Glabrous- and pubescent-glumed populations of spring wheat, Triticum aestivum L., were derived by bulking seed from F2 plants and F3 lines. These near-isogenic populations were evaluated at two locations for grain yield and other plant variables and for grain quality. Agronomic data indicated that the gene governing glume pubescence had little, if any, influence on plant productivity. The small quality differences between pubescent and glabrous types, even though significant in a few cases, are considered too small to have a major beneficial effect on a population.
White- and brown-glumed populations of spring wheat, Triticum aestivum L., derived by compositing seed from F2 plants and F3 lines, were evaluated at two locations for grain quality, grain yield, and other plant variables. The similarity of data from the two populations suggests that the gene, or genes, governing brown glume has little, if any, influence on most of the agronomic and quality characteristics of spring wheat, although small differences were observed in plant height at Bozeman, in spikelets per head at Huntley, and in farinograph stability at Bozeman.
Underlying physiological mechanisms of intraspecific variation in growth response to elevated CO2 concentration [CO2] were investigated using two spring wheat (Triticum aestivum L.) cultivars: Yitpi and H45. Leaf blade elongation rate (LER), leaf carbon (C), nitrogen (N) in the expanding leaf blade (ELB, sink) and photosynthesis (A) and C and N status in the last fully expanded leaf blade (LFELB, source) were measured. Plants were grown at ambient [CO2] (~384µmolmol–1) and elevated [CO2] (~550µmolmol–1) in the Australian Grains Free Air CO2 Enrichment facility. Elevated [CO2] increased leaf area and total dry mass production, respectively, by 42 and 53% for Yitpi compared with 2 and 13% for H45. Elevated [CO2] also stimulated the LER by 36% for Yitpi compared with 5% for H45. Yitpi showed a 99% increase in A at elevated [CO2] but no A stimulation was found for H45. There was a strong correlation (r2=0.807) between LER of the ELB and soluble carbohydrate concentration in LFELB. In ELB, the highest spatial N concentration was observed in the cell division zone, where N concentrations were 67.3 and 60.6mg g–1 for Yitpi compared with 51.1 and 39.2mg g–1 for H45 at ambient and elevated [CO2]. In contrast, C concentration increased only in the cell division and cell expansion zone of the ELB of Yitpi. These findings suggest that C supply from the source (LFELB) is cultivar dependent and well correlated with LER, leaf area expansion and whole-plant growth response to elevated [CO2].
Elevated CO2 (free-air CO2 enrichment) increases grain yield of aluminium-resistant but not aluminium-sensitive wheat (Triticum aestivum) grown in an acid soil