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171.
Said Ennahli Sorkel Kadir Houchang Khatamian David Scurlock Hafida Hanine 《International Journal of Fruit Science》2017,17(1):1-19
Simultaneous responses of American (Concord), European (Pinot Noir), and American-European hybrid (Traminette) cultivars to seasonal and diurnal variation in field environmental conditions were assessed to propose suitable cultivars for potential use for selection and breeding in grapevines in dry areas. ‘Pinot Noir’ had higher gas exchange parameters, higher water potential, and chlorophyll fluorescence, while ‘Concord’ had the lowest values in all three seasons and experienced moderate stress by the end of each season. The dry conditions in 2005 caused water potential to decline sharply compared to values recorded in 2004 and 2006. ‘Pinot Noir’ and ‘Traminette’ exhibited a mild stress, while ‘Concord’ exhibited a moderate stress in 2006. Photosynthetic rate decreased slightly during the summer with a slight recovery at the beginning of September, and did not differ across the seasons among cultivars. Stomatal conductance followed the same pattern. However, in both 2004 and 2005, stomatal conductance dropped sharply late in the season because of frequently occurring high temperatures that were greater than 32 °C. Maximum morning values of Fv/Fm were within the optimal range. The study suggests the presence of marginal photoinhibition during mid-summer in Concord cultivars, because no full recovery of photochemical efficiency early in the evening was observed. The European cultivar (Pinot Noir) and the American-European hybrid (Traminette) are more adapted to field conditions in Kansas than Concord cultivars. However, high cold-mortality of Pinot Noir due to high sensitivity to cold winter temperature makes the hybrid cultivars the most suitable cultivar for Midwest regions with relatively cold winters. 相似文献
172.
Teresa Mosquera Vásquez Sara Del Castillo David Cuéllar Gálvez Luis Ernesto Rodríguez 《Potato Research》2017,60(3-4):361-381
Global challenges like sustainable development, climate change, malnutrition and gender inequality can be tackled from an agricultural perspective. Micronutrient deficiency is a major problem for the health and food security of the population. In Colombia, iron deficiencies affect 32% of the children under the age of five; and 43% of the Colombian population have zinc and vitamin A deficiencies. We designed and implemented a research-for-development programme that links agriculture and nutrition through a two-stage project. In the first stage, we selected three new yellow potato cultivars with better nutritional contents, higher yield and better resistance to late blight than the traditional yellow cultivars. We characterized the Colombian germplasm, Solanum tuberosum Group Phureja, for its nutritional attributes. During this stage, studies of the social and nutritional status of the communities were also conducted. In the second stage, we focused on scaling up new potato cultivars to reach potato producers and consumers by promoting the production and marketing of good quality seed potatoes, by establishing four Rural Entrepreneurs Nuclei. The programme promotes gender equity, good dietary habits, the consumption of more nutritious potatoes and empowers local leadership to strengthen governance. Field work was conducted in southern and central regions of Colombia by employing social strategies such as the Family Farming Community Schools. In 50% of the cultivated area, we are replacing the originally used traditional yellow potatoes by the new, more nutritious, potatoes to reach 6 million consumers. A good quality seed system for small-scale potato growers has been implemented. These achievements have been reached through a comprehensive approach in a period of two years. 相似文献
173.
Krystina D. Mossop Nicholas P. Moran David G. Chapple Bob B. M. Wong 《Landscape Ecology》2017,32(5):1065-1078
Context
Dispersal has important fitness consequences for individuals, populations, and species. Despite growing theoretical insights into the evolution of dispersal, its behavioral underpinnings remain empirically understudied, limiting our understanding of the extent and impact of responses to landscape-level heterogeneity of environments, and increasing the risk of inferring species-level responses from biased population sampling.Objectives
We asked if predictable ecological variation among naturally fragmented arid waterbodies is correlated with disparate dispersal responses of populations of the desert goby Chlamydogobius eremius, which naturally inhabits two habitat “types” (permanent springs, ephemeral rivers), and different levels of hydrological connectivity (high and low) that potentially convey different costs and benefits of dispersal.Methods
To test for possible behavioral divergence between such populations, we experimentally compared the movement behaviors (correlates of emigration and exploration) of wild-caught fish. We used two biologically relevant spatial scales to test movement relevant to different stages of the dispersal process.Results
Behavior differed at both spatial scales, suggesting that alternative dispersal strategies enable desert gobies to exploit diverse habitat patches. However, while emigration was best predicted by the connectivity (flood risk) of fish habitats, exploration was linked to their habitat type (spring versus river).Conclusions
Our findings demonstrate that despite a complex picture of ecological variation, key landscape factors have an overarching effect on among-population variation in dispersal traits. Implications include the maintenance of within-species variation, potentially divergent evolutionary trajectories of naturally or anthropogenically isolated populations, and the direction of future experimental studies on the ecology and evolution of dispersal behavior.174.
Context
Sustained timber harvesting conflicts with the long-term viability of boreal caribou (Rangifer tarandus caribou) populations. The spatial arrangement of harvest blocks in the landscape could mitigate the impact of logging on caribou populations. For the forest industry, however, these measures represent constraints that reduce the annual allowable cut (AAC).Objective
Estimate the long-term impacts of spatial constraints to harvesting, applied alone or in combination, on AAC and boreal caribou populations.Methods
We divided a 30,000 km2 region into 20 harvest block sizes varying from 50 to 1000 km2, and modeled the implementation of spatially explicit harvest schedule plans in combination with wildfire and caribou population dynamics. We then evaluated the probability of persistence of boreal caribou populations.Results
The probability of maintaining an AAC target declined with increasing target AAC, increasing size of operating area, and increasing adjacency constraints. In contrast, the probability of maintaining caribou populations declined with increasing AAC, decreasing size of operating areas, and decreasing adjacency constraints. An increase in operating area size from 50 to 300 km2 produced a considerable gain in AAC for all adjacency constraints.Conclusions
Because adjacency constraints led only to a small increase in the probability of maintaining caribou populations, we recommend adopting less constraining landscape management actions, such as a 70-year period between two consecutive harvests in the same ~300-km2 operating area.175.
Kihoon Kim Jong Yoon Lee Hyun Kim Jaiho Shin Yongwon Shin Young Tai Yoo Hwi-Yool Kim 《Fibers and Polymers》2017,18(2):231-239
In recent decades, tremendous research has focused on the production of nanoscale fibers using synthetic polymers, with the goal of fabricating nanofibrous scaffolds for wound healing. However, the hydrophobicity of such polymers typically hinders attachment and proliferation of the cells. In this study, we combined poly-d,l-lactide-co-glycolide (PLGA) and small intestine submucosa (SIS) to fabricate blended nanofibers for wound healing by electrospinning. PLGA and SIS were dissolved in 1,1,1,3,3,3-hexafluoro isopropanol to produce different weight ratios of PLGA/SIS-blended nanofibrous membranes (NFM). Physicochemical characterization of the electrospun NFM was performed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, water contact angle analysis, degradation test and tensile testing. The PLGA/SIS-blended NFM showed improved hydrophilicity and tensile strength. Better infiltration, attachment and proliferation of rat granulation fibroblasts of PLGA/SIS-blended NFMs compared to PLGA NFMs were identified by morphological differences determined by SEM and a water-soluble tetrazolium salt assay kit. Based on our results, the PLGA/SIS blended NFMs were found to be suitable for use as a potential material for wound dressing. 相似文献
176.
Dennis N. Lozada R. Esten Mason Md Ali Babar Brett F. Carver Gina-Brown Guedira Keith Merrill Maria Nelly Arguello Andrea Acuna Lucas Vieira Amanda Holder Christopher Addison David E. Moon Randal G. Miller Susanne Dreisigacker 《Euphytica》2017,213(9):222
Genome-wide association studies (GWAS) are useful to facilitate crop improvement via enhanced knowledge of marker-trait associations (MTA). A GWAS for grain yield (GY), yield components, and agronomic traits was conducted using a diverse panel of 239 soft red winter wheat (Triticum aestivum) genotypes evaluated across two growing seasons and eight site-years. Analysis of variance showed significant environment, genotype, and genotype-by-environment effects for GY and yield components. Narrow sense heritability of GY (h 2 = 0.48) was moderate compared to other traits including plant height (h 2 = 0.81) and kernel weight (h 2 = 0.77). There were 112 significant MTA (p < 0.0005) detected for eight measured traits using compressed mixed linear models and 5715 single nucleotide polymorphism markers. MTA for GY and agronomic traits coincided with previously reported QTL for winter and spring wheat. Highly significant MTA for GY showed an overall negative allelic effect for the minor allele, indicating selection against these alleles by breeders. Markers associated with multiple traits observed on chromosomes 1A, 2D, 3B, and 4B with positive minor effects serve as potential targets for marker assisted breeding to select for improvement of GY and related traits. Following marker validation, these multi-trait loci have the potential to be utilized for MAS to improve GY and adaptation of soft red winter wheat. 相似文献
177.
Andrea C. Varella David K. Weaver Jason P. Cook Nancy K. Blake Megan L. Hofland Peggy F. Lamb Luther E. Talbert 《Euphytica》2017,213(7):153
Plant landraces have long been recognized as potential gene pools for biotic and abiotic stress-related genes. This research used spring wheat landrace accessions to identify new sources of resistance to the wheat stem sawfly (WSS) (Cephus cinctus Norton), an important insect pest of wheat in the northern Great Plains of North America. Screening efforts targeted 1409 accessions from six geographical areas of the world where other species of grain sawflies are endemic or where a high frequency of accessions possesses the resistance characteristic of solid stems. Resistance was observed in approximately 14% of accessions. Half of the lines displayed both antixenosis and antibiosis types of resistance. Among the resistant accessions, 41% had solid or semi-solid stems. Molecular genetic screening for haplotypes at the solid stem QTL, Qss.msub.3BL, showed that 15% of lines shared the haplotype derived from ‘S-615’, the original donor of the solid stem trait to North American germplasm. Other haplotypes associated with solid stems were also observed. Haplotype diversity was greater in the center of origin of wheat. Evaluation of a representative set of resistant landrace accessions in replicated field trials at four locations over a three year period identified accessions with potential genes for reduced WSS infestation, increased WSS mortality, and increased indirect defense via parasitoids. Exploitation of distinct types of plant defense will expand the genetic diversity for WSS resistance currently present in elite breeding lines. 相似文献
178.
Christopher J. Smallwood Jason D. Gillman Arnold M. Saxton Hem S. Bhandari Phillip A. Wadl Benjamin D. Fallen David L. Hyten Qijian Song Vincent R. Pantalone 《Journal of Crop Science and Biotechnology》2017,20(4):243-253
Soybean [Glycine max (L.) Merrill] yield and seed fatty acids, protein, and oil content are important traits for which an improved understanding of significant genomic regions would be useful. To accomplish this, a soybean population consisting of 203 F5 derived recombinant inbred lines (RILs) was developed and genotyped with 11,633 polymorphic single nucleotide polymorphisms (SNPs). Each RIL was grown in a single plot at Knoxville, TN in 2010; followed by replicated, multi-location field trials in 2013 and 2014. The data from 2010, 2013, and 2014 were analyzed together in order to detect quantitative trait loci (QTL) for these traits, and 30 total QTLs were detected. Five QTLs are candidates for confirmed status and one QTL is a candidate for positional confirmation. Many of the genes with mutations in close proximity to the fatty acid QTLs are involved in biological processes for fatty acids and/or lipids and could be considered possible candidate genes. Similarly, genes with mutations in genomic regions near yield, protein, and oil QTLs were plentiful and may contribute to the variation observed in these traits. Except for yield and stearic acid, each trait displayed pleiotropic effects with other traits in this study. Notable are the pleiotropic effects for oleic and linolenic acid on chromosomes 9, 13, and 19. Overall, the findings from this research contribute new information to the genetic understanding of soybean yield and seed fatty acids, protein and oil content. This understanding will be useful in making trait improvements. 相似文献
179.
Inja Naga Bheema Lingeswar Reddy Suk-Young Lee Yong-Jin Park Taek-Ryoun Kwon 《Journal of Crop Science and Biotechnology》2017,20(2):137-152
Salinity is one of the major abiotic stresses that severely effects rice production throughout the world. Previously, there have not been many studies which focused on studying diversity among rice germplasm based on specific physiological traits for salt tolerance. Our diversity study was based on physiological traits such as Na+ concentration, K+ concentration, K+/Na+ ratio, osmotic potential, and biomass which are major components determining salt tolerance. This study has systematically analyzed phenotypic data of 191 germplasms in two different salt concentrations apart from the control. The current study identified salt tolerant germplasms based on their response to a single physiological trait as well as a combination of different physiological traits. Some of the germplasm identified outperformed known salt tolerant cultivar Pokkali. This study identifies correlation among various physiological traits. The salt tolerant germplasms can be taken forward into developing better varieties by conventional breeding and exploring genes for salt tolerance. 相似文献
180.
Han-Yong Kim Jonghan Ko Seungtaek Jeong Jun-Hwan Kim Byunwoo Lee 《Journal of Crop Science and Biotechnology》2017,20(5):417-427
Determining effective measures to alleviate the impact of climate change on crops under various regional environments is one of the most urgent issues facing agriculture. In this study, geographic regions of South Korea for future-adjusted barley cultivation were outlined and the impact of climate change on barley production in the next 100 years was evaluated under two greenhouse gas concentration trajectory scenarios: the representative concentration pathway (RCP) 4.5 and RCP 8.5. To achieve our intended study goals, a geospatial crop simulation modeling (GCSM) scheme was formulated using CERES-barley model of Decision Support System for Agricultural Technology (DSSAT) crop model package version 4.6 to simulate grid-based geospatial crop yields. Two experiments were carried out at an open field to obtain model coefficients for the nation and at temperature gradient field chambers to evaluate the performance of the CERES-barley model under elevated temperature conditions. Suitable cultivation regions for three different types of barley (naked, hooded, and malting) under changing climate were projected to expand to the northern regions under both RCP 8.5 and RCP 4.5. However, they were projected to expand more rapidly under RCP 8.5 than those under RCP 4.5. Projected yields of four barley varieties were increased with a slow phase as year progressed under RCP 4.5 scenario. However, they were rapidly increased under RCP 8.5 scenario. It appears that geospatial variation in barley yield under changing climate can be effectively outlined. Therefore, GCSM system might be useful for determining impacts of climate change on geospatial variations of crops, potentially providing means to impede food insecurity. 相似文献