bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interrelationship of Temperature, Sugar Concentration, and Pollen Parent on Alfalfa Pollen Germination and Tube Growth In vitro1
Authors: Barnes D. K. , Cleveland R. W. 
Published: July 2010

In vitro pollen studies with alfalfa (Medicago sativa L.) indicated that both sugar concentrations and temperatures affected pollen germination and pollen‐tube growth. Requirements for pollen germination were less specific than those for pollen‐tube growth. At 18 C 60% of more pollen germination occurred on media containing 7, 14, 21, and 28 g of sugar/100 ml water. At temperatures of 24 and 30 C sugar concentrations of 35 and 42 g also produced germinations greater than 60%. At 36 C germination remained high on sugar concentrations of 14 through 42 g sugar, but declined at lesser concentrations.In contrast, maximum pollen‐tube length at 18 C was obtained on media with 7 to 14 g sugar. At 24 C media with 7 through 28 g sugar produced maximum pollen‐tube development. At 30 C pollen‐tube growth of some clones was markedly reduced on low sugar media, whereas other clones were less affected. At 36 C very little pollen‐tube growth was observed.The interaction between sugar concentrations and temperatures suggested to us that alfalfa may have a type of buffering system that allows pollen germination and pollen‐tube growth to occur over a wide range of environments. The data presented in this paper also indicated the existence of temperature‐sensitive genes that may influence pollen‐tube development.
Pollen Distribution and the Seedset on Triticum aestivum L.1
Authors: Khan Mir N. , Heyne E. G. , Arp Adrian L. 
Published: July 2010

Wheat (Triticum aestivum L. em Thell.) pollen dispersion was estimated, utilizing the Kramer‐Collins spore trap and tape on glass rods, in Kansas during 1966, 1968, and 1969. Seedset and yield were recorded in 1966 and 1968 on cytoplasmic male‐sterile (cms) lines. The malesterile sources were cms ‘Bison,’ ‘Shawnee,’ ‘Parker,’ ‘Scout,’ and ‘Aztec,’ with Shawnee B‐line as the pollen source. The male‐sterile lines extended 60 m north to south and 48 m east to west in 1968 and 1969, and 60 m in four directions in 1966.Pollen distribution, measured continuously in the Kramer‐Collins spore trap, gave a diurnal pattern in 1966 but not in 1968. Cold, cloudy weather in 1968 resulted in a low but nearly continuous pattern throughout the pollinating period. Pollen grains, as measured by tape on glass rods, decreased in numbers as distance from the pollen source increased, but were recorded as far as 60 m from the source. Beyond 3 m, the amount of pollen decreased rapidly.Seedset and yield patterns were similar to that of pollen number; thus, pollen number and seedset correlated significantly.
Effect of Nitrogen and Potassium Fertilization on Organic Acids of Bromus Inermis L. and Dactylis Glomerata L.1
Authors: Barta A. L. 
Published: July 2010

The effect of nitrogen and potassium fertilization on the organic acids of Dactylis glomerata L. (orchardgrass) and Bromus inermis L. (bromegrass) was characterized from initiation of spring growth to maturity.Nitrogen fertilization significantly increased malic, trans‐aconitic, and citric acids in bromegrass and citric acid in orchardgrass, but significantly decreased shikimic and quinic acids in both species. Potassium significantly reduced levels of malic, quinic, and shikimic acids in both species and trans‐aconitic acid in bromegrass. No effect of K on citric acid concentration was noted. Citric, shikimic, and quinic acid concentrations declined with increasing maturity, while the levds of the predominant organic acids (malic and trans‐aconitic) remained constant
Diallel Analysis of Leaf Area Heterosis and Relationships to Yield in Maize
Authors: Johnson G. R. 
Published: July 2010

Estimates of leaf area index (LAI) at individual leaf positions on 10 commercially adapted maize (Zea mays L.) inbred lines and their diallel set of crosses, and yields of the F1 hybrids, were obtained in order that the mode of inheritance of LAI and the relationship of LAI and distribution of LAI within the canopy to yield could be examined.Leaf area estimates were obtained from five randomly chosen plants per plot in an experiment in which the parent inbreds and F1 hybrids were arranged in two randomized blocks of one‐row plots, while yields of the F1 hybrids were obtained from an experiment in which the crosses were grown in two‐row plots arranged in a 7 by 7 simple lattice design in two randomized blocks. Row spacing and population in both experiments were 76 cm and 60,000 plants/ha, respectively. Multiple regression models were used to compute analyses of LAI heterotic effects and the relationship of LAI to yield.The results of the study indicated that: (i) LAI was inherited in a highly heterotic manner; (ii) distribution of leaf area within the canopy accounted for a significant portion of the variation in yield beyond that accounted for by total LAI; and (iii) variation in leaf area near the canopy extremes accounted for most of the yield variation attributable to leaf area distribution.
Influence of Seeding Rate upon Seed and Oil Yield and Their Components in Flax1
Authors: Albrechtsen R. S. , Dybing C. D. 
Published: July 2010

Five cultivars of flax (Linum usitatissimum L.) were each seeded at four rates to determine the influence of seeding rate on seed and oil yields, their components, and other plant and seed characteristics. A path coefficient analysis technique was employed to partition yield components into direct and indirect effects to assess the usefulness of yield components as selection criteria in a flax breeding program. Rates of seeding that were used in the study gave 0.8, 1.6, 2.8, and 3.9 viable seeds per cm of row.Seed yield, oil yield, oil content, iodine value, seed size, seeds per boll, bolls per area, and test weight were not significantly affected by variations in seeding rate. Bolls per plant and height were decreased and maturity was hastened by increased seeding rate. Approximately 85% of the variation in oil yield could be attributed to variation in bolls per area, seeds per boll, seed size, and percent oil. Stand accounted for only an additional 1% of the variation in oil yield.Path coefficient analysis showed bolls per unit area to be the most important component determining seed and oil yields, both directly and indirectly. Seeds per boll, seed size, and percent oil showed nonsignificant and negative correlations with oil yield, because the positive direct effects they exerted on yield were canceled by negative indirect effects through other components.
Pollen Germination and Tube Growth after Selfing and Crossing Coronilla varia L1
Authors: Baluch S. J. , Risius M. L. , Cleveland R. W. 
Published: July 2010

Crownvetch, Coronilla varia L., is relatively self‐incompatible. Plants selected to represent the full range of self‐fertility of a large sample of C. varia L. ‘Penngift’ were used in greenhouse experiments to locate the site or sites of incompatibility of self‐pollinations. Pollen germination and pollen tube growth in pistils after self‐ and cross‐pollinations were observed employing UV fluorescence microscopy.Pollen germination on the stigma and pollen tube penetration of the style occurred within the first 12 hours after self‐ and cross‐pollination. Pollen tubes reached ovaries within 24 hours for both types of pollination.In one experiment, the average number of germinated pollen grains on stigmas was significantly higher after crossing than after selling. However, this relationship between the two types of pollination was not consistent over the plants studied. For most plants, pollen germination on stigmas after cross‐pollination was about twice that after self‐pollination. This suggested that self‐incompatibility existed on the stigma. In the second experiment, using a different pollen source, the average number of germinated pollen grains on the stigma after crossing was not significantly different from that after selfing and the site of incompatibility seemed to be in the style.Pollen tube behavior in the ovary was the same for selfing and crossing in both experiments. For selfing, less ovules matured as seed than were penetrated by pollen tubes. Thus, both fertilization failure and post‐fertilization ovule abortion could have affected the amount of seed set after selling.Pollen germination and pollen tube behavior were the same in flowers from excised stems and stems growing on plants.
Inheritance of a New Brachyism in Corn, Zea mays L.1
Authors: Legg J. G. , Fleming A. A. 
Published: July 2010

The mode of inheritance for a new brachyism in Zea mays L., which shortens the internodes of the plant only above the top ear, was studied using the partitioning method of analysis. Chi‐square values for the F2 frequency distribution suggest that two major pairs of genes differentiate the parents used. The genes for nonbrachyism showed a partial phenotypic dominance in the F1 of three families. In a fourth family, partial phenotypic dominance for brachyism occurred, but genic dominance was toward the nonbrachytic character.Estimates of heritability in the narrow sense for families 1 and 4 were 85 while families 2 and 3 had .29 and –.34, respectively. A negative association with an average r value of –.41 occurred between the brachytic trait and plant height, whereas the average positive value between brachyism and stalk diameter was only .18. Ear height and brachyism were correlated significantly in family 1. Ear number per plant and ear weight showed no significant correlation with brachyism at the 40,772 plant population per hectare (16,500 per acre).These results indicate the possibility of the breeder using this new brachyism to lower plant height without altering ear height and of developing a plant with a new type of canopy for more efficient use of light in high plant populations.
Nitrate Reductase Activity in Corn Leaves as Related to Yields of Grain and Grain Protein1
Authors: Deckard E. L. , Lambert R. J. , Hageman R. H. 
Published: July 2010

The objective was to determine whether a relationship between nitrate reductase activity (NRA) and grain yields and grain protein could be detected for six corn (Zea mays L.) hybrids grown under field conditions with supplemental N and irrigation. NRA was expressed as seasonal input of reduced N (kg N ha‐1) and as seasonal averages of activity (µmoles N, g fresh wt‐1, hr‐1). The treatment variables were plant density (59,300 and 79,000 plants ha‐1) and tune of application (14 days after tassel initiation, at tassel emergence, and at silking) of nitrate‐N (337 kg N ha‐1).Each supplemental N treatment, regardless of time of application, significantly increased the percent of grain protein for all genotypes and amount of grain protein ha‐1 for all but one hybrid (No. 3). In contrast, the supplemental N treatments did not cause significant increases in grain yields within a given genotype. There were significant differences in grain yield and grain protein among the genotypes. The treatments increased leaf blade nitrate concentration which resulted in a corresponding increase in NRA. However, each successive N application was less effective in increasing and maintaining leaf nitrate content and enzyme activity. None of the hybrids were able to maintain a high concentration of leaf blade nitrate after silking, even though massive amounts of nitrate were applied to the soil. Compared to all other hybrids, hybrid No. 4 maintained a slightly higher level of nitrate concentration and enzyme activity in the leaves during the post‐anthesis stage.NRA of the total leaf canopy, expressed as seasonal averages or converted into seasonal input of reduced N, showed a significant positive correlation with grain protein (kg N/ha), grain yield, and total reduced N in the vegetative material (above ground) and grain and stover at maturity. The highest correlations between NRA and yields of grain and grain protein (kg N/ha) were obtained during the stages of ear initiation and development. This suggests that a minimal number (1 to 3) of samplings would be as effective as the laborious full season samplings (12 or more dates) in selecting individual plants or varieties that have a high potential for grain yields or grain protein production.
Trypsin Inhibitor in Corn (Zea mays L.) as Influenced by Genotype and Moisture Stress1
Authors: Halim A. H. , Wassom C. E. , Mitchell H. L. 
Published: July 2010

This study was undertaken to evaluate the distribution of trypsin inhibitor in kernels of genetically different strains of corn (Zea mays L.) and to determine the levels of the inhibitor in kernels as affected by water stress conditions. Crude extracts of endosperms and embryos (including scutellum) were separately analyzed for trypsin inhibitor activities.Corn kernels contained more trypsin inhibitor in endosperms than embryos. The endosperm inhibitor level varied widely from line to line. Endosperms containing the opaque‐2 gene exhibited much higher concentrations of trypsin inhibitor than normal corn, but the reverse was the case for endosperms containing the floury‐2 gene.Trypsin inhibitor activities varied within strains when plants were subjected to differential water stress at different growth stages. Generally, there was less inhibitor in endosperms of all lines when irrigation was discontinued at pollination time, but when irrigation was discontinued about 21 days before pollination some genotypes had increased inhibitor activities. However, the increase was not significantly different from that under highest water conditions for most varieties. Trypsin inhibitor in embryos seemed to be influenced little by water stress.The amounts and pattern of trypsin inhibitor activities of corn strains suggest that both genotype and environmental stress influenced formation of inhibitors, particularly in the endosperms.
Photoperiodic Responses of Peanuts1
Authors: Wynne J. C. , Emery D. A. , Downs R. J. 
Published: July 2010

In an initial experiment the response to photoperiod of six lines representing the two subspecies of Arachis hypogaea L. was measured under two long‐day and two short‐day photoperiodic treatments in the North Carolina State Unit of the Southeastern Environment Laboratories. All treatments were at constant day/night temperatures of 30/26 C for 64 days.Vegetative growth of the plants was reduced by shortday treatments. However, plants grown under short days produced more fruit than plants subjected to long‐day treatments.A second experiment tested the interactions of photoperiod with temperature and their effects on reproductive and vegetative characters of peanuts. Three lines of A. hypogaea were exposed to long and short days at 30/26, 26/22, and 22/18 C.Plants grown under short days were smaller in size but produced more fruit than plants grown under long days. The greater fruit production of plants grown under short days was not caused by differences in flowering intensity, but by factors that occurred after flowering.
Distribution and Utilization of 14C‐labelled Assimilates in Soybeans1
Authors: Hume D. J. , Criswell J. G. 
Published: July 2010

Individual soybean [Glycine max (L.) Merr.] plants grown in the field during 2 years were allowed to assimilate 14CO2 either during vegetative growth, at first flowering, at early pod development, or during rapid seed development. Some of the labeled plants were harvested immediately after labelling, and others after 1 week, at incipient leaf drop, or at maturity. Radioactivity was measured in the component parts of each labelled plant.Plant parts that were growing actively at the time of labelling accumulated more 14C than those parts that were not growing actively. When the plants were growing vegetatively, most of the 14C was incorporated into structural leaf and stem tissue. As labelling tunes became later during ontogeny, stems contained decreasing amounts of 14C, and more 14C accumulated in seeds by maturity. After rapid seed development began, roots and nodules accumulated little 14C.If plants were labelled before vegetative growth was completed, 30 to 40% of the 14C present immediately after labelling was recovered in plants grown to maturity. Plants labelled during rapid seed development retained 65% of the original 14C at maturity. Calculated losses of 14C due to respiration averaged 20%. Most of the 14C lost by maturity was in abscised tissue.The proportions of 14C assimilated at the four stages of development and recovered in seeds at maturity were quite similar to comparable proportions of assimilated 14C recovered in the seeds of maize (Zea mays L.) grown nearby,
Effects of Genetic Background on Monogenic Resistance to Helminthosporium turcicum in Maize (Zea mays L.)1
Authors: Calub A. G. , Dunn G. M. , Routley D. G. 
Published: July 2010

A “drop‐diffusion” technique was used to determine the effects of genetic background upon the production of phytoalexin or other inhibitory substances in corn (Zea mays L.) with monogenic resistance (Ht/Ht) to Helminthosporium turcicum Pass. Seedling leaves were inoculated with drops of an aqueous suspension of spores of H. turcicum in a humid chamber at 21C, 100% RH, and a light intensity of 3230 lux for up to 6 days. Drops of the suspension were then withdrawn from the leaf surfaces 1 to 6 days after inoculation and centrifuged. The supernatant or diffusate, then free of spores and germ tubes, was mixed with a drop of fresh spore suspension. Diffusates that inhibited spore germination or delayed the growth of the germ tube was assumed to contain phytoalexin or other inhibitory substance. Five standard susceptible inbred lines (ht/ht), their nearly isogenic resistant counterparts (Ht/Ht), and the five F1 hybrids (Ht/ht) of paired isogenic lines were bioassayed.The incorporation of the Ht gene into any of the five inbred lines significantly increased the amount of inhibitory substances. Homozygous resistant inbred lines (Ht/Ht) produced significantly more phytoalexin or other inhibitory substances than the heterozygotes (Ht/ht) which in turn produced significantly more inhibition than susceptible inbred lines (ht/ht). The genetic background affected the amount and to a certain extent the time of production of inhibitory compounds. Bioassay tests and percent leaf infection following standard inoculation were not significantly correlated.
Cultivar‐Environment Interaction Study of Alfalfa Yields in Oklahoma1
Authors: Taliaferro C. M. , Denman C. E. , Morrison R. D. , Holbert D. 
Published: July 2010

Forage yield data from 14 alfalfa (Medicago sativa L.) cultivars harvested for 3 years (1966 through 1968) at each of 5 Oklahoma locations were used to study CE (cultivar × environment) interactions. Mean squares, estimated variance components, and regression analyses statistics were used to draw conclusions.Statistically nonsignificant mean squares and small variance components for the first order CL (cultivar × location) and CY (cultivar × year) interaction components suggested minimal effects of locations and years per se on relative yields of alfalfa cultivars. The second order CLY (cultivar × location × year) interaction effect was of large magnitude and highly significant, indicating that CE interactions in alfalfa yields were attributable to factors other than years and locations. These results emphasized the necessity for multiple environment testing but gave little information which would elucidate how these tests should be distributed over years and locations. Cultivar regression coefficients, though in most cases not statistically different from unity, suggested some possible differential cultivar reaction to varying environments. Cultivars with regression coefficients above one had either a better than average response to high yield environments or a smaller than average response to low yield environments. Mean square deviations from regression (s2d) revealed specific instances of yield instability which presumably resulted from CE interaction.Due to the perennial nature of alfalfa and the need to evaluate stand persistence in new lines, it would seem most feasible to extend tests over years using a minimum of test locations. Locations, however, should probably be divided to include both high‐ and low‐yielding sites. In Oklahoma, alfalfa strains and cultivars can very likely be adequately evaluated for forage yield ability by testing for 3 years (4 years including the year of seeding) at three to four selected locations.
Floral Induction and Development in Festuca rubra L. — Differential Clonal Response to Environmental Conditions1
Authors: Murray J. J. , Wilton A. C. , Powell J. B. 
Published: July 2010

Development of suitable procedures for production of inflorescence and subsequent seed production of red fescue, Festuca rubra L., under controlled conditions would facilitate earlier completion of breeding procedures and genetic tests. Two studies were conducted in 1970–71.The first study was to determine the date of floral induction. Propagules from 15 clones were removed from the field every 14 days beginning October 28, 1970 through January 14, 1971, and grown under cool temperature and long photoperiods for 24 days to initiate floral primordia. They were then grown under warm temperature and long photoperiods for the production of inflorescence. Variation among clones in the required length of exposure to the field environment for floral induction was 30 days. By January 1 virtually all plants were induced. Days to heading decreased and number of panicles increased with increasing exposure to the field environment.The second study was to determine the controlled temperature and photoperiod favorable for floral development after induction in the field. Twenty‐four clones brought from the field on January 24 were placed under cool temperature and either normal daylight or continuous light for 28 days. They were then grown under controlled temperature and photoperiod regimes. Heading was earlier, number of panicles increased 17%, and number of seeds increased 45%, where the initial treatment was normal daylight. Number of panicles and seeds was greatest where the final treatment was normal daylight supplemented with 1 hour of light at midnight and 21 to 24 C. Biotypes within this species differed in their environmental requirements for floral production. By manipulating environmental conditions, we produced sufficient seed of good quality for experimental use during winter months in the greenhouse.
Storage of Sugarbeet Roots in Controlled Atmospheres to Conserve Sucrose1
Authors: Wyse R. E. 
Published: July 2010

Storage of sugarbeet (Beta vulgaris L.) root in controlled atmospheres showed no consistent effect of oxygen and carbon dioxide on raffinose, reducing sugar, or amino acid content in the varieties studied. Controlled atmosphere (CA) storage reduced the tendency of one variety to accumulate reducing sugars, but showed no consistent improvement in the other varieties testedCarbon dioxide concentrations up to 10% had no beneficial effect on sucrose conservation or impurity accumulation. Although decreasing the oxygen content to 3 to 5% significantly reduced storage losses of sucrose in these experiments, large‐scale studies will be required to determine if CA storage has any practical advantage over low‐temperature storage in air.