bluuebunny/crossref_metadata_2025 huggingface dataset:
Interrelations Among Protein, Lysine, Oil, Certain Mineral Element Concentrations, and Physical Kernel Characteristics in Two Maize Populations1
Authors: Arnold J. M. , Bauman L. F. , Aycock H. S.
Published: July 2010

The interrelationships among whole kernel protein, lysine, oil, P, K, Mg, Fe, and Zn concentrations and physical kernel characteristics were determined in a heterozygous opaque‐2 population and a homozygous opaque‐2 maize (Zea mays L.) population. Compared to normal kernels the opaque‐2 kernels were higher in lysine, P, K, Mg, Fe, and Zn concentrations. However, on a kernel weight or kernel volume basis, the opaque‐2 kernels were significantly greater only for lysine, K, and Zn. Our results indicated that the opaque‐2 gene, or closely linked genes, had a direct influence on K and Zn content as well as on lysine content. The correlation of the differences between the normal and opaque‐2 kernels for percent lysine and percent Zn was positive and significant. This relationship may indicate that modifier genes that are influencing the effect of the opaque‐2 gene on lysine concentration may also be influencing the effect of the opaque‐2 gene on Zn concentration in a similar manner. Several significant correlations were detected between percent lysine and the mineral element concentrations, but none were of sufficient magnitude to be of value as a selection criteria for lysine content. Percent lysine was not correlated with kernel weight or volume but was negatively correlated with kernel density. The coefficients for the correlation between percent lysine and percent protein were +0.50 and +0.70, respectively, for the normal and opaque‐2 kernels in the heterozygous population and +0.83 for the homozygous opaque‐2 population. The magnitude of these correlation coefficients indicated a rather strong tendency for lysine concentration to increase as protein concentration increased, especially in the opaque‐2 kernels. Protein concentration was found to be the best selection criteria for lysine concentration except for possibly the lysine concentration per se.
Effects of Low Levels of Ozone on Growth of Crimson Clover and Annual Ryegrass1
Authors: Bennett J. P. , Runeckles V. C.
Published: July 2010

Studies have been conducted on short term exposure of plants to broad ranges of O3 concentration. Our purpose was to investigate long term exposure of plants to O3 levels that were below those normally causing visible injury. Annual ryegrass (Lolium multiflorum Lam.) and crimson clover (Trifolium incarnatum L.) were grown for 6 weeks in chambers within a greenhouse and fumigated for 8 hours/day with 0.03 and 0.09 ppm O3 in air. Treated plants showed less growth and yield than the controls despite the absence of visible injury. Both total dry weight and leaf area of treated plants were as much as 22% lower than the controls, but percent dry weight was significantly higher. Root growth was impaired the most, followed by stems and leaves, respectively, as evidenced by a lower root/shoot ratio and a slightly higher leaf weight ratio with O3 treatment. Both species showed significantly lower specific leaf areas and leaf area ratios in O3 compared to the control, but higher net assimilation rates led to relative growth rates which were unaffected. It was concluded that although the relative size of the leaf system was very sensitive to prolonged exposure to low O3, compensation in growth parameters occurred to counteract the stress response.
Serpentine Sunflower, Helianthus Exilis, as a Genetic Resource1
Authors: Jain S. K. , Olivieri A. M. , Fernandez‐Martinez J.
Published: July 2010

The common weedy species Helianthus bolanderi Gray and a rare endemic, H. exilis Gray, were studied comparatively for population variation and ecology. Seeds from nature and from populations grown in a greenhouse were used in germination tests and fatty acid analysis of oil. The potential value of H. exilis as a genetic resource resides in its higher linoleic acid content in oil and germination polymorphism related to the response to red/far‐red light and low temperatures that may be useful in eliminating dormancy problems.
Laboratory Germination and Sand Emergence Responses of Alfalfa Seed to Radiofrequency Electrical Treatment1
Authors: Nelson S. O. , Kehr W. R. , Stetson L. E. , Wolf W. W.
Published: July 2010

The use of radiofrequency (RF) dielectric heating was studied for rendering hard seeds of alfalfa (Medicago sativa L.) permeable to water. The treatment increased laboratory germination and greenhouse‐sand emergence of several alfalfa seed lots that contained high percentages of hard seed. The treatments produced corresponding reductions in hard‐seed percentages and, at proper exposures, did not damage seed viability. At moisture contents from 2.7 to 9.8%, effectiveness of treatment improved as seed moisture content was lowered before treatment. At normal contents of seed moisture (about 6 to 8%), treatments that reduced hard seed content without detrimental effects resulted in final seed temperatures of about 70 to 80 C. Greenhouse‐sand emergence tests and normalseedling counts in laboratory germination tests were generally in good agreement. Numbers of abnormal seedlings in treated and untreated samples were not significantly different. Quality of RF‐treated seed, maintained in storage at 4 C and 50% relative humidity for up to 15 years after treatment, was as good as that of untreated control seed.
A Quantitative Approach to Source Potentials and Sink Capacities Among Reciprocal Grafts of Sweet Potato Varieties1
Authors: Hahn S. K.
Published: July 2010

Economic yield of sweet potato, Ipomoea batatas L., may be limited by either photosynthetic source potential or tuberous root sink capacity. The relationships between source and sink were investigated quantitatively with special reference to the yield of dry tuberous root yield through the use of reciprocal grafts of a set of varieties in all possible combinations.

Responses of the sink to the source and of the source to the sink were examined. The varieties with large sink capacities showed greater responses of sinks to source than the varieties with poor sink capacities. The varieties with the greater source potential showed the greatest response of source to sink.

Source‐sink relationships as determinants of yield in the sweet potato are discussed.
Pleiotropic Effects of the tr Trichomeless Gene in Pearl Millet on Transpiration, Forage Quality, and Pest Resistance1
Authors: Burton G. W. , Hanna W. W. , Johnson J. C. , Leuck D. B. , Monson W. G. , Powell J. B. , Wells H. D. , Widstrom N. W.
Published: July 2010

The single recessive tr gene when homozygous suppresses all trichomes in pearl millet, Pennisetum americanum (L.) Leeke. By comparing the near‐isogenic Tilt 23S (tr tr) and the pubescent Tilt 23H (Tr Tr) the following pleiotropic effects were discovered. The tr gene reduced transpiration from 8.9 to 35.0% in eight genotypes without altering stomate length or frequency. The tr gene imparted a smooth wax‐like surface to the cuticle of the leaves that caused the leaves (blades) to accumulate more dew, kept the leaves wet longer, and increased the rate at which rust developed on them. This modified tr cuticle apparently reduced in vitro dry matter digestibility (IVDMD) rates in intact leaf sections and slowed the drying rate of excised green leaves. The tr gene increased the palatability of pearl millet forage for cattle and tended to increase intake for the first few days of a green feeding test. However, it failed to increase overall livestock gains, probably because the slower digestion rate of tr forage slowed its passage through the gastrointestinal tract, reduced intake, and offset its greater palatability. The tr gene significantly reduced oviposition of the fall army worm, Spodoptera frugiperda J. E. Smith and corn earworm, Heliothis zea Boddie and reduced the foliar feeding of first and second instar fall army worms fourfold.
Rooting Patterns of Semi‐dwarf and Tall Winter Wheat Cultivars under Dryland Field Conditions1
Authors: Cholick Fred A. , Welsh James R. , Cole C. Vernon
Published: July 2010

The rooting patterns of two tall and three semi‐dwarf winter wheat (Triticum aestivum L. em Thell.) cultivars were evaluated under dryland field conditions in eastern Colorado. Radioactive phosphorus (32P) was foliar applied at the soft dough stage of plant development and allowed to distribute through the root system for a 5‐ day period. Root systems were then evaluated by measuring the relative distribution of radioactivity in soil‐root cores at 30‐cm increments through the soil profile to a 300‐cm depth. Soil moisture contents, determined at harvest, were used to compare the five cultivars for associated soil profile moisture contents. We found no significant relationships between cultivar height and rooting depth or moisture extraction patterns. All cultivars rooted to a minimum depth of 300 cm both years of this experiment.
Effect of Water Stress on Carbon Assimilation and Distribution in Soybean Plants at Different Stages of Development1
Authors: Silvius J. E. , Johnson R. R. , Peters D. B.
Published: July 2010

The effects of water stress on carbon dioxide (CO2) exchange rates (CER) and assimilate distribution were studied in chamber‐grown soybean plants (Glycine max (L.) Merr., ‘Fiskeby’) in the vegetative, flowering, and pod‐filling stages of development. When water was withheld, the decrease in CER was correlated with the increase in stomatal resistance at leaf water potentials as low as −21 bars. Under the above conditions, CER and stomatal resistance recovered to predesiccation levels within 24 hours after rewatering. When leaf water potentials were allowed to drop below −21 bars, recovery of CER lagged behind the return of stomatal resistance to predesiccation levels, suggesting that additional factors may be involved. Whole plants were exposed to labeled CO2 at the three different stages of development and the percent distribution of 14C was determined. At leaf water potentials of −15 to −20 bars, plants displayed alterations in 14C distribution among plant parts corresponding to alterations in dry weight distribution. Compared to well‐watered plants, relatively more 14C was found in the roots of water‐stressed plants before the pod‐filling stage. Less 14C was retained in the leaf blades of these plants, but this response was reversed during pod‐filling. Reduction in 14C in nodules was associated with water stress at all growth stages. Percentage of radioactivity increased in leaves and reproductive structures of plants rewatered and exposed to 14CO2 following return of CER to predesiccation levels. Our results suggest that drought decreased CER and altered assimilate distribution, producing growth modifications that favor efficient use of the limited supply of fixed carbon.
Haploid Breeding Technique for Flax1
Authors: Thompson T. E.
Published: July 2010

A haploid breeding technique for flax (Linum usitatissimum L.) using a twin seedling character is described. The haploid twin can be distinguished from the diploid twin by seedling size 3 days after germination, plant height at any growth stage, and by the production of sterile flowers. The twinning frequency of 54 random entries from the USDA World Flax Collection was 1 set to 5,869 normal seed; a workable level in a flax cultivar development program. Use of a flax rust [Melampsora lint (Ehrenb.) Lev.] resistance marker gene showed the haploid twin to be of maternal origin, presumably produced by apogamety. In a breeding program this indicates haploid selection and doubling could be conducted in the F2 to allow for genetic recombination. A 16‐month breeding program to produce completely homozygous breeding lines ready for field evaluation is described. This developmental period includes screening for rust resistance and selection for oil content and quality.
Field Evaluation of Resistance in Sorghums to Banks Grass Mite1
Authors: Foster D. G. , Teetes G. L. , Johnson J. W. , Rosenow D. T. , Ward C. R.
Published: July 2010

The Banks grass mite, Oligonychus pratensis (Banks), is a serious pest of sorghum, Sorghum, bicolor (L.) Moench. Because of the unreliability of chemical control, mite resistant sorghums would be extremely valuable in controlling this pest. To determine levels of resistance in 19 sorghum lines and hybrids, field tests with natural mite infestations were conducted near Pecos, Tex. Evaluations were based on mite numbers, population density ratings, and damage ratings.

Field evaluation of selected sorghum lines and F, hybrids indicated the presence of resistance to Banks grass mite. Grain type sorghums of similar maturity did not differ significantly in mite infestations, but some were damaged less than others; those with less damage were relatively high in sugar and were “non‐senescing” types. The two sorghums least infested were late maturing (SC 56‐14) or both late maturing and high in tillering (‘Sweet Sudan’). B Tx 618 was more resistant to damage than B Tx 378, and this resistance was reflected in hybrids between these lines and SC 599. Sorghums identified in this study should be useful in the development of mite resistant sorghum hybrids.
Agronomic Performance and Nature of Gene Effects in Progenitor Species‐Derived Genotypes of Tobacco1
Authors: Oupadissakoon S. , Wernsman E. A.
Published: July 2010

An investigation was conducted to determine the nature of genetic effects in segregating populations produced by crossing selected progenitor species‐derived tobacco (Nicotiana tabacum L.) lines to the tobacco cultivar used in the original interspecific hybridization.

Two genetically stable tobacco lines developed from interspecific crosses of N. tabacum ✕ N. sylvestris Speg. and Comes and N. tabacum ✕ N. otophora Griesbach, respectively, were crossed with the flue‐cured tobacco cultivar, ‘SC 58’, and F2 and backcross generations were produced. Data on agronomic characters and chemical constituents of cured leaf were collected and subjected to generation means analyses.

The tobacco parent exhibited poorer performance than other generations for all agronomic characters, except grade index and chemical attributes of cured leaves. Conversely, species‐derived lines were frequently higher performing for yielding ability, days to flower, plant height, and number of leaves per plant, but cured leaf quality was inferior to other genetic entries. Significant positive heterosis for yield was found in three of the four families, and inbreeding depression was usually low.

Additive genetic effects were significant for all characters in all families. Yield had significant dominance effects for every family while other chacacters varied from family to family. Frgm an evolutionary aspect of gene action, species germplasm tended to exhibit dominance in a positive direction for yield, days to flower, plant height, and number of leaves per plant, and in a negative direction for leaf quality. Deviations from the additive and dominance model were not observed.
Alfalfa Seed Germination Response to Electrical Treatments1
Authors: Nelson S. O. , Kehr W. R. , Stetson L. E. , Stone R. B. , Webb J. C.
Published: July 2010

Two types of electrical treatment that render impermeable alfalfa seeds permeable to water were tested for effectiveness in lowering hard seed percentages and for effects of the treatments on resulting seedlings and on seed longevity. Several alfalfa (Medicago sativa L.) seed lots representing five cultivars were exposed to electrical treatments and tested for effects of the treatments on germination between blotters and on emergence from sand in greenhouse benches. Exposure to either radio‐frequency (RF) electric fields or to gas‐plasma radiation in an electric glow discharge increased germination of seed lots that contained appreciable quantities of hard seeds. Gas‐plasma treatments also accelerated emergence in the greenhouse, but RF treatments that produced increases in germination and emergence equivalent to those of the gas‐plasma treatments did not accelerate emergence. Both types of electrical treatment were more effective in increasing germination when applied at low moisture content (2.7%) than at normal moisture content (7.8%). Quality of seed samples exposed at proper levels remained as good as that of untreated samples for up to 12 years in storage after electrical treatment. Thus, the electrical treatments offer a safe means for reducing hard seed percentages in alfalfa seed lots that contain high percentages of hard seed.
Germination of Polycross Seed of Cicer Milkvetch as Affected by Year of Production1
Authors: Townsend C. E.
Published: July 2010

In many species, environmental conditions during maturation of seed influence subsequent germination. Comparable information is lacking for cicer milkvetch, Astragalus cicer L. Therefore, the objective of this study was to determine whether environmental conditions, as measured by year of production, influence germination of polycross seed from selected clones of cicer milkvetch. Seeds produced in different years were germinated at 5 to 15, 5 to 20, and 15 to 25 C.

Year of seed production significantly influenced subsequent seed germination at all temperature treatments. Germination was most rapid at 15 to 25 C and slowest at 5 to 15 C. Germination by the 14th day (total germination) was generally highest at 15 to 25 C, hut was also high in some years at 5 to 20 C. Variability between years for germination was greatest at 5 to 15 C.

Within each year of production there were significant differences among polycross progenies for both rate of germination and total germination at all temperature treatments. Progenies that germinated rapidly at 5 to 20 C also tended to germinate rapidly at 15 to 25 C. However, some progenies that germinated rapidly at 15 to 25 C germinated slowly at 5 to 20 C. Rate of germination and total germination were substantially lower at 5 to 15 C than at the other temperature treatments for all progenies, but several progenies germinated comparatively rapidly at all treatments.
Response of Indeterminate and Determinate Soybean Cultivars to Defoliation and Half‐plant Cut‐off1
Authors: Fehr W. R. , Caviness C. E. , Vorst J. J.
Published: July 2010

The estimation of yield loss from defoliation and stem cut‐off is based on the assumptions that soybean (Glycine max (L.) Merr.) cultivars do not differ appreciably in their ability to recover from plant injury, recovery is similar across locations, and percentage yield loss at all reproductive stages can be approximated from research involving only three of the stages. The objective of our study was to test the validity of the assumptions by comparing the response of indeterminate and determinate soybean cultivars to 100% defoliation and 100% half‐plant cut‐off at six reproductive stages from R2 to R7. Two indeterminate cultivars, ‘Hark’ and ‘Beeson’, were studied at Ames, Iowa, and Lafayette, Ind., and two determinate cuitivars, ‘Hill’ and ‘Lee’ were evaluated at Stuttgart, Ark.

The determinate cultivars had significantly greater yield reduction from 100% defoliation than did the indeterminate cultivars at all reproductive stages, except R7. Average yield reduction from defoliation for all stages was 59% for the determinate cultivars, compared with 39% for the indeterminate cultivars. Maximum yield loss from 100% defoliation occurred at R4 (86%) and R5 (88%) for determinate cultivars and at R5 (82%) for indeterminate cultivars. Average yield loss from half‐plant cut‐off was similar for indeterminate (34%) and determinate (33%) cultivars, but there was a significant interaction with stages. Yield loss for indeterminate cultivars increased from R2 to R5, then remained constant from R5 to R7. The yield loss from half‐plant cut‐off with determinate cultivars increased progressively rom R2 to R7. The determinateness of a cultivar should be considered when assessing yield reductidn from defoliation and half‐plant cut‐off during reproductive development. Damage from hail, insects, and other factors will be most accurately estimated by establishing separate loss values for indeterminate and determinate types.

There was no significant difference between Iowa and Indiana in the percentage of yield loss from 100% defoliation. For the cultivars and locations studied, location effects were not important in the estimation of yield loss from plant injury.

Yield loss from 100% defoliation at the six reproductive stages did not follow the relationship predicted from previous studies. Our data indicated that maximum loss for indeterminate cultivars occurred at R5, not R4 as has been assumed. Some yield loss occurred at R7 indicating that the description used to identify plants at physiological maturity was incorrect. A new description based on pod or seed maturation is needed to identify plants that have reached physiological maturity.
Physiological Components of Yield and Tolerance to Frequent Harvests in Alfalfa1
Authors: Chatterton N. J. , Akao S. , Carlson G. E. , Hungerford W. E.
Published: July 2010

Alfalfa (Medicago sativa L.) cultivars consist of genotypes that vary in herbage yield and tolerance of frequent harvests. Our objectives were to identify genotypes differing in yield and harvest tolerance and to determine whether these differences were correlated with specific physiological and biochemical differences. We established 144 alfalfa clones in field plantings (30 cm spacings) and harvested them four times the 1st year and then 7 to 8, 5, or 4 times annually for the next 2 years. On 30 October of the 3rd year, herbage, crown and root tissues of 12 selected clones were analyzed for several carbohydrate, N and P components. The high‐yielding clones identified in this experiment had statistically higher concentrations of soluble carbohydrates, starch, inorganic P, and NH4+ in various plant parts than did low yielding clones. Clones tolerant of frequent harvests generally had higher concentrations of nonstructural carbohydrates, starch, organic and inorganic phosphorus, and amide‐N in roots and crowns than did harvest‐intolerant clones. Selection criteria may be developed through a refinement of these relationships and used to identify desired alfalfa plant types with improved yield and persistence.
Inheritance of Kernel Hardness in Spring Wheat1
Authors: Baker R. J.
Published: July 2010

An “inbred‐backcross” technique was used to study the inheritance of kernel hardness in two spring wheat (Triticum aestivum L.) crosses. Seventy‐three inbred lines from the second backcross of ‘Pitic 62’ to ‘Neepawa’ and 91 inbred lines from the second backcross of ‘Glenlea’ to Neepawa were evaluated in four‐replicate randomized block experiments in each of 2 years. Grinding time was used as the measure of kernel hardness. The difference between Pitic 62, a soft wheat, and Neepawa, a hard wheat, was found to be governed by two major genes and one or more minor genes. A single major gene and one or more minor genes accounted for the difference in grinding time between Glenlea, a very hard wheat, and Neepawa.
Flag Leaf Physiological Analysis of Oat Isolines That Differ in Grain Yield from Their Recurrent Parents1
Authors: Brinkman M. A. , Frey K. J.
Published: July 2010

An early and a midseason series of oat (Avena sativa L.) isolines were developed for resistance to crown rust Puccinia coronata Cda var. avenae Frazier and Ledingham), but they were significantly higher or lower yielding than their recurrent parent in each series. The purpose of this study was to determineif the isolines in each series had significant differences in physiological characteristics of flag leaves from their respective recurrent parent that may have contributed to the deviant grain yields.

Plants were grown in field plots and CO2 exchange rates (CER) and transpiration (T) were measured on intact leaves. In the early series, the two high yielding isolines had higher CER, and in the midseason series the low yielding isoline had a lower CER than the respective recurrent parent. Rates of T and specific leaf weights (SLW) were similar to the recurrent parent T and SLW in each series.

Differences in CER between isolines and their recurrent parent were attributable primarily to differences in residual (mesophyll) resistance (rr) to CO2 diffusion in both series. There was no association between CER and SLW within the two sets of closely related lines.
Empirical Evaluation of Single‐Plant and Family Selection Strategies in Wheat1
Authors: Thakare R. B. , Qualset C. O.
Published: July 2010

Random F3 families from the cross of two high‐yielding short‐statured spring wheats (Triticum aestivum L.) ‘Anza’ and ‘Bluebird‐2’ were space‐planted in two blocks in a field planting. From each F3 family, two to five of the best appearing plants from one block and five random plants in the second block were selected to study four selection strategies. Grain yields of the F3 plants were obtained and 36 random families, each having three random and two visually selected lines, were studied in the F4 in field trials at two locations using the commercial seeding rate. The F3 selection strategies and F4 yield results, given as percentages over the random F4 mean yield for the random and visually selected progenies, respectively, were as follows: (1) individual selection, 0.33 selection intensity, 4.21 and 4.73%; (2) within family selection, best plant in each family selected, 2.43 and 2.87%; (3) family selection, 0.33 selection intensity, 1.01 and 5.52%; and (4) combined family and within family selection, 0.33 selection intensity for families with the best plant selected within families, 3.56 and 7.57%. Three‐stage selection using (1) visual selection of plants, (2) selection of families on the basis of the mean of yields of visually selected plants, and (3) selection of best plants within selected families appears to be an effective and easily applied strategy worthy of further evaluation.
Anatomical Study of Seed Shattering in Bahiagrass and Dallisgrass1
Authors: Burson Byron L. , Correa Jario , Potts Howard C.
Published: July 2010

Seed shattering is a major problem in ‘Pensacola’ bahiagrass (Paspalum notatum Flugge) and dallisgrass (P. dilatatum Poir.) which often reduces availability and quality of seed of these species. An anatomical investigation of the abscission layer formation in the pedicel of Pensacola bahiagrass, common dallisgrass, and yellow‐anthered dallisgrass was conducted to determine the sequential histogenesis of the layer, and to relate its development to different morphological stages of the developing infloresences for each species. The abscission layer was located in the pedicel just below the glumes in both species. In bahiagrass it became distinguishable while the infloresence was in the boot stage, and by anthesis it was fully developed. The layer appeared as a ribbon of thick walled cells, five to seven cells wide, extending across the pedicel. Eight to 10 days after anthesis the abscission cells elongated and collapsed. Small lacunae were initiated adjacent to the vascular strands and continued to increase in size until the crushed vascular and pith cells had completely disintegrated. Spikelets remained attached to the pedicels by the epidermal cells until abscission occurred approximately 13 days after anthesis.

In both dallisgrass biotypes the layer became distinguishable when the inflorescence was intermediate between early boot and boot stages, and was fully developed by anthesis. The layer appeared as a slightly wedge‐shaped band of thick walled cells, six cells wide at the epidermal edge and four cells wide at the vascular bundles, extending across the pedicel. Six days after anthesis, abscission layer cells in yellow‐anthered dallisgrass became elongated, and 9 days after anthesis a similar behavior was observed in common dallisgrass. In both biotypes, cells in the layer collapsed, leaving a crushed mass of cells. This and the remaining events were similar to those observed in bahiagrass. Abscission occurred on the 15th day after anthesis in the yellow‐anthered biotype, and on the 18th day in common dallisgrass. It appears that the abscission process in these three grasses is primarily biochemical in nature. These findings are probably indicative of the abscission process in other Paspalum species.
Factors Affecting Efficiency of Hybridization and Selection in Cassava1
Authors: Kawano Kazuo , Amaya Alvaro , Daza Pablo , Rios Maria
Published: July 2010

An analysis of genetic variability in several populations of cassava (Manihot esculenta Crantz) revealed that it is a highly heterozygous species. This species is monoecious, and no genetic or physiological barrier to prevent self‐fertilization was found. Both self and crosspollination occurred naturally. Thirty meters of separation between populations was sufficient to ensure genetic isolation. The average yield of selfed lines was about half the average yield of the parental genotypes. The degree of inbreeding depression varied greatly in different genotypes. Average yields of populations derived from open pollination of male‐fertile genotypes were lower than the average yields of populations derived from the controlled pollinations of the same genotypes. In male.sterile genotypes, no yield difference was observed between the open‐pollinated progenies and those from the controlled pollinations. Controlled pollinations are recommended as a general method of hybridization in cassava. If a breeder chooses open pollinations, use of male steriles is recommended. Correlations of root yield and harvest index (proportion of root weight to total plant weight) between the seedling plant and the same genotype when planted with stem cuttings were high. Root yield in a single‐row trial was not correlated with root yield in a replicated population trial, but harvest index in the single.row trial was significantly correlated with the root yield in the population trial. Intergenotypic competition caused a yield difference of more than 100%, but there was no significance in harvest‐index difference. Harvest index was highly heritable, and it is an excellent selection character.
Performance of Anther‐Derived Dihaploids and Their Conventionally Inbred Parents as Lines, in F1 Hybrids, and in F2 Generations1
Authors: Arcia M. A. , Wernsman E. A. , Burk L. G.
Published: July 2010

Dihaploid lines of tobacco (Nicotiana tabacum L.) were developed from anther cultures of two long‐term, conventionally inbred cultivars. Ten dihaploids from ‘Coker 139’ and 10 dihaploids from ‘NC 95’ were selfed and randomly crossed to produce 10 dihaploid F1's. Each F1 was selfed to produce a dihaploid F2. The conventional cultivars were crossed to produce a conventional F1, which was selfed to produce an F2. All genetic materials were evaluated for agronomic performance and chemical composition.

Dihaploid lines grew more slowly, yielded approximately 15% less, and were agronomically inferior to their conventional pure‐line parents. Dihaploid F1's and F2's yielded less than the conventional F1 and F2. Enforced complete homozygosity in tobacco may not be entirely responsible for the reduction in yield of dihaploid lines developed by anther culture methods. The dihaploid technique as presently employed may be mutagenic.

Reduced yields of dihaploid lines produced by the anther culture technique and the inferiority of crosses of dihaploid lines compared to conventional entries, suggest that this technique may not be suitable for a tobacco breeding program, where increased yield is of primary interest.
Seed Proteins of Common Bean1
Authors: Ma Yu , Bliss F. A.
Published: July 2010

Fractionation of bean (Phaseolus vulgaris L.) cotyledon storage proteins using an improved separation procedure revealed a protein profile in which globulin‐I was the major fraction (about 40% of the total cotyledon protein), followed in importance by an alkali‐soluble fraction (about 25%) containing glutelin and albumin, free amino acids, ginbulin‐2, prolamine, and residue fractions. SDS‐acrylamideg el electrophoresis was performed to determine banding patterns of total cotyledon polypeptides and the purity of the fractions. Amino acid analyses using an autoanalyzer were performed on total protein and protein fractions. The alkali‐soluble fraction had the highest concentration of methionine (2% of the protein by weight), while the methionine percentage of globulin‐1 (0.88%) and albumin (1.0%) was less than that of the respective cotyledons (1.10%). The alkali‐soluble and globulin‐1 fractions comprised three‐fourths of the total cotyledon methionine. Total cotyledon protein was positively correlated with globulin‐1, free amino acids, alkali‐soluble, and globulin‐2 fractions. Significant positive correlations between amount of methionine in the cotyledons and that in the alkalisoluble fraction were also found. This finding suggests that selection for high protein genotypes in which the alkali‐soluble fraction is increased should result in improved methionine content. Since quantitative estimation of this fracion is time‐consuminga, simplified procedure for determining the amount of protein insoluble in ascorbate‐NaCl solution is suitable for identifying strains with large amountos f the alkali‐soluble fraction.
Issues in Diallel Analysis
Authors: Baker R. J.
Published: July 2010

Critical issues in the use of diallel analysis are reviewed. From a statistical point of view the critical issue concerns the choice of a model with fixed or random genotypic effects. From a genetical point of view, two assumptions are critical in attempts to interpret the resuits of diallel analyses. The assumption concerning the independent distribution of genees in the parents is most critical to proper interpretation and seems to be least acceptable in actual practice. The second assumption, that there is no epistasis, may frequently be incorrect. Epistasis affects estimates of general and specific combining ability mean squares, variances, and effects in an unpredictable manner. As an alternative to genetic interpretation, the statistical description provided by dialiel analysis can be used to help answer questions concerning the importance of specific combining ability and the predictability of hybrid performance using general combining ability or parental performance.
Factors Associated with Differential Response of Oat Cultivars to Iron Stress1
Authors: Brown J. C. , McDaniel M. E.
Published: July 2010

Oat (Arena byzantina C. Koch) cultivars developed differential Fe chlorosis symptoms when grown in field trials on alkaline soils in south Texas. To determine why they differed, ‘TAM 0‐312’ (Fe‐inefficient), ‘Coker 227’ (Fe‐efficlent), and ‘TAM 0‐301’ and ‘73C1952’ (intermediate in Fe response) oats were tested in alkaline soils and in nutrient solutions. Physiologically, Coker 227 responded more favorably to Fe stress (reduced Fe3+ to Fe2+ at the root) than TAM 0‐312. More significantly, the Ca concentration was consistently about 2,500 µg/g dry matter greater in TAM 0‐312 than in Coker 227. Although not consistent, the P concentration was often greater in TAM 0‐312 than in Coker 227 which would also accentuate Fe chlorosis. We suggest that Ca effectively competes with or inactivates Fe in TAM 0‐312, thus causing Fe chlorosis to develop in this cultivar but not in Coker 227.
Inheritance of a Second Gene for Brachytic Stem in Soybeans1
Authors: Boerma H. R. , Jones B. G.
Published: July 2010

The inheritance of a second gene for the control of the brachytic stem trait in soybeans, Glycine max (L.) Merr., was studied. This recessive gene, designated sb2, was found in the brachytic‐stemmed line, PI 227224, when it was crossed with the normal‐stemmed cultivar, ‘Davis.’ Classification of plants in the F1, F2, and F3 generations indicated two recessive gene pairs were involved in the expression of the brachytic trait. The results indicated that sb2 is at a different locus than Sb, sb. Thus, it is suggested that the first locus should now be called Sb1, sb1 to distinguish it from the second locus, Sb2, sb2.
Genetic Variation Within Cotton For Seed N and Amino Acid Content1
Authors: Meredith William R. , Elmore C. D. , King E. E.
Published: July 2010

The objective of this study was to investigate the genetic variability for seed N and amino acid content among currently available cottons (Gossypium hirsutum L.). In 1974 and 1975, 35 cultivars and strains were grown in two replications at Stoneville, Miss. Significant genetic variability was detected for N and eight amino acids in dehulled cottonseed. Seed N ranged from 5.0% for ‘Delfos 9169’ to 6.1% for ‘Q1’. Significant genotype ✕ year interactions were detected for lysine, histidine, and phenylalanine. Significant phenotypic correlations of N with lysine, threonine, glycine, alanine, and leucine were –0.36, –0.85, –0.66, –0.72, and –0.64 respectively. Genotypic correlations were generally of the same sign and magnitude as the phenotypic correlations.

Results of the study indicated a modest amount of genetic variability within G. hirsutum for N and amino acid content. Old cultivars and new strains originating from interspecific hybridizations appeared to be the most promising sources for useful breeding material. There were little differences in N and amino acid contents among the commonly used cultivars regardless of their geographic use patterns.
Dormancy of Kentucky Bluegrass Seed in Relation to the Color of Spikelets and Panicle Branches at Harvest1
Authors: Phaneendranath Bangalore R. , Duell Robert W. , Funk C. Reed
Published: July 2010

One of the most important factors affecting germination of Kentucky bluegrass (Poa pratensis L.) seed is maturity at harvest. This study evaluated degrees of seed dormancy in 10 cultivars and selections of Kentucky bluegrass harvested at various stages of change in color of spikelet and panicle branches from green to brown.

Significant differences in the degree of dormancy at different stages of change in color of panicle branches existed among the entries. ‘Merion’ exhibited the most prolonged dormancy of seed during this period of change in color. The reduction in dormancy was generally accompanied by changes in color, of the panicle branches in particular, from green to brown. A color index was, therefore, proposed to determine the right time for harvesting Kentucky bluegrass seed to obtain maximum germination.
Four Independent Mutations at the ms1, Locus in Soybeans1
Authors: Palmer Reid G. , Winger Carol L. , Albertsen Marc C.
Published: July 2010

Four independent recessive mutations for male sterility were identified in soybeans, Glycine max (L.) Merrill. The mutations, designated the North Carolina, Urbane, Tonica, and Ames male steriles, arose spontaneously and independently of each other. The North Carolina and Tonica male steriles were found in farmers' fields as off‐type plants. The Urbane male sterile was found in an F3 breeding population. The Ames male sterile was identified in a population segregating for the desynaptic gene st4. Genetic evidence, both from testcrosses and segregation from fertile testcrosses, indicated that these four mutations were at the ms1 locus. The data did not discriminate between identical mutations and a multiple allelic series at the ms1 locus. This is the first report, as far as the authors are aware, of four independently occurring recessive mutations for failure of cytokinesis at the same locus.
Calcium Content, Adenylate Energy Level, and Seed Vigor in Peanuts1
Authors: Crompton Carrie , Wynne J. C. , Patterson R. P.
Published: July 2010

Germination disorders and seed calcium deficiency are frequently associated in Virginia peanut (Arachis hypogaea L.) cultivars, while neither condition is common in Spanish peanuts. Embryonic Ca concentration was compared with (a) germination percentage after 3 days of cold treatment and (b) total adenylate pool in the embryonic axis after 12 hours of germination in the parents and F3 embryos of a Virginia ✕ Spanish cross. Ca concentration was found to be positively correlated with germination percentage and total adenylates for plants of the Virginia parent and the cross but not for the Spanish parent. Means for the percent cold germination, Ca concentration and total adenosine phosphates were at least 85% greater for the Spanish than for the Virginia parent. High means for adenylate concentration and percent cold germination for the F3 progeny suggested that the genetic variance for these traits was nonadditive, while intermediate Ca values for the progeny suggested that additive genetic variance was important in the inheritance of seed Ca concentration. The adenylate assay correlated with differences in seed vigor among the parents and F3 progeny but was less sensitive than Ca concentration in detecting differences within populations. Energy charge (E.C.) values calculated from adenylate data according to the formula E.C. = [(ATP) + 1/2 (ADP)]/[(ATP) + (ADP) + (AMP)] were not significantly correlated with germination percentage, implying that respiratory phosphorylation rate in early germination was not as limiting as other factors in peanut seed germination. High broad‐sense heritability estimates for Ca concentration (H = 0.68), percent cold germination (H = 0.74) and total adenylates (H = 0.88) suggest that seed quality as related to the above parameters can be improved through breeding.
Optimal Environments for Yield Testing1
Authors: Allen F. L. , Comstock R. E. , Rasmusson D. C.
Published: July 2010

This research was undertaken to obtain information about the type of yield trial environment that will foster maximum progress from selection. Theory and parameter estimates from five crops that are relevant to the question of the optimum nursery environment for yield testing are reported. The five crop species were barley, Hordeum vulgare L.; wheat, Triticum aestivum L.; oats, Avena sativa L.; soybean, Glycine max (L.) Merr.; and flax, Linum usitatissimum L. Analyses of variance of yield data (a separate analysis for each year and location) reconstructed from information in the annual reports of Uniform Nursery Trials were the sources of our parameter estimates. We defined as the value of a genotype relative to a test environment, as the value of a genotype relative to the entire population of environments in which a selected genotype would be used, and H as σ2y/(σ2y + σ2e/n) where σ2y is the variance of , σ2e, is plot error variance and n is the number of replications in the field trial comparison used as the basis for selection. We then found the proper measure of test environment value to be r√H where r is the correlation between and . This is because r√H reflects genotype ✕ environment interaction as well as ✕2e and n, appropriately. The single environment variance analyses available to us provided estimates of ✕2y and ✕2e but not of r. In general, both ✕2y and ✕2e were larger when the nursery yield level was higher. Estimates of √H from the data of low, intermediate and high yielding trials were not greatly different. The indicated advantage (given n = 3) of favorable (high yield) environments over intermediate environments were 4% and 7% for wheat and soybeans, respectively, but in the case of barley, oats and flax, there were no indications that high yield environments were superior. Our results indicate that if any class of environments is eventually established as substantially superior for testing purposes, it will be because the correlation between and is comparatively high for that class of environments.
Grain Yield Variations in Oats Associated with Differences in Leaf Area Duration Among Oat Lines1
Authors: Helsel Diana Bloethe , Frey Kenneth J.
Published: July 2010

Growth and yield component analyses were used to attempt to define the source of grain yield increases (27 to 30% above the cultivar ‘Clintford’) found in oat (Avena sativa L.) lines developed through introgression of Avena sterilis L. germplasm into the Clintford background. Leaf area and leaf area duration were found to be the two traits that could account for the higher yielding ability of the derived lines. By developing a larger leaf‐blade area and delaying senescence, the cultivars had the potential to produce more photosynthate than Clintford. Early development of greater leaf‐blade area probably caused the initiation of a larger number of spikelets per panicle, and the maintenance of a large photosynthetically active system longer after flowering could have caused the development of larger kernels. Higher yield of the derived lines was due to more spikelets per panicle and increased kernel weight. Apparently, the A. sterilis germplasm contributed genes for enhanced leaf growth and delayed senescence which, inserted into the Clintford background, resulted in lines with higher grain yields.
Effect of Pod Removal on Nonstructural Carbohydrate Concentration in Soybean Tissue1
Authors: Ciha A. J. , Brun W. A.
Published: July 2010

The effects of filling pods on the production and partitioning of nonstructural carbohydrates (NSC) were determined in field‐grown ‘Clay’ soybeans (Glycine max (L.) Merr.) by periodically sampling the NSC concentrations in stems, leaflets and petioles of control and depodded plants from flowering to maturity. Rates of dry matter accumulation were greater in control plants than in depodded plants, but total dry matter accumulation at the time of pod maturity was similar in control and depodded plants, primarily because the depodded plants did not drop their leaves. Concentrations of NSC in stems, leaflets, and petioles remained fairly constant in control plants, but all increased markedly in depodded plants, primarily due to starch accumulation. Leaflets and especially petioles in the upper part of the canopy were major sites of starch storage in depodded plants.
Additional Sources of Monogenic Resistance in Corn to Helminthosporium turcicum1
Authors: Hooker A. L.
Published: July 2010

Seedlings and adult plants of 28 inbred lines, representing a diversity of endosperm types and cultivar origin, expressed chlorotic lesions when infected with Helminthosporium turcicum Pass. The resistance in each line was inherited as a single dominant gene.
Visual Detection of Aluminum Tolerance Levels in Wheat by Hematoxylin Staining of Seedling Roots1
Authors: Polle E. , Konzak C. F. , Kattrick J. A.
Published: July 2010

When seedling roots of wheat (Triticum aestivum L. em Thell.) are treated with solutions containing A13+ and then stained in an aqueous solution of hematoxylin, they develop a pattern of staining that correlates remarkably well with their A1 tolerance level as estimated by root elongation methods and field trials. A rapid and simple method for evaluating A1 tolerance hi wheat varieties with hemotoxylin is presented. The method is based on a visual estimation of the stainability of the root tips of young seedlings and is calibrated with wheat varieties of known A1 tolerance. Since seedlings tested by this method are still viable and can be transplanted for growing to maturity, the method can also be adapted for screening segregating populations.