Root biomass, water-use efficiency, and performance of wheat-rye translocations of chromosomes 1 and 2 in spring bread wheat 'Pavon'

Positive performance is reported for centric translocations of chromosome 1 of rye (Secale cereale L.) in bread wheat (Triticam aestivum L.). Objectives were to determine the effects of short arm translocations of rye chromosome 1 (1RS) derived from 'Kavkaz' winter wheat, in 'Pavon' spring wheat background, on root biomass, water-use efficiency, and agronomic performance. Pavon and its its tanslocations were evaluated in glasshouse pot experiments in 1997 and 1998 and in field experiments in 1999 and 2000 under well-watered and droughted treatments. The 1RS translocations in Pavon delayed maturity, reduced plant height in some cases, and increased root biomass. Association between root biomass and grain yield was significant under droughted and under well-watered conditions. The 1RS translocations increased grain yield and grain weight, especially under well-watered field conditions. The overall mean grain yield was 4.066 Mg ha(-1) for Pavon, 4.895 Mg ha(-1) for 1RS.1AL, 4.503 Mg ha(-1) for 1RS.ABL, and 4.632 Mg ha(-1) for 1RS.1DL. The 1RS translocations, in general, were more tolerant to field environmental stresses than Pavon. These results encourage the development and use of the 1RS.1AL and 1RS.1DL translocations in wheat breeding programs.