bluuebunny/crossref_metadata_2025_split huggingface dataset:
European Corn Borer Resistance in Half‐Sib Families from a Sorghum Random‐Mating Population1
Authors: Ross W. M. , Kindler S. D. , Kofoid K. D. , Hookstra G. H. , Guthrie W. D. , Atkins R. E. 
Published: July 2010

One hundred half‐sib families from a sorghum [Sorghum bicolor (L.) Moench] random‐mating population were artificially infested with European corn borer [Ostrinia nubilalis (Hubner)] egg masses, and the same families were treated with an insecticide to reduce natural infestation. A two‐replicate split‐plot design with treatments as whole plots and families as subplots was used for 2 years. Agronomic effects of insect damage were assessed, and a quantitative genetic analysis provided information for use in recurrent selection.Total grain yield (including that from lodged stalks and heads) was reduced 13.0% by infestation and subsequent damage, combine grain yield (excluding lodged stalks and heads) was reduced 18.4 %, and potential yield loss (excluding all unlodged stalks and unfallen heads with borer cavities plus lodged stalks and heads) was 48.7%. Weight of 100 seeds determined from total grain yield samples was reduced 7.9 % by infestation. Borer damage (breakage) traits generally had strong negative correlations with grain yield in the infested families.Total grain yield, combine grain yield, seed weight, and stalk breakage had heritabilities of 0.60, 0.64, 0.80, and 0.56, respectively, in the infested families. Selection for these traits, in the presence of borers, should initially improve a population for resistance to the European corn borer. Head damage was determined easily by hand breakage but had a heritability of only 0.32 because of a high family ✕ year interaction and a seemingly nonrandom distribution.
Interrelationships among Wheat Genes H3, H6, H9, and H10 for Hessian Fly Resistance1
Authors: Stebbins Nancy B. , Patterson F. L. , Gallun R. L. 
Published: July 2010

The resistance of ‘Elva’ wheat, CI 17714, (Triticum turgidum L. durum group) to biotype D of Hessian fly [Mayetiola destructor (Say)] was studied at the tetraploid and hexaploid chromosome levels at 20C. In testcross analysis at the tetraplold level, Elva wheat has two independent dominant genes that confer resistance to biotype D of Hessian fly. A backcross breeding scheme to common wheat (Purdue 5517 sel./2/‘Monon’/Elva) generated three resistant F4 common wheat selections, 812‐24 (named ‘Stella’), 817‐2, and 822‐34 (named ‘Ella’). Prior research showed Stella and sel. 817‐2 have two linked partially dominant genes 36 map units apart (designated H9 and H10). Ella has the H9H9 gene pair. The linked genes were separated using a BC1 test‐cross of Stella. Ella (H9H9) was used in crosses to distinguish lines derived from Stella that have the H9H9 or H10H10 gene pair. Ella was used in a similar manner with 817‐1 selections (817‐1 is a F4 sister line of 817‐2 but 817‐1 was heterozygous for reaction) to identify lines of 817‐1 that have the H9H9 or HIOHIO gene pair. Repulsion phase F3 line analysis revealed that H9 and HIO were independent.The H6 gene (in ‘Caldwell’) was found linked 2.02 ± 2.01 map units from H9 (in Ella). Thus the gene order on chromosome 5A wheat most likely is H3, H6, H9.
Oil and Protein in Field Crops Treated with Morphactins and other Growth Regulators for Senescence Delay1
Authors: Dybing C. Dean , Lay Charles 
Published: July 2010

Studies were conducted to determine whether growth regulators which delay senescence also affect oll and protein in flax (Linum usitatissimum L.), soybean [Glycine max (L.) Merr.], wheat [Triticum aestivum (L.) em. Thell.], and oats (Avena sativa L.). Treatment with a morphactin, chlorflurenol (methyl 2‐chloro‐9‐hydroxytiuorene‐9‐carboxylate), significantly increased percent oil in all four crops. Levels of increase were 0.1 to 0.3 percentage units for the cereals, 0.3 to 1.6 units for soybean, and 0.8 to 4.8 units for flax. Dichlorflurenol (methyl 2,7‐dichloro‐9‐hydroxyfluorene‐9‐carboxylate) also increased percent oil but to a lesser degree than chlorflurenol. Optimum treatments were 25 g/ha (chlorflurenol) and 100 g/ha (dichlorflurenol) applied postbloom for flax or at R6 stage for soybean, and 1000 g/ha (either chemical) applied 4 to 5 days postanthesis for the cereals. The increase in percent oil was consistent over several years of testing for flax and soybean. Percent protein declined as percent oil increased in flax and soybean but not in the cereals. Yield of oil per hectare was more closely associated with seed yield than with percent oil for all crops. As a result, oil yield of flax was significantly increased by chlorflurenol treatment in two of seven trials and significantly decreased in one trial.Seed size of flax declined as percent oil increased, except when treatment was late in the life cycle, when rate was reduced, or when dichlorflurenol was used instead of chlorflurenol. No relations between seed size and change in oil percent were observed for the other crops. Treatments which raised percent oil also delayed canopy yellowing for flax and soybean but not for the cereals. Iodine value of flax usually was not affected by morphactin treatment. Further research is needed to determine causes of the changes in chemical composition and to adapt the technique to commercial practice.
Effects of Generation and Method of Synthesis on Performance of Orchardgrass Cultivars1
Authors: McClain E. F. 
Published: July 2010

Commercial Syn‐1 seed produced by pollination among S1 or S1F1 (first‐generation increase of an S1 family in isolation) families of the parental clones of a conventional synthetic to produce generations designated here as 1‐Syn‐1 and 2‐Syn‐1, respectively, might more fully utilize heterosis. Effects of increased inbreeding in the parental populations, however, theoretically are not completely eliminated in the autotetraploid F1. Applicability of these considerations to orchardgrass (Dactylis glomerata L.) for forage yield, panicle production, and rust (Puccinia spp.) reaction was assessed by comparing Syn‐1, Syn‐2, Syn‐3, 1‐Syn‐1, and 2‐Syn‐1 generations of 29 experimental synthetics (clonal combinations) in three tests. Tests I, II, and III contained primarily two, four, and two parents per clonal combination, respectively.Generation means expressed as percent of the Syn‐1 and based on 2‐year forage yields were 91.3 (Syn‐2), 87.3 (Syn‐3), and 88.2 (1‐Syn‐1) in Test I and 100.2 (1‐Syn‐1) in Test II. Mean yields of the 1‐Syn‐1 and 2‐Syn‐1 as percent of the Syn‐3 were 113.3 and 107.1, respectively, in Test III. No consistent change occurred in panicle production or rust scores. Significant interactions for clonal combinations with generations occurred in Tests I and III for yield and rust and in Tests I and II for panicle production. Correlation coefficients between generations generally were significant only for panicle production and rust score. Although yield depression generally increased as inbreeding increased, selection of clonal combinations with attenuated inbreeding depression appears possible. However, selection of such combinations would tend to exclude the more productive Syn‐1's
Effects of Plant Density on the Performance of 10 Barley Cultivars
Authors: Baker R.J. , Briggs K.G. 
Published: July 2010

The effects of plant density on yield and related traits were studied in ten cultivars of spring barley, Hordeum vulgare L., to determine if selection in low density stands is effective in improving expression in dense stands. Five plant densities (1.6, 6.2, 25, 100, and 400 plants/m2) were evaluated in each of 3 years.Spikes/plant, shoot weight and grain yield were the only characteristics that had significant cultivar × density interactions. All three characteristics increased asymptotically as density decreased and did not show significant changes in cultivar rank.Interplant variability, although minimum at a density of 100 plants/m2 for spikes/plant, shoot weight and grain yield, showed a significant decrease at a density of 6.2 plants/m2 (40 × 40 cm) for all traits. Our results show that single plant selection may be most effective at plant spacings near 40 × 40 cm and that selection under low densities should be effective in improving dense seeding expression of yield and several related traits.
Comparative Growth Analysis of Two Spring Wheats and One Spring Barley1
Authors: Baker R. J. , Gebeyehou Getinet 
Published: July 2010

Two cultivars of spring wheat, Triticum aestivum L., cvs. ‘Neepawa’ and ‘Pitic 62’, and one cultivar of spring barley, Hordeum vulgare L., cv. ‘Bonanza’, were compared for grain yield and its relationship to patterns of leaf area development and dry matter accumulation. Each cultivar was planted at an early and a late seeding date at Saskatoon in 1980 and in 1981. Leaf area (cm2/plant) and biological yield (g/m2) were determined at weekly intervals commencing five weeks after seeding. Grain yield, components of grain yield, and final biological yield were measured at maturity. Grain yield was found to be a curvilinear function of final biological yield in Pitic 62 and Bonanza but the relationship appeared to be linear for Neepawa. Within a cultivar, higher biological yield gave higher grain yield.Bonanza barley produced more dry matter and greater leaf area than either wheat cultivar early in the season. This advantage disappeared as the crop approached maturity. Pitic 62, although having greater maximum leaf area index and greater leaf area duration than Neepawa, tended to have a similar pattern of dry matter accumulation early in the season. Pitic 62 had greater final biological yield and grain yield by virtue of its later maturity. Yield of wheat might be increased without delaying maturity by searching for types which grow quickly under cool spring conditions.
Comparison between Free‐Choice and No‐Choice Seedling Bulk Tests for Evaluating Resistance of Rice Cultivars to the Whitebacked Planthopper1
Authors: Saxena R. C. , Khan Z. R. 
Published: July 2010

During a screening of rice, Oryza sativa L., cultivars for resistance to the whitebacked planthopper Sogatella furcifera (Horváth) by the routinely used free‐choice seedling bulk test, a significantly higher insect population was observed to move over to the susceptible check cultivar soon after infestation. This uneven distribution of insects caused unbalanced infestation among the test cultivars. To avoid this shortcoming, a no‐choice seedling bulk test was conducted in which each row of test cultivar seedlings was excluded from the other by an intervening, vertical, mylar plastic partition, and was exposed to equal insect infestation. The resistance scores of 10 genetically diverse cultivars—‘Muskhan 41’ (Wbph 1), ‘N22’ (Wbph 1), ‘N32’ (Wbph 1), ‘ARC 10239’ (Wbph 2), ‘ADR 52’ (Wbph 3), ‘Podiwi A8’ (wbph 4), ‘Colombo’ (Wbph 2 + 1 recessive ?), ‘WC 1240’ (Wbph I + 1 recessive ?), ‘1R 2035‐117‐3’ (Wbph 1 + Wbph 2), and ‘Taichung Native 1’ (no resistance gene)—from free‐choice and no‐choice seedling bulk tests were compared. Podiwi A8 and N22, rated as moderately resistant and resistant in the free‐choice test, proved to be susceptible and moderately resistant, respectively, in the no‐choice test.The no‐choice test ensures an even distribution of test insects on cultivars and excludes any possibility of their escape from infestation. The technique has important implications in screening for resistance against a number of mobile insect pest species on a wide variety of plants.
Yield Potential, Plant Assimilatory Capacity, and Metabolic Efficiencies
Authors: Loomis R. S. , Amthor J. S. 
Published: July 2010

ABSTRACTThe structure, control, and efficiency of photosynthetic and respiratory systems are examined. Genetic control is complex and highly conserved. While many features are still unresolved, basic efficiency seems little altered by domestication and breeding of crops. Rubisco, the carboxylase–oxygenase enzyme central to photosynthesis and photorespiration, remains a weak point but may be amenable to improvement. However, the actual radiation‐use efficiency of crops is generally less than the potential with present rubisco kinetics, leaving considerable room for improvement without change in rubisco. Good opportunities for progress lie in definition of optimal canopies of leaves having suitable acclimation and photoprotection. The efficiency of the respiratory system also seems unaffected by plant breeding. Precise evaluation of the roles and efficiencies of the glycolytic pathway and the tricarboxylic acid cycle in production is difficult because, in addition to being sources of energy carriers and reductant, those systems also supply carbon skeletons for biosyntheses. How those systems are controlled and balanced for such diversions is largely unknown. The alternative oxidase found in mitochondria may be involved in that balance but its true role(s) is also unknown. Distinguishing two components of respiration, one related to maintenance and the other to growth, remains a powerful tool in theoretical studies. In such work, the respiratory system appears efficient, but proving that in experiments remains elusive.
Physiological and Genetic Changes of Irrigated Wheat in the Post–Green Revolution Period and Approaches for Meeting Projected Global Demand
Authors: Reynolds M. P. , Rajaram S. , Sayre K. D. 
Published: July 2010

ABSTRACTGlobal demand for wheat (Triticum aestivum L.) is growing faster than gains in genetic yield potential are being realized, currently a little under 1% per year in most regions. Improvement in yield of semidwarf wheat has generally been associated with increased harvest index (HI) and grain per square meter. For CIMMYT (International Maize and Wheat Improvement Center) varieties released between 1962 and 1988, yield increase was also associated with higher flag‐leaf photosynthetic rate and related traits, but not higher biomass. Nevertheless, significantly higher biomass has been reported in more recent CIMMYT lines. Improved HI is associated with higher N use efficiency (yield per unit of available N) and improved yield of semidwarf lines is expressed at high and low levels of N input. Where interplant competition for light and soil factors are manipulated, yield improvement is associated with adaptation to high plant density. Studies have confirmed that the juvenile spike growth phase is critical in determining both grain number and kernel weight (sink) potential. Improving assimilate availability during this stage, perhaps by lengthening its relative duration, may be one way to improve yield potential. Traits that could potentially be exploited for improving assimilate (source) capacity include early vigor, stay‐green, leaf‐angle, and remobilization of stem reserves. Use of alien chromatin is a successful approach for introducing yield‐enhancing genes into elite genetic backgrounds. Examples include the 1B/1R chromosome translocation from rye (Secale cereale L.), and more recently the LR19 segment from tall wheatgrass [Agropyron elongatum (Host) P. Beauv.] Improving the efficiency of early‐generation selection may be another strategy for raising yield potential by increasing the probability of identifying physiologically superior lines by techniques such as infrared thermometry and spectral reflectance.
Genetics of Soybean Agronomic Traits: I. Comparison of Three Related Recombinant Inbred Populations
Authors: Orf J. H. , Chase K. , Jarvik T. , Mansur L. M. , Cregan P. B. , Adler F. R. , Lark K. G. 
Published: July 2010

ABSTRACTMolecular markers provide a rapid approach to breeding for desired agronomic traits. To use them, it is necessary to determine the linkage between quantitative trait loci (QTLs) and such markers. The objective of this research was to determine such linkage in recombinant inbred (RI) soybean [Glycine max (L.) Merrill] populations. To do this, RI soybean segregants were characterized for molecular genetic markers and traits measured in several different environments. QTLs then were identified by interval mapping. Agronomic traits were measured and compared in large (about 240 segregants) RI populations derived from crosses between the cultivars Minsoy and Noir 1 (MN population), Minsoy and Archer (MA population), and Noir 1 and Archer (NA population). The MA and NA populations were grown together as two replications in each of four environments. Measurements from the MN population were reported previously and were taken from three replications grown in four environments. Traits measured were plant height, lodging, date of flowering, reproductive period, maturity, yield, seed weight, seed oil, seed protein, leaf length, and leaf width. Additional traits were derived from these primary measurements. Each of the three RI populations was also characterized by a large (>400) number of molecular genetic markers including RFLP (restriction fragment length polymorphism) and SSR (simple sequence repeat polymorphisms). QTLs were identified for all of the primary and derived traits at a significance level ≥LOD 3 on 17 of the 20 linkage groups and tended to be clustered on three. QTLs with major effects (R2 > 10%) were identified for all traits, and for many, these explained more than half of the heritable variation. Comparison of QTLs between the three RI populations established that for the majority of the traits, only two alleles could be identified. In only a few instances could a third allele be detected. Many of the significant QTLs identified in one population were confirmed in another. However, an almost equal number were found in only one population, suggesting that a dependence on the genetic background for expression (epistasis) was common.
Potential of Using Plant Row Yield Trials to Predict Soybean Yield
Authors: Hegstad J. M. , Bollero G. , Nickell C. D. 
Published: July 2010

ABSTRACTPlant row yield trials (PRYT) are measured as an indicator of yield potential for many private and public soybean breeding programs. To identify elite lines and develop new cultivars, the highest yielding PRYT lines are usually advanced to multiple replications in different environments. Early generation PRYT testing has the advantage of identifying elite lines in the initial phases of the selection process. The objective of this study was to determine if single row PRYT testing is a reliable predictor of yield in multiple environment advanced yield testing. In 1996, five F2:3 populations of crosses between different elite cultivars were grown as single row PRYT. After the 1996 PRYT test, the top 10, middle 10, and bottom 10 yielding PRYT lines from each population were selected for advanced testing in 1997 and 1998. Yield and yield rank correlations between selected 1996 PRYT and advanced yield testing were highest for the ‘Jack’ × ‘Resnik’ and ‘Asgrow A3733’ × ‘Burlison’ populations, respectively. Matrix analysis indicated that the lines selected from the Asgrow A3733 × Burlison population were the most stable when 1996 PRYT data are compared with advanced yield test data. Approximately five lines can be identified from each population that are the highest yielding in PRYT testing and advanced yield testing. Additionally, approximately five lines could be identified from each population that are the lowest yielding in PRYT testing and advanced yield tests. In the populations examined it can be concluded that early generation PRYT testing would allow for progress to be made in identifying elite soybean lines with high yield potential.
FISH and RFLP Marker‐Assisted Introgression of Festuca mairei Chromosomes into Lolium perenne
Authors: Chen C. , Sleper D. A. 
Published: July 2010

ABSTRACTPlant breeders and geneticists have attempted for several decades to combine perennial ryegrass (Lolium perenne L.) with fescue (Festuca spp.) to create novel forage grasses containing both high forage quality and good drought tolerance. Difficulty in selecting true hybrids with alien chromatin or chromosome addition–substitution has been a major barrier in Festuca × Lolium breeding programs. In this investigation, fluorescence in situ hybridization (FISH) and restriction fragment length polymorphism (RFLP) markers were used to monitor transfer of Festuca mairei St. Yves chromosomes into L. perenne through intergeneric hybrids. Among 64 hybrid plants of the BC1G1 generation (intercrossed progeny of first backcross to L. perenne), chromosome addition and substitution of F. mairei were identified by FISH using total genomic DNA of F. mairei as a probe. Forty‐two clones from a Pst I‐genomic DNA library of F. arundinacea Schreb. were used to screen for the presence of F. mairei DNA in the hybrid plants. These RFLP probes rapidly identified presence of the F. mairei genome in F1, F2, BC1, but not in BC2 plants. In contrast, genomic FISH on meiotic cells effectively detected any F. mairei chromosomes as well as chromosomal pairing relationships in any hybrid. By monitoring and selectively introducing F. mairei chromosomes into ryegrass, these molecular markers may accelerate the Festuca × Lolium breeding for improvement of ryegrass.
Using Amplified Fragment Length Polymorphisms and Simple Sequence Length Polymorphisms to Identify Cultivars of Brown and White Milled Rice
Authors: Bligh H. F. J. , Blackhall N. W. , Edwards K. J. , McClung A. M. 
Published: July 2010

ABSTRACTIncrease in world rice consumption combined with the recent World Trade Organization General Agreement on Trade and Tariffs agreement on import tariffs have resulted in a need for a method to distinguish between white milled rice (Oryza sativa L.) cultivars sold at a premium from other milled cultivars. We have used two DNA‐based methods, amplified fragment length polymorphisms (AFLPs) and simple sequence length polymorphisms (SSLPs), to distinguish six genetically related long‐grain rice cultivars, and a premium Basmati cultivar. Of the two methods, AFLPs proved difficult to reproduce due to the quality of DNA that could be extracted from the samples, while SSLPs showed sufficient variation to distinguish all seven cultivars with only a small number of markers. Our study demonstrates that, using white milled grains, SSLPs are a more robust and efficient method than AFLPs for the identification of rice cultivars. We also report the development of six new SSLP primer sets.
Soybean Canopy Development as Affected by Population Density and Intercropping with Corn: Fractal Analysis in Comparison with Other Quantitative Approaches
Authors: Foroutan‐pour Kayhan , Dutilleul Pierre , Smith Donald L. 
Published: July 2010

ABSTRACTTo better understand how crops intercept light, the complexity of plant structure needs to be characterized. Fractal analysis provides a novel approach for quantifying the geometric structure of individual plants. The objectives of this study were to determine (i) an appropriate methodology for estimating fractal dimension (FD) two‐dimensionally for complex three‐dimensional structures of plants such as soybean [Glycine max (L.) Merr.]; (ii) whether the temporal pattern of FD for soybean structure is altered by population density or intercropping with corn (Zea mays L.); and (iii) how the FD for soybean structure compares with other quantitative measures of shoot development. Soybean plants were randomly sampled in monocropped soybean and intercropped corn‐soybean plots grown at the same site in three successive years. Sampled plants were cut at the stem base, and leaf blades were immediately detached. Leafless plant structure was photographed from the side which allowed maximum appearance of branches and petioles. The FD was estimated two‐dimensionally from the scanned and processed images. Fractal dimension of soybean leafless structure increased with time for all treatments, coincident with the increasing complexity of structure as shoots developed. The rate of linear increase of FD with time varied among treatments. Leaf area per plant, plant height, and number of leaves per plant increased with time for all treatments, indicating a positive correlation with FD. In contrast, light penetration decreased during canopy development, and was negatively correlated with FD. Whereas leaf area evaluates the surface available for light interception, FD characterizes its geometric distribution in space.