Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/26/2003
Publication Date: 7/1/2003
Citation: OWUOCHE, J.O., SEARS, R.G., BROWN GUEDIRA, G.L., GILL, B.S., FRITZ, A.K. HETEROTIC EFFECTS OF WHEAT-RYE CHROMOSOMAL TRANSLOCATIONS ON AGRONOMIC TRAITS OF HYBRID WHEAT (TRITICUM AESTIVUM L.) UNDER AN ADEQUATE MOISTURE REGIME. EUPHYTICA. 2003. 132(1):67-77. Interpretive Summary: Development of hybrid wheat varieties has been a goal of many wheat breeding programs world-wide. One reason for the lack of success of hybrid wheat has been the lack of sufficient levels of hybrid vigor. Wheat lines that have genes from rye have been used successfully for development of high yielding pure line varieties. However, the effect of these rye chromosomes on yield and yield components of hybrid wheat has not been evaluated. In this study, thirteen hard winter wheat hybrids and their parents that had genes from rye were evaluated in Berthoud, CO for two years under irrigation. The presence of rye chromosomes had a generally positive effect on yield and yield components of the hybrids evaluated, although the magnitude of improvement depended on the hybrid These data indicate that the chromosome segments from rye may also be useful to increase the level of hybrid vigor in winter wheat under irrigation.
Technical Abstract: Translocated chromosomes T1BL 1RS and T1AL 1RS have been widely used in many wheat (Triticum aestivum L.) breeding programs to develop high yielding cultivars. The objective of this study was to evaluate the heterotic effects of T1BL 1RS+T1AL 1RS, T1BL 1RS, and T1AL 1RS on yield and yield components of hybrid wheat grown under adequate moisture regimes. Thirteen hybrid wheats and seven parents with different chromosome constitutions relative to T1AL 1RS and T1BL 1RS were evaluated in a randomized complete block design. Variable performance was observed among the hybrids tested. Two of the three hybrids with T1BL 1RS+T1AL 1RS, produced 25.26% and 44.64% more grain than the hybrids with only T1BL 1RS. This was due to increased biomass, harvest index (HI) and spike density. However, the combination of these two translocations resulted in reduced kernels/spike, spikelets/spike and spike length compared to theT1BL 1RS translocation alone. When comparing closely related parents, the parent with T1AL 1RS produced 23.51% more grain yield than the non-translocated parent. The presence of T1AL 1RS resulted in 10.37% heterotic advantage for yield due to increased biomass, KW, and spike density. When the two wheat-rye translocated chromosomes are present in the same hybrid, T1AL 1RS seems to have a positive effect on yield through spike density and HI, but masks the effects of T1BL 1RS for some agronomic traits.