bluuebunny/crossref_metadata_2025_split huggingface dataset:
Yield Stability of Sorghum Random‐Mating Populations1
Authors: Kofoid K. D. , Ross W. M. , Mumm R. F. 
Published: July 2010

With the advent of random‐mating populations in sorghum [Sorghum bicolor (L.) Moench], recurrent selection techniques are being utilized. The success of recurrent selection procedures depends on the yield level and yield stability of the base population to which the selection method is applied. To determine yield level and yield stability, four random‐mating populations (two fertility restoring or R and two fertility nonrestoring or B), eight population crosses (combinations of R ✕ B and B ✕ R), and two F1 hybrids were tested in five environments. Although no group was clearly the most stable, the F1 hybrids had the highest yield and their coefficient for the regression of yield on an environmental index was nearest to unity. However, their deviation from regression was significantly higher than the pooled error. The population crosses, having the second best yield level and regression coefficient, the smallest deviation from regression, and presumably, the largest genetic variance for yield, were judged to be the most stable group.The analysis of variance showed significant differences for yield within the F1 hybrids, within the populations, and among the means of the F1's and the population material. In addition, a significant entry X environment interaction was found. This interaction was shown to be significant in its component terms of comparison ✕ environment (linear) among and within groups. These interactions indicated differences among and within groups for their response to a change in environment.Within each population type, the wide based population with a larger genetic variance for yield was as stable as its narrower based counterpart. These wider based populations should respond successfully to population improvement techniques.
Nonstructure Carbohydrate and Dry Matter Relationship in Alfalfa Tap Roots1
Authors: Wolf D. D. 
Published: July 2010

Total nonstructural carbohydrates (TNC) in the fleshy tap root are often used as an indicator of the physiological status of perennial forage plants such as alfalfa (Medicago sativa L.). TNC determinations involve considerable time and expense after the root samples are obtained. An alternative gravimetric method is pro. posed that involves determining percentage dry matter (DM). Tap roots are dug from the field, and the crown and lateral roots are removed. The remaining root is trimmed to a 10‐cm length, cleaned free of soil, and soaked in water for 2 hours. Root segments are blotted dry with paper towels and weighed (saturated weight). Roots are then oven dried and weighed (dry weight). Dry matter is expressed as a percentage of saturated weight.Experiments conducted over 11 years under a wide range of varieties, plant ages, management practices, and sampling dates indicate highly significant correlations (r2 ranged 0.70 to 0.96) between TNC and DM. TNC and DM show similar cyclic patterns caused by plant growth and degree of defoliation. An equation for predicting percent TNC values from percent DM was determined from linear regression analysis.
Cytoplasmic‐Genotypic Effects in the GT 112 Maize Inbred with Four Cytoplasms1
Authors: Rao A. P. , Fleming A. A. 
Published: July 2010

The study of cytoplasmic effects on the expression of agronomic characters is important in learning about cytoplasmic‐nuclear interactions and their influence on breeding and genetic programs. The genotype of the longtime maize (Zea mays L.) inbred, GT 112, was backcrossed six or seven times into three cytoplasms other than its own. Thus, each cytoplasmic source of seed was assumed to have the same nuclear genotype.The four cytoplasms, studied previously in a double‐cross hybrid, were compared in inbred GT 112 in all possible combinations for 2 years with 10 replications per year. Significant differences among the cytoplasms occurred for germination, number of dead seedlings due to Fusarium sp., diseased plants, plant vigor, color, leaf rolling, date of tasseling and silking, plant and ear heights, yield, and grain quality.Certain combinations of cytoplasm and inbred genotype gave more desirable performances than others under certain environments. There was a significant or highly significant interaction for year ✕ cytoplasm within pairs for all of the characters tested 2 years except for germination and number of plants before thinning.Results from these experiments provide further support for cytoplasmic effects on agronomic characters in maize. They also emphasize that the environment can influence the performance of a cytoplasm from one year to another.
Growth Analysis of Tall Fescue Genotypes Differing in Yield and Leaf Photosynthesis1
Authors: Wilhelm W. W. , Nelson C. J. 
Published: July 2010

Relationships between leaf photosynthesis and yield have not been well defined in forage grasses. Therefore, leaf growth, dry matter distribution, carbohydrate concentration, and growth analysis of four genotypes of tall fescue (Festuca arundinacea Schreb.) were examined. Genotypes, selected in the field for high and low CO2 exchange rate (CER) in combination with high and low yield, were compared in an attempt to study the relationship between photosynthesis and yield.In the vegetative growth stage, high yielding genotypes produced greater amounts of all plant parts (leaves, stem bases, and roots) than did low yielding genotypes; however, low yielding genotypes produced more leaf tissue relative to total increase in plant dry weight than did high yielding genotypes. Water‐soluble carbohydrate (WSC) concentrations of plant parts were significantly different among genotypes, with high‐CER genotypes having highest levels during early stages of regrowth. High yielding genotypes had highest WSC concentrations at later stages regardless of CER rating.Mean relative growth rates of the four genotypes were similar. Mean net assimilation rates and mean relative leaf area growth rates tended to be greater for the high yielding genotypes than for the low yielding genotypes. Results indicated the greater yields exhibited by the high yielding genotypes regardless of CER rating resulted from (1) greater carbohydrate reserves to initiate new leaf growth, (2) more rapid leaf area development, and (3) partitioning a greater amount of newly assimilated dry matter into leaf tissue during the first 16 to 19 days of regrowth.
Screening Field Peas for Resistance to White Mold1
Authors: Blanchette Bonnie L. , Auld Dick L. 
Published: July 2010

Breeding lines and plant introductions were screened in a greenhouse to determine if genetic resistance to white mold (Sclerotiorum sclerotiorum (Lib) de Bary) exists in field pea (Pisum sativum L.). All experiments were conducted in mist chambers maintained at approximately 18 C and 90% relative humidity. Eleven‐day‐old seedlings were inoculated by placing one fungus infested oat kernel next to the base of each stem. Three days after inoculation, disease severity was determined by estimating the length of stem lesions.Significant differences in disease severity were detected by this visual scoring method. The following plant introductions, breeding lines, and cultivars were more resistant than the susceptible check (‘Garfield’): PI 155109, PI 166188, PI 189171, PI 261622, PI 262189, PI 263027, PI 272191, PI 272205, PI 272209, ID 89‐1, ID 2, Dark Skin Perfection, Perfection 132, and Wisconsin Perfection.
Protein Content and Composition of Karl and Related Barleys1
Authors: Burger W. C. , Wesenberg D. M. , Carden J. E. , Pawlisch P. E. 
Published: July 2010

The six‐rowed malting barley (Hordeum vulgare L.) cultivar ‘Karl’, which is lower in protein than other malting barleys, was studied to determine how its protein composition differed from that of other six‐rowed barleys. Karl and one of its parents, CI 7147, had significantly lower concentrations of total protein and hordein than ‘Traill’ its other parent, closely related cultivars ‘Good Delta’ and ‘Everest’, and ‘Larker’, a check cultivar. The “Karl‐type” barleys tended to have a greater proportion of salt‐soluble proteins than the other barleys, but glutelin and residual proteins did not differ markedly between the two types.Lysine concentration of the grain averaged 4.1 g/100 g protein in four Karl‐type barleys and 3.4 in seven non‐Karl type barleys, but lysine concentrations on a sample basis (g amino acid/100 g barley, dry basis) were 0.52 and 0.54, respectively. Under conditions of varied N uptake, hordein was the major repository of protein N in Karl barley. In this respect Karl is similar to other barleys.
Dry Matter Accumulation in Maize Hybrids Near Isogenic for Endosperm Mutants Conditioning Protein Quality1
Authors: Baenziger P. S. , Glover D. V. 
Published: July 2010

Six near isogenic genotypes of four maize (Zea mays L.) single‐cross hybrids were grown in a randomized complete block design with a split‐split‐plot arrangement of treatments with four replications. The genotypes were sugary‐2 (su2), waxy (wx) and opaque‐2 (o2), the double mutant combinations [sugary‐2 opaque‐2 (su2 02) and waxy opaque‐2 (wx o2)], and the normal counterpart. The plants in each plot were sib‐pollinated twice by hand to insure full seed sets. Harvests were made at 7‐day intervals beginning 10 days after pollination (DAP) and continuing through 73 DAP. The purpose of this experiment was to determine the effect of the six genotypes on kernel dry matter accumulation (grain weight), cob weight, and grain moisture percentage during the grain filling period.On the average su2, o2, wx o2, and su2 02 accumulated 13, 18, 20, and 25% less grain weight than normal. The reduction in kernel dry matter accumulation was the result of shorter grain filling periods and less rapid rates of grain filling during the reproductive phase. Waxy accumulated 4% less grain weight than normal. The lower grain weight accumulation of wx was because of a less rapid rate of grain filling and not because of a shorter grain filling period. Opaque‐2 and su2 o2 showed a 9 and 11% reduction of cob weight, respectively, compared to the normal hybrids throughout development. Waxy, wx o2, and su2 hybrids were similar to normal in cob weight accumulations. All of the genotypes retained a higher moisture percent during development than their normal counterpart hybrids. However, on the average, 02 was not significantly different in moisture than normal at 73 DAP.
A Dynamic Model for Plant Growth: Adaptation for Vegetative Growth of Soybeans1
Authors: Wann Mien , Raper C. David 
Published: July 2010

A dynamic model for vegetative plant growth has been constructed with a set of nonlinear, ordinary differential equations. The model accepts photosynthetically active radiance (PAR) between 400 and 700 nm wavelengths as input and quantitatively predicts the partitioning of photosynthate to leaves, stems, and roots over a normal range of temperatures. The parameter values for the model which were not measured were estimated with data from an experiment in controlled environment rooms. A determinate cultivar of soybean (Glycine max (L.) Merrill ‘Ransom’) was grown at day/night temperatures of 18/14, 22/18, 26/22, 30/26, and 34/30 C; PAR of 75.0 nE cm‐2sec‐1 during a 9‐hour light period; and CO2 concentration of 400 µliter liter‐1. An interruption in the middle of the dark period by incandescent lamps was used to prevent floral induction. Plants from all treatments were sampled at approximately 2‐day intervals for measurement of total leaf area and dry weights of leaves, stems, and roots.A comparison of calculated and measured dry weights for soybean plants demonstrated that the model, which previously had been adjusted for simulation of growth for tobacco (Nicotiana tabacum L.), is capable of describing growth of soybeans. Only minor modification of functional forms and parameter values were required for adaptation of the model for simulation of soybeans.
Growth, Development, and Cold Tolerence of Fall‐acclimated Cereal Grains1
Authors: Fowler D. B. , Carles R. J. 
Published: July 2010

Areas of adaptation of winter cereals are determined primarily by each species' ability to tolerate cold. These differences in cold hardiness were investigated during fall acclimation of spring and winter cultivars of rye (Secale cereale L.), wheat (Triticum aestivum L.), barley (Hwrdeum vulgwre L.), and oats (Avena sativa L). Material for these studies was acclimated under field conditions in the fall of 1972, 1975 and/or 1977 at Saskatoon, Sask., Canada.Spring cultivars ocasionally demonstrated a limited ability to acclimate to cold. The maximum cold hardiness attained by the hardiest cultivar of each species when fully acclimated was −13, −15, −21, and −30 C for. oats, barley, wheat, and rye, respectively.During acclimation, crown and shoot dry weight increased and days to head and percent crown water decreased for most of the cultivars considered. In both spring and winter cultivars, dry matter accumulated at a rate which would suggest that energy production during the acclimation period was not a limiting factor for cold acclimation under normal fall field conditions. Percent crown water was closely associated with cold hardiness for comparisons within species. However, there were differences in the responses among species indicating that acclimation to cold was more complex than simply the regulation of tissue water content.
Improving Corn Population for Grain Yield and Resistance to Leaf Blight and Stalk Rot1
Authors: Miles J. W. , Dudley J. W. , White D. G. , Lambert R. J. 
Published: July 2010

Estimates of among and within half‐sib family varl. ance components for disease scores in each of two corn (Zea mays L.) populations were obtained from artificially inoculated experiments in 1, 2, or 3 years. These estimates were used to predict response to mass, half‐sib, and S1 selection for resistance to northern corn leaf blight (caused by Helminthosporium turcicum Pass.), Diplodia stalk rot [caused by Diplodia maydis (Berk.) Sacc.], and anthracnose leaf blight and stalk rot [caused by Colletotrichum graminicola (Ces.) Wils.]. In addition, among half‐sib family variance component estimates for yield were obtained from unlnoculated experiments for the same families. Genetic correlations among yield and reactions to the four diseases were estimated.Per‐year predicted gains in ieaf blight resistance for mass selection with pollen control were greater than for either S1 or half‐sib family selection (with 20 plants per family). Per‐year predicted gain for mass selection‐for stalk rot resistance was greater than that for half‐sib family selection (20 plants per family), For a given selection intensity and effective population size, predicted gain in stalk rot resistance for mass selection with pollen control is about equal to that for S1 selection at a great reduction in the number of plants rated for disease reaction and at no increase in the required number of hand pollinations.Genetic correlations between grain yield in the absence of disease and disease reactions were all near zero and nonsignificant. All significant genetic correlations among disease reactions were positive. These results suggest that mass selection would be the most efficient method of improving disease resistance in corn populations and that such improvement would not affect yield potential of the populations if adequate effective population size is maintained.
Facultative Apomixis in Buffelgrass1
Authors: Sherwood R. T. , Young B. A. , Bashaw E. C. 
Published: July 2010

We studied embryo sac morphology, chromosome number, reproductive behavior, and phenotype of buffelgrass (Cenchrus ciliaris L.) line 18‐35 to obtain further evidence regarding the occurrence of facultative apomixis in the species. Line 18‐35 is an F1 llne derived from a cross of obligately sexual TAM‐CRD B‐Is with an apomictic plant from Africa. Within line 18‐35, pistils with single sexual embryo sacs of the Polygonum type occurred at a low frequency in the same inflorescences as pistils with aposporous apomictic embryo sacs of the Oenothera type. Some pistils contained a sexual sac and one or more aposporous sacs. A sample of 2,057 pistils from three field plantings and one greenhouse planting had 85.8% apomictic pistils, 5.8% sexual pistils, and 8.4% mixed pistils. Frequency of sexual pistils differed between sampling dates of one field, indicating that environment may have influenced embryo sac type.In a spaced planting of 1,292 open‐pollinated progeny of 18‐35, 1,252 progeny resembled the maternal parent, and 40 progeny were offtype. Line 18‐35 and 21 of the offtype progeny were tetraploid (2n = 36). Four of these offtype tetraplold progeny produced primarily or exclusively sexual pistils. The 21 offtype tetraplold progeny probably originated by fertilization of reduced eggs. Fifteen offtype progeny were hexaploid and were believed to originate by fertilization of unreduced eggs. We concluded that line 18‐35 is facultatively apomictic.
Stormproof Boll in Upland Cotton. II. Heritability and Agronomic Relationships1
Authors: Quisenberry J. E. , Dilbeck R. E. , Roark Bruce 
Published: July 2010

The stormproof boll is an important characteristic of cotton (Gossypium hirsutum L.) cultivars grown in regions where severe weather prevails after bolls open and where once‐over stripper‐type harvesters are used. The objectives of the study were to determine the heritability of the stormproof trait and to evaluate the relationships among stormproofness and other agronomic and fiber characteristics. A composite cross population was developed from six stormproof and four nonstormproof cultivars. From this population, 79 random F3 plants were advanced by self‐pollination to the F4 and F5 generations. The study was conducted at two locations in 2 years.At both locations the mean stormproofness of the F4 was significantly larger (by 1.5%) than the mean of the F5 in the same year, indicating residual dominance of the stormproof boll after three generations of selling in the population. Heritability was high for the stormproof trait when calculated by parent‐offspring regression, but was more consistent over locations and years when it was calculated in standard deviation units. Of the 10 agronomic and fiber traits measured, seed size, fiber length, and fiber strength exhibited a consistent positive association with stormproofness. High stormproof values were related to larger seed and longer, stronger fiber. We speculate that the relationships with fiber length and strength were associated with the tendency of fiber in stormproof bolls to be caught in the folds of the carpel walls. Positive correlations between lint yield and stormproofness at both locations in a year with severe environmental stress was explained as a physical holding of the fiber in the boll (rather than as a genetic effect).
Improvement of Sugarcane Fertility by Modification of Cross‐pollination Environment1
Authors: Berding Nils , Skinner J. C. 
Published: July 2010

For routine cross‐pollinatlon of sugarcane (Saccharum sp.), the Queensland Bureau of Sugar Experiment Stations maintains cut flowering stalks in sulfurous acid solution, with panicles enclosed in sheltered, pollen‐proof, cotton bags (lanterns) that are hung in roofed sheds sheltered from wind by light forest. Experiments were conducted in 1975 and 1977 to determine whether seed setting could be improved by modifying the lantern environment (temperature, relative humidity, and light) or by relocating the lanterns. Eight treatments were assessed with a factorial polycross of four female and four male clones, each male being isolated in a separate lantern. When pollination finished, spikelet availability on each panicle and the condition (healthiness) of each flowering stalk were subjectively assessed. Age at harvest, “seed” yield, germination/1 g “seed” sample, and total number of seeds germinated were determined for each panicle. Males were also assessed for pollen fertility in lanterns.The number of seeds germinated from female panicles was approximately doubled by heating an insulated lantern wi th a 60 W incandescent bulb; heat without light was slightly better than heat with light. A heated but uninsulated lantern gave a 50% improvement in seedlings germinated over the control. A lantern with a clear plastic panel facing the morning sun also performed well but has practical limitations. Lanterns located in a temperature controlled building gave poor results despite temperatures being favorable.Pollen fertility was not affected by the treatments. Environmental assessment using cross‐pollinated females differed from that with self‐pollinated males, indicating that selection of environments for cross‐poliinatlon based on results with self‐pollination is inappropriate.
Predictive Equations for Maize Inbred Emergence1
Authors: Navratil R. J. , Burris J. S. 
Published: July 2010

Accurate estimates of maize (Zea mays L.) inbred seedling emergence are currently unavailable. Inbred planting rates, therefore, are adjusted by using criteria normally applied to hybrid seed.In this study, temperature‐dependent predictive equations that would assist the seedsman in estimating planting rates, to obtain acceptable stands during the planting season, were developed for 15 maize inbreds. The equations were developed on the basis of the multiple linear regression of field emergence on standard germination and days to 50% emergence for all dates of planting. The slopes of the regressions differed among inbreds.The equations are applied by calculating the days to 50% emergence on the basis of the known number of growing‐degree units that a particular inbred would require to reach 50% emergence. Past meteorological data would be used to estimate the probable number of days required to accumulate the growing‐degree units for any planting date.It was assumed initially that growing‐degree units to 50% emergence would remain constant while days to 50% emergence could vary for each inbred line and would vary for different field plantings. However, growing‐degree units to 50% emergence for lots within inbred lines, field plantings, and the field plantings by inbred line interactions were all significant at the 0.01 probability level.Although the variability in growing‐degree units to 50% emergence indicates that we have not yet arrived at a final answer, the predictive equations show considerable promise in reducing the subjectivity presently involved in determining planting rates. The refinement and ultimate application of these equations, as superior predictors of field emergence, will require testing under actual production conditions and a more complete understanding of temperature effects, not accounted for in the formula used to compute growing‐degree units.
Laboratory Packed Sand Test for Measuring Vigor of Sugarbeet Seed1
Authors: Akeson W. R. , Widner J. N. 
Published: July 2010

Emergence of sugarbeet (Beta vulgaris L.) seedlings is a major problem affecting stand establishment in sugarbeet production. Our objectlve was to evaluate a packed sand laboratory procedure for measuring vigor of sugarbeet seed and relate it to field emergence under a range of conditions.Results from the packed sand test measuring percent emergence of seedlings through silica sand, 3.8 cm thick, 4% water (wt/wt), and 10 C, were highly correlated (r = 0.89 to 0.98) with field emergence in tests with seed lots of commercial cultivars, whereas standard germination was not a reliable indicator of emergence potential. The average field emergence of seed lots of four commercial cultivars, ‘GWH 45,’ ‘GWH 48,’ ‘GWH 93,’ and ‘GWH 115,’ ranged from 29.7 to 54.3, 34.3 to 68.8, 30.9 to 49.7 and 19.5 to 29.0%, respectively. Identification and utilization of high vigor seed lots would improve overall seedling emergence under most conditions. The procedure as described provides a tool for investigating cultural practices influencing emergence as well as a quality control test to aid in processing seed for improved seed vigor.