Inbred Line Extraction From Improved Breeding Populations1

Thumbnail Image
Penny L.H
Darrah L.L
Journal Title
Journal ISSN
Volume Title
Inbred maize lines were extracted from the second cycle of reciprocal recurrent selection in Kitale II and Ecuador 573. These were evaluated as S3 X S3 single crosses and three way crosses were predicted. The best predicted three-way crosses were made and grown in comparison with the current variety cross. Yields of the best 1 per cent of the second cycle three-way crosses exceeded the predicted value of foul1th cycle of the variety cross by only 2 per cent. The gain in yield of the three way crosses over the variety· cross did not justify the additional work required for four years of development. While gain from selection in the variety cross remains linear, the decision to extract lines must be based on anticipated agronomic or seed production improvements.involved reciprocal recurrent selection [1] with two synthetic Varieties’. Populations from this type of programme May be used as open-pollinated varieties, in a variety cross, as an advanced generation variety cross, or as sources of inbred lines for traditional hybrids. The level of farming practiced and national capability to produce quality seed are critical to the choice of which selection product to use. Developing countries with good seed industries Lack knowledge of the comparative differences between reciprocal recurrent selection to produce a variety cross and line extraction from The same populations to produce traditional single-, three-way, or double-cross hybrids. This paper presents data for such a comparison With the two synthetic varieties used in the selection programme at Kitale.
East African Agricultural And Forestry Journal, 41 (1), p. 2-8