bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abscission Processes in Cotton: Induction by Plant Water Deficit1
Authors: McMichael B. L. , Jordan W. R. , Powell R. D. 
Published: July 2010

AbstractPremature boll shedding is characteristic of the cotton (Gossypium hirsutum L.) growth habit, but the extent of this shedding is quite variable. This study was undertaken to evaluate the effects of water stress on boll and leaf abscission. The experiments were conducted in a greenhouse using plants grown in pots containing sand. Plant water deficits were induced by withholding water. Leaf water potentials measured with a pressure bomb were used to quantify the plant water deficit.The extent of both boll and leaf abscission increased in a linear manner as leaf water potentials decreased from −10 to −24 bars. Abscission induced by water stress was dependent upon age of the tissue. Older leaves were shed as a result of relatively mild water deficits, while juvenile leaves did not abscise even after severe water deficits. Young, immature bolls were most sensitive to water stress. Bolls that remained on the plant approximately 14 days were retained by the plant even after exposure to a severe plant water deficit. A predawn leaf water potential of about −8 bars was required to induce significant leaf abscission.
Light Reflectance by Leaflets of Pubescent, Normal, and Glabrous Soybean Lines1
Authors: Gausman H. W. , Cardenas R. 
Published: July 2010

AbstractThe premise that hairy coverings on leaves diffuse and entrap incoming light was tested by comparing differences in spectrophotometrically measured reflectance, transmittance, and absorptance over the 500 to 2500‐nm wavelength interval among terminal leaflets of densely pubescent (hairy), normal (medium hairy), and glabrous (hairless) soybean [Glycine max (L.) Merr.] lines.Upper (adaxial) surfaces of pubescent leaflets reflected less light (1.5%) than glabrous leaflets over the 750 to 1,350‐nm near‐infrared (IR) region. Pubescent leaflets absorbed 4.1% and glabrous leaflets absorbed 2.3% of the near‐IR light.Results suggest that leaf hairs diffuse and entrap incoming near‐IR light and thereby increase its absorptance and decrease its reflectance.
Water Relations, Growth, and Dry Matter Accumulation of Sorghum Under Post‐Rainy Season Conditions1
Authors: Sivakumar M. V. K. , Seetharama N. , Singh Sardar , Bidinger F. R. 
Published: July 2010

AbstractSorghum (Sorghum bicolor (L.) Moench) is one of the important crops grown under the residual soil moisture situation during the post‐rainy (rabi) season in India. Field studies were conducted at the ICRISAT center on deep vertisols on the effects of water stress on the growth and dry matter accumulation of sorghum. Leaf water Potential and stomatal conductance were measured diurnally on four dates during the growing season.Irrigated sorghum crop exhibited higher stomatal conductance and higher leaf water potentials as compared to the nonirrigated sorghum. Higher transpiration rates observed in the case of the irrigated sorghum could be explained by the increased net radiation measured over the irrigated canopy. Lower leaves in the sorghum canopy showed lower stomatal conductance. Irrigated sorghum plants showed higher leaf area index and greater dry matter accumulation than those of the nonirrigated sorghum plants. There were significant differences in the final yield between the two treatments as reflected by less teritiary brancheslsecondaries, lower seed number/panicle and smaller seed size in the case of the nonirrigated sorghum.On a seasonal basis, the nonirrigated sorghum crop used 213 mm of water to produce 0.51 kg m‐2 of dry matter, whereas the irrigated sorghum extracted 321 mm of water to produce 0.93 kg m‐2 of dry matter.
A Modified Flail Mower for Harvesting Forage Research Plots1
Authors: Barnes G. L. , McLaughlin G. L. , Foster W. D. , McMurphy W. E. 
Published: July 2010

AbstractHarvesting forage plots for yield determination usually involves separate cutting and collection operations. A standard commercial hammer knife (flail) mower was modified by an addition of an Al collecting box for recovery of cut forage from individual plots. A tophinged rear door facilitated easy removal of harvests onto small tared tarpaulins for subsequent weighing. The modified unit proved to be effective for excellent recovery of cut alfalfa (Medicago sativa L.) forage.
An Analysis of the Carbohydrate Status of Mefluidide‐Treated Annual Bluegrass
Authors: Cooper R. J. , Street J. R. , Henderlong P. R. , Koski A. J. 
Published: July 2010

AbstractThe intense spring seedhead production of annual bluegrass (Poa annua L.) is a major factor limiting its quality as a turfgrass. Developing seeds are unsightly, and monopolization of assimilates by developing seeds may be partially responsible for the shallow root system and poor stress tolerance of annual bluegrass. A greenhouse study was conducted to determine if seedhead suppression resulting from the plant growth regulator mefluidide [N(2,4‐dimethyl‐5‐{[(trifluoromethyl)sulfonyl]amino} phenyl) acetamide] would result in a redistribution of carbohydrates to the roots of annual bluegrass. Mefluidide was applied prior to seedhead emergence at rates ranging from 0 to 0.21 kg a.i. ha−1. Complete seedhead suppression associated with the 0.14 and 0.21 kg a.i. ha−1 rates resulted in greater concentrations of fructose and glucose in annual bluegrass roots compared to roots of untreated plants during peak seedhead emergence. Redistribution of carbohydrates was short lived, with no differences in carbohydrate content occurring among treatments after peak seedhead emergence. Mefluidide had little effect on leaf and stem carbohydrates. Regardless of mefluidide rate, concentrations of fructose, sucrose, and fructans were considerably greater in leaf and stem tissue than in roots. Annual bluegrass stems were the major storage organ for fructans, with only minor fructan storage occurring in roots. The carbohydrate content of mefluidide‐treated annual bluegrass decreased substantially in leaf, stem, and root tissue following growth inhibition due to a post‐inhibition growth surge.
Heterosis and Combining Ability in a Diallel Cross Among Nine Varieties of Oriental Tobacco1
Authors: Marani A. , Sachs Y. 
Published: July 2010

Nine varieties of oriental tobacco and all possible F1 hybrids among them were evaluated at two locations in srael. Yield of cured leaves, mean weight per cured leaf, number of leaves per plant, plant height, combustibility, total alkaloid content, and days to flowering were determined.The average yield of cured leaves of the hybrids was 21% above that of the parental varieties. Other traits with the exception of combustibility and total alkaloid content exhibited significant heterotic effects. The magnitude of heterosis was similar at both locations.The ranking of the varieties according to their relative general combining ability was similar, in most cases, to their ranking according to parental performance. It was suggested that additive genetic variance was predominant for all the traits that were examined, but there was an indication that nonadditive components of genetic variance may also be present. We concluded that the procedure of selecting homozygous lines from the segregating progeny of a cross would be more suitable than using first‐generation hybrid varieties for breeding oriental tobacco.
Seedling and Biochemical Differences Within a Long‐Time Maize (Zea mays L.) Inbred1
Authors: El‐Eryani A. A. , Fleming A. A. 
Published: July 2010

Significant differences in seedling agronomic and quantitative biochemical characters (total carbohydrates) were obtained between four stocks of the same long‐time inbred line of maize.Apparently, 3 different biotypes have evolved in the 4 stocks of the inbred Cl 7. The stocks from North Carolina and Arkansas have diverged widely from each other as well as from the Athens and Beltsville stocks. Athens and Beltsville stocks have remained similar to each other. In general, the stocks which had agronomic differences in a previous study also had seedling agronomic and biochemical differences in this study.Hereditary variations reported herein may be attributed to relic heterozygosity, mutation, or a combination of the two. These causes and the significance of the variations are discussed in a previous paper (2).Studies in the determination of heterogeneity between stocks of the same inbred line are not limited to field experiments. Results of this experiment show that seedling characters in the greenhouse and quantitative biochemical analysis in the laboratory may be used successfully in differentiating stocks within a long‐time inbred line. Furthermore, this information should be of value in relating biochemical studies to both applied and basic genetical research.
A Second Locus for Pollen Color in Pima Cotton, Gossypium barbadense L.1
Authors: Turcotte E. L. , Feaster Carl V. 
Published: July 2010

Pollen color in the amphidiploid species of Gossypium varies from deep golden yellow to cream and is conditioned by one pair of alleles, P and p, with yellow dominant to cream. A mutation causing orange pollen was found in ‘Pima S‐I’, a normally yellow pollen commercial variety of Pima cotton (Gossypium barbadense L.). The mutant, when selfed, showed pleiotropic effects which gave ranker plants that flowered later and fruited higher. Also, the flower buds were not conical and the stigma extruded beyond the scalloped tips of the corolla.The inheritance of orange pollen was determined from crosses of yellow with mutant orange, yellow with cream, and cream with mutant orange pollen strains. Single gene differences conditioned pollen color in the first two crosses; yellow was dominant. Pollen color in the cross of cream with mutant orange was conditioned by two complementary genes, giving an F2 segregation of 9 yellow: 3 orange: 4 cream. One of the cream phenotypes in F2 was found to be conditioned by the homozygous double recessive — a new genotype for cream pollen.The symbols P1 or p1 and P2 or p2 are proposed for the genes conditioning pollen color in G. barbadense. True breeding yellow and cream pollen strains would have the genotypes P1P1P2P2 and p1p1P2P2, respectively. The orange pollen mutant would have the genotype P1P1p2p2.
Radiation Studies with Sexual Yellow‐Anthered Dallisgrass, Paspalum dilatatum Poir
Authors: Bashaw E. C. , Patrick Keith H. 
Published: July 2010

Dormant seed of an erect, sexual, but highly uniform dallisgrass, Paspalum dilatatum Poir., ecotype were irradiated with gamma rays and neutrons in an effort to induce favorable changes in growth habit. Radiation caused extensive changes in morphology and growth characteristics and also resulted in severe seedling mortality and high sterility. Most of the mutants were inferior to untreated plants, but a few highly fertile, vigorous, decumbent mutants of potential value were recovered in the M2 generation.In general, prominent changes in growth characteristics were accompanied by chromosomal aberrations, reduced viability of male and female gametophytes, and low fertility. Abortion of the female gametophyte corresponded very closely to the reduction in pollen quality. Degeneration of sporogenous tissue was noted at all stages of megasporogenesis and embryo sac development, and there was no evidence of selectivity for a balanced megaspore within the linear tetrad.
Lateral Root Development in Progenies of Creeping and Noncreeping‐Rooted Medicago sativa L.1
Authors: Avendano Raul E. , Davis Ralph L. 
Published: July 2010

Progenies between 2 creeping‐rooted and 2 noncreepingrooted clones crossed in all combinations were evaluated for differences in root development. Plant heights and dry weights of tops and roots were measured.Lateral root development began within the first 3 months of growth and a cross involving 2 creeping clones produced the highest proportion of progeny with lateral roots. The first vigorous lateral roots produced on plants from creeping ✕ creeping clones were closer to the crown (nearer the soil surface) and formed a larger angle with the main root than laterals on plants from noncreeping ✕ noncreeping clones. Crosses of the 2 creeping‐rooted clones produced more plants with adventitious shoot sites on roots and more sites per plant than other crosses. Adventitious shoots were observed as early as 5 months after planting.Forage yields between progenies of creeping ✕ creeping and noncreeping ✕ noncreeping crosses were not significant. Negative but nonsignificant correlations were found between the distance from the base of the crown to the first vigorous lateral and the angle formed between this lateral and the main root. Dry weight of the roots in the top 18 inches of soil was positively and significantly correlated with height and yield. The lateral roots on the creeping‐rooted plants developed early and suggested that such types less than one year old may resist heaving better than noncreeping types.
Components of Seed Yield and Associated Characteristics in Lotus corniculatus L.1
Authors: Albrechtsen R. S. , Davis R. L. , Keim W. F. 
Published: July 2010

Data were obtained on 12 variables in a replicated clonal nursery containing 20 genotypes of birdsfoot trefoil, Lotus corniculatus L., with plants spaced at 40‐inch centers. Broad sense genetic variability (heritability) estimates suggested that a large part of the phenotypic variation present was genetically controlled. Values of expected gain from selection suggested that seed yidds of 93% over the mean of the population studied should be attainable through selection of the top 10% of the population. Prostrate‐type plants had higher mean values for seed yield and all of its potential components than did upright‐type plants.Progeny plants from crosses in all combinations between 2 prostrate and 2 upright‐type clones included in the clonal nursery were studied in 2 progeny nurseries. Plants in one of these nurseries were spaced at 36‐inch centers and those of the other at 12 by 16‐inch spacing. Genetic variability estimates were generally higher at the 12 by 16‐inch spacing than corresponding estimates from the wider‐spaced nursery. Progenies from crosses of prostrate X upright types (and reciprocals) were superior to progeny from prostrate X prostrate or upright X upright for most of the characters studied. This differential in performance was usually greatest at the closer spacing.Path coefficient analyses showed that number of umbels setting seed had the greatest influence upon seed yield, both directly and indirectly, of components analyzed. Phenotypic and genotypic coefficients of determination for the actual components studied in the clonal nursery were 89% and 96%, respectively, compared to those of 27% and 45% for the potential components.
A Cytological Study of Certain Autotetraploid Avena Hybrids1
Authors: Muehlbauer F. J. , Marshall H. G. 
Published: July 2010

Autotetraploid hybrids of Avena brevis ✕ A. hirtula, A. hirtula ✕ A. strigosa, and reciprocal were studied for cytological behavior, self‐fertility, and cross‐fertility in the C1 and C2 generations. There was no statistical difference between hybrids or generations for these characters. Cells with 10 bivalents and 2 quadrivalents were the most common type of chromosome pairing at metaphase I of meiosis. The overall means were .52 univalents, 9.86 bivalents, .33 trivalents, and 1.69 quadrivalents. Complete bivalent pairing was occasionally observed. When compared to data for autotetraploids of A. strigosa, the hybrids showed an increase of 4 to 5 bivalents, a decrease in multivalents, and about 20% higher self‐fertility.It was suggested that the increased meiotic stability of the autotetraploid hybrids was caused either by genic control of chromosome pairing or by cryptic structural differences between homologues from the As genomes of the parental species.
Inheritance of Seed Size in Sorghum, Sorghum vulgare Pers1
Authors: Voigt R. L. , Gardner C. O. , Webster O. J. 
Published: July 2010

A large‐seeded variety of sorghum, ‘Big Seed’, and a small‐seeded variety, ‘Norghum’, their F1 and F2 cross generations, and the two first backcrosses were investigated to gain a better understanding of how seed size is inherited and to assess the possibility of increasing seed size through selection. A preliminary study indicated that a 300‐seed sample from each plant would give adequate precision.Population means and variances provided the basic data from which conclusions were drawn. All populations were approximately normally distributed on the original scale. Transformation to √Y‐2 caused the largeseeded parent to depart from normality but eliminated the correlation between means and variances. Gene action appeared to be almost entirely additive. Evidence for dominance or epistasis as an important contributor to seed size was lacking. A minimum of 3 or 4 genetic factors or blocks of genes, primarily additive in their effect, appear to control seed size.Heritability for seed size was estimated to be 60% indicating that considerable progress could be made in shifting mean seed size by selecting and recombining large‐seeded F2 plants.
Rating of Alfalfa Varieties for Cold Resistance by Germination in Solutions of Different Osmotic Values1
Authors: Dovrat A. , Waldman Miriam 
Published: July 2010

Seven alfalfa varieties differing in degree of winterhardiness were germinated in water and in 6‐atm mannitol solution (500 ml substrate) at 20 C in the dark. The delay in germination was expressed as the ratio between the rate of germination over the period at which most of the slope of the germination curve is near linear in the 0‐ and 6‐atm solutions, respectively. This ratio (R0R0 value) was found to be closely related to the apparent winterhardiness of the varieties.The test enabled fair separation between 19 and 21 seed lots of ‘Ranger’ and ‘Vernal’ alfalfa, respectively. The lots represented different generations of increase and were derived from a wide latitudal range of seed production areas. However, all were from the same harvesting year.
Variations in the Total, Nonprotein, and Amide Nitrogen Fractions of Agrostis palustris Huds. Leaves in Relation to Certain Environmental Factors1
Authors: Beard James B. , Daniel William H. 
Published: July 2010

The influence of certain environmental factors on the seasonal variation in the total, nonprotein, glutamine, asparagine and total amide nitrogen fractions of Agrostis palustris Huds. leaf tissue were investigated. Five linear multiple correlation‐regression analyses indicated temperature to be the major environmental factor influencing seasonal variations in the five nitrogen fractions measured. Temperature accounted for three‐fourths of the predicted variation in total nitrogen. Daily maximum soil temperature at 15 cm was most highly correlated of the measured air and soil temperatures with the five nitrogen fractions.The coefficient of determination for the non‐protein nitrogen fraction was quite low, indicating a minimum response to soil and air temperatures, light intensity, and soil moisture.The total nitrogen content measurements throughout the season showed total nitrogen levels above 5% to be closely related to soil temperatures which exceeded 18 C. When soil temperatures exceeded 24 C a decrease in the total nitrogen content was noted.The nonprotein nitrogen fraction increased slightly during the higher temperature periods of late July and August, but decreased when soil temperatures exceeded 27 C.Glutamine showed the greatest response to temperature of the five nitrogen fractions, with quite low levels occurring at soil temperatures above 24 C. Asparagine responded much less than glutamine to seasonal variation related to temperature. The total amide content responded decidedly to increases in temperature with the major response being attributed to the glutamine fraction.
Cytogenetic Effects and Responses of Agronomic Characters in Grain Sorghum (Sorghum vulgare Pers.) Following Atrazine Application1
Authors: Liang George H. L. , Feltner K. C. , Liang Y. T. S. , Morrill J. L. 
Published: July 2010

Three varieties and two hybrids of grain sorghum were sprayed with atrazine at the rate of 2.7 kg a.i./ha (2.4 lb a.i./A). A single treatment was given to each plot and applications were made at weekly intervals, beginning 1 week after emergence. Pollen mother cells collected from each genotype treated at seven developmental stages were examined.Many affected microsporocytes were observed. Abnormalities consisted of multinucleate cells, bridges, and increased chromosome numbers, some of which were not a multiple of the basic number. Dyads and quartets often contained micronuclei. Atrazine treatment apparently interfered with meiotic stability regardless of time of application. Statistical analyses of grain yield, head weight, kernel weight, fertility, stalk diameter, and germination percentage indicated that treated groups did not differ from the control group. Plant height, however, differed between control and treated groups. No consistent relationship was observed between content of protein, soluble and total carbohydrates, and date of treatment. Also, no apparent relationship existed between frequency of chromosomal aberrations and agronomic responses following atrazine application.
Influence of Environment on Stability of Corn During Vegetative Growth1
Authors: Andrew R. H. 
Published: July 2010

Purpose of this study was to determine stability during vegetative growth for a diallel series of 10 corn hybrids (Zea mays L.) and their 5 inbred parents under greenhouse and field environments and to compare parenthybrid relationships in the two environments. Measurements were taken on fresh weight, adventitious root number, and leaf number at successive ages.Analyses of variance within ages, across environments, and within environments across ages were completed for each character. Genetic variation in terms of other variability was expressed by ratios between genotype and environmental variance. Correlations between parents and hybrid progeny in each environment and between characters within and between environments were determined.Growth was more rapid in the field. Leaf number was least variable and fresh weight most variable. For each character and type of germplasm there was greater variation between locations than between years. Environmental variance and ratios between field and greenhouse means for individual genotypes usually were higher for hybrids, while relative genetic variation in terms of other variability was higher for inbreds.Respective variances were usually higher in the field. Age ✕ replicate and age ✕ genotype ✕ replicate interaction variances for both inbreds and hybrids were higher in the field where measurements were taken on different plants than in the greenhouse where successive measurements were taken on the same plants.The association of inbred performance with general combining ability rating by diallel analysis was higher in the constant greenhouse environment. Also, hybrid performance was always more closely related to respective midparent values in the greenhouse. Associations between environments for fresh weight leaf number were usually significant by the third age of sampling at 650 thermal units. In all environments, associations between fresh weight and leaf number were most marked.