Cotton output under threat as non-Bt varieties found contaminated

LAHORE: The official comprehensive tests of cotton seeds have revealed that all non-Bt varieties, including standard elite lines, have been contaminated with Bt genes, leading to productivity losses due to growing resistance against the toxic protein, The News learnt on Saturday.

The Bt cotton has been genetically modified by the insertion of one or more genes from a common soil bacterium, Bacillus thuringiensis (Bt). These genes encode for the production of insecticidal proteins, and thus, genetically transformed plants produce one or more toxins as they grow.

Pakistan Central Cotton Committee, in a meeting held in Multan, learnt that all the widely cultivated fifteen non-Bt cotton varieties, developed by public and private sector institutions, included in the biochemical test (BCT) under the National Coordinated Varietal Trials (NCVT) 2018 have emerged as contaminated.

According to the BCT results, compiled in accordance with the lab examination of four leading institutions, the standard elite varieties of CIM-620 and CRIS-129 developed by Central Cotton Research Institutes (CCRIs) located at Multan and Sakrand respectively, are also no more conventional seed types.

The standard seed varieties are elite lines of cotton and their different characteristics also act as a benchmark for comparing it with new competing varieties.

Monsanto, the multinational agrochemical and agricultural biotechnology corporation, first developed a cotton variety, containing a gene derived from the Bt bacterium. This gene is inserted into cotton plants that produce a toxic protein which eventually kills the bollworm.

The successful functioning of Bt cotton also depends on cultivation of non-Bt varieties on the same field to avoid development of resistance in pests against the toxic protein.

With the disclosure that many non-Bt cotton varieties have been contaminated with Bt gene, one of the main reasons hindering cotton output may have been discovered. Many believe that it is a tip of an iceberg associated with our ailing cotton economy.

The growing pest resistance against Bt cotton seed that produces proteins in the plant for killing bollworms has been termed as one of the main reasons for dwindling cotton production in the country. This is alarming as it leads to increasing resistance in pests as it has happened without any gene transformation technique, backcrossing or breeding process, but probably due to various gene flows.

Ibrahim Mughal, chairman Agri-Forum Pakistan, said the bollworm had emerged as the biggest threat to cotton in the country as they inflicted the biggest dent to the national output. The damages done by bollworms have been estimated at as high as 3.8 million bales of cotton annually, which is huge if compared with maximum production of about 14 million bales, Mughal said.

Dr Khalid Abdullah, the federal cotton commissioner, termed carelessness on the part of department concerned as the main reason of contamination of non-Bt cotton varieties. He, however, did not agree that this unwelcoming development was due to contamination of cotton seed. “You can call it mixing of Bt seeds in the non-Bt verities that takes place during ginning process,” Abdullah claimed and said,” We need to gin Bt and non-Bt cotton varieties separately.”

As far as resistance management is concerned against the Bt cotton varieties, he acknowledged that cotton production could be adversely affected due to non-practice of refuge as it was found that many non-Bt cotton varieties had been lost.

“I totally agree with the point that resistance in bollworms would definitely increase, which is not a good omen. We have asked the department concerned to take immediate measures for eliminating cotton contamination from non-cotton varieties,” Abdullah said.

Hadyat Ullah Bhutto, senior scientific officer CCRI Sakrand, said there was no consistency in the results of labs about presence of Bt genes in the non-Bt cotton varieties. “The varied results are also not dependable in the sense that we cannot properly do scientific work,” Bhutto said.

To a question, he said there was a possibility of contamination of non-Bt varieties due to cross pollination even during propagation level.

The contamination of non-Bt cotton would invite onslaught of bollworms on greater extent due to altering of gene expression, he observed.

The genetic contamination of cotton varieties points to a messy situation of our seed research and development chain that has been laced with flawed agronomic practices.

Dil Baugh Muhammad, principal scientific officer at CCRI Multan, said cross pollination could be a reason of this contamination. He agreed that there was a likelihood of increase in resistance in bollworm due to sowing of non-Bt varieties as refuge that in fact had become Bt, having a varied gene expression.

Dr Neil Forrester, a leading Australian scientist who closely monitored cotton related developments during research and development work in Pakistan was very much clear about negative impact of such worrying developments.

Forrester observed that continuation of these high levels of Bollgard gene contamination would ultimately lead to resistance to the insecticidal Bt genes and thus loss of the utility of this key set of genes for control of lepidopteran pests in cotton (and other hosts crops).

“Impurity of herbicide resistance genes in a field of cotton sprayed with that herbicide (eg roundup glyphosate) will lead to death of the non-glyphosate tolerant plants in the sprayed crop,” the Australian expert said.

About remedy for dealing this complex situation, Forrester said the government regulation of all transgenic genes in all crops is needed. Help from governments in countries who have successfully already done this should be sought, he added.

A spokesman of Punjab Agriculture Department said the provincial government always stressed on planting non-Bt crop with Bt cotton, but the important point here was that Bt cotton planted in Pakistan is Bollgard-I technology, which had become obsolete and lost effectiveness against Pink bollworm and less effective against Heliothis. “Being old technology, there are issues of purity and gene expression,” the spokesman said.

It is very imperative to mention here that India switched to Bollgard-II Bt technology in 2006. In Australia, 100 percent GMO cotton is Bollgard-III which is the latest version of Bt and glyphosate resistance.

The spokesman added that Punjab government was now transforming cotton research system to align it with advanced technologies. “In this context, a Punjab Cotton Mission 2025 has been drafted for increasing Punjab cotton productivity from 8 million bales to 15 million bales,” the provincial agriculture department official said.