Proceedings of the Fifth Asian Regional Maize Workshop - Search ...

HYBRID RESEARCH AT CI~ TO ACCELffiATE HYBRID MAIZE BREEDIOO
IN THE OEVELOPIOO CXUffRIES
S. K. Vasal and G. Srinivasan 11
Abstract
This paper discusses the various hybrid research activities at CIMMYT which will help in
accelerating the hybrid maize research efforts in the developing countries. The paper starts
with an account of hybrid adoption in both developing and developed nations. Although the
adoption of hybrid maize in developed countries has been spectacular in the current century, the
developing world has been lagging behind in this technology. The emphasis on hybrids in the
developing world has been see-sawing over the years, but has picked up momentum in recent years,
due to the increased presence of the private sector in many countries and also due to the demand
for hybrids from the farmers. Several reasons are speculated and discussed for this trend
including the increased growth of national and mUltinationals, an increase in hybrid research
efforts on the part of several national programs, and relatively less apparent impact of the open
pollinated varieties (OPVs) for the past several decades. "rhe activities of the hybrid program
at CIMMYT are discussed emphasizing several aspects including characterization of CIMMYT germplasm,
development of hybrid oriented source populations, development of inbred and non-inbred
progenitors, testers, integrated population improvement and hybrid research activities, development
and performance of hybrids and the recent announcement of CIMMYT maize lines (CML). The
development of hybrid oriented source germplasm is discussed in detail highlighting the development
of germplasm tolerant to inbreeding stress, enhanced combining ability and cross-bred
performance, formation of new heterotic groups while improving the existing heterotic patterns
through interpopulation improvement schemes, formation of new inbred-based populations and
special trait germplasm. Heterotic patterns among CIMMYT germplasm have been reported and the
performance of various kinds of hybrids has been presented. The recent release/announcement of
CIMMYT maize lines and their adaptation are presented for possible use by the national programs.
The different sections of the paper detail how the information and germplasm generated by
CIMMYT's hybrid research activities will greatly benefit and accelerate hybrid related activities
in the national programs. This ecological zone. In this paper, CIMMYT's expanded role in hybrid
research will be described highlighting those activities which will help directly or indirectly
in accelerating hybrid maize breeding in the developing countries.
I. Introduction
In maize (Zea mays L.), a wide array of germplasm products can be developed by the breeder
to meet the farmers need in various distinct environments encountered in the developing world
countries. Presently, approximately 58.5 m ha of non-temperate maize are grown in different
regions of the developing world. The above figure does not take into account about 16 m ha grown
in temperate China, Argentina, Chile and Turkey. The coverage of maize area with improved maize
varieties has been somewhat slow and currently no more than 50% of the area in the developing
countries is planted with improved maize varieties. In South, East, and South-east Asia, the
improved maize varieties cover roughly 57%.of the total available area, of which 72.8% is
comprised of lowland tropical, 26.8% subtropical and only 0.4% highland. The impact of improved
germplasm thus has been greatest in the lowland tropics as in evident from more than two-thirds
of the acreage planted to this ecology. In this paper, CIMMYT's expanded role in hybrid research
!I Maize Breeders, International Maize and Wheat Improvement Center (CIMMYT), Lisboa 27, Apdo.
Postal 6-641, Mexico, D.F., Mexico.
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