Low weight not a negative for GM mustard DMH-11, says Deepak Pental

Says yield as against ICAR's check variety not comparable as parent gene same

The low weight of the seed of DMH-11, the genetically modified (GM) mustard hybrid that was under trial at six sites last season, is not a big negative factor because in many mandis mustard is now being bought and sold on the basis of oil content and not the seed size or weight, according to Deepak Pental, former vice-chancellor of Delhi University and the brain behind DMH-11.

“Earlier the seed size was considered an important trait because there was a feeling that a bigger seed would have more oil. But that is not true because size and oil content are independent of each other,” Pental told Business Standard.

Delhi University’s Centre for Genetic Manipulation of Crop Plants (CGMCP) and the National Dairy Development Board (NDDB) are the joint applicants for GM mustard.

Recently the first official field trials of DMH-11 had raised objections on two counts. The first was inadequate proof that the potential yield of the hybrid was sufficiently more than its next best available hybrids in accordance with ICAR (Indian Council for Agricultural Research) protocols and also the low weight and seed size of DMH-11.

On the low seed weight, Pental said there could be some problems in mechanised harvesting for small-sized mustard seeds, but these issues were being raised as part of some “mischief” by anti-GM activists.

“Ultimately farmers will decide whether they want to grow a more productive small-seeded crop or not,” he said.

On the second argument on the potential yield of DMH-11 being not much better than the current hybrid check DMH-1 in accordance with the ICAR field trials, Pental said: “The two parental lines used for DMH-11 and the check hybrid used by ICAR-DMH-1 are very similar and, therefore, one should not expect a significant yield difference between the two.”

“DMH-11 was developed in 2002. It is a 20-year-old hybrid and yet it gives around 20 per cent more yield than the best varieties developed by publicly funded breeding programmes. We have hybrids that are bold-seeded and are higher yielding than DMH-11,” Pental said.

“DMH-11 is based on a GM pollination control system, and DMH-1 uses a cytoplasmic sterility system, which unfortunately is unstable at low temperatures and therefore purity of hybrid seed is low”.

Pental said a major insight his group made into mustard breeding in the 1990s was that there were two gene pools in oilseed mustard -- the Indian gene pool and the East European gene pool -- and that the hybrids between lines/varieties belonging to the two divergent gene pools had higher yield than the parents.

For a successful hybrid breeding programme, one needs a pollination control mechanism.

The GM-based pollination control method is the most versatile system for hybrid seed production. It does not by itself increase the yield, which depends on the selection and further breeding of the lines used as parents.

“A versatile pollination control system is a one-time affair, and the development of better hybrids with more desirable traits will be an ongoing activity. The GM pollination control system after the stipulated post-release activities will be available widely. This will ensure more productive hybrids in the future,” Pental added.