HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Keyes, G. Articles by Sorrells, M. E. Search for Related Content PubMed Articles by Keyes, G. Articles by Sorrells, M. E. Agricola Articles by Keyes, G. Articles by Sorrells, M. E.

Rht1 and Rht2 Semidwarf Genes Effect on Hybrid Vigor and Agronomic Traits of Wheat

Monsanto/C3SE, 800 N Lindbergh, St. Louis, MO 63167
Dep. of Plant breeding and Biometry, Cornell Univ., Ithaca, NY 14853

^* Corresponding author.

The ‘Norin 10’ dwarfing genes, Rhtl and Rht2, have been an effective source of stature control in commercial cultivars of hexaploid wheat (Triticum aestivum L.). Various and conflicting studies have reported on the yield effects associated with these genes. The present study was undertaken to examine pleiotropic effects on yield and yield related characters in inbreds and F₁ hybrids near-isogenic for Rht1 and Rht2. Isogenic series for six diverse cultivars at three levels of dwarfing; tall (no Rht alleles), semidwarf (2 Rht alleles), and double-dwarf (4 Rht alleles) were intercrossed in all possible combinations within each dwarfing level, without reciprocals, to construct three near-isogenic series of 15 F₁ hybrids. Parents and hybrids were grown in replicated field trials in each of two locations for two years. Mean grain yield of all genotypes declined significantly as a linear function of the number of Rht genes. Negative effects of Rht were a consequence of significantly reduced kernel weights that were not offset by other yield components. Midparent heterosis for one measure of yield was greatest for tall hybrids (14%), followed by semidwarfs (10%), and double-dwarfs (2%). The Norin 10 Rht alleles appear to limit the expression of hybrid vigor.

Received for publication September 26, 1988.