bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ecology of Exotic Races of Maize. I. Leaf Number and Tillering of 16 Races Under Four Temperatures and Two Photoperiods1
Authors: Stevenson J. C. , Goodman M. M. 
Published: July 2010

Use of photosensitive types of maize (Zea mays L.), such as the approximately 250 Latin American races, is severely limited by late flowering and excessive growth under field conditions encountered in latitudes exceeding 30°%. It is known that both shorter day lengths and lower temperatures tend to reduce excessive growth by initiating flowering at an earlier stage of development. The joint effects and possible interactions of such treatments apparently have not been previously studied. Sixteen races of maize, adapted to varying altitudes, growing conditions, and latitudes, were grown in the North Carolina State University Phytotron at day/night temperatures ranging from 10/6 to 34/30 C under short (9‐hr) days. The same races were grown under long days at temperatures ranging from 18/14 to 34/30 C. The photoperiod difference was much more effective than temperature in decreasing leaf numbers, and while the interaction of photoperiods and temperatures was significant, it was relatively small. Lowest leaf numbers were generally obtained under the 18/14 C 9‐hour day regime. Since these numbers ranged as high as 20 leaves per plant, additional reduction, perhaps by using shorter days with temperatures in the range of 14 to 22 C, would be desirable.In contrast, temperature rather than photoperiod length is more effective in altering the numbers of tillers per plant. With a single exception, the races that tillered did so more profusely at the lower temperatures.
Effects of Genetic Diversity on Heterosis in Tall Fescue1
Authors: Moutray J. B. , Frakes R. V. 
Published: July 2010

The object of this study was to determine the extent of heterosis for plant height, anthesis date, panicle number, seed yield, and fall vigor rating in a tall rescue (Festuca arundinacea Schreb.) group selected for diverse morphology, origin, and anthesis date. Nine parents, nine single‐cross progeny, and eight S1 progeny were included.Single‐cross progeny were superior to their parents in all characteristics except seed yield, while the parents exceeded their respective Sl's except in plant height.Single crosses average 15, 28, and 5% above the midparent for plant height, panicle number, and seed yield, respectively, had a 3% earlier anthesis date, and were 23% lower in fall vigor rating (more vigorous). Single crosses averaged 6% above the high parent for panicle number and 10% below the low parent for fall vigor rating.Crosses between maturity groups resulted in the greatest heterosis above the midparent for all characteristics. Crosses within the early maturity group were tallest (106% of high parent) and had the most vegetative vigor (115% of high parent).Indications are that crosses between clones of diverse morphology, origin, and anthesis date can result in greater heterosis than has been observed in crosses between clones selected on similarities.
Nitrate Reductase Activity and its Relationship to Accumulation of Vegetative and Grain Nitrogen in Wheat (Triticum aestivum L.)1
Authors: Eilrich G. L. , Hageman R. H. 
Published: July 2010

Nitrate, nitrate reductase activity, soluble protein of total leaf tissue, fresh and dry weight, and reduced nitrogen of total shoot tissue of ‘Arthur’ wheat (Triticum aestivum L.) were measured at intervals throughout the spring growing season in response to three rates of nitrogen [as CA(NO3)2] applied on each of five dates. Yield of straw and grain and their respective concentration of reduced nitrogen at maturity were also obtained.A positive relationship observed between nitrate content and nitrate reductase activity of the leaf tissue substantiated the dependency of the enzyme activity upon availability of substrate. The increase in nitrate reductase activity in response to added nitrogen was paralleled by an increase in vegetative reduced nitrogen, indicating a casual relationship between enzyme activity and accumulation of reduced nitrogen in the plant. Since translocation of vegetative nitrogen to the grain was uniform across treatments, a significant positive correlation was found between nitrate reductase activity (expressed as moles N ha‐1 per season) and grain nitrogen (kg N ha‐1) at maturity. Seasonal nitrate reductase also correlated significantly and positively with grain yields (kg ha‐l). Similar results were obtained in the preceding season with ‘Ottawa’ and ‘Gage’ wheats, except that the application of nitrogen to Gage caused excessive lodging and thus eliminated the signifiraut correlations between enzyme activity and grain yield and grain nitrogen.Maintenance of nitrate reductase activity during the reproductive phase in varieties resistant to lodging can increase the yield of grain protein aud prevent the depression of percent grain protein frequently observed when grain yields are high.
Alfalfa Seed Size as an Indicator of Hybridity1
Authors: Pedersen M. W. , Barnes D. K. 
Published: July 2010

The size of hybrid and selfed alfalfa (Medicago saliva L.) seed were studied with a view to utilizing size differences in breeding procedures. Pollen parents and seed parents both had a measurable effect on alfalfa seed size. On the average, selfed seeds on a given seed parent were about 10% smaller than F1 hybrid seed. Some pollen parents produced larger hybrid seeds than other pollen parents. Maternal parent ✕ pollen parent interactions also influenced seed size. The reduction in selfed‐seed size was attributed to inbreeding depression. The hybrid‐seed size response was considered to be an expression of heterosis.Seed size was used as a basis to separate hybrid seeds by sieving open‐pollinated seed of white‐flowered alfalfa grown in plots adjacent to colored‐flowered alfalfa. A seedling hypocotyl‐color test was used to identify hybrid seedlings. Seed size and percent crossing were closely correlated in a positive manner.Applications of these results that deserve further study include: (i) the relationship between combining ability for seed size and combining ability for forage yield; (ii) sieving to improve quality of seed stocks; and (iii) increasing the proportion of hybrid seed in hybrid seed cultivars.
Influence of Temperature and Photoperiod on Floral Initiation and Leaf Number in Sorghum1
Authors: Quinby J. R. , Hesketh J. D. , Voigt R. L. 
Published: July 2010

Twelve sorghum [Sorghum bicolor (L.) Moench] cultivars were grown in the field at two elevations in Arizona and in two day lengths and five temperature regimes in phytotron greenhouses in an effort to obtain a better understanding of the influence of photoperiod and temperature on time of floral initiation and leaf number in sorghum.Maturity genotypes were known for seven of the cultivars tested. Alleles at all four maturity loci responded differently to temperature. All cultivars responded to differences in temperature differently in the two photoperiods, indicating interaction between temperature and photoperiod.Regardless of length of photoperiod, most cultivars produced more leaves in the warmer night temperature regime of 32/29 C than in the 32/23 C regime, but leaf numbers also tended to be high in the cold 17/11 C regime. Plastochrons varied among cultivars.
Bulk, Pedigree, and Early Generation Testing Breeding Methods Compared in Soybeans1
Authors: Luedders V. D. , Duclos L. A. , Matson A. L. 
Published: July 2010

Soybean (Glycine max (L.) Merr.) lines selected from populations advanced by the pedigree, early generation (F4 and F5) testing, and 2 bulk methods were evaluated in the F6 and F7. Differences in the yield of these lines due to method of generation advance were not significant. However, with selection on 2‐year means and in each individual year, the complete bulk (CB) and early generation testing (EGT) methods retained a few more lines than the maturity bulk (MB) and pedigree (P) methods. Methods of generation advance were highly significant for four character‐population combinations but these appeared to occur at random except for seed quality‐maturity in population 6. This association was not unexpected because seed quality and later maturity are significantly correlated in 14 out of 24 cases. Heritability estimates ranged from 10 to 40% for yield, 29 to 88% for height, and 23 to 72% for lodging.We suggest that plant breeders discard approximately 75% of their yield‐tested lines each year. This would permit larger populations to be evaluated and should result in the retention of more stable high‐yielding lines.
Environmental and Cultural Preconditioning Effects on the Water Use Rate of Agrostis palustris Huds., Cultivar Penncross1
Authors: Shearman R. C. , Beard J. B. 
Published: July 2010

Preconditioning effects of light intensity, growing temperature, irrigation frequency, cutting height, mowing frequency, and nitrogen nutrition level on water use rate and stomatal density of ‘Penncross’ creeping bentgrass (Agrostis palustris Huds.) were investigated. Water use rates were recorded as percent moisture lost during exposure to (1) 33 C, (2) 40% relative humidity, (3) lux light intensity, and (4) a constant airflow of 186 sec−1 in a special wind tunnel apparatus. Stomatal density counts were made at 430X from nitrocellulose replications of the leaf surface.The preconditioning effects of cutting height, light intensity, and nitrogen nutrition level had the greatest influence on water use rate. Irrigation and mowing frequency were intermediate in their influence. Growing temperature had the least effect among the factors considered.Stomatal density was influenced most by light intensity, and growing temperature had the next greatest effect. Irrigation frequency had an intermediate effect. Nitrogen nutrition level had the least influence of the factors studied. Water use rate was positively correlated (r = 0.88) to stomatal density in the light intensity study. However, it was negatively correlated (r = −0.98) to stomatal density for the nitrogen nutrition level study. No significant correlations were observed for growing temperature or irrigation frequency.
High Lysine Mutant Gene (hl that Improves Protein Quality and Biological Value of Grain Sorghum1
Authors: Singh Rameshwar , Axtell John D. 
Published: July 2010

Seeds from over 9,000 lines in the world sorghum [Sorghum bicolor (L.) Moench] collection were classified for endosperm phenotype to identify floury endosperm lines and evaluate each for potential increases in lysine concentration. Sixty‐two floury endosperm lines were selected and analyzed for protein and lysine composition. Two floury lines of Ethiopian origin, IS 11167 and IS 11758, were exceptionally high in lysine at relatively high levels of protein.The average whole grain lysine concentration of high lysine lines IS 11167 and IS 11758 was 3.34 and 3.13 (g/100g protein) at 15.7 and 17.2% protein, respectively. Both lines were also high in percent oil. Carbohydrate analyses of whole grain samples of the two high lysine lines were similar to that of normal sorghum grain except for a twofold increase in sucrose concentration.The high lysine gene altered the amino acid pattern in hl hl hl endosperm tissue relative to normal endosperm checks. The major changes were increased lysine, arginine, aspartic acid, glycine, and tryptophan concentrations and decreased amounts of glutamic acid, proline, alanine, and leucine in the hl hl hl endosperm.Inheritance studies suggest that the increased lysine concentration of each line is controlled by a single recessive gene, although it is not known whether the genes from both lines are allelic. The high lysine gene(s) present in IS 11167 and IS 11758 from Ethiopia is (are) herein designated as hl. The endosperm of kernels homozygous for the hl gene is partially dented.The biological value of the high lysine lines was much higher than that of average sorghum lines. In a 28‐day isonitrogenous feeding experiment the weight gain of weanling rats was three times higher on an IS 11758 ration and twice as high on an IS 11167 ration as weight gains on rations prepared from normal sorghum lines. When fed rations without any dilution except the usual 2% vitamin and 4% mineral supplementation, rats gained 94 g on high lysine sorghum (IS 11758) and 28.5 g on our current best nutritional quality sorghum line (IS 2319), versus 91.5 g on opaque‐2 corn (Zea mays L.) and 30.2 g on normal corn in a 28‐day feeding trial. Feed efficiency ratios for this trial were 3.0 for high lysine sorghum, 6.8 for IS 2319, 3.4 for opaque‐2 corn, and 7.4 for normal corn.
Persistence of Several Temperate Grasses Grown with Alfalfa and Harvested Two, Three, or Four Times Annually at Two Stubble Heights1
Authors: Smith Dale , Jacques A. V. A. , Balasko J. A. 
Published: July 2010

Six grass species were established in 1968 in rows within a seeding of alfalfa (Medicago sativa L.) at Arlington, Wisconsin. The mixtures were harvested two, three, or four times annually at two stubble heights, 4 and 10 cm, during 1969 and 1970. Alfalfa was eliminated by spraying with a selective herbicide during autumn of 1970. Grasses were then evaluated for stand persistence and dry matter yields during the first growth of 1971.Orchardgrass (Dactylis glomerata L.), reed canarygrass (Phalaris arundinacea L.), and meadow foxtail (Alopecurus pratensis L.) persisted well with alfalfa under all cutting schedules and stubble heights. Tall rescue (Festuca arundinacea Schreb.) was nearly eliminated by cutting twice at the short stubble height, but persisted well in other treatments. Stands of timothy (Phleum pratense L.) and bromegrass (Bromus inermis Leyss.) were affected most by the cutting practices. Stands of both grasses were reduced more by three than four cuts annually and were significantly lower with both cutting schedules at the short than at tall stubble height; stands were nearly eliminated with three cuts at the short stubble height. With two cuts annually, cutting height had no significant effect on stand persistence, but timothy stands were poor at both stubble heights.Survival of the grasses as related to stage of development at time of cutting and to tillering pattern is discussed, especially with regard to their persistence with alfalfa under the three‐cutting schedule used widely in the northern Great Lakes States. Of the grasses studied, orchardgrass and reed canarygrass showed wide adaptability to all cutting practices used and were most amenable for use in mixture with alfalfa harvested three times annually.
Inheritance of Indole Alkaloids in Reed Canarygrass (Phalaris arundinacea L.). I. Heritability Estimates for Alkaloid Concentration1
Authors: Barker R. E. , Hovin A. W. 
Published: July 2010

Our objectives were to estimate genotypic and environmental variances and heritability of indole alkaloid concentration in reed canarygrass (Phalaris arundinacea L.) The variance component estimates for genotype ✕ environment and genotype ✕ cutting interactions were significant but small as compared to the estimate for genetic variance among 31 unrelated clones of diverse origin. Genotype ✕ environment ✕ replication in environments interactions were statistically nonsignificant. Thus, variation in alkaloid concentration was largely associated with genotypes.Heritability studies included 36 clones and their 18 two‐clone crosses grown at 2 locations. Heritability estimates from the second cutting were higher than corresponding estimates from the third cutting. Combining data from two regrowth cuttings in one season reduced the bias introduced as a result of sampling the forage at different growth stages. When based on parents in the 0.17 to 1.37% overall alkaloid concentration range, realized heritability estimates for the combined August and September cuttings ranged from 0.67 to 0.72. All heritability estimates were slightly higher for the high alkaloid concentration range compared to estimates for the low range. Narrow‐sense heritability estimates were nearly as large as the corresponding broad‐sense estimates; thus, total genetic variance was largely additive. Parent‐offspring regression analyses of identical materials confirmed this conclusion. Our results suggest that genetic gain in alkaloid concentration can be realized from selection among individual plants.
Effect of Genetic Sampling Technique on Variation Within Populations Derived by Crossing, Selfing, or Random‐Mating Other Populations1
Authors: Hammond J. J. , Gardner C. O. 
Published: July 2010

Methods of sampling to form genetic populations used in the Gardner‐Eberhart model for the diallel cross and related populations vary considerably. Sometimes the same plants are used to form the selfed progeny, the random‐mated progeny, and the crosses in order to save nursery space. The purpose of this research was to use computer simulation to generate genetic populations according to some different sampling methods currently in use and to examine the effect of sampling techniques on means and genetic variation.Methods of sampling did not affect the means but they did affect the variances. Sampling with replacement (using a plant more than once) increases the within population genetic variation of variety crosses, crosses selfed, and crosses random‐mated. The amount of bias is inversely related to sample size. Adjustment for the bias was possible by utilizing expected number of parental individuals.Conclusions reached are: 1) plants should be used only once as a male or female, 2) each kind of population should be developed from an independent set of parents, and 3) a balanced composite of seed with equal numbers from each female parent should be used rather than bulk seed. The sample size of parents affects the precision of means estimated for progenies. Twenty to 30 plants are believed to be reasonably adequate to represent a segregating population.
Genotypic Responses in Sorghum to Drought Stress. I. Response to Soil Moisture Stress1
Authors: Blum A. 
Published: July 2010

This study evaluated the variability within cultivated sorghums (Sorghum bicolor (L.) Moench.) in some physiological responses to water stress imposed by limited supply of soil moisture in the field.In 1971 and 1972, 14 and 12 sorghum genotypes were planted, respectively. Water was supplied exclusively by stored soil moisture. During the growing season, periodic determinations were made of leaf water potential, leaf diffusion resistance, and (1972 only) amount of soil moisture.The most drought susceptible genotypes was ‘Shallu’ which under increasing soil moisture stress had relatively low leaf water potential, high leaf diffusion resistance, and the lowest total soil moisture extraction. ‘Combine Kafir‐60’ and ‘RS 610’ hybrid had, under stress, comparatively high leaf water potential and low leaf diffusion resistance, and were therefore regarded as “drought avoidant.” ‘Feterita’ had the greatest amount of soil moisture extraction, which was associated with very low leaf water potential, but relatively low leaf diffusion resistance. ‘Durra’ also had low leaf diffusion resistance in spite of reduced leaf water potential.Genotypes differed significantly by nearly 20% in the amounts of stored soil moisture extracted. Appreciable intergenotypic differences also were revealed in the amount of soil moisture extracted prior to heading as determined by percent of the total at maturity.
Morpho‐developmental Factors Related to Winter Survival of Wheat. I. Association of Characteristics of Dark Grown Seedlings and Winter Survival1
Authors: Ashraf M. , Taylor G. Allan 
Published: July 2010

We examined the relationship between morpho‐developmental characteristics and winter wheat (Triticum afstivum L.) survival utilizing six diverse cultivars planted at five depths in a darkened controlled environment chamber.Cultivars and planting depths differed significantly for coleoptile length, emergence rate index (ERI), seedling height, and subcrown internode length. The cultivar ✕ depth interaction was significant only for ERI. ‘Froid,’ ‘Yogo,’ and ‘Crest’ had long coleoptiles, high ERI's, and tall seedlings. MT6928, ‘Cheyenne,’ and ‘Itana’ had short coleoptiles, low ERI's, and short seedlings. Froid and Yogo developed the shallowest crown nodes followed by Itana, MT6928, Cheyenne, and Crest in that order.A significant correlation was noted between coleoptile length and ERI, but not between coleoptile length and mature plant height. Crest, a short cultivar, possesses long coleoptiles and rapid emergence, and should be a useful germplasm source for developing other short winter wheats with these characteristics.The significant positive correlation (.86*) of subcrown internode length with field winter survival suggests that long subcrown internode lengths (or shallow crowns) are associated with higher levels of winter survival. The determination of long subcrown internode cultivars should be an effective winter survival selection method in winter wheat breeding programs developing cultivars for environments similar to those of Montana.
Effect of Temperature Treatments on Combining Ability for Seed Set in Alfalfa1
Authors: Dane Fenny , Haaland Ronald , Lentner Marvin , Melton Bill 
Published: July 2010

Five selected clones of alfalfa (Medicago sativa L.) were crossed in a diallel fashion under four temperature treatments with and without emasculation. Data for seeds per flower were analyzed to determine combining ability components and the interactions across the different temperature treatments.General combining ability (GCA) was of more importance in determining seed set than specfic combining ability (SCA) across all temperatures. Differences in reciprocal crosses were significant at all temperatures.Significant interactions for GCA, SCA, and reciprocal effects across temperatures frequently occurred. This indicated that these components of combining ability for seed set were not stable across environments.Differences due to temperature or emasculation effects were larger in clones with high self‐ and cross‐compatibility ratings than those with low ratings.
Variation Among Soybean Cultivars in Seed Growth Rate During the Linear Phase of Seed Growth1
Authors: Kaplan S. L. , Koller H. R. 
Published: July 2010

This investigation tested the hypothesis that differences can exist among soybean [Glycine max (L.) Merr.] cultivars in the accumulation rate of seed dry matter during the linear phase of seed growth. At West Lafayette, Ind., in 1971, the fruit of ‘Harosoy 63,’ ‘Beeson,’ ‘Calland,’ and ‘Kent’ cultivars was harvested at weekly or more frequent intervals from replicated, 1‐m row lengths. Sampling extended from soon after anthesis until past maturity. Seeds were separated from subsamples of the dried fruit. Growth rate of the seed component during the linear phase of seed growth was estimated by regressing seed weight on days from planting after eliminating nonlinear data. Seed numbers were also determined for three of the harvests.Contrary to results of an earlier study, seed growth rates differed significantly at the 5% level during the linear growth phase from 7.94 to 9.80 g m−2 day−1. Seed numbers did not differ significantly among the cultivars, indicating that the individual seeds had different mean growth rates among the cultivars.