Amylose and β‐glucan are important components of barley (Hordeum vulgare L.) grain. Factors such as seed yield, test weight, seed plumpness, protein content, field location, and seasonal variation may have an effect on β‐glucan and amylose concentrations, and therefore, require additional study. Twenty‐seven barley cultivars and advanced lines with varying levels of β‐glucan (4–9%) and amylose (6–27%) were grown in 2004 and 2005 in replicated plots at three locations in Idaho to evaluate agronomic traits and genotype × environment interactions. Seed yield, test weight, percentage of plump kernels, β‐glucan percentage, amylose/amylopectin ratio, and protein percentage were measured for seed samples from all plots. Estimates of variance components showed that about 49% of the variability in β‐glucan concentration and about 48% in amylose starch levels can be attributed to year, location, year × location, and their interactions with genotype. Amylose was found to be negatively correlated with protein and β‐glucan content but was positively, though weakly, correlated with seed yield and test weight; β‐glucan was positively correlated with protein and percentage plump kernels but showed a weak negative correlation with seed yield.

Wheat (Triticum aestivum) and jointed goatgrass (Aegilops cylindrica) can cross with each other, and their self-fertile backcross progenies frequently have extra chromosomes and chromosome segments, presumably retained from wheat, raising the possibility that a herbicide resistance gene might transfer from wheat to jointed goatgrass. Genomic in situ hybridization (GISH) was used to clarify the origin of these extra chromosomes. By using T. durum DNA (AABB genome) as a probe and jointed goatgrass DNA (CCDD genome) as blocking DNA, one, two, and three A- or B-genome chromosomes were identified in three BC2S2 individuals where 2n = 29, 30, and 31 chromosomes, respectively. A translocation between wheat and jointed goatgrass chromosomes was also detected in an individual with 30 chromosomes. In pollen mother cells with meiotic configuration of 14 II + 2 I, the two univalents were identified as being retained from the A or B genome of wheat. By using Ae. markgrafii DNA (CC genome) as a probe and wheat DNA (AABBDD genome) as blocking DNA. 14 C-genome chromosomes were visualized in all BC2S2 individuals. The GISH procedure provides a powerful tool to detect the A or B-genome chromatin in a jointed goatgrass background, making it possible to assess the risk of transfer of herbicide resistance genes located on the A or B genome of wheat to jointed goatgrass.

The release of herbicide resistant wheat (Triticum aestivum L.) raises concerns with gene flow between wheat and jointed goatgrass (Aegilops cylindrica Host). Hybrids between the two species and backcrosses with either species have been observed in the field. Gene flow is dependent on jointed goatgrass being the paternal parent of the BC1 generation. Differences in the genomes of wheat (AABBDD) and jointed goatgrass (CCDD) could be used to determine the paternity of the BC1 generation. Twenty BC1 plants (10 of each paternal type) were used to determine if the number of C genome chromosomes based on genomic in situ hybridization (GISH) could be used to determine BC1 paternity. Differences between the two BC1 paternal types for number of C genome chromosomes indicates that C genome chromosome counts could be used to determine the paternity BC1 plants providing a more accurate estimate of the potential for gene flow between the two species.

No abstract

No abstract