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Conventional wisdom regarding potato breeding indicates that a strong triploid block prevents the development of viable triploid seeds from crosses between tetraploid and diploid clones. However, in a recent set of crosses between elite tetraploid potatoes and an improved diploid hybrid population derived from group Stenotomum and group Phureja, 61.5% of the resulting clones were found to be triploid. If clones derived from one diploid parent suspected of producing a high frequency of unreduced gametes were excluded, then the frequency of triploid clones increased to 74.4%. Tubers of these triploids are generally intermediates of the two parental groups. Our findings indicate the possibility of using triploid potatoes in potato variety development programs and in genetic and genomic studies.

Fusarium crown rot (FCR) of winter wheat (Triticum aestivum L.), caused by Fusarium pseudograminearm and Fusarium culmorum, is a yield‐limiting disease in arid wheat‐producing areas of the inland Pacific Northwest. Foliar fungicide applications and currently available seed treatments do not control FCR. Alternative crops that provide a rotational benefit to reduce disease are not economically feasible. Major‐gene resistance is unavailable, but there is preliminary evidence that some wheat and barley (Hordeum vulgare L.) cultivars are more resistant than others. We followed up on preliminary work by growing 14 varieties of winter wheat, planted with in‐furrow FCR inoculum, in 2018 and 2019 in Morrow County, Oregon—one of the world's driest wheat producing regions. Two barley cultivars were added to the experiment during the second year of research. Evaluations of cultivar resistance were made by conducting aboveground visual assessments by counting whiteheads, prematurely senesced wheat heads that are indicative of FCR infection. Whitehead count information was correlated with yield and grain volume weight data. Maximum whitehead counts were measured in plots of the FCR‐susceptible check cultivar ‘Stephens’. There was no evidence of a cultivar‐specific relationship between whitehead count and corresponding values for yield and grain volume weight. There was limited evidence that some cultivars have the capacity to compensate for effects of disease.

Meloidogyne chitwoodi (Columbia root-knot nematode, CRKN) can cause serious damage in potato production systems, decreasing tuber value in the fresh market and processing industries. Genetic resistance to CRKN was first identified from the wild diploid potato species Solanum bulbocastanum accession SB22 and was successfully introgressed into tetraploid potato breeding material. To expand the base of genetic resistance, 40 plant accessions representing nine wild potato species were screened for their resistance to M. chitwoodi. Greenhouse screening identified fifteen clones from S. hougasii, one clone from S. bulbocastanum, and one clone from S. stenophyllidium with moderate to high levels of resistance against three isolates of M. chitwoodi. Geographical mapping showed that the resistance sources identified in this and previous studies primarily originated in the states of Jalisco and Michoacan in west-central Mexico. These new sources of resistance will be introgressed into elite potato populations to facilitate the development of potato cultivars with durable resistance to M. chitwoodi.

Classic evolutionary theory suggests that mutations associated with antimicrobial and pesticide resistance result in a fitness cost in the absence of the selective antimicrobial agent or pesticide. There is experimental evidence to support fitness costs associated with resistance to anti-microbial compounds and pesticides across many biological disciplines, including human pathology, entomology, plant sciences, and plant pathology. However, researchers have also found examples of neutral and increased fitness associated with resistance, where the effect of a given resistance mutation depends on environmental and biological factors. We used Zymoseptoria tritici, a model evolutionary plant pathogenic fungus, to compare the competitive ability of fungicide-resistant isolates to fungicide-sensitive isolates. We conducted four large-scale inoculated winter wheat experiments at Oregon State University agriculture experiment stations. We found a significant change in the frequency of fungicide resistance over time in all four experiments. The direction and magnitude of these changes, however, differed by experimental location, year of experiment, and inoculum resistance treatment (fungicide-resistant, resistant/sensitive mixture, and fungicide-sensitive). These results suggest that the competitive ability of resistant isolates relative to sensitive isolates varied depending upon environmental conditions, including the initial frequency of resistant individuals in the population.

Congeneric species with the same native and non-native ranges, but exhibiting different invasiveness, provide opportunities to assess the relative importance of factors contributing to successful invasions. For example, comparing the competitive ability of such congeners against other species from the native and non-native regions of invasive species can provide insight into the role of evolutionary experience with different competitors. We selected two congeneric Centaurea species with overlapping native and non-native ranges but with strikingly different invasive success, Centaurea solstitialis and C. calcitrapa, and conducted experiments with populations from each region using a suite of different native grass species from each region. When grown with Spanish grass species, competitive responses were 32% stronger for C. calcitrapa and 30% stronger for C. solstitialis, than when in competition with grasses native to California. Centaurea solstitialis from California had 66% higher competitive effects on grasses, all species considered together, than Spanish C. solstitialis; whereas the competitive effects of C. calcitrapa on grasses were not significantly different between C. calcitrapa ranges. Our results are consistent with the prediction that the evolution of increased competitive ability (EICA) might contribute to the devastating success of C. solstitialis in California, and that its absence might contribute to the modest naturalization of the non-invasive C. calcitrapa. Escape from the strong competitive effects and responses of grasses from Spain may also contribute to invasive success in California. Our results suggest that studies of EICA should be based on competitive tests, since biomass alone is not always a good predictor of competitive ability., We would like to thank Giles Thelen, Andrea Krutulis, David Hooper, and Margarita Zorrilla for their help with greenhouse and laboratory work. DM received funding from the Spanish Micinn (2008-0662), and by the Portuguese Fundação para a Ciência e a Tecnologia—FCT, through national funds and co-funding by the European PT2020, and COMPETE 2020 programs, within the Grants and Projects: IF-00066-2013; PTDC/BIA-PLA/0763/2014; and UID/BIA/04004/2013. RCG was funded by the MILES/HHMI program of The University of Montana. RMC thanks the NSF EPSCoR Track-1 EPS-1101342 (INSTEP 3).

We studied the relationships among wood anatomy, hydraulic conductivity, density and shear parallel to the grain in the stem of Handroanthus vellosoi trees with the goal to identify possible trade-offs between hydraulic conductivity and mechanical properties. For this study we felled 12 trees with 24-year-old and cut 10-cm-thick disks at three heights: base of the trunk, one meter in height, and two meters in height. We propose that the relationship between hydraulic conductivity and mechanical resistance found along the H. vellosoi trunk indicates greater mechanical investment in the wood at the base of the trunk compared with the other two heights (1 and 2 meters). Anatomically, this would be represented by smaller diameter vessels and fibers with thicker walls. Consequently, strength investment implies lower water conductivity at the stem base. However, more studies are needed to determine whether this lower value with respect to 1 and 2 meters represents a significant effect on water transport along the stem. Resumo Foram estudadas as relações entre anatomia da madeira, condutividade hidráulica, densidade aparente e cisalhamento paralelo à grã no tronco de árvores de Handroanthus vellosoi objetivando-se identificar os possíveis trade-offs entre a condutividade hidráulica e propriedades mecânicas. Para este estudo foram cortadas 12 árvores com 24 anos de idade, discos com 10 cm de espessura foram retirados em três alturas: base do tronco, um e dois metros de altura. Propomos que a relação entre a condutividade hidráulica e resistência mecânica encontrados ao longo do tronco H. vellosoi parece indicar um maior investimento mecânico na base do tronco em comparação com as outras duas alturas (1 e 2 metros), anatomicamente representada por vasos de menor diâmetro e fibras com paredes mais espessas. Consequentemente, um investimento em maior resistência mecânica implica em menor condutividade de água, contudo, mais estudos são necessários para determinar se este valor mais baixo em relação ao 1 e 2 metros representa um efeito significativo no transporte de água ao longo do tronco.

10 'Alba' (Reg. No. ______) is a winter, six-row barley released by the Oregon Agricultural 11 Experiment Station in 2012. The name “Alba” was chosen due to the bright and attractive 12 appearance of the crop at maturity. In high rainfall environments, it has a notable yield advantage 13 over check varieties and maintains excellent test weight and kernel plumpness. These advantages 14 are, in part, attributable to resistance to barley stripe rust (incited by Puccinia striiformis f. sp. 15 hordei) and scald (incited by Rhynchosporium commune). The principal end-use of Alba grain is 16 as feed, but it could also be used for food (after pearling) and preliminary tests show that it can 17 be successfully malted and used in craft brewing. 18

Barley breeding is essential for the provision of varieties optimized for disease resistance, agronomic performance and for utilization as malting, food or feed barleys. Selection for malting quality is difficult as there are many genes involved. Nevertheless, much is now known about the genetics of the barley genome, and marker-assisted selection is proving valuable in increasing the efficiency of barley breeding.

Successful exotic plant invasions are likely to be caused by multiple, non-mutually exclusive mechanisms, and it is exceptionally difficult to weight the relative importance of these mechanisms identified in different experiments. To this end we used individual-based models to explore how integrating empirical results from experiments might help to elucidate the relative importance of seed origin, biogeographic differences in competitive outcomes, and disturbance in exotic plant invasion. We integrated results from (1) competition experiments between Centaurea solstitialis derived from populations in the non-native range (California), the native range (Spain), and co-occurring native species from both ranges, (2) seed production by Centaurea plants from the different ranges grown in a common-garden environment, and (3) responses to disturbance experiments with plants from different native and non-native ranges. Californian C. solstitialis reached slightly higher abundances than its Spanish counterparts in every scenario, mainly due to higher seed production of Californians than their Spanish conspecifics, indicating the potential importance of evolutionary changes in the non-native range. In the absence of disturbance, grass species native to Europe showed stronger competitive effects on C. solstitialis than grass species native to North America, suggesting that release from competition in the native range may have some explanatory power for successful C. solstitialis invasion. However, the intensity of competition depended on the disturbance regime used in models. When intense disturbance was incorporated into the model, C. solstitialis was favored, with plants from Californian seed sources reaching higher densities than plants from Spanish seed sources. Our results are consistent with the idea that disproportional positive responses to disturbance in California, relative to those in the invader's native range of Spain, may be an important factor in the dominance of C. solstitialis in its non-native ranges. It is not clear why disturbance would have more beneficial effects on the invader in its non-native range, but the powerful effects of disturbance appear to interact in subtle ways with biogeographic differences in evolutionary trends, competitive intensities, life histories, and reproductive rates., DM was funded by the Spanish Micinn (2008-0662), by the Portuguese FCT (PCT/BIA-PLA/3389/2012 and IF-00066-2013), and by the European Commission (FP7-PEOPLE-MC-CIG-321909); FCT is partially funded by the EU via QREN, COMPETE and FEDER. SX thanks the State Key Program of the National Natural Science of China (31230014, 41430749), the Program for New Century Excellent Talents in University (NCET-13-0265), the Central University Special Fund (lzujbky-2014-k09, lzujbky-2014-200), the National Key Technology R&D Program (No. 2014BAC05B02), and the National Natural Science Foundation of China (31470492).

Comparisons of introduced exotics that invade and those that do not can yield important insights into the ecology of invasions. Centaurea solstitialis, C. calcitrapa, and C. sulphurea are closely related, share a similar life history and were each introduced to western North America from Southern Europe ~100-200 years ago. However, of these three species, only C. solstitialis has become invasive. We collected seeds from different populations for each of the three species both in the native range of Spain and the non-native range of California, measured individual seed mass, and grew plants from these seeds in a greenhouse experiment in Montana. The invasive C. solstitialis had the smallest seeds and seedlings of the three congeners. However, in contrast to its non-invasive congeners, C. solstitialis had the highest relative growth rates when grown in competition. C. solstitialis was also the only species to show significant differences in traits between populations from different ranges, with plants from the non-native range of California demonstrating greater competitive resistance, larger seed size, and larger seedling mass than plants from the native range in Spain. This suggests that C. solstitialis may be evolving toward larger seed and seedling sizes in this non-native range. Relative growth rate showed no inter-regional variation for any species, but was higher for C. solstitialis than its congeners when in competition, and thus may interact with the evolution of larger seeds and plant mass in ways that contribute to the extraordinary invasive success of this species. © 2012 Springer Science+Business Media B.V.

The Genome-Wide Association Studies approach was used to detect Quantitative Trait Loci associated with tocochromanol concentrations using a panel of 1,466 barley accessions. All major tocochromanol types- α-, β-, δ-, γ-tocopherol and tocotrienol- were assayed. We found 13 single nucleotide polymorphisms associated with the concentration of one or more of these tocochromanol forms in barley, seven of which were within 2 cM of sequences homologous to cloned genes associated with tocochromanol production in barley and/or other plants. These associations confirmed a prior report based on bi-parental QTL mapping. This knowledge will aid future efforts to better understand the role of tocochromanols in barley, with specific reference to abiotic stress resistance. It will also be useful in developing barley varieties with higher tocochromanol concentrations, although at current recommended daily consumption amounts, barley would not be an effective sole source of vitamin E. However, it could be an important contributor in the context of whole grains in a balanced diet.