Scientists develop pest resistant transgenic sugarcane varieties

Panaji, July 9 (UNI) In a major breakthrough, scientists at the Coimbatore-based premier Sugarcane Breeding Institute (SBI) have developed transgenic varieties, which are resistant to the dreaded red-rot disease and borer pests.

''We have also started identifying the genes resistant to the red-rot and pests from indigenous sugarcane species, particularly from the wild, in collaboration with the New Delhi-based National Research for Plant Biotechnology (NRPB),'' the SBI director Dr N Vijayan Nair said.

Dr Nair told UNI they had earlier bred transgenic plants using the imported genes to check the deadly diseases and pests in sugarcane.

They would be tested under the specially-built glass houses for their efficacy. The indigenous gene identification has also picked up momentum, with India having no transgenic varieties so far.

''Red-rot is a major fungal disease and we used anti-fungal genes drawn from other plant sources such as alfalfa plant for glucanase and paddy plant for chitenase and Dahlia flowers for anti-microbial peptides for developing the transgenic varieties,'' Institute's crop improvement division's principal scientist Dr N Subramonian.

The scientists developed the transgenic varieties by bombarding the genes with a particle gun into the subject sugarcane plant known for very high sucrose yield such as COC-671 and screened them for red-rot disease resistance.

The scientists had also been developing borer-resistant varieties using bacillus turungienses (BT) genes, which are known to have insecticidal properties.

Tested in a proteus inhibitor, the new varieties were found to have moderate resistance to top borers. The scientists have now tested them with bovine pancreatic trypsin inhibitor using aprotinin for its efficacy, Dr Subramonian said.

''We are also sparing no effort to identify and isolate anti-microbial genes to develop peptides from other plant resources to inhibit red-rot,'' he added.

Brazilian and Australian scientists have now engaged in similar task on some other aspects such as increasing sucrose content and other parametres while in India the focus is on eliminating the pests and diseases.

Various plant breeding strategies failed to achieve cent per cent result in checking the red-rot disease, which had been claiming an estimated 10 to 12 per cent crop loss and the borer pests 15 per cent.

''We cannot rule out the possibility of the red-rot disease striking the sugarcane crop despite developing susceptible/resistant varieties which break down after a few years and hence the transgenic programme,'' Dr Nair said.

The loss owing to wool aphid pest which played havoc in tropical regions over the last four years, is quite lesser this year with various measures undertaken.

Pest and disease resistant transgenic may be the hope for the crop in India where it was planned to produce at least 400 million tonnes by the year 2020 as against the present 300 million tonnes.

It was also targetted to enhance productivity to 100 tonnes per hectare by the year 2020 against the present 65 to 70 tonnes per hectare besides increasing the sugar recovery to 11 per cent as against the 10 per cent now.

The SBI, he said, had been adopting multi-pronged strategies to check prevelance of these hurdles over the years. They included application of bio-technology such as tissue culture for rapid multiplication of varieties of healthy seeds and molecular breeding.

Incidentally, the SBI is one of the oldest sugarcane research institute established in 1912 and set up by the Dutch after the one in Java.

It had so far developed as many as 2800 clones, which had been used by 30 other countries including the US and Australia as parents for their breeding programmes.

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