Breeding approaches for varietal improvement in rice, with special reference to genetic yield enhancement and stability, and reflections on 35 years of rice breeding in eastern India

IRRI Seminar

By S.R. Das
Emeritus professor
Orissa University of Agriculture and Technology
India

1315-1415 H, Thursday, 25 October 2012
Havener Auditorium, IRRI

Video of seminar on Ustream (63:01)
Seminar slides on Scribd

Abstract:

National and international rice improvement programs have not made any significant increase in the genetic yield potential of varieties since the release of IR8 in the 1960s; rice improvement programs have only added value to the semidwarf high-yielding varieties by conferring them resistance to or tolerance against yield-destabilizing biotic and abiotic stresses. If this trend continues in the coming years, and if we fail to stabilize the yield growth level at where it stands today at least, it may not be possible to sustain self-sufficiency in rice.

We need to make concerted research efforts to raise the genetic ceiling of yield in rice.

It had been stated that continuous growth, no doubt with plateaus at different phases since 1900, suggests that a perfect variety has yet to be developed. Still, there is unexploited genetic variability that can be used to affect the direct and indirect components of yield. This variability also provides enough scope for the development and use of more efficient breeding and selection techniques to improve rice yield.

Some breeding approaches, such as multiple convergent crossing, modified back-crossing, three-way crosses, gene pool concept and use of weedy relatives, male sterile facilitated composites, recurrent selection, and population improvement have been discussed in the contest of breaking yield barriers in rice. The strategies of rice breeding in eastern India are also now being revisited.