A ProMED-mail post
ProMED-mail is a program of the International Society for Infectious Diseases

June 13, 2003
Source: Dawn-National, 20 January 2003 [edited]


The lethal cotton leaf curl virus (CLCuV) which hit the crop badly in early 1990s in the country has re-emerged this year.

An unnamed senior scientist at the National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, told Dawn that tests carried out by Pakistani and Australian scientists had found that the current spate of the virus, branded by some experts as 'Bura virus', was very similar to that of the 'Jiminy virus' that gave the cotton growers sleepless nights early in the last decade.

The affected crops were first noted in the Burewala tehsil of Vehari district in the year 2001-2002. According to the official Cotton Crop Management Group, hot spots of virus infection were found in almost all the cotton districts of the Punjab. The worst-hit areas were Vehari, Rahim Yar Khan, Dera Ghazi Khan, Bahawalpur, Multan, Lodhran, Muzaffargarh, and Layyah districts. All the popular commercial varieties of cotton, including those marketed as CLCuV-resistant, came under attack.

In Pakistan, CLCuV first appeared in cotton fields, especially in the Punjab, which produces about 80 percent of the crop. Yield losses occurred after a record crop (12.8 million bales) in 1991-92 and decreased to 8-9 million bales/yr in the next 2 years.

Cotton scientists in the country succeeded in producing CLCuV-resistant and tolerant cultivars in a short time but at the cost of fibre quality, strength, and staple length. Higher production costs due to increased
application of farm chemicals and low yields/acre resulted in a search for new cultivars with higher yields and higher quality combined with resistance to CLCuV.

According to cotton market analysts, this situation resulted in a 'seed mafia'. Premature cotton cultivars started flowing into the market for several years, well before the granting approval by the federal seed certification department and provincial seed council. Moreover, the disease has resulted in demands that the government look into the failure of the previous research on CLCuV before releasing funds for more research.

The federal government has earmarked Rs 100 million as the first installment for research to get rid of the virus. Project proposals from the scientists have been invited.

A progressive grower from Kabirwala, Saddiq Akbar Bokhari, has urged the government to check the link between official cotton breeders and unscrupulous seed dealers to avoid exploitation of the growers through the marketing of premature and unapproved varieties.

[Byline: Nadeem Saeed]

[Cotton leaf curl geminivirus (CLCuV), tentatively regarded as a begomovirus species by the ICTV, causes a serious disease of cotton in Asia and Africa. It is the main constraint to production of cotton fiber and cotton seed oil in Pakistan. The crop is grown on 12-14 million acres; average production is about 210 kg/ha of lint and 500 kg/ha of oil seed. Cotton leaf curl has been reported in Sindh (1998), Northwest Frontier Province in Baluchistan (2001), and recently in Nepal on susceptible varieties.

According to Tariq Mahmood, Central Cotton Research Institute, Multan, Pakistan, CLCuV markedly affects seed quality and quantity. Disease management will likely depend upon selection of resistant cultivars, but success will depend upon the stability of the resistance. Over 3300 germplasm lines are being evaluated for resistance to CLCuV.

I thank Tariq Mahmood for providing information on the effect of CLCuV infection on cotton seed quantity and quality.

In an aside, does anyone know what the 'Jiminy virus' is? Could it be a bastardization of 'gemini'? Let me know.

References:
<http://www.ccri.org.pk/news/latest.htm>
<http://gemini.biosci.arizona.edu/viruses/clcumv/index.html> - Mod.DH]