Access the full text.
Sign up today, get DeepDyve free for 14 days.
R. Briddon, S. Mansoor, I. Bedford, M. Pinner, K. Saunders, J. Stanley, Y. Zafar, K. Malik, P. Markham (2001)
Identification of dna components required for induction of cotton leaf curl disease.Virology, 285 2
M. Rahman, Dildar Hussain, Y. Zafar (2002)
Estimation of genetic divergence among elite cotton cultivars: Genotypes by DNA fingerprinting technologyCrop Science, 42
R. Briddon, S. Bull, I. Amin, A. Idris, S. Mansoor, I. Bedford, P. Dhawan, N. Rishi, Surender Siwatch, A. Abdel-Salam, Judith Brown, Y. Zafar, P. Markham (2003)
Diversity of DNA beta, a satellite molecule associated with some monopartite begomoviruses.Virology, 312 1
Mansoor Mansoor, Bedford Bedford, Pinner Pinner, Stanley Stanley, Markham Markham (1993)
A whitefly‐transmitted geminivirus associated with cotton leaf curl disease in PakistanPakistan Journal of Botany, 25
Cotton leaf curl disease (CLCuD), a devastating disorder of cotton in Pakistan, is caused by a whitefly‐transmitted begomovirus ( Cotton leaf curl virus ; CLCuV) that requires a satellite DNA β to cause disease symptoms ( Mansoor ., 1993 ; Briddon ., 2001 ). CLCuD‐resistant cotton varieties, in which no virus can be detected, have been developed through conventional breeding ( Rahman ., 2002 ). During the 2001 growing season, symptoms of CLCuD were observed on all hitherto resistant varieties at Burewala, District Vehari, Pakistan, and by 2002 disease symptoms were seen throughout the district. To determine if a resistance‐breaking strain of CLCuV had arisen, resistant and susceptible varieties were grown in the field at NIBGE (Faisalabad) and at the Cotton Research Station (Vehari). Plants of six commercial virus‐resistant varieties (CIM 448, CIM 443, CIM 446, CIM 473, CIM 435 and FH 900) showed no disease symptoms at Faisalabad, while susceptible varieties S‐12 and CIM70 had symptoms typical of CLCuD. At Vehari, plants of the same six resistant varieties showed between 15 and 50% infection, while the two susceptible varieties were all infected. Scions of CLCuD‐affected resistant varieties, collected from Vehari, were grafted onto 10 plants of each resistant genotype at NIBGE. This resulted in disease symptoms on 20–40% of plants, confirming a breakdown of resistance. To identity the resistance‐breaking virus, nucleic acid was extracted from plants with and without symptoms collected at both sites. Samples were Southern‐blotted and probed with a biotinylated DNA A clone of CLCuV. The probe detected both the ss and ds DNA forms characteristic of begomoviruses, confirming the association of a begomovirus with the disease. Universal primers for DNA β of CLCuV were used to amplify DNA β from leaves with symptoms collected from resistant varieties in the Vehari area and the PCR product from one location was cloned in a T/A cloning vector (Fermentas). Since CLCuV DNA β is specific to CLCuV ( Briddon ., 2003 ), a DNA β cloned from cotton plants of resistant varieties showing symptoms of CLCuD in the Burewala area was used as a disease‐specific probe in Southern blot hybridizations. The probe hybridized only with DNA extracted from CLCuV affected cotton plants while no signal was detected from a tomato plant ( Lycopersicon esculentum ) that was previously shown to be associated with a DNA β distinct from that associated with CLCuV ( Briddon ., 2003 ). Samples collected from both locations hybridized with this probe. A duplicate blot was probed with a previously reported CLCuV DNA β ( Briddon ., 2001 ) and this resulted in a similar pattern of hybridization. Based on the data presented here, it was concluded that the plants of resistant varieties were infected with CLCuV ( Briddon ., 2001 ). These results strongly suggest the emergence of a resistance‐breaking strain of CLCuV in Pakistan.
Plant Pathology – Wiley
Published: Dec 1, 2003
You can share this free article with as many people as you like with the url below! We hope you enjoy this feature!
Read and print from thousands of top scholarly journals.
Already have an account? Log in
Bookmark this article. You can see your Bookmarks on your DeepDyve Library.
To save an article, log in first, or sign up for a DeepDyve account if you don’t already have one.
Copy and paste the desired citation format or use the link below to download a file formatted for EndNote
Access the full text.
Sign up today, get DeepDyve free for 14 days.
All DeepDyve websites use cookies to improve your online experience. They were placed on your computer when you launched this website. You can change your cookie settings through your browser.