bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Temparature and Dormancy on Germination of Tall Fescue1
Authors: Boyce K. G. , Cole D. F. , Chilcote D. O. 
Published: July 2010

The effects of alternation and duration of temperature levels on the germination of dormant and nondormant seed of tall fescue (Festuca arundinacea Schreb ‘Fawn’) were evaluated. Dormancy induction and temperature preconditioning of dormant seed were also studied.Dormancy was greater in seed matured at 15 C compared to that matured at 26.6 C. The expression of dormancy was also more pronounced at a higher germination temperature (26.6 C).Temperature preconditioning of dorma nt fescue seed was important in relieving dormancy; germination response was essentially confined to imbibing temperatures of ≥ 15 C. Preconditioning time was important and 48 days at 1 C, 24 or 48 days at 5 C, and 24 days at 10 C gave near maximum germination response.Germination of dormant and nondormant seed was influenced differentially by level and alternation of temperature and by the amplitude of temperature fluctuation. For nondormant seed, constant temperature at 20 to 25 C was optimum. For dormant seed, alternating temperatures were more favorable, and the optimum regime was 8 hours at 20 to 25 C and 16 hours at 10 to 15 C with the range of response to temperature being more restricted than for nondormant seed. Germination response of dormant seed diminished as the time period at the higher temperature increased.The germination responses of dormant seed observed in this study indicate that at least two physiological phenomena may be involved. The thennogradient response could be a combination of the effects of temperature on the germination processes, per se, and on the metabolic and/or physical processes involved in dormancy. In nondormant seed, only the rate and extent of germination was affected by the temperature regime.
Inheritance of High Lysine in Maize1
Authors: Choe Bong‐Ho , Zubér M. S. , Krause G. F. , Hilderbrand E. S. 
Published: July 2010

Two maize (Zea mays L.) families with high and two with low lysine were selected from the first cycle of Zuber and Helm's recurrent selection experiment in Logan County Composite. Plants from these four families were selfed and crossed to opaque‐2.The level of lysine from the high and low families was transmitted to the testcross F1's and to both the normal and opaque phenotypes of the F2 populations. The results indicate that two genetic systems are involved in lysine synthesis, one associated with the opaque‐2 gene per se and the second operating independently of opaque‐2. Several of the opaque phenotypes from the F2's involving the high‐lysine parents had more lysine than the opaque‐ 2 parents. The two genetic systems appeared to complement each other in an additive manner.Although the selection criterion in the recurrent selection for high lysine was only lysine content on a whole kernel basis, the protein level for the'high‐lysine families and their crosses was higher than that for the low‐lysine families. Thus recurrent selection for high lysine resulted in higher levels of protein.
Top and Root Growth of Irrigated and Nonirrigated Soybeans1
Authors: Mayaki W. C. , Teare I. D. , Stone L. R. 
Published: July 2010

Root depth and distribution in the field were correlated with easily measurable above‐ground morphological paranfeters of soybeans (Glycine max L. Merr. ‘Williams’) at specific physiological stages. Previous research on soybean rooting depth and distribution was conducted with pots or field soil containing a barrier limiting full expression of root development. Other studies sampled a limited numberof times in a barrier free soil.We investigated soybean root depth and distribution under irrigated and nonirrigated conditions in a deep barrier‐free Muir silt loam soll profile. Irrigated plots received a total of 28 cm of water in three furrow applications. We measured plant height and dry weight, root depth, root distribution, and leaf area index each time roots were sampled. Each soil increment sampled (75 cm wide, 7.5 on thick, and in 15 cm increments to the 180 cm depth) was soaked and roots washed free of soil using a 35‐mesh screen. We used neutron moderation and gravimetric sampling to obtain soil water measurements.Soybean roots reached the 160 cm depth in both irrigated and nonirrigated plots. Root depth increased faster than plant height. At physiological maturity, 67% of the soybeans' root dry matter was in the 0–15 cm layer and 89% in the 0‐90 cm layer of the irrigated soil compared with 51% in the 0‐15 cm layer and 83% in the 0–90 can layer of nonirrigated soil.A quick estimate of rooting depth after six node stage (V3) in nonirrigated soybeans, based on our work, would be twice the top height. With irrigated soybeans, root depth would be twice top height from V3 until pod development began (R5.5) and 1.4 ✕ top height thereafter. The coefficient of determination (R2) for root depth vs. plant height was 0.994 and 0.987 for irrigated and nonirrigated soybeans, respectively.
Heritability of Soluble Proteins in Alfalfa1
Authors: Gutek L. H. , Goplen B. P. , Howarth R. E. 
Published: July 2010

This study was conducted to assess the feasibility of breeding alfalfa cultivars with low soluble protein concentrations as a means of reducing the bloat‐causing potential of alfalfa (Medicago sativa L.). Narrow‐sense heritability estimates were obtained for soluble fraction I, fraction II, and total soluble protein concentrations in alfalfa. Heritability estimates (h2) were based on the parent‐offspring regression method using data from 32 unselected clones and their open‐pollination progenies.The h2 estimates for the soluble proteins for 1972 and 1973 were as follows: soluble fraction I (19 and 20%), soluble fraction II (19 and 27%), total soluble protein (23 and 31%). These relatively low heritability estimates indicate that it should be possible to lower the soluble protein content of alfalfa by consecutive cycles of recurrent selection procedures involving well‐replicated progeny tests.
Sequential Trait Development and Breeding for High Yields in Safflower1
Authors: Abel G. H. , Driscoll M. F. 
Published: July 2010

The development of the sequential traits of seed yield (heads/area, seeds/head, and seed wt) of safflower, Carthamus tinctorius L., and the breeding for high and low yield were studied. The original data for each of the three traits were standardized by two transformations and compared.Of the sequential traits, genotype had a large effect on seed wt and smaller effects on seeds/head and heads/ area. Location effects were generally highly significant for each trait; dates of planting were less important.The sequential traits show independence in a correlation analysis. Together the traits account for 97% of the variation in yield, with head numbers and seeds in the head accounting for most of the variation. For each trait separately, seed wt accounts for most of the variation in yield, followed by seeds/head and head numbers. Standardized partial regression coefficients indicate that for selection, one should give more weight to head numbers and seeds/head when all these traits are considered simultaneously and to head numbers when one trait is considered at a time.In general, head numbers or seeds/head or both traits could be responsible for high yielding lines. Seed wt was generally inflexible in different environments, but heads/ area and seeds/head were more flexible. Line A1186‐1 was among the five highest yielding lines in nearly all locations and for all planting dates, indicating the highest adaptation to the range of environments in the experiments.
Hybrid Wheat seed Production Methods for North Dakota1
Authors: Miller J. F. , Lucken K. A. 
Published: July 2010

A North Dakota male fertility restorer, R5 (Triticum zhukovskyi Men. & Er./3* T. aestivum L. em ThelL ‘Justin’), and several male‐sterile wheat lines (T. aestivum with T. timopheevi (Zhuk.) Zhuk. cytoplasm) were planted in a systematic arrangement of alternate drill strips to evaluate hybrid wheat seed production. Approximate ratios of 1:1, 2:1, and 3:1 of male sterile to restorer were tested over several environments from 1972‐1974. Drillstrip widths of the male sterile ranged from 3.1 to 11.0 m. Overall mean yields of hybrid seed were 13.7, 10.0, and 8.4 quintals/ha for the 1:1, 2:1, and 3:1 ratios, respectively. A production unit concept was used to compare the efficiencies of the three different ratios from a commercial perspective. Actual yields of hybrid seed from a production ha were 6.9, 6.7, and 6.3 quintals for the 1:I, 2:1, and 3:I ratios, respectively.Narrowing the drill.strip width of male‐sterile and restorer parents within the 1:1 or 2:1 ratios from 3.1:3.1 m to 1.5:1.5 m or from 6.1:3.1 m to 3.1:1.5 m did not increase yields of hybrid seed. Therefore, adequate hybrid seed production can be accomplished with machinery (2.1 to 3.7 m/drill section) currently used on North Dakota farms.The growing degree day technique was used to determine timing of planting dates between a male sterile and its maintainer for proper synchronization of maximum pollination of the male line and optimal floret opening of the female line. In 2 years of study, higher yields were obtained with the projected 44 C growing degree day difference than with 0, 22, or 66 growing degree day differences.Hybrid seed production yields were highly correlated with restorer yields over several environments indicating that hybrid seed production would be most successful in high yielding production regions. Decreases in hybrid seed yields at low yielding environments were due to environmental factors affecting yield and pollination potential of both parents. The low yields of the restorer, especially in adverse environments, were attributed to its low vigor and poor adaptability. Consequently, successful hybrid seed production is dependent on availability of high yield environments and on stable, high yielding, adapted parents.
Response to Inbreeding in Alfalfa Populations Derived from Single Clones1
Authors: Hill R. R. 
Published: July 2010

Spring growth and plant heights at each of three harvest times in each of 2 years were studied in progenies from three clones each in ‘MSA‐W4’ and ‘MSB‐W4’ alfalfa (Medicago sativa L.). The generations from five of the clones were S0, S1, S1‐SYN‐1, S3, and S3‐SYN‐1. One of the clones from MSB‐W4 had the S4‐SYN‐1 generation, but not the S1‐SYN‐1. The data were analyzed by multiple regression on the coefficients of inbreeding, by Gallais's genetic model, and by a newly developed genetic model for autotetraploid populations.Except for first harvest height in MSB‐W4, additive and digenic genetic effects were responsible for more than half the total genetic variation among and within families. Trigenic or quadrigenic effects for individual families were frequently significant, but significant average trigenic or quadrigenic effects were rare. Deviations from neither genetic model were significant, but better fits were obtained with my model and regression on the coefficients of inbreeding than with Gallais's model.Large differences due to parental clone were observed in the response to inbreeding—two clones showed almost no response and others were drastically reduced in vigor by the S3 or S3‐SYN‐1 generations. The frequent presence of an inbred generation with greater vigor than a less inbred, previous generation was attributed to unavoidable selection during development of the inbred progenies.
Effect of Increasing Morphological Component Expression on Yield in Corn1
Authors: Kuhn W. E. , Stucker R. E. 
Published: July 2010

A backcross‐conversion program was utilized to increase expression of number of ears/plant, ear length, and kernel depth in five corn (Zea mays L.) inbreds. Four versions (normal, deep‐kerneled, long‐eared, and multiple‐eared) of the inbreds were evaluated as lines per se and in single‐crosses in separate experiments at Waseca and Lamberton, Minnesota in 1973. Yield component expression was greater in the converted lines than in their normal counterparts, but direct responses to conversion varied significantly for different inbred backgrounds. Correlated responses for the two unselected morphological components and three agronomic traits occurred in the lines themselves.Single‐crosses involving converted lines were higher yielding than singlecrosses of normal lines. However, this yield advantage occurred primarily in the lower yielding single‐cross backgrounds (low yielding normal ✕ normal crosses). Single‐crosses involving multiple‐ear and deepkernel lines had the highest and lowest yields, respectively, relative to the normal ✕ normal control.
Photosynthetic Efficiency of Alfalfa with Increasing Potassium Nutrition1
Authors: Wolf D. D. , Kimbrough E. L. , Blaser R. E. 
Published: July 2010

Potassium concentration in alfalfa (Medicago sativa L.) herbage has been used to indicate sufficient levels to attain maximum dry matter productions. Since photosynthesis is the source of dry matter, the relationships of potassium concentration to CO2 exchange rate (CER) was studied in an attempt to find an optimum level. Several soil K rates were applied to four alfalfa plant populations. CER measurements were made for single leaves and canopies of alfalfa during early vegetative growth. CER increase due to added increments of K could be camouflaged by differential growth rates of canopies and mutual shading of leaves that result from increased fertility. The confounding was avoided by adjusting CER to similar leaf area index values across K rates.CER increased 22% as the K concentration in prebud herbage increased by 133% (1.62 to 3.77). A herbage K concentration of about 2.0% resulted in 90% of maximum observed CER. K concentration of 2.0% for prebud herbage relates to a concentration of 1.3% for one‐tenth bloom herbage. The CER and K concentrations of individual young and old leaves increased with added soil K increments. High K rates prolonged CER as leaves aged. These data indicate a lower critical K percentage for maximum CER than is reported in literature for maximum yields; thus, other growth processes may be more limiting by low K concentrations than photosynthesis. Plant development, plant part sampled, leafiness, and geographic locality may influence the K sufficiency concentration.
Improved Soybean Growth in Urea with pH Buffered by a Carboxy Resin1
Authors: Lahav E. , Harper J. E. , Hageman R. H. 
Published: July 2010

An improved nutrient culture technique has been devised for producing vigorous soybean [Glycine max (L.) Merr.] plants with urea as the only source of N. Of the sources of reduced‐N tested, (urea, amides, and ammonium salts of citrate, malate, fumarate, succinate, and sulfate), urea caused the least amount of plant injury. However, seedlings grew less when cultured with urea than with nitrate. The rapid decline of solution pH was likely responsible for the limited plant growth with the reduced N sources. Adjusting the solution pH daily did not alter the injurious effects. Addition of the Ca form of a carbpxy resin (Amberlite IR.C‐50, 50 g/liter) to the urea nutrient medium stabilized the pH and permitted plant growth equivalent to that of nitrate grown seedlings. In the presence of resin, plant growth with urea was superior to that with ammonium salts [e.g., (NH4)2SO4].Growth of soybeans and wheat (Triticum aestivum L.)was equivalent with urea (in the presence of resin) and nitrate while growth of peas (Pisium sativum) and velvet leaf (Abutilon theophrasti) was less with urea than with nitrate. All species grown on urea contained low amounts of nitrate (about 10% of nitrate grown controls) indicating that some interconversion of urea to nitrate occurs, although no nitrate was detectable in the nutrient solutions. In vivo nitrate reductase activity was low [less than 0.21 /μmoles NO2 (g fresh wt‐hour)−1] with all species while in vitro activity ranged from 68% (soybean) to 11% (peas) of the activity of respective nitrate‐grown controls.
Nonstructural Carbohydrate in the Spring Herbage of Temperate Grasses1
Authors: Jung G. A. , Kocher R. E. , Gross C. F. , Berg C. C. , Bennett O. L. 
Published: July 2010

Nonstructural carbohydrates are sources of readily available energy that enhance rumen microbial activity and forage utilization. Experiments were conducted in Pennsylvania and West Virginia to determine the effect of maturity on total nonstructural carbohydrate (TNC) concentrations in spring herbage of eight grass species and determine TNC concentrations in herbage at immature and mature growth stages on a given day. The grasses were fertilized early each spring and summer with 0, 60, 120, or 240 kg N/ha.Determinations for TNC were made using the Smith takadiastase technique. Mean TNC concentration in the spring herbage of ‘Masshardy’ orchardgrass (Dactylis glomerata L.), ‘Climax’ timothy (Phleum pratense L.), and ‘Sac’ smooth bromegrass (Bromus inermis Leyss.) decreased seven or more percentage units with maturation from vegetative to full bloom stage, but decreased less than four percentage units in ‘Fawn’ tall fescue (Festuca arundinacea Schreb.), ‘Kenblue’ Kentucky bluegrass (Poa pratensis L.), and redtop (Agrostis alba L.). Mean TNC concentration was 50% higher in ‘Pennfine’ perennial ryegrass (Lolinm perenne L.) than in Kenblue Kentucky bluegrass or redtop. Concentration of TNC was inversely related to maximum air and soil temperatures and was affected much more by harvest date than by maturation of the herbage. Concentration of TNC was usually lower in N‐fertilized herbage than in unfertilized controls at early growth stages, but N had little effect on TNC concentration of herbage at full bloom.Maximum yields of TNC were obtained at the stem elongation stage with ryegrass, at flower‐head emergence with Pennmead orchardgrass and ‘Ky. 31’ tall rescue, and at full bloom with other grasses. N fertilization increased TNC yield of orchardgrass, tall rescue, and reed canarygrass; decreased TNC yield of smooth bromegrass and redtop; and had little effect on TNC yield of ryegrass and timothy.
Genotypic Responses in Sorghum to Drought Stress. III. Free Proline Accumulation and Drought Resistance1
Authors: Blum A. , Ebercon Adelina 
Published: July 2010

We explored a possible association between free proline amino acid accumulation in water‐stressed leaves and the drought resistance of various grain sorghum [Sorghum bicolor (L.) Moench] cultivars.Eight sorghum cultivars were grown in a growth chamber under a drying cycle (to a leaf water potential of −18 to −21 bars) and a subsequent recovery phase. Free proline, free ammonia, dark respiration rate, and recovery rating were recorded, as well as desiccation tolerance of each cultivar when grown in the field.Free proline accumulation was initiated in leaves of all cultivars as leaf water potential was reduced to −14 to −16 bars. Free ammonia concentration in leaves of all cultivars did not change appreciably during the drying cycle. Upon rewatering, free proline content was reduced and free ammonia concentration was increased, both rather abruptly. Cultivars difered significantly in maximum free proline accumulation and post‐stress free ammonia concentration, dark respiration rate, and recovery rating.Correlations indicated that desiccation tolerance was not related to any of the attributes measured, or even to recovery rating. Free proline accumulation during water stress was correlated significantly with post‐stress recovery rating, free ammonia concentration, and dark respiration rate.It is suggested that accumulated free proline in water‐stressed sorghum leaves is related to the ability of a cultivar to recover upon the relief of stress, possibly by way of proline's role as a source of respiratory energy in the recovering plant.
Space‐planted and Mass‐seeded Progeny Tests for Seed Yield and Seed Size in Tetraploid Crested Wheatgrass1
Authors: Schaaf H. M. 
Published: July 2010

Twenty‐four tetraploid crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult.] genotypes were evaluated as clones (parents), open‐pollination (OP) progenies, and topcross (TC) progenies. Parents and OP's were grown in replicated spaced plantings and assessed for spikes/plant, seeds/spike, seed yield, and seed size (mg/100 seeds). Mass‐seeded OP's and TC's were evaluated for seed yield and seed size in replicated singlerow plots.Although space‐planted and mass‐seeded progenies provided similar evaluations of seed‐yidd potential, method of culture caused sizable shifts in the expression of seed size. When seeking simultaneous improvement of both characters, selecting parents on the basis of spaced‐progeny performance appeared to retain some undersirable genotypes, the effects of which could decrease the efficiency of recurrent selection. The heritability of all four characters was lower for the spaced progenies than for the seeded progenies. In addition, space‐planting altered the relationship of seed size to spikes/plant, seeds/spike, and seed yield.Correlations of 0.83 and 0.85 (P < 0.001) for seed yield and seed size, respectively, demonstrate close similarity of OP and TC performance in mass‐seeded tests.
Interrelationships of Seedling Vigor Criteria of Wheat Under Different Field Situations and Soil Water Potentials1
Authors: Gul Azam , Allan R. E. 
Published: July 2010

The relationships among emergence rate index (ERI), total stand (TS), culm length, coleoptile length, seedling height, root weight, and kernel weight of 93 wheat (Triticum aestivum L. em Thell.) lines and four check cultivars were studied at four different water potentials (—2.2, —6.0, —10.2, and —14.4 bars) in the laboratory and in three eastern Washington field situations (Lind shallow‐sown, Lind deep‐sown, and Pullman).The ERI values of the three field tests correlated with one another but they gave small or nonsignificant r values with ERI's from the four laboratory water potential levels. The marked differences in planting depth and water potential level between the field and laboratory could explain the lack of relationship.Coleoptile length, seedling height, and culm length correlated positively with field ERI. In the laboratory, however, ERI at only —2‐2 bars correlated significantly with coleoptile length and seedling height. Kernel weight inconsistently correlated with ERI and gave significant positive r values with field ERI on two occasions but had a significant negative r value with ERI of one laboratory water potential level. In the laboratory, the association between ERI and TS, ERI and root weight, and TS and root weight became progressively closer as the water potential decreased and verified other work that showed fast‐rooting lines emerge better than slow ones under low soil‐water potential.As with ERI, significant correlations were found between both TS and coleoptile length and TS and seedling height in field studies. These seedling traits (field) were independent of the TS values obtained at the four water potentials (laboratory). Kernel weight gave low or nonsignificant r values with field and laboratory TS values. Comparisons of both ERI and TS values in field tests and at low water potentials (laboratory) suggest that different genetic systems regulate the growth potential of these wheat lines under these contrasting environments.The optimum advance from selection should be achieved by testing wheat lines for seedling vigor (ERI, TS) under diverse field situations and at low soil water potentials (—10.2, —14.4 bars).