Crop Science Grow Your Career with CSSA
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Published in Crop Sci 11:283-286 (1971)
© 1971 Crop Science Society of America
677 S. Segoe Rd., Madison, WI 53711 USA
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hill, R. R.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Hill, R. R., Jr.
Agricola
Right arrow Articles by Hill, R. R.

Effect of the Number of Parents on the Mean and Variance of Synthetic Varieties1

R. R. Hill, Jr.2

The effect of the number of parents per synthetic on the mean and variance of synthetic varieties was studied for diploid and autotetraploid species. The mean of synthetics with a small number of parents each will usually be less than the mean of the source population from which the parents were chosen, and the mean of the synthetics approaches the mean of the source population as the number of parents per synthetic increases. The genetic variance among the means of the synthetics decreases as the number of parents per synthetic increases, and the decrease is more rapid for the nonadditive than the additive portion.

The findings indicated the following: (1) Selection among experimental hybrids or synthetics utilizes genetic variance more efficiently when the number of parents per experimental variety is small. (2) Hybrids make slightly more efficient use of nonadditive genetic variance than synthetics with a comparable number of parents, and most of the advantage of hybrids would be lost with one generation of seed increase. (3) Most of the progress in development of medium to broad-based synthetics results from selection of the parents and very little additional gain would be expected from selection among medium to broad based combinations of the selected parents.

Key Words: Forage crops breeding • Breeding methods

1 Contribution No. 236 of the U.S. Regional Pasture Research Laboratory, Crops Research Division, Agricultural Research Service, U.S. Department of Agriculture.

2 Research Agronomist, U.S. Regional Pasture Research Laboratory, University Park, Pa. 16802.

Received for publication September 30, 1970.




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
The SCI Journals Agronomy Journal Vadose Zone Journal
Journal of Plant Registrations Soil Science Society of America Journal
Journal of Natural Resources
and Life Sciences Education		 Journal of
Environmental Quality
Copyright © 1971 by the Crop Science Society of America.