APPLICATION OF THE DYA METHOD TO COMPARE WHEAT CULTIVAR YIELDS

At the 1998 conference, we proposed use of the DYA (differential yielding ability) method to compare the yielding ability of wheat cultivars. In this paper we review the method: its models and assumptions, and then show computation of sample statistics. An example will exhibit the output from performance trial yields when the method is applied in one of the nine ecogeographic areas of fall-planted wheat in the Midwest. Results of comparable outputs over years forecasted which cultivars would become popular with growers in Kansa

Naprava male površine velikog naboja za otkrivanje radioizotopa

Objective: Radionuclide imaging is used to determine the distribution of radioactively labelled radiopharmaceuticals following application to establish the anatomy affected by a variety of neoplastic, metabolic and inflammatory conditions. This is accomplished through recording radioactive emissions using a gamma camera of a SPECT system, neither of which provides high resolution. The purpose o f this investigation was to determine whether a charge-coupled device designed for intraoral radiography could be modified to detect high energy emissions made by radiopharmaceutical agents. Methods: A RadioVisioGraphy (RVG) 32000 (Trophy Radiologie, Vincennes, France) with an unsealed sensor was employed so that the scintillator could be varied. The system was further modified to be activated by a CCX timer (Trophy Radiologie, Vincennes, France) disassociated from an x-ray generator. Radionuclides tested included 125I, 133Xe, 99mTc, 1311 and 60Co. Images were attempted of metallic test objects of known outline. Images were stored in a PC-compatible computer using the proprietary software provided by Trophy Radiologie for digital dental radiography. Results: Discernible images were found with Tc-99m calibrated at 900-925 mCi. No deterioration o f the sensor occured despite the high energy of the source, hence the tungsten glass fiberoptic prism of the RVG 32000 was effective in protecting the change-coupled device (CCD) from radiation damage. Conclusions: While further studies are needed, this preliminary study shows that there is a potential fo r using small surface CCDs for the detection of radiopharmaceuticals and, hence, to better localize the distribution of deposition within small cavities such as the mouth.Ciljevi: Slikanje radionukleidima uporabljeno je da bi se odredila distribucija radioaktivno označenih radiofarmaceutskih preparata nakon njihove primjene, s namjerom da se utvrdi područje zahvaćeno tumorom, metaboličkim ili upalnim procesom. To je ostvareno tako da je biljezeno radioaktivno zračenje gama kamerom ili SPECT sustavom od kojih ni jedan ne osigurava visoku rezoluciju. Svrha ovog istraživanja bila je odrediti, da li naprava male površine velikog naboja za intraoralnu radiografiju može biti modificirana za otkrivanje zračenja jake snage stvorenog radiofarmaceutskim preparatima. Metode. Radioviziograf (RVG) naprava tipa 32000 (Trophy Radiologie, Vincennes, Francuska) s nazaštićenim senzorom rabio se, da bi se omogućilo variranje scintilatora. Sustav se i dalje modificirao da se može aktivirati putem CCX timera (Trophy Radiologie, Vincennes, Francuska) koji nije povezan s generatorom x-zraka. Testirani su radionukleidi 125I, 133Xe, 99mTc, 1311 and 60Co. Učinjene su probne slike metalnih probnih objakata poznatog obrisa. Slike su se pohranile u PC- -kompatibilnom računalu koristeći program od Trophy Radiologie za digitalnu dentalnu radiografiju. Rezultati: Vidljive slike su nađene s 99mTc kalibriranim na 900-925 mCi. Nije došlo do smanjene kakvoće senzora bez obzira na visoku energiju izvora, dakle RVG 32000 tungsten staklena fiberoptička prizma bila je efikasna u štićenju naprave male površine velikog naboja od oštećenja zračenjem. Zaključci: Iako je potrebno dalje istraživanje, ovo je preliminarno istraživanje pokazalo, da postoji mogućnost uporaba naprave male površine velikog naboja za otkrivanje radiofarmaceutika te zato do bolje lokalizacije i distribucije njihova odlaganja unutar malih šupljina poput usne šupljine

Characterizing changes in soybean spectral response curves with breeding advancements

Citation: Christenson, Brent S., William T. Schapaugh, Nan An, Kevin P. Price, and Allan K. Fritz. “Characterizing Changes in Soybean Spectral Response Curves with Breeding Advancements.” Crop Science 54, no. 4 (2014): 1585–97. https://doi.org/10.2135/cropsci2013.08.0575.Soybean (Glycine max (L.) Merr.) crop yield has steadily increased in the past 60 yr due in part to breeding advances. Relations between canopy spectral reflectance to specific plant functions may help characterize the impact of breeding on soybean cultivar development. The objectives of this study were to: 1) find specific regions of the soybean canopy spectral reflectance response curves that show genotypic differences; and 2) determine the effect of the breeding process on spectral reflectance response curves of soybean cultivars. Canopy spectral reflectance measurements were taken on 20 maturity group III (MGIII) and 20 maturity group IV (MGIV) soybean cultivars ranging in release year from 1923 to 2010 (arranged in a randomized complete block design) in 2011 and 2012 in Manhattan, KS. Large genotypic differences were found among cultivars, especially in the green (500 nm–600 nm), red (600 nm–700 nm), and red-edge (700nm–730 nm) portions of the spectra. Reflectance in the visible (VIS) (400–700 nm), red-edge (700–730 nm), and near-infrared (NIR) (730–1305) portions of the spectra varied with year of release (YOR) among cultivars. The more recently released cultivars tended to have lower reflectance values in the VIS and red-edge spectra portions and higher values in the NIR portion of the spectra than earlier-released cultivars. Results also indicate that spectral reflectance in the NIR portion of the spectra are highly confounded with maturity and other agronomic traits. These results indicate that breeding advancement has had an impact on canopy spectral reflectance curves and the VIS and red-edge portions of the spectra may be a source of variation for further cultivar development and advancement

Genome-wide association analysis on pre-harvest sprouting resistance and grain color in US winter wheat

Citation: Lin, M., Zhang, D. D., Liu, S. B., Zhang, G. R., Yu, J. M., Fritz, A. K., & Bai, G. H. (2016). Genome-wide association analysis on pre-harvest sprouting resistance and grain color in US winter wheat. Bmc Genomics, 17, 16. doi:10.1186/s12864-016-3148-6Background: Pre-harvest sprouting (PHS) in wheat can cause substantial reduction in grain yield and end-use quality. Grain color (GC) together with other components affect PHS resistance. Several quantitative trait loci (QTL) have been reported for PHS resistance, and two of them on chromosome 3AS (TaPHS1) and 4A have been cloned. Methods: To determine genetic architecture of PHS and GC and genetic relationships of the two traits, a genome-wide association study (GWAS) was conducted by evaluating a panel of 185 U.S. elite breeding lines and cultivars for sprouting rates of wheat spikes and GC in both greenhouse and field experiments. The panel was genotyped using the wheat 9K and 90K single nucleotide polymorphism (SNP) arrays. Results: Four QTL for GC on four chromosomes and 12 QTL for PHS resistance on 10 chromosomes were identified in at least two experiments. QTL for PHS resistance showed varied effects under different environments, and those on chromosomes 3AS, 3AL, 3B, 4AL and 7A were the more frequently identified QTL. The common QTL for GC and PHS resistance were identified on the long arms of the chromosome 3A and 3D. Conclusions: Wheat grain color is regulated by the three known genes on group 3 chromosomes and additional genes from other chromosomes. These grain color genes showed significant effects on PHS resistance in some environments. However, several other QTL that did not affect grain color also played a significant role on PHS resistance. Therefore, it is possible to breed PHS-resistant white wheat by pyramiding these non-color related QTL

Genomic Selection for Processing and End-Use Quality Traits in the CIMMYT Spring Bread Wheat Breeding Program

Citation: Battenfield, S. D., Guzman, C., Gaynor, R. C., Singh, R. P., Pena, R. J., Dreisigacker, S., . . . Poland, J. A. (2016). Genomic Selection for Processing and End-Use Quality Traits in the CIMMYT Spring Bread Wheat Breeding Program. Plant Genome, 9(2), 12. doi:10.3835/plantgenome2016.01.0005Wheat (Triticum aestivum L.) cultivars must possess suitable end-use quality for release and consumer acceptability. However, breeding for quality traits is often considered a secondary target relative to yield largely because of amount of seed needed and expense. Without testing and selection, many undesirable materials are advanced, expending additional resources. Here, we develop and validate whole-genome prediction models for end-use quality phenotypes in the CIMMYT bread wheat breeding program. Model accuracy was tested using forward prediction on breeding lines (n = 5520) tested in unbalanced yield trials from 2009 to 2015 at Ciudad Obregon, Sonora, Mexico. Quality parameters included test weight, 1000-kernel weight, hardness, grain and flour protein, flour yield, sodium dodecyl sulfate sedimentation, Mixograph and Alveograph performance, and loaf volume. In general, prediction accuracy substantially increased over time as more data was available to train the model. Reflecting practical implementation of genomic selection (GS) in the breeding program, forward prediction accuracies (r) for quality parameters were assessed in 2015 and ranged from 0.32 (grain hardness) to 0.62 (mixing time). Increased selection intensity was possible with GS since more entries can be genotyped than phenotyped and expected genetic gain was 1.4 to 2.7 times higher across all traits than phenotypic selection. Given the limitations in measuring many lines for quality, we conclude that GS is a powerful tool to facilitate early generation selection for end-use quality in wheat, leaving larger populations for selection on yield during advanced testing and leading to better gain for both quality and yield in bread wheat breeding programs

Evaluation and Association Mapping of Resistance to Tan Spot and Stagonospora Nodorum Blotch in Adapted Winter Wheat Germplasm

Tan spot and Stagonospora nodorum blotch (SNB), often occurring together, are two economically significant diseases of wheat in the Northern Great Plains of the United States. They are caused by the fungi Pyrenophora tritici-repentis and Parastagonospora nodorum, respectively, both of which produce multiple necrotrophic effectors (NE) to cause disease. In this work, 120 hard red winter wheat (HRWW) cultivars or elite lines, mostly from the United States, were evaluated in the greenhouse for their reactions to the two diseases as well as NE produced by the two pathogens. One P. nodorum isolate (Sn4) and four Pyrenophora tritici-repentis isolates (Pti2, 331-9, DW5, and AR CrossB10) were used separately in the disease evaluations. NE sensitivity evaluation included ToxA, Ptr ToxB, SnTox1, and SnTox3. The numbers of lines that were rated highly resistant to individual isolates ranged from 11 (9%) to 30 (25%) but only six lines (5%) were highly resistant to all isolates, indicating limited sources of resistance to both diseases in the U.S. adapted HRWW germplasm. Sensitivity to ToxA was identified in 83 (69%) of the lines and significantly correlated with disease caused by Sn4 and Pti2, whereas sensitivity to other NE was present at much lower frequency and had no significant association with disease. As expected, association mapping located ToxA and SnTox3 sensitivity to chromosome arm 5BL and 5BS, respectively. A total of 24 potential quantitative trait loci was identified with −log (P value) \u3e 3.0 on 12 chromosomes, some of which are novel. This work provides valuable information and tools for HRWW production and breeding in the Northern Great Plains

A 1.8 million year history of Amazon vegetation

During the Pleistocene, long-term trends in global climate were controlled by orbital cycles leading to high amplitude glacial-interglacial variability. The history of Amazonian vegetation during this period is largely unknown since no continuous record from the lowland basin extends significantly beyond the last glacial stage. Here we present a paleoenvironmental record spanning the last 1800 kyr based on palynological data, biome reconstructions, and biodiversity metrics from a marine sediment core that preserves a continuous archive of sediments from the Amazon River. Tropical rainforests dominated the Amazonian lowlands during the last 1800 ka interchanging with surrounding warm-temperate rainforests and tropical seasonal forests. Between 1800 and 1000 ka, rainforest biomes were present in the Amazon drainage basin, along with extensive riparian wetland vegetation. Tropical rainforest expansion occurred during the relatively warm Marine Isotope Stages 33 and 31 (ca. 1110 to 1060 ka), followed by a contraction of both forests and wetlands until ca. 800 ka. Between 800 and 400 ka, low pollen concentration and low diversity of palynological assemblages renders difficult the interpretation of Amazonian vegetation. A strong synchronicity between vegetation changes and glacial-interglacial global climate cycles was established around 400 ka. After 400 ka, interglacial vegetation was dominated by lowland tropical rainforest in association with warmer temperatures and higher CO2. During cooler temperatures and lower CO2 of glacial stages, tropical seasonal forests expanded, presumably towards eastern Amazonia. While this study provides no evidence supporting a significant expansion of savanna or steppe vegetation within the Amazonian lowlands during glacial periods, there were changes in the rainforest composition in some parts of the basin towards a higher proportion of deciduous elements, pointing to less humid conditions and/or greater seasonality of precipitation. Nevertheless, rainforest persisted during both glacial and interglacial periods. These findings confirm the sensitivity of tropical lowland vegetation to changes in CO2, temperature, and moisture availability and the most suitable conditions for tropical rainforests occurred during the warmest stages of the Mid Pleistocene Transition and during the interglacial stages of the past 400 kyr

Winter Wheat Yield Response to Plant Density as a Function of Yield Environment and Tillering Potential: A Review and Field Studies

Wheat (Triticum aestivum L.) grain yield response to plant density is inconsistent, and the mechanisms driving this response are unclear. A better understanding of the factors governing this relationship could improve plant density recommendations according to specific environmental and genetics characteristics. Therefore, the aims of this paper were to: i) execute a synthesis-analysis of existing literature related to yield-plant density relationship to provide an indication of the need for different agronomic optimum plant density (AOPD) in different yield environments (YEs), and ii) explore a data set of field research studies conducted in Kansas (USA) on yield response to plant density to determine the AOPD at different YEs, evaluate the effect of tillering potential (TP) on the AOPD, and explain changes in AOPD via variations in wheat yield components. Major findings of this study are: i) the synthesis-analysis portrayed new insights of differences in AOPD at varying YEs, reducing the AOPD as the attainable yield increases (with AOPD moving from 397 pl m-2 for the low YE to 191 pl m-2 for the high YE); ii) the field dataset confirmed the trend observed in the synthesis-analysis but expanded on the physiological mechanisms underpinning the yield response to plant density for wheat, mainly highlighting the following points: a) high TP reduces the AOPD mainly in high and low YEs, b) at canopy-scale, both final number of heads and kernels per square meter were the main factors improving yield response to plant density under high TP, c) under varying YEs, at per-plant-scale, a compensation between heads per plant and kernels per head was the main factor contributing to yield with different TP.Fil: Bastos, Leonardo M.. Kansas State University; Estados UnidosFil: Carciochi, Walter Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Kansas State University; Estados UnidosFil: Lollato, Romulo P.. Kansas State University; Estados UnidosFil: Jaenisch, Brent R.. Kansas State University; Estados UnidosFil: Rezende, Caio R.. Kansas State University; Estados UnidosFil: Schwalbert, Rai. Kansas State University; Estados UnidosFil: Vara Prasad, P.V.. Kansas State University; Estados UnidosFil: Zhang, Guorong. Kansas State University; Estados UnidosFil: Fritz, Allan K.. Kansas State University; Estados UnidosFil: Foster, Chris. John Deer; Estados UnidosFil: Wright, Yancy. John Deer; Estados UnidosFil: Young, Steven. John Deer; Estados UnidosFil: Bradley, Pauley. John Deer; Estados UnidosFil: Ciampitti, Ignacio Antonio. Kansas State University; Estados Unido