bluuebunny/crossref_metadata_2025_split huggingface dataset:
Substitutions and Deletions of Genes Related to Grain Hardness in Wheat and Their Effect on Grain Texture
Authors: Tranquilli G. , Heaton J. , Chicaiza O. , Dubcovsky J. 
Published: July 2010

ABSTRACTThe Hardness (Ha) locus on chromosome 5D is the main determinant of grain texture in hexaploid wheat (Triticum aestivum L.). Puroindoline (Pina‐D1, Pinb‐D1) and Grain Softness Protein (Gsp‐D1) genes are tightly linked at this locus. Additional copies of the Gsp‐1 gene are present on chromosomes 5A and 5B. Mutations in the Pina‐D1 and Pinb‐D1 genes have been individually associated with grain hardness, but it is not known if mutations at both loci may further increase hardness or if additional copies may reduce it. In addition, there is no clear evidence of the effect of the Gsp‐1 genes on grain texture. To answer these questions, we compared the effect of different dosages of puroindoline and Gsp‐1 genes on grain texture. Isogenic substitution and deletion lines for homoeologous group 5 in ‘Chinese Spring’ (CS) were evaluated in two replicated field trials with 13 blocks each. Deletions or allelic variants of Gsp‐A1 and Gsp‐B1 did not produce significant effects on grain texture, suggesting that these genes do not have a critical role in grain hardness. Simultaneous deletions of Pina‐D1 and Pinb‐D1 in deletion line 5DS‐2 and substitution line CS (Red Egyptian 5D) resulted in significantly higher hardness index values than all other lines including CS (Timstein 5D) carrying a single Pina‐D1 deletion (P = 0.02). The incorporation of additional copies of Pina‐Am1 and Pinb‐Am1 from T monococcum L. in recombinant substitution line 5A/5Am in CS resulted in significantly softer grains than those from the CS control (P < 0.01).
Reactions of Smooth Bromegrass Clones with Divergent Lignin or Etherified Ferulic Acid Concentration to Three Fungal Pathogens
Authors: Delgado N. J. , Casler M. D. , Grau C. R. , Jung H. G. 
Published: July 2010

ABSTRACTIncreased digestibility of smooth bromegrass is associated with a reduction in lignin concentration or etherified ferulic acid (EthFA) concentration, either of which may reduce host resistance to fungal diseases. The objective of this study was to determine the relationship of lignin and EthFA concentration with disease reaction in smooth bromegrass. Host clones, divergently selected for lignin and EthFA concentration, were challenged by three pathogenic fungi, one biotroph (Puccinia coronata Corda) and two necrotrophs [Pyrenophora bromi (Died.) Drechs., anamorph = Drechslera bromi (Died.) Shoem., and Bipolaris sorokiniana (Sacc.) Shoem]. Significant positive and negative associations were found between lignin or EthFA and host reaction to P. bromi or B. sorokiniana The frequencies of these associations suggested that they arose by chance associations between alleles, rather than tight linkages or pleiotropic (causal) effects. Host reaction to P. coronata was consistently and negatively associated with lignin, less so with EthFA. These associations, together with results from other species, suggest that lignin, and perhaps EthFA, may be important components of rust resistance mechanisms in the Poaceae. If these mechanisms are real, they will cause considerable difficulty for breeders attempting to simultaneously improve both rust resistance and forage nutritional value.
Genetic Characterization of CIMMYT Inbred Maize Lines and Open Pollinated Populations Using Large Scale Fingerprinting Methods
Authors: Warburton Marilyn L. , Xianchun Xia , Crossa Jose , Franco Jorge , Melchinger Albrecht E. , Frisch Matthias , Bohn Martin , Hoisington David 
Published: July 2010

ABSTRACTThe International Maize and Wheat Improvement Center (CIMMYT) currently holds about 17 000 samples of maize (Zea mays L.) and teosinte (Z. mays, several subspecies), a wild relative of maize. Seven CIMMYT populations and 57 inbreds were characterized by simple sequence repeat (SSR) markers. SSRs chosen from almost every bin in the maize genetic map were tested for repeatability, ease of automation in allele calling, and discrimination (information content). Eighty‐five SSRs were found to be repeatable and easily automated, and were run on all material in the study. Fifty‐three of these SSRs were found to be the most discriminatory and will be used in future routine fingerprinting studies. The seven breeding populations clustered as would be predicted on the basis of pedigree and heterotic grouping. Genetic diversity within each population was significantly higher than diversity between populations, indicating that the populations are heterogeneous at the molecular level. The inbreds also showed a high level of genetic diversity, indicating that CIMMYT breeders have successfully incorporated considerable genetic diversity into CIMMYT maize germplasm. Only lines closely related by pedigree clustered together. Population of origin and heterotic grouping were not associated with the clusters formed on the basis of SSR markers, a result consistent with the high level of diversity within source populations of the inbreds. Although this will make it more difficult to assign CIMMYT inbred lines to currently existing heterotic groups by means of markers, the markers may be useful in refining the CIMMYT heterotic groups into additional and more uniform groups.
Development of Redroot Pigweed Is Influenced by Light Spectral Quality and Quantity
Authors: Rajcan Irena , AghaAlikhani Majid , Swanton Clarence J. , Tollenaar Matthijs 
Published: July 2010

ABSTRACTLight quantity (photosynthetic photon flux density, PPFD) and quality (red:far‐red ratio, R:FR) may affect phenological development of weed species growing under a crop canopy. An indoor study was conducted to quantify the effects of incident PPFD and R:FR on development and dry matter accumulation of redroot pigweed (Amaranthus retroflexusL.). Pigweed was grown in growth cabinets from the one‐leaf stage to the initiation of seed set under three different PPFD/R:FR treatments: (i) high PPFD (550 μmol m−2s−1) and high R:FR (1.4) (HH), (ii) low PPFD (180 μmol m−2s−1) and high R:FR (1.4) (LH), and (iii) low PPFD (180 μmol m−2s−1) and low R:FR (0.8) (LL). The experiment was undertaken at 12‐ and 16‐h daylengths with three replications. Rate of leaf appearance (RLA) was accelerated with an increase in PPFD (HH vs. LH) at both daylengths. The FR enrichment (LL) negated the effect of low PPFD on RLA under the 12‐h but not under the 16‐h daylength. Low PPFD delayed the occurrence of floral primordia, flowering and initiation of seed set. Plant height was a result of the complementary effects of PPFD and R:FR. Total dry matter accumulation and partitioning, with the exception of dry matter accumulation to the stem, were influenced by PPFD only. Results of this study show that both light quality and quantity influence the phenology of pigweed.
Using Satellite and Field Data with Crop Growth Modeling to Monitor and Estimate Corn Yield in Mexico
Authors: Báez‐González Alma Delia , Chen Pei‐yu , Tiscareño‐López Mario , Srinivasan Raghavan 
Published: July 2010

ABSTRACTThe large‐scale monitoring and estimation of crop yield is essential for food security in Mexico. This study developed and validated a method of monitoring and estimating corn (Zea maysL.) yield by means of satellite and ground‐based data. In autumn–winter 1999 and spring–summer 2000, eight locations under irrigated and nonirrigated conditions in corn valleys of Mexico were localized by Global Positioning Systems (GPS) and were sampled every 15 d. Photosynthetic active radiation (PAR), leaf area index (LAI), crop development stage (DVS), planting dates, and grain yield data were gathered from the field. The normalized difference vegetation index (NDVI) was derived from NOAA‐Advanced Very High Resolution Radiometer (AVHRR) images. A growth model was developed to integrate satellite and ground data. Net primary productivity (NPP) was estimated using PAR and NDVI. Dry weight increase (kg ha−1d−1) was determined considering NPP and the partitioning factor. Results indicated that the model accounts for 89% of the variability in yields under irrigated conditions and 76% under nonirrigated conditions. The methodology seems advantageous in large‐scale monitoring and assessment of corn yield.
Influence of Septoria tritici on Yield, Yield Components, and Test Weight of Wheat under Two Nitrogen Fertilization Conditions
Authors: Simón M. R. , Perelló A. E. , Cordo C. A. , Struik P. C. 
Published: July 2010

ABSTRACTNitrogen fertilization is required for achieving high yields in wheat (Triticum aestivum L.), but N may enhance the development of leaf blotch (Septoria tritici Roberge in Desmaz., teleomorph Mycosphaerella graminicola (Fuckel) J. Schröt. in Cohn). The present study was undertaken to investigate how Septoria leaf blotch affects yield, yield components, and test weight (TW) of different cultivars under different N supplies. Field experiments with six cultivars were carried out in a split‐split plot design during 1996 and 1997. Inoculation treatments were the main plots, N fertilization levels were the subplots, and cultivars were the sub‐subplots. Thousand‐kernel weight (TKW) was higher and TW lower in 1996 than in 1997. Interaction year × inoculation was not significant for any trait; year × fertilization was significant for yield and EPM2, and year × cultivar was significant for all traits except TKW. The separated analysis for each year indicated that additional N increased yield, EPM2, and KPE, but not TKW or TW. Inoculation with S tritici reduced yield and KPE, in both years and TKW, TW, and EPM2 in 1996. Differences between cultivars occurred for all traits except EPM2 in 1996. The percentage reduction in yield, yield components, and TW due to the inoculation was similar in fertilized and nonfertilized conditions, despite the increase in the area under disease progress curve (AUDPC) values by N fertilization in 1996. Cultivar differences in tolerance is suggested.
Turfgrass Evaluation of Native Grasses for the Northern Great Plains Region
Authors: Mintenko A. S. , Smith S. R. , Cattani D. J. 
Published: July 2010

ABSTRACTA range of native grass species evolved under the environmental extremes of a continental climate in the northern Great Plains, but most have not been evaluated for their suitability as turf. The objective of this research was to evaluate the turfgrass potential of a range of native grasses under three mowing heights. Twelve species (a total of 28 entries) were evaluated under three mowing heights (62, 38, and 18 mm), for turf quality, color, and density at two locations in Manitoba, Canada. The species evaluated included alpine bluegrass (Poa alpina L.), alkali grass [Puccinellia nuttalliana (Schult.) Hitchc.], alpine fescue [Festuca ovina L. var. brachyphylla (Schult. & Schult. f.) Piper, syn. F. brachyphylla Schult. & Schult. f.], blue grama [Bouteloua gracilis (Kunth) Lag. ex Griffiths], buffalograss {Buchloe dactyloides (Nutt.) Engelm. [= Bouteloua dactyloides (Nutt.) Columbus]} Canada bluegrass (Poa compressa L.), fescue spp., fowl bluegrass (Poa palustris L.), Idaho bentgrass (Agrostis idahoensis Nash), marsh muhly [Muhlenbergia racemosa (Michx.) Britton et al.], prairie junegrass [Koeleria macrantha (Ledeb.) Schult.], rough hairgrass {Agrostis scabra Willd. [= A. hyemalis var. scabra (Willd.) H. L. Blomq.]}, side‐oats grama [Bouteloua curtipendula (Michx.) Torr.], and tufted hairgrass [Deschampsia cespitosa (L.) P. Beauv.]. Entries showed similar results across all mowing heights. ‘Bad River’ blue grama, Minnesota ecotype blue grama, and ‘Barkoel’ prairie junegrass entries showed high quality ratings across all years and locations. Blue grama, a warm‐season grass, was drought tolerant and maintained consistent green color throughout the growing season. Although a number of the species showed promise, most entries will require a breeding and selection program before release as low‐maintenance turfgrasses.
Phosphorous Uptake and Concentration of Timothy Genotypes under Varying N Applications
Authors: Bélanger G. , Brégard A. , Michaud R. 
Published: July 2010

ABSTRACTImproving P uptake in timothy (Phleum pratense L.) would reduce excess soil phosphate while producing forage with greater P nutritional value. A strong relationship exists between N and P concentration in plants, and we hypothesized that genotypes characterized for contrasting N concentration or uptake may also exhibit contrasting P concentration and uptake. Two timothy populations derived from divergent selection for high and low forage N concentration were studied in Experiment 1. These two populations were also studied in Experiment 2, along with seven half‐sib families identified in a field study as having contrasting dry matter (DM) yield and N concentration. In both experiments, a reference population, ‘Champ’, was included and plants were grown in a growth room with varying N rates. Independent of applied N, the genotypes differed for P concentration, P uptake, and P to N ratio (P/N), in forage and total biomass, as well as for leaf P concentration, leaf weight ratio (LWR), root weight ratio (RWR) and efficiency of P uptake for each unit of root biomass (PUPEroot). Averaged across N rates in Experiment 2, forage P concentration among genotypes ranged from 4.1 to 5.1 g P kg−1 DM, while forage P uptake ranged from 10.0 to 14.6 mg P per plant. Variations in P uptake and concentration were related to genotypic differences in DM yield, leaf P concentration, LWR, and RWR. Phosphorus concentration and uptake decreased under N stress. We conclude that variation exists among timothy genotypes for P concentration and uptake.
Plant Density and Environment Effects on Orchardgrass–White Clover Mixtures
Authors: Sanderson M. A. , Elwinger G. F. 
Published: July 2010

ABSTRACTEarlier research indicated that orchardgrass (Dactylis glomerata L.) cultivars affected white clover (Trifolium repens L.) stolon structure during establishment. We conducted a field study to determine if plant density and environment modified the effect of orchardgrass cultivars on white clover. ‘Dawn’ and ‘Pennlate’ orchardgrasses were established at 10‐, 20‐, or 40‐cm spacings in mixture with ‘Will’ white clover in a systematic plant spacing design. Plots were established in September 1996 on a Hagerstown, Berks, or Rayne soil in central Pennsylvania. Orchardgrass was harvested monthly from May to September 1997 and 1998 to determine yield and tiller number per plant. White clover plants were dug from each plant spacing and site in the fall to determine stolon structure. Orchardgrass cultivar did not affect white clover stolon structure. Orchardgrass and white clover plants were larger and more complex on the Hagerstown soil than on the lower fertility Berks and Rayne soils. The highest stolon densities occurred at the 40‐cm plant spacing on the Hagerstown soil in 1998 with >22 m of main stolon m−2 along with 8 m of first‐order branches and 1 m of second‐order branches. On the Rayne soil, plant spacing had little effect on stolon structure. Weed competition was greater on the Rayne soil (788 plants m−2 from 33 species) than on the higher fertility Hagerstown soil (157 plants m−2 from 19 species). Interspecific competition, edaphic factors, and climate interacted to govern the structure of white clover stolons and overwhelmed orchardgrass cultivar effects.
Molecular Breeding for the Development of Blast and Bacterial Blight Resistance in Rice cv. IR50
Authors: Narayanan N. N. , Baisakh N. , Vera Cruz C. M. , Gnanamanickam S. S. , Datta K. , Datta S. K. 
Published: July 2010

ABSTRACTThe objective of this study was to improve IR50, an elite Indica rice line, by molecular breeding approach involving marker‐aided selection (MAS) and genetic transformation for resistance against blast (BL) and bacterial blight (BB). On the basis of BL pathogen population dynamics and lineage exclusion assays in southern India, the major BL resistance gene Piz‐5 can exclude most Pyricularia grisea Sacc. {= P. oryzae Cavara [teleomorph: Magnaporthe grisea (Hebert) Barr]} lineages. Resistant CO39 near‐isogenic line (NIL) C101A51 carrying Piz‐5 was used as the donor parent and IR50 as the recurrent parent in backcrossing up to four generations. BC4F1 plants were finally selfed to produce BC4F2 seeds. A polymerase chain reaction (PCR)‐based sequence‐tagged site (STS) marker RG64 was used to identify Piz‐5 in the segregating population and the resultant resistant progenies were obtained through phenotypic assays and MAS. To have further resistance to bacterial blight in this cultivar, these blast‐resistant isolines were transformed with Xa21, which is known to confer resistance to all races of Xanthomonas oryzae pv. Oryzae [= X. campestris pv. Oryza (Ishiyama 1922) Dye 1978] (Xoo). Stable integration and inheritance of the Xa21 gene were demonstrated by PCR and Southern blot analysis from three independent transformants. Bioassay data showed that transgenic IR50 is resistant to pathogens, M. grisea and Xoo. Apart from that, pedigree analysis and phenotypic studies with IR50 revealed the endogenous presence of the Xa4 gene, which may show an increased level of resistance to the BB pathogen along with the transformed Xa21 gene. This is the first report documenting the stacking of two major genes (Piz‐5 + Xa21) in rice using molecular breeding through MAS and transformation.
Design and Application of Microsatellite Marker Panels for Semiautomated Genotyping of Rice (Oryza sativa L.)
Authors: Coburn J. R. , Temnykh S. V. , Paul E. M. , McCouch S. R. 
Published: July 2010

ABSTRACTThe objective of this study was to develop a systematic and flexible method for assembling multiplex simple sequence repeat (SSR) marker panels for high throughput genome analysis in rice, Oryza sativa, and to test these panels on a set of cultivated rice germplasm. To do this, 159 microsatellite markers were fluorescently labeled and assembled into 21 multiplex panels for semiautomated genotyping, providing genome‐wide coverage of the 12 rice chromosomes. Panels are comprised of an average of eight markers each, occurring at approximately 11‐centimorgan (cM) intervals throughout the genome. On a standard set of 13 genetically diverse cultivars of Oryza, these markers detected an average of five alleles per locus and had a mean polymorphism information content (P.I.C. value) of 0.67. Polymerase chain reactions (PCR) were optimized on a per marker basis to generate a uniform amount of PCR product and each primer pair was assessed in replicated trials for reliability of allele size estimates. T4 DNA polymerase was used to treat PCR products where the standard deviation of allele molecular weight was greater than 0.5 base pairs (bp). This treatment minimized the variance so that, in the multiplex set reported here, the average std. dev./marker was 0.24 bp, allowing accurate discrimination of alleles that differed by a single nucleotide. The resulting data on allele sizes were then entered into GeneFlow analysis software for the evaluation of polymorphism patterns among diverse rice cultivars. The use of an automated software tool for designing multiplex panels on the basis of both highly polymorphic and more conservative SSR markers resulted in the development of a highly informative semiautomated genotyping system for applications in rice genetics and breeding.
Microsatellite Repeats in Common Bean (Phaseolus vulgaris)
Authors: Gaitán‐Solís E. , Duque M. C. , Edwards K. J. , Tohme J. 
Published: July 2010

ABSTRACTPhaseolus beans are distributed worldwide and are cultivated in the tropics, subtropics, and temperate zones. The common bean is the most important grain legume for direct human consumption in the world. The objectives of this study were to isolate microsatellite repeats and to establish their discriminatory power (DL) to be used in bean diversity characterization and mapping. We isolated, cloned, and sequenced genomic DNA fragments that contained microsatellite loci from three genomic libraries of Phaseolus vulgaris L. The polymorphism of the microsatellites was evaluated in a panel of 21 P. vulgaris genotypes made up of cultivated and wild beans from the Mesoamerican and Andean pools, and nine genotypes from four Phaseolus species. The number of alleles per microsatellite locus ranged from 1 to 14, with an average of 6 alleles per primer pair. Almost all the microsatellite loci showed high levels of discriminatory power, with the highest value being 0.94. These results indicate that microsatellites can be valuable genetic markers for assessing genetic diversity in the P. vulgaris. The high levels of polymorphism of these new bean microsatellites and their wide cross‐species transportability make these new markers useful for mapping and molecular characterization of Phaseolus species.
Estimation of Genetic Divergence among Elite Cotton Cultivars–Genotypes by DNA Fingerprinting Technology
Authors: Rahman M. , Hussain D. , Zafar Y. 
Published: July 2010

ABSTRACTEpidemics of cotton leaf curl virus disease (CLCD) was the compelling factor in the decision to devise new strategies for cotton breeding programs of Pakistan. The genetic similarity among the elite cotton (Gossypium spp.) cultivars released before the advent of CLCD epidemics was in the range of 81.5 to 93.41%. New cultivars were developed by crossing the exotic resistant germplasm (LRA‐5166, CP‐15/2, and Cedix) with adapted varieties highly susceptible to CLCD. A study was designed to assess the genetic relatedness or diversity among the newly released, extremely resistant and resistant cultivars. After screening 27 cotton genotypes by different diagnostic methods such as field evaluation, whitefly‐transmission studies, grafting, dot‐blot hybridization, and multiplex PCR using conserved primers sequences, 20 extremely resistant and resistant cultivars were selected for a random amplified polymorphic DNA (RAPD) analysis. The genetic similarity of the exotic germplasm with the elite cultivars was in the range of 81.45 to 90.59%. Similarly, the genetic relatedness among the elite cultivars was in the range of 81.58 to 94.90%. The average genetic similarity among all studied genotypes was 89.55%. We have demonstrated that only cultivar VH‐137 possesses a diverse genetic background. Our study suggests the need to breed for high genetic diversity to serve as a buffer against potential epidemics.
Genetic Diversity of Perilla and Related Weedy Types in Korea Determined by AFLP Analyses
Authors: Lee Ju Kyong , Nitta Miyuki , Kim Nam‐Soo , Park Cheol Ho , Yoon Kyung Min , Shin Young‐Boum , Ohnishi Ohimi 
Published: July 2010

ABSTRACTPerilla frutescens (L.) Britton var. frutescens is extensively cultivated on a large scale throughout the Korea, whereas var. crispa is not. The weedy types of both var. frutescens and var. crispa are often found along roadsides, waste lands, and around farmers' fields. Although Perilla is one of the important leafy vegetable and oil crops in Korea, systematic analyses on its genetic structure have been limited and are needed for future breeding progress. The objective of this study was to determine genetic diversity and relatedness in Korean accessions of Perilla. Field surveys and amplified fragment length polymorphism (AFLP) analyses were conducted to determine genetic diversity. Analyses of 30 Perilla accessions by seven AFLP primer combinations identified a total of 121 fragments, of which 72 (60%) were polymorphic at the species level. Shanon's index of diversity Hs of the AFLP variations for cultivated type of var. frutescens, weedy type of var. frutescens, and weedy type of var. crispa were 0.63, 2.00, and 1.75, respectively. The weedy type of var. frutescens exhibited the highest variation. Most of the AFLP variation (78%) resided within populations. In the phylogenetic tree, two major clusters were recognized: (i) cultivated type of var. frutescens and weedy type of var. frutescens and (ii) weedy type of var. crispa. Although the wild species of P. frutescens has not been identified, the weedy Perilla is the key taxon for our understanding of the origin of cultivated var. frutescens.