RA 00110.pdf - OAR@ICRISAT

Breeding for Adaptation to Environmental Stress
F.R. Bidinger 1 , V. Mahalakshmi 2 , P. Soman 2 , and B.S. Talukdar 3
Abstract
Although breeding for adaptation to environmental stresses is a more complicated problem than breeding
for adaptation to biotic stresses, the basic procedure is virtually identical. Initial steps include understanding
the specific problems, and establishing methods to identify better-adapted materials. This is followed by
determining if useful genetic variability for adaptation exists, and if so, deciding upon the best means to
select for improved adaptation in a breeding program. The results of these steps then allow a rational
decision on whether breeding for better adaptation is justified.
This procedure is illustrated using two different environmental stress problems in pearl millet: failure of
stand establishment and drought stress during grain filling. Useful progress has been made on understanding
the problems involved and developing screening and selection methods. Current efforts center on
assessing the genetic variability for these traits and evaluating the response to direct selection for
adaptation.
Introduction
The title of this paper has been deliberately phrased
as a question because there has traditionally been
considerable skepticism about breeding for 'resistance'
to environmental stresses. Selection for tolerance
to certain stresses—such as freezing temperatures,
low p H , and aluminium-toxic soils—has been
effective (Blum 1985), but plant breeders have been
far more willing to devote resources to breeding for
disease and insect pest resistances than to breeding
for adaptation to environmental stress.
Research on environmental stress is admittedly
more complex than research on biotic stress. While
1. Principal Physiologist, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, A.P. 502 324, India.
2. Physiologists, at the same location.
3. Plant Breeder, at the same location.
Submitted as CP 372 by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).
ICRISAT (International Crops Research Institute for the Semi-Arid Tropics). 1987. Proceedings of the International Pearl Millet
Workshop, 7-11 April 1986, ICRISAT Center, India. Patancheru, A.P. 502324, India. ICRISAT.
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