y (PVY), Bean yellow mosaic virus (BYMV) and Zucchini yellow mosaic virus (ZYMV), one begomovirus; Tomato yellow leaf curl virus, two carlaviruses, Potato virus S (PVS) and Cowpea mild mottle virus (CPMMV) and one tombusvirus; Grapevine Algerian latent virus (GALV) in Iraqi potato and vegetable samples. Based on nucleotide (nt) sequence analyses, BYMV from broad bean and ZYMV from zucchini were 97% and 99% identical to equivalent sequences from the GenBank sequences, respectively. Two PVY strains were distinguished when sequences from potato and tomato showed 99% maximum nt identity to equivalent PVYO: N and PVYNTN GenBank sequences, respectively. Full-length sequence from tomato amplified by RCA showed 99% maximum nt identity to equivalent TYLCV sequences from the GenBank. Sequence comparison of carlavirus sequences isolated from potato and cowpea were 99% and 96% identical to equivalents PVS and CPMMV sequences from the GenBank, respectively. All tombusvirus sequences amplified from tomato and eggplant showed 93% maximum nt identity to equivalent GALV GenBank sequences. The high similarities (93-99%) of virus sequences isolated suggest, viruses isolated may have been introduced into Iraq from other countries, through international trading of plant materials used for cultivation as Iraq import most of plant materials for agriculture.