RA 00110.pdf - OAR@ICRISAT

Practical Recurrent Selection in Cross-pollinated Crops 1
W . A . Compton 2 , M . A . Thomas-Compton 3 , and D.J. Andrews 4
Abstract
Techniques used to carry out recurrent selection, especially in cross-pollinated crops, are discussed in some
detail. Topics covered are (1) the influence of effective population size and selection pressure on fixation of
favorable genes, (2) choice of the population in which to practice selection, (3) the target environment, (4)
sampling environments, and (5) blocking techniques. Intrapopulation and interpopulation selection
methods are discussed and compared, including advantages and disadvantages of each and the appropriate
prediction equations. Data from a large study comparing line per se selection with reciprocal recurrent
selection are reported. Results indicate a similar rate of gain in the variety cross using each of the two
systems, but in each case the gain is due to very different genetic changes. Line per se selection has
apparently increased the variety cross largely through additive effects while reciprocal recurrent selection
appears to have improved the performance of the variety cross through nonadditive effects, as suggested by
theory.
Introduction
Both pearl millet (Pennisetum americanum) and
maize [Zea mays (L.)] are highly cross-pollinated
crops, but far more quantitative genetic studies and
recurrent selection experiments using maize as a test
organism have been reported (Sprague 1977, Hallauer
and Miranda 1981). Much more data, therefore,
are available for maize which can be of value to
those engaged in recurrent selection in pearl millet.
While the genetic responses to selection in pearl
millet and maize are expected to be similar (Rai and
1. Published as Paper No.7952, Journal series, Nebraska Agricultural Research Division.
2. Plant Breeder, Department of Agronomy, University of Nebraska, Lincoln NE 68583, USA.
3. Biotechnologist and Popcorn Breeder in the same department.
4. Plant Breeder, 279, Plant Sciences, East Campus, UNL, Lincoln, NE 68583-0910, USA.
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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