bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic Variation in Physiological Discriminators for Cold Tolerance—Early Autotrophic Phase of Maize Development
Authors: Lee E. A. , Staebler M. A. , Tollenaar M. 
Published: July 2010

ABSTRACTEarlier spring planting to maximize the duration of the growing season has increased the importance of early‐season cold tolerance in maize (Zea mays L.). The objectives of this study were to assess the response of several physiological parameters associated with cold tolerance in maize during early autotrophic development and to quantify variability in the response to cold stress among 49 maize inbred lines. At the 7‐leaf tip stage, maize inbred lines were subjected to two day/night temperature regime treatments, 25/15°C (control) and 15/3°C (cold). Carbon exchange rate (CER), leaf chlorophyll content, quantum efficiency of Photosystem II, leaf conductance, dry weight, root/shoot ratio, and rate of development were measured at the 8‐leaf tip stage for genotypes under both treatments. The cold treatment effects were significant for all parameters except root/shoot ratio. Genetic diversity for most traits investigated was observed for the response of the inbred lines to cold stress. Results of this study show that leaf CER and rate of development are good discriminators of cold tolerance during early phases of development.
Nitrogen Application and Critical Shoot Nitrogen Concentration for Optimum Grain and Seed Protein Yield of Pearl Millet
Authors: Kennedy Charles , Bell Paul , Caldwell David , Habetz Bob , Rabb Jim , Alison M. A. 
Published: July 2010

ABSTRACTPearl millet [Pennisetum glaucum (R) Br.] is a promising alternative grain crop for the Southeast and mid‐South regions of the USA, but additional N fertility information is needed to optimize its production. Identification of a critical tissue N level at early growth stages is necessary to determine the need for subsequent applications of N. Field experiments were conducted to determine the response of hybrid ‘HGM 100’ grain yield, protein yield, and shoot N concentration to N application rate and to determine the relationship of grain yield and protein yield with shoot N concentration at different growth stages. Grain yield response to N fertilizer applications from 0 to 168 kg ha−1, in 34‐kg increments, varied among five field environments ranging from sandy loam to silty clay loam soils and resulted in a moderately low correlation (r2 = 0.36). Relative total protein yield was more consistent (r2 = 0.67). Tissue N concentration of shoots harvested 44 ± 4 d after seeding [early boot(EB)] was related to relative grain yield (r2 = 0.65). A critical N concentration of 31 g kg−1 dry matter (dm), determined by regression and “old” Cate–Nelson procedures, resulted in optimum grain yield. On a per hectare basis, total relative protein yield also correlated moderately high with shoot tissue N concentration at EB (r2 = 0.70). The use of Cate–Nelson procedures determined a critical N concentration in shoot tissue at EB of 32 g kg−1 dm. Determination of a critical N level at an earlier growth stage resulted in low correlations with yield parameters. On the basis of critical values at the EB stage, N amendments could possibly be applied in time to enhance some yield components, although the effective application window is narrow.
Effect of Priming Temperature on Storability of Primed sh‐2 Sweet Corn Seed
Authors: Chiu K. Y. , Chen C. L. , Sung J. M. 
Published: July 2010

ABSTRACTPriming offers a means to raise seed performance in many crop species, but the longevity of primed seed is generally decreased. The exact causes of the more rapid deterioration of primed seed are still not established. This study evaluated the effects of priming and storage temperatures on germination and antioxidative activities of sweet corn seed (Zea mays L.) carrying the shrunken‐2 (sh‐2) gene. Seed were solid‐matrix primed in moistened vermiculite at 10, 15 or 20°C for 36 h, then air‐dried to near original moisture level. Primed seed were stored at 25, 10, or −80°C for up to 12 mo. Solid‐matrix priming improved germination, reduced lipid peroxidation, enhanced antioxidative activities, and increased seedling growth. Seed longevity was decreased when 20°C‐primed seeds were stored at 25°C for 12 mo. Seed primed at 10 and 15°C had superior viability and vigor responses compared with nonprimed control seeds when they were stored at 25°C for 12 mo. Reduced storability of the 20°C‐primed seeds was attributable to enhanced peroxidation and decreased antioxidative activities. Storage at 10 or −80°C extended the storability of matrix primed sh‐2 seed for at least 12 mo. Enhanced antioxidative activity plays a role in maintaining the viability and vigor responses of solid matrix primed seed stored at cool (10°C) or subzero (−80°C) temperatures. Moreover, 10 or 15°C‐primed sh‐2 seed can retain viability for 12 mo, provided that the primed seed is stored at 10°C.
Tall Fescue Performance Influenced by Irrigation Scheduling, Cultivar, and Mowing Height
Authors: Richie W. E. , Green R. L. , Klein G. J. , Hartin J. S. 
Published: July 2010

ABSTRACTPrudent water management on turfgrass is an important issue. There is a need to define best management practices (BMPs), including optimal irrigation frequency for tall fescue (Festuca arundinacea Schreb.) when irrigated at a level that would be less than a typical industry practice of ETcrop/irrigation uniformity, where ETcrop = crop evapotranspiration = reference evapotranspiration (ETo) × crop coefficient (Kc). A 2‐yr field study was conducted in Riverside, CA, to determine if the visual quality of tall fescue could be improved during the warm season by altering irrigation frequency (two, three, or four irrigation events per week), cultivar selection (a dwarf cultivar, ‘Shortstop’ or a turf‐type cultivar, ‘Jaguar III’), and mowing height (3.8 or 6.4 cm) when irrigated at 80% ETcrop/irrigation uniformity. Volumetric soil water content at the 30‐, 61‐, and 91‐cm depths was also measured on each Jaguar III sub‐subplot. During the first year, visual quality was significantly higher for Jaguar III and the lower mowing height. During the second year, overall visual turfgrass quality was significantly highest for plots irrigated twice per week. Visual turfgrass quality was significantly correlated with soil water content. In summary, data from this study support recommendations for deeper, less frequent irrigation of established tall fescue grown on sandy loam soils in southern California interior valleys with an irrigation budget of 80% ETcrop/irrigation uniformity.
Relative NaCl Tolerance of Kentucky Bluegrass, Texas Bluegrass, and Their Hybrids
Authors: Suplick‐Ploense M. R. , Qian Y. L. , Read J. C. 
Published: July 2010

ABSTRACTGovernment regulations to force water conservation have escalated the use of secondary water high in soluble salts for turfgrass irrigation in the arid and semiarid western USA, thus increasing the need for more salt‐tolerant turfgrasses. This study was initiated to determine the variability in salt tolerance within and among two Poa species and their hybrids. Two experiments were conducted during 2000 in the greenhouse at Fort Collins, CO, in solution culture to examine the effects of NaCl on leaf firing and shoot and root growth reduction of nine Kentucky bluegrass (KBG; Poa pratensis L.) cultivars representing three ecotypes, three Texas bluegrass (TBG; P. arachnifera Torr.) accessions, and five of their hybrids (P. pratensis × P arachnifera). In Exp. I, conducted during late winter through spring 2000, overall salt tolerance based on leaf firing and electrical conductivity (EC) of 50% shoot growth reduction (ECshoot 50) placed seven KBG cultivars in the most tolerant group. In Exp. II, conducted during summer though early fall 2000, overall salt tolerance rankings placed 4 KBG and 3 TBG cultivars in the most tolerant group. On the basis of percentage leaf firing and the salinity levels that caused 25 and 50% shoot growth reduction, compact (low, compact growth habit) and aggressive (aggressive, lateral growth habit) KBG ecotypes showed more salt tolerance than common ecotypes in both Exp. I and II. A broad range of variability in leaf firing and shoot and root growth reduction in response to salinity was found to exist within and among these Poa species and their hybrids, indicating that improvement in the salt tolerance of bluegrasses may be possible. Additionally, differences in salt tolerance of KBG and TBG between Exp. I and Exp. II suggested that environmental conditions could affect bluegrass salt tolerance expression.
Modified Rapid DNA Extraction Protocol for High Throughput Microsatellite Analysis in Wheat
Authors: Hill‐Ambroz Kristi L. , Brown‐Guedira Gina L. , Fellers John P. 
Published: July 2010

ABSTRACTNew technology is allowing marker‐assisted selection to fulfill the promise of increasing efficiency of cultivar development. However, these techniques depend upon the ability to extract DNA from large populations of plants. The objective of this project was to develop a high‐throughput DNA extraction procedure without the need for greenhouse space or growing wheat (Triticum aestivum L.) plants. A sodium hydroxide rapid DNA extraction was modified for a 96‐well format to reduce costs. Seeds were germinated in 8‐well tissue culture plates, and 4‐d‐old seedling tissue was used to extract DNA by means of sodium hydroxide methodology. Approximately 1 μg of genomic DNA per 10 mg of tissue was isolated at a cost of about $0.10. The DNA quality was verified by amplification of microsatellite markers. Results were consistent with either fresh or stored tissue extracts. This technique allows one person to extract nearly 1000 storage‐stable DNA samples daily, while keeping costs at a minimum.
Variation of Condensed Tannins in Roundhead Lespedeza Germplasm
Authors: Springer T. L. , McGraw R. L. , Aiken G. E. 
Published: July 2010

ABSTRACTRoundhead lespedeza, Lespedeza capitata Michx., is a deep‐rooted, perennial legume native to the eastern and central USA and is relatively common on remnant upland prairies throughout the Midwest. Information on condensed tannin (CT) concentrations from different plant parts is needed for cultivar development and also to provide data for developing management and feeding strategies. The objectives of this study were to determine variation of CT concentrations in roundhead lespedeza leaves, stems, and inflorescences; evaluate genotype variation over environments; and select germplasm lines that could be used for breeding parents and/or bulked into a synthetic variety. Thirty‐nine roundhead lespedeza plant introductions (PI) were sampled from replicated nurseries grown in two environments in 1996. Plant shoots were collected at flowering and seed filling. Each plant shoot sample was divided into leaf, stem, and inflorescence. Condensed tannin concentrations were determined by means of a modified vanillin–HCl method. We found that variation due to the environment was low, variation due to genotype was high, and variation due to genotype × environment interaction was high. Of these 39 plant introductions, we selected eight that were common to both environments and had low CT concentrations in leaves at flowering. The CT content of these plant introductions, however, was still relatively high when compared with sericea lespedeza [Lespedeza cuneata (Dumont) G. Don] that was bred for low tannin content. Collections should be made from a larger geographical region to look for germplasm with lower CT concentrations.
Salinity Tolerance in Phaseolus Species during Early Vegetative Growth
Authors: Bayuelo‐Jiménez Jeannette S. , Debouck Daniel G. , Lynch Jonathan P. 
Published: July 2010

ABSTRACTThe genus Phaseolus includes important cultivated species as well as wild species with diverse ecological adaptations. Characterization of the ecological adaptations of the wild species would be useful for improved understanding, conservation, and utilization of these genetic resources. Salinity tolerance during vegetative growth was evaluated for 132 accessions for 14 wild Phaseolus species (P. acutifolius A. Gray, P. angustissimus A. Gray, P. carteri Freytag & Debouck, P. filiformis Bentham, P. glabellus Piper, P. leptostachyus Bentham, P. lunatus L., P. micranthus Hook & Arnold, P. microcarpus Mart, P. mcvaughii A. Delgado, P. oligospermus Piper, and P. vulgaris L.) and 11 accessions representing five cultivated species (P. acutifolius, P. coccineus L., P. lunatus L., P. polyanthus Greenman, and P. vulgaris) in nutrient solution containing 0 and 180 m M sodium chloride for 21 d. When plants were salinized after the emergence of the first trifoliate leaf, wild accessions of P. acutifolius, P. filiformis, P. lunatus, and P. vulgaris showed a wide range of variation in their salinity tolerance as defined by total dry weight reduction (PR) as a percentage of the unsalinized controls, salt susceptibility index (SSI), and root: shoot ratio (RSR). SSI and PR were correlated positively, indicating either trait could be used to select salt‐tolerant accessions. Cluster analysis revealed substantial intraspecific and interspecific variation in salinity tolerance. Salinity tolerance was observed in wild P. micranthus, P. mcvaughii, P. lunatus, cultivated P. coccineus, and several accessions of wild P. filiformis, and P. vulgaris Of these, P. filiformis was noteworthy in having 9 of 11 accessions rated as highly tolerant. Wild P. vulgaris was more salinity tolerant than the three cultivated P. vulgaris accessions included in the study. Many tolerant accessions originated in arid, coastal, or saline areas. We conclude that the genus Phaseolus has substantial diversity in salinity tolerance.
Assessment of the Genetic Diversity in Argentine Rice Cultivars with SSR Markers
Authors: Giarrocco L. E. , Marassi M. A. , Salerno G. L. 
Published: July 2010

ABSTRACTGenetic diversity of rice (Oryza sativa L.) cultivars that are historically significance to rice breeding and production in Argentina were evaluated at the DNA level. Sixty‐nine accessions were surveyed with 26 simple sequence repeat (SSR) markers revealing the genomic relationship among cultivars. A total of 219 polymorphic bands were detected. Cluster analysis based on pair‐wise comparisons of cultivar genetic similarities resolved the O. sativa accessions into two major O. sativa groups, indica and japonica, and the japonica group into the subgroups, tropical and temperate These clusters agree with the pedigree information available on the accessions and almost all Argentina‐released cultivars grouped within the japonica cluster. Application of DNA polymorphism analysis revealed genomic relationships in Argentine rice germplasm, generating a database useful for cultivar identification, local germplasm conservation, and breeding programs.
Determination of Cultivar Coefficients of Peanut Lines for Breeding Applications of the CSM‐CROPGRO‐Peanut Model
Authors: Suriharn B. , Patanothai A. , Pannangpetch K. , Jogloy S. , Hoogenboom G. 
Published: July 2010

ABSTRACTBreeding applications of a crop simulation model require cultivar coefficients for a large number of breeding lines, making the recommendation to determine these coefficients from field experiments conducted over several environments impractical. The objective of this study was to confirm our earlier findings that experimental data from only two seasons are sufficient to determine the cultivar coefficients of peanut lines for breeding applications of the CSM‐CROPGRO Peanut model. Seventeen peanut lines varying in yield level, seed type and maturity duration were selected for this study and were grown during the 2002 rainy and 2003 dry seasons. Data were collected on plant development and growth characteristics and were then used for model calibration to determine the cultivar coefficients of the individual peanut lines. A separate experiment was conducted in the dry season of 2004 for model evaluation. The calibration resulted in cultivar coefficients that provided simulated values of the various traits that were close to their corresponding observed values. Similar results were obtained for model evaluation with an independent data set. Differences among peanut lines were also expressed in the derived cultivar coefficients. These results confirmed our earlier finding that the cultivar coefficients of peanut lines derived from detailed experimental data for two seasons are sufficiently accurate for breeding applications of the CSM‐CROPGRO‐Peanut model.
Re‐examining the Relationship between Degree of Relatedness, Genetic Effects, and Heterosis in Maize
Authors: Lee E. A. , Ash M. J. , Good B. 
Published: July 2010

ABSTRACTThe dominance hypothesis is one of two major genetic hypotheses that have been proposed regarding heterosis in maize (Zea mays L.). This study examines two underlying tenets of the dominance hypothesis: (i) Dominant gene action must occur at many loci in order for heterosis to be expressed; and (ii) genetic diversity is a good predictor of heterosis (i.e., differences in gene frequency are required for the expression of heterosis). To examine these tenets, we used a unique set of genetic materials, sister‐line inbred lines. Sister‐line inbred lines are highly related inbred lines that are derived from a common parental cross. Three sets of six sister lines were used in this study, ranging between 47 and 77% identical‐by‐descent (IBD), creating a series of lines that potentially vary in gene frequency. The sister lines were mated using a partial diallel to form sister‐line hybrids. The sister‐line hybrids and the parental inbred lines were evaluated in replicated yield trials for grain yield, grain moisture, broken stalks, and test weight in five environments. The genotypic variance was partitioned using Gardner and Eberhart's Analysis III to examine additive and nonadditive genetic effects. Three relevant findings regarding heterosis for grain yield can be drawn from our results: Substantial genome‐wide heterozygosity is not a requirement for the expression of heterosis, there is not a consistent relationship between degree of relatedness and the magnitude of heterosis, and the presence of nonadditive genetic effects is not a requirement for the manifestation of heterosis.
Genotypic Correlation and Multivariate QTL Analyses for Cell Wall Components and Resistance to Stalk Tunneling by the European Corn Borer in Maize
Authors: Krakowsky M. D. , Lee M. , Holland J. B. 
Published: July 2010

ABSTRACTCorrelations between concentrations of cell wall components (CWCs) in the leaf sheath and stalk and resistance to stalk tunneling by the European corn borer (ECB) [Ostrinia nubilalis (Hübner)] have been reported in some maize (Zea mays L.) populations. Evaluations of resistance to ECB stalk tunneling (ECB‐ST) and concentrations of neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) have been performed on recombinant inbred lines (RILs) developed from the cross of maize inbred lines B73 (susceptible to ECB‐ST, low to moderate CWC concentrations) and DE811 (resistant to ECB‐ST, high CWC concentrations). The objective of this study was to estimate genotypic correlations between ECB‐ST and CWC concentrations and compare locations and effects of quantitative trait loci (QTL) for those traits. Genotypic correlations between ECB‐ST and CWCs were not significant, but clustering of QTL for ECB‐ST and CWCs was observed. Negative genotypic correlations between ECB‐ST and CWC concentrations were observed at some loci, and resistance to ECB‐ST may be associated with a subset of the QTL observed for CWCs and ADF in particular. Resistance to ECB‐ST may also be associated with starch concentration in the stalk, which could explain the detection of resistance alleles contributed by B73. Examination of temporal differences in CWC and starch concentrations, and marker‐assisted transfer of select alleles, could provide more information on mechanisms of resistance to ECB‐ST.
An Accelerated Postharvest Seed‐Coat Darkening Protocol for Pinto Beans Grown across Different Environments
Authors: Junk‐Knievel Donna C. , Vandenberg Albert , Bett Kirstin E. 
Published: July 2010

ABSTRACTPinto beans (Phaseolus vulgaris L.) that darken more slowly than conventional pinto beans would be more desirable in the market place and have been identified in the bean breeding program at the University of Saskatchewan. To incorporate the slow‐darkening trait into new cultivars there is a need for a quick, reliable, and inexpensive method to accelerate darkening without affecting seed germination. Three different accelerated darkening protocols were compared. The greenhouse protocol was conducted in the greenhouse by placing the bean seeds in plastic bags with a 1‐cm2 piece of moistened felt. For the ultraviolet C (UVC) light protocol, bean seeds were placed 10 cm below a 254‐nm UVC lamp. For the third protocol, bean seeds were placed in a cabinet set at 30°C, 80% relative humidity, and full fluorescent light. All three protocols examined could be used to distinguish darkening beans from slow‐darkening beans, however the UVC protocol was considered superior as it was quick, consistent over years, and economical and, unlike the greenhouse and the cabinet protocols, had no effect on seed germination. A genotype by environment (g × e) study was conducted to validate the UVC light protocol. After accelerated darkening, line and environment effects were found to be significant (P < 0.0001) but the g × e interaction was not significant (P = 0.29), which indicated that the UVC protocol could be used to distinguish slow‐darkening pinto beans from darkening pinto beans, regardless of where the beans were grown.
Pilot Scale Milling Characteristics of Transgenic Isolines of a Hard Wheat Over‐Expressing Puroindolines
Authors: Martin J. M. , Meyer F. D. , Morris C. F. , Giroux M. J. 
Published: July 2010

ABSTRACTWheat (Triticum aestivum L.) grain texture is an important determinant of milling properties and end product use. Two linked genes, puroindoline a (Pina) and puroindoline b (Pinb), control most of the genetic variation in wheat grain texture. Our goal was to examine milling characteristics of transgenic isolines of the hard red spring wheat cultivar Hi‐Line overexpressing Pina (HGA), Pinb (HGB), or both (HGAB), which have soft (HGAB and HGB), intermediate (HGA), and hard (Hi‐Line) grain texture. A second goal was to evaluate the flour quality of the genotypes for cookies and bread. Genotypes were grown in replicated trials in two environments. Grain was milled in a Miag Multomat pilot scale flour mill which closely emulates a commercial long flow mill. Stream yield and ash and protein content were determined from 10 flour and four bran streams. Cookie and bread quality was determined from straight grade flour. Break flour yield ranged from 404 g kg−1 for HGAB to 202 g kg−1 for Hi‐Line. Straight grade flour yield ranged from 711 g kg−1 for HGAB to 744 g kg−1 for Hi‐Line. Cumulative ash curves showed harder textured wheats (Hi‐Line and HGA) had greater ash content from break streams, but more horizontal slope than soft wheats (HGAB and HGB) for the portion of the curve describing the relationship between ash and flour extracted from the endosperm. Flours from the soft isolines, HGAB and HGB, suffered less starch damage than flour from intermediate HGA or hard Hi‐Line. Flours from HGAB and HGB were best suited for cookies. All three transgenic isolines overexpressing either or both puroindolines had smaller loaves of bread than Hi‐Line. Puroindolines directly impact milling properties and may indirectly affect end use properties such as cookie properties and loaf volume by modifying water hydration traits.