Search

Context: Long-term multi-environment trials (METs) could improve genomic prediction models for plant breeding programs by better representing the target population of environments (TPE). However, METs are generally highly unbalanced because genotypes are routinely dropped from trials after a few years. Furthermore, in the presence of genotype × environment interaction (GEI), selection of the environments to include in a prediction set becomes critical to represent specific TPEs. Aims: The goals of this study were to compare strategies for modelling GEI in genomic prediction, using large METs from oat (Avena sativa L.) breeding programs in the Midwest United States, and to develop a variety decision tool for farmers and plant breeders. Methods: The performance of genotypes in TPEs was predicted by using different strategies for handling GEI in genomic prediction models including systematic and/or random GEI components. These strategies were also used to build the variety decision tool for farmers. Key results: Genomic prediction for unknown genotypes, locations and years within TPEs had moderate to high predictive ability, accuracy and reliability. Modelling GEI was beneficial in small, but not in large, mega-environments. The latest 3 years were highly predictive of performance in an upcoming year for most years but not for years with unusual weather patterns. High predictive ability, accuracy and reliability were obtained when large datasets were used in TPEs. Conclusions: Deployment of historical datasets can be accomplished through meaningful delineation and prediction for TPEs. Implications: We have shown the performance of a simple modelling strategy for handling prediction for TPEs when deploying large historical datasets. Rankings of genotypic performance may change from one environment to the next, creating genotype × environment interaction (GEI), which can impact genomic prediction and complicate identification of superior genotypes. We compared strategies for predicting the performance of individuals in the presence of GEI. The results provide useful tools for the optimisation of training populations and testing environments for the prediction of individuals in the targeted populations of environments. [ABSTRACT FROM AUTHOR]

Wheat and soybean producers pay a small amount per bushel produced as a check-off. Funds are used for research, outreach, and crop promotion. Commodity organizations and Extension joined forces to develop multi-state educational outreach on spring wheat and soybean production. Participatory planning involved producers in developing these educational events. The financial resources and availability of contact information from the commodity groups combined with the knowledge base and teaching skills from Extension resulted in well attended, valuable educational events. "Speed" hands-on demonstrations were well received. Extension working together with commodity groups can be a model for other Extension programming efforts. (Contains 6 tables.)

Increasing kernel weight has been proposed as a method to increase flour extraction in spring wheat (Triticum aestivum L.). Recurrent selection was initiated to increase kernel weight while maintaining genetic variation for the unselected traits. Our objectives were to determine (i) genetic gain for kernel weight after eight cycles of selection, (ii) the indirect effects of the selection for kernel weight on other agronomic traits, kernel morphology, milling fractions, and grain protein concentration, and (iii) the level of genetic variability among lines within selection cycles for kernel weight and unselected traits. Ten lines, selected for high kernel weight, were originally intermated to form the base population. About 20 [F.sub.2] plants with the highest kernel weight were selected (~2% of the population), and about three of their [F.sub.3] progeny were intermated to form the next cycle. This procedure was repeated for eight cycles, with an average of 60 crosses per cycle. Forty random lines from each cycle were used to evaluate agronomic traits in three environments. Kernel weight increased linearly at about 4.5% [cycle.sup.-1]. Cycle means did not differ for plant height and grain yield, but tillers per square meter and kernels per spike decreased 2.4 and 1.6% per cycle, respectively. Spikelets per spike, kernels per spikelet, test weight, and days to heading decreased, whereas spike length increased in response to selection for kernel weight. The proportion of bran and shorts decreased, and flour extraction and grain protein concentration increased 0.58 and 0.16% [cycle.sup.-1], respectively. No clear trend towards decreased genetic variance for kernel weight was observed since gain was linear over eight cycles. The observed gain from selection and heritability estimates point to kernel weight being controlled by several genes with small effects. Selection for increased kernel size in this population resulted in increased flour yield., RECURRENT SELECTION is a cyclical breeding strategy designed to accumulate favorable gene combinations while maintaining genetic variability within a population. This procedure is used extensively in allogamous species. Initial studies [...]

Key message: Oat crown rust is one of the most damaging diseases of oat. We identified a new source of resistance and developed KASP and TaqMan markers for selection in breeding programs.Abstract: A new highly effective resistance to oat crown rust (Puccinia coronata f. sp. avenae) was identified in the diploid oat Avena strigosa PI 258731 and introgressed into hexaploid cultivated oat. Young plants with this resistance show moderate susceptibility, whereas older plant tissues and adult plants are resistant with no virulent isolates encountered in over 8 years of testing. Resistance was incorporated into hexaploid oat by embryo rescue, colchicine chromosome doubling followed by backcrosses with a hexaploid parent, and selection for stable transmission of resistance. To mitigate flag leaf and panicle chlorosis/necrosis associated with the resistance, crosses were made with derived resistant lines to breeding lines of divergent parentage followed by selection. Subsequently, two F2 sister lines, termed MNBT1020-1 and MNBT1021-1, were identified in which the chlorosis/necrosis was reduced. These two lines performed well in replicated multi-location state trials in 2015 and 2016 out-yielding all cultivar entries. Segregating F2:3 plants resulting from crosses of MNBT lines to susceptible parents were genotyped with the oat 6K SNP array, and SNP loci with close linkage to the resistance were identified. KASP assays generated from linked SNPs showed accurate discrimination of the resistance in derivatives of the resistant MNBT lines crossed to susceptible breeding lines. A TaqMan marker was developed and correctly identified homozygous resistance in over 95% of 379 F4 plants when rust was scored in F4:5 plants in the field. Thus, a novel highly effective resistance and associated molecular markers are available for use in breeding, genetic analysis, and functional studies. [ABSTRACT FROM AUTHOR]

Increasing temperatures and changes in precipitation are expected to effect a change in production of coolseason crops such as spring barley and oat. To determine whether observed changes may already have had an impact on these crops in the Northern Plains of the United States and Canada, first-differences of growing-season temperature and precipitation and of annual yield data were analysed via multiple linear regression for 1980-2012 for the genetically stable cultivars of 'Robust' spring barley (Hordeum vulgare L.) at three sites in Minnesota, and for 'Gopher' oats (Avena sativa L.) at five sites in Minnesota and neighbouring states and provinces. Temperature and precipitation impacts also were assessed for the top-three yielding barley and oat cultivars at each site to assess whether newer varieties responded similarly to the older varieties. Barley yield at the coolest site showed a modest relationship with climate while the warmer sites showed stronger relationships between climate variability and barley yield, particularly for negative impacts of high temperatures. Climate variability also had a significant impact on yield at the five oat sites. Warm pre-sowing temperatures enhanced yields at cooler sites while high temperatures later in the growing season reduced yields across the sites. Results for the top-three barley and oat cultivars often were similar to those for the older cultivars. Our results suggest that observed climate changes have contributed to the relative decrease in barley and oat yields in the region, that more recent releases have partially compensated for the negative impacts of observed temperature and precipitation trends, and that model projected changes in temperature and precipitation will continue to present both benefits and challenges for barley and oat production in the Northern Plains. [ABSTRACT FROM AUTHOR]

The article presents a study which analyzes the associations of sulfur content, protein size distribution, and free amino acids in flour mill streams (FMS) to dough rheology and breadmaking traits. The study discovers that break FMS has higher nitrogen and sulfur quantities compared with reduction FMS. It finds higher levels of asparagine, a major amino acid in flour, in the third break and third reduction.