bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Synthetic Varieties of Upland Cotton Developed Under Two Levels of Natural Outcrossing1
Authors: Kohel R. J. , Richmond T. R.
Published: July 2010

For the development of synthetic varieties of cotton (Gossypium hirsutum L.), we chose four parental strains expected to exhibit high heterotic responses for yield. The synthetic varieties were developed over a three‐yearperiod in an area of high natural crossing, and in an area of low natural crossing. In each area, combinations of self‐ and open‐pollination were imposed to vary the level of heterozygosity in the resulting synthetic varieties

The synthetic variety produced by open‐pollination in the area of high natural crossing contained a calculated 42% heterozyosity, and it yielded equal to the bulk of F1 hybrids among the parent strains. The synthetic variety produced by open‐pollination in the area of low natural crossing contained a calculated 12% heterozygosity, and it exhibited no significant heterosis

The largest expressions of heterosis were for yield and to a lesser extent for boll size. Heterotic performance was correlated with the calculated heterozygosity of the synthetic varieties. The performance of the remaining characters appeared to be controlled by additive gene action.
Relationships between Parents and Selection in Crosses of Dry Beans, Phaseolus vulgaris L.1
Authors: Quinones Ferdinand A.
Published: July 2010

A study was made of the relationships between 160 F8 dry bean selections tested in 1966 and their parents tested in 1959, the year the decision to make the 22 crosses was made. Statistically significant interannual correlations were found for yield, maturity, growth habit, and infection of common bacterial blight, Xanthomonas phaseoli (E. F. Sm.), but not for seed size.
Inheritance of Reaction to Race 8 of Puccinia hordei Otth. in Two Barley Crosses1
Authors: Dillard M. W. , Brown A. R.
Published: July 2010

The F2 and F3 generations of the cross ‘Ga‐Jet’ ✕ ‘G. I. 11540’ and its reciprocal were studied for resistance to culture 64.2 of race 8 of Puccinia hordei in the seedling stage. The F2 generation of Ga‐Jet ✕ ‘Cebada Capa’ was also observed for seedling reaction to the same culture of leaf rust. The results indicated that C. I. 11540 had one incompletely dominant gene conditioning resistance to leaf rust, while Cebada Capa had one completely dominant gene.
Correlated Truncation Selection for Yield in Soybeans1
Authors: Byth D. E. , Weber C. R. , Caldwell B. E.
Published: July 2010

Random genetically heterogeneous, F2‐derived maternal lines and genetically homogeneous, F5‐derived daughter lines of two soybean crosses were evaluated for nine characters in three environments in the F0‐F7 generations.

Heritability was relatively consistent across environments for all traits except seed yield. For yield, heritability was greatest under favorable growth conditions and least when moisture stress was alleviated by irrigation. Variability over environments in correlations of all traits with yield was related largely to the degree of moisture stress in each environment. Crosses revealed similar magnitudes of correlation with yield for all traits except chemical composition. This was related to the chemical composition of parents used in these crosses. Correlations of early lodging with yield in genetically homogeneous lines were generally greater than for genetically heterogeneous lines. This was related to the relative uniformity of the plant canopy in these populations.

Because of the inconsistency in character associations, predictions of yield advance from selection in any environment were inaccurate estimates of actual advance evaluated over environments. Selection of yield invariably resulted in maximum actual yield advance. Chemical composition was generally the best yield predictor for heterogeneous lines, while early lodging was the most effective trait for correlated yield selection in genetically homogeneous lines.
Spring Growth of Reed Canarygrass (Phalaris arundinacea L.) and Climax Timothy (Phleum pratense L.) Under Different Harvesting Systems1
Authors: Horrocks R. D. , Washko J. B.
Published: July 2010

During the spring of 1965 and again in 1966 measurements were recorded at 2‐ to 4‐day intervals on the growth rate of reed canarygrass and ‘Climax’ timothy as influenced by the residual effect of the previous year's treatments. The 1965 results of these treatments were: reed canarygrass — significantly lower rate of growth when clipped at the 4‐cm vs 9‐cm height; Climax timothy — no significant difference. The growth measurements recorded in the spring of 1966 reflected the residual influence on spring growth of clipping height as it interacted with plant maturity at the first harvest. Comparing the 4‐ and 9‐cm clipping heights over the maturity stages showed the following: reed canarygrass — slower growh rate at 4‐ than at 9‐cm heights if the first harvest was removed when the growing point was 5, 10 or 20 cm above the soil (Systems 1,2, and 3), but no difference if 30 cm above the soil or heads had emerged (Systems 4 and 5); Climax timothy — slower growth rate at the 9‐cm height it the first harvest was removed under Systems 2 or 3, but not under the other systems. Considering only the residual effect of the stage of maturity at which the first harvest was removed, harvesting under System 2 was detrimental to growth of reed canarygrass. No significant effect of management system on growth rate was noted for Climax timothy.
Instability for Crown Rust Reaction and Kernel Color in F6 ‐F10 Lines of a Derived‐Tetraploid ✕ Avena sativa Hybrid1
Authors: Forsberg R. A. , Nishiyama I.
Published: July 2010

Major genes governing dark kernel color and resistance to the crown rust fungus (Puccinia coronata Cda. f. sp. avenae Fraser & Led.) were linked in four F6 lines from the oat cross derived‐tetraploid C.I.7232 (2n‐28) ✕ Avena sativa L. var. ‘Clarion’ (2n=42). Most dark‐resistant (D‐R) plants were not true breeding; abnormal and irregular segregation ratios of D‐R and light‐susceptible (L‐S) plants occurred in F6‐F10 lines from D‐R parents. L‐S plants were highly self‐fertile and bred true. Cytological investigations revealed aneuploid plants (2n=43) in which the D‐R genes were carried on an extra chromosome and euploid plants (2n=42) in which the genes were in a closely paired bivalent. Differential gamete frequencies, certation, or nonviability of homozygous‐resistant genotypes due to abnormal dosage effects could account for the distorted ratios obtained and for the absence of stable, resistant lines.
Some Effects of Leaf Area, Solar Radiation, Air Temperature, and Variety on Net Photosynthesis in Field‐Grown Soybeans1
Authors: Jeffers D. L. , Shibles R. M.
Published: July 2010

The effect of leaf area index, solar radiation, and air temperature on photosynthesis (net CO2 assimilation) leaf canopies of three soybean (Glycine max L., Merr.) varieties was studied. Sections of field plots (1.16‐m2) were enclosed in transparent chambers, and CO2 assimilation rates were determined by infrared gas analysis. From a maximum of about 60 mg CO22/dm2 (ground area) .hr on July 5, the assimilation rate declined to 53 mg CO2/dm2.hr by Sept. 9. Maximum variety differences were 8 mg CO2/dm2.hr. An interaction occurred between LAI and solar radiation in their effect of photosynthesis; the critic:d LAI was 5 to 6 at 0.2 ly/min solar radiation and greater than 8 (maximum LAI attained) at 1.2 ly/min. Below LAI of four canopies showed light saturation. Optimum air temperature was 25–30 C.
Tolerance of Cynodon Clones to Phytotoxemia Caused by the Two‐lined Spittlebug1
Authors: Taliaferro C. M. , Leuck D. B. , Stimmann M. W.
Published: July 2010

A highly variable collection of 398 vegetatively propagated Cynodon accessions was screened for host‐plant resistance to the two‐lined spittlebug, Prosapia bicincta (Say). Clonal reaction to spittlebug attack ranged from slight to very severe injury at the end of 7 to 8‐day test periods. Among the 398 clones, about 5% (19) were rated highly tolerant, 47% (189) intermediate in tolerance, and 48% (190) as very susceptible to spittlebug phytotoxemia. All of the clones could be severely injured by prolonged spittlebug infestation. The specific mode of action responsible for differential clonal response appears to be a tolerance mechanism which enables some genotypes to withstand the spittlebug toxin better than others. The wide range in clonal reaction to spittlebug attack, and the acceptable levels of tolerance found in these investigaions, offer hope that breeding methods can be used to increase the level of spittlebug resistance in bermudagrass.
Apomixis and Tetraploidy in Pennisetum orientate Rich.1
Authors: Chatterji Asoke K. , Timothy D. H.
Published: July 2010

Five accessions of Pennisetum orientate Rich were tetraploid with 2N = 36. Pairing at diakinesis and metaphase I was generally normal, as was anaphase I disjunction. Quadrivalent frequency per cell ranged from zero to eight, but was usually three to five. Pollen sterility was about 28% and due, in part, to laggards, rare unequal disjunction, and univalent misdivision. Embryo development was aposporous. Development of nucellar embryo sacs was accompanied by degeneration of sexual tissue. multiple embryos were not found.
Sweetclover Weevil Feeding Stimulants: Isolation and Identification of Glucose, Fructose, and Sucrose1
Authors: Akeson W. R. , Gorz H. J. , Haskins F. A.
Published: July 2010

The water‐soluble fraction of Melilotus leaves previously referred to as Stimulant A was further fractionated by preparative paper chromatography into three factors, each having a stimulatory effect on sweetclover weevil feeding. The three factors, designated Stimulant A1, A2, and A3, were identified as sucrose, glucose, and fructose, respectively, by co‐chromatography with known sugars on cellulose‐coated thin‐layer plates. Silver nitrate, anisidine phthalate, and anthrone were employed as detection agents. The isolated compounds and corresponding reagent grade sugars were identical in chromatographic and chemical behavior, as well as in feeding stimulant activity. Sucrose stimulated the greatest amount of feeding when the three sugars were compared at equal concentration in the same bioassay. Disks treated with glucose and fructose were fed upon equally at the three concentrations tested. Although these sugars probably play a significant role in the mechanism of resistance and susceptibility of Melilotus plants to weevil feeding, it is not likely that they are wholly responsible for the host specificity displayed by tire sweetclover weevil.
Relationships of Seed Weight, Seedling Vigor and Mitochondrial Metabolism in Barley1
Authors: McDaniel Robert G.
Published: July 2010

Because of the effects of seed size on seedling vigor in small grains, it was of importance to distinguish seed size effects accurately within barley genotypes from heterotic seedling vigor of barley (Hordeum vulgate L.) hybrids. Measurements of seedling vigor of germinating seedlings of several six,rowed, spring barley cultivars were made concomitantly with a study of seedling heterosis in barley hybrids.

Seedling fresh weight, seedling mitochondrial protein and mitochondrial biochemical activity were positively correlated with seed weight. The increased quantity of mitochondrial protein of seedlings produced from heavy seeds is indicative of a higher respiratory rate and greater amount of energy (ATP) production. Thus, these seedlings have a greater growth potential than seedlings produced from lighter seeds of the same pure line. These experiments provided an accurate means of measuring the relative contributions of seed weight, genotype, and heterosis to seedling vigor in barley.
Vegetative and Floral Responses of Three Alfalfa Genetic Stocks to Growth Regulators1
Authors: Yeh K. J. , Bingham E. T.
Published: July 2010

Three alfalfa clones related by descent, but carrying genes producing simple (sl), trifoliolate (tf), and multifoliolate (mf) leaves, respectively, responded differently to daily treatment with indoleacetic acid (IAA), gibberellic acid (GA), and triiodobenzoic acid (TIBA). Plant height, leaflet and floral characteristics, and selfed‐seed set of the tf clone were comparatively stable under all treatments, whereas sl and mf clones were very sensitive and affected both positively and negatively by growth regulators. Results indicated that GA may be useful in enhancing the growth and seed production of specific stocks.
A Chemically Induced Mutation for Stem Rust Resistance in ‘Little Club’ Wheat1
Authors: Edwards L. H. , Williams N. D. , Gough F. J. , Lebsock K. L.
Published: July 2010

We treated seeds of ‘Little Club’ wheat (Triticum aestivum L.) with ethyl methanesulfonate (EMS) and tested M. seedlings for reaction to stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn.). Mutants resistant to races 111, 15B, and 32 of stem rust were recovered. Every resistant plant in the mutant family was light green in color; whereas, every susceptible plant was normal dark green.
Efficiency of Water Use and Seedling Drougth Tolerance of Boer Lovergrass, Eragrostis curvula Nees1
Authors: Wright L. Neal , Dobrenz A.K.
Published: July 2010

Efficiency of water use of five selections of boer lovegrass, Eragrostis curvula Nees (equals E. chloromelas Steud.), was determined under greenhouse and growth chamber environments at Tucson, Ariz. These apomictic selections, which represented extremes for seedling drouth tolerance, were evaluated as seedlings and as mature plants. Significant differences in water‐use efficiency, measured as the number of units of water transpired per unit of dry matter produced, were found among selections within environments. Water‐use efficiency values were lower for seedling than mature plants, yet relative ranking of selections did not change within stages of maturity. Selections with highest water use were most seedling drouth tolerant. A correlation coefficient of r = .80 indicated a significant negative association between seedling water‐use efficiency and seedling drouth tolerance. The same association was shown for seedling drouth tolerance and mature‐plant water‐use efficiency.
Serological Evaluation of Winter Wheat Aneuploids1
Authors: Volin R.B. , Welsh J.R.
Published: July 2010

Antigenic components from the leaves of several monosomic (2n ‐ 1) and disomic (2n) plants from each of 18 monosomic lines of winter wheat, Triticum aestivum L. em. Thell. (aestivum group) ‘Kharkof MC22’ (2n = 42), were compared serologically.

Antibodies were produced in rabbits by injecting them with leaf extract antigens from two sources: (1) a disomic which was derived from segregating monosomic and disomic lines of the variety Kharkof MC22 and (2) a single plant selection from Kharkof MC22. Two lots of crude sap and two lots treated with ammonium sulfate saturation methods were used.

Gel‐diffusion techniques revealed no differences between the different antigens or between the monosomic and disomic antigens when reacted against any one antiserum. Precipitation lines of partial or non‐identity were not present. No antibodies remained following antiserum absorption with monosomic plant extract.

No differences could be found between antigens inherent in the monosomic and disomic genetic conditions when compared serologically.
Some Characteristics of Mutual Pollination Progenies of Bromus inermis1
Authors: Drolsom P. N. , Nielsen E. L.
Published: July 2010

Seven S1 generation smooth bromegrass (Bromus inermis Leyss.) plants from a broad base source population were crossed in all combinations by the mutual‐pollination technique. Plants with certain contrasting morphological features were chosen as representatives of different uniform S1 progenies. Differences among progenies of all crosses were significant for vigor, plant type, plant diameter, plant height, and green weight per plant but not for leafspot reaction. Specific combining ability was most important. General combining ability and reciprocal effects were less prominent.
Effects of Temperature, Light, and Variety in Controlled Environments on Floret Number and Fertility in Barley1
Authors: Tingle J. N. , Faris D. G. , Ormrod D. P.
Published: July 2010

In a series of experiments using combinations of 17 barley (Hordeum vulgare L.) varieties we studied the effects of 12, 18, and 24 C constant and 18/12 C day/night temperatures; 12‐, 16‐, and 24‐hour photoperiods; 5,500 and 22,000 luxes light intensities; and light low and high in far‐red energy on numbers of florets and perceut fertility per main head and tiller head and per plant.

Number of florets per head and per plant were lowest at 24 C. Lengthening the photoperiod decreased the number of florets per head. At the low light intensity there were slightly fewer florets per head with a pronounced reduction in tillering. An increase in number of florets per tiller head was noted with the virtual absence of far‐red energy but there was no effect on tillering.

Percent fertility was highest at 18 C. Tiller head fertility was further increased under an alternating day/night temperature. Plants in the 12‐hour photoperiod had the lowest fertility. Reduction in light intensity or in far‐red energy decreased plant fertility. The varieties ‘Betzes,’ ‘Palliser,’ ‘O. A. C. 21,’ and ‘Trebi’ failed to head in short photoperiods, in low light intensity, or in light low in far‐red energy.
Gene Action in the Inheritance of Fiber Properties in Intervarietal Diallel Crosses of Upland Cotton, Gossypium hirsutum L.1
Authors: Al‐Rawi K. M. , Kohel R. J.
Published: July 2010

We grew nine selected cotton varieties, all possible F1 hybrid combinations among these varieties, and their corresponding F2's in a split‐plot design with four replications. Heterosis, when measured as the departure from the average midparent value, was manifested at a low level for 50% span length (4.0%), 2.5% span length (2.8%), fiber strength (5.6%) and fiber elongation (8.5%). Heterosis was not observed for fiber fineness. Inbreeding depression, measured as a reduction in F2 below F1 performance, was not significant for any of the fiber properties measured. General and specific combining ability were both highly significant for all fiber properties.

Jinks‐Hayman's method of diallel cross analysis showed that all fiber properties were within the range of partial dominance (except fiber fineness, which showed overdominance, possibly caused by repulsion linkage) and that all are polygenically inherited characters.

Heritability, as the ratio of the additive, or additive ✕ additive epistatic variance, or both, to the total phenotypic variance, was relatively high for all fiber properties measured, except fiber fineness. This result suggested that a major part of the total phenotypic variance was additive.
Field Emergence and Growth of Crested Wheatgrass From Pretreated vs Nontreated Seeds1
Authors: Bleak Alvin T. , Keller Wesley
Published: July 2010

Seeds of ‘Nordan’ crested wheatgrass, Agropyron desertorum (Fisch. ex Link) Schult., grown in 1965 were kept wet, but not submerged, for 50 hours at 17.2 C, dried for 2 days, and subsequently planted. Thirteen plantings, made between May 9 and June 6, were under conditions generally favorable for seedling emergence and growth. Nontreated seeds produced an average of 61.9 seedlings per 100 seeds planted while treated seeds gave 68. These plantings, harvested August 15, yielded an average of 45 g dry weight per 100 seeds planted from nontreated seeds and 51.5 g from treated seeds. Six additional plantings were made June 19 to July 20, under generally much less favorable conditions. Twenty eight to 39 days after planting, nontreated seeds produced an average of 22.1 seedlings per 100 seeds planted, while treated seeds gave 30.8. The advantage of preplanting seed treatment was enhanced as conditions favoring emergence deteriorated.
Effect of Endosperm Mutants on Pericarp Thickness in Corn1
Authors: Helm J. L. , Glover D. V. , Zuber M. S.
Published: July 2010

Pericarp thickness was measured for mutant and normal kernels obtained from ears segregating for various endosperm mutants in the corn (Zea mays L.) inbred lines Oh43 and B37. The pericarp, being maternal tissue, was not greatly influenced by the genotype of the endosperm when averaged over all mutants. In the B37 series, only the pericarp thickness for the sh2 mutant significantly exceeded its normal sibbed kernels. while in the Oh43 series, ae and su2 mutant kernels had significantly thicker pericarp tissue and su1 mutant kernels had thinner pericarp. While significant these differences were small in magnitude. There is a lack of evidence for a metaxenia effect of endosperm phenotype on pericarp thickness when averaged over all nine mutants.
Effect of Endosperm Mutants on Drying Rate in Corn (Zea mays L.)1
Authors: Nass H. G. , Crane P. L.
Published: July 2010

Nine endosperm mutants in three hybrid backgrounds were used to study the effect of the endosperm of the coru (Zea mays L.) kernel on drying rate. Drying rate was determined by the percent moisture loss from husked ears in a forced‐air dryer at 38 C for 24 hours.

Dull, ae, sh1, and su1 had a significantly greater drying rate than normal at each of the seven harvests from 35 to 77 days after pollination. Opaque‐2 showed a significantly greater drying rate at the first five harvests. Sugary‐2 had a significantly lower drying rate than normal at the first five harvests, while h was significantly lower than normal at 35 and 70 days after pollination. Floury‐1 and wx did not differ significantly in drying rate from normal at any of the harvests.

A relationship was found between percent moisture and drying rate per ear within harvest dates. Osmotic pressure increased as days to harvest increased but was not correlated with drying rate.

It is proposed that drying rate is regulated in part by hydrophilic compounds in the endosperm of the coru kernel.
Effects of Three Gene Loci in the Inheritance of Quantitative Characters in Maize1
Authors: Russell W. A. , Eberhart S. A.
Published: July 2010

Backcross‐derived sublines of inbred B14, differing by single marker genes and chromosome segments linked to these gene loci, were used in an analysis of the types of gene action in the inheritance of nine quantitative plant and ear characters. Three genes, Rpd1, Rf1, and Wx, and their recessive alleles were used to give the 27 genotypes for all combinations of the homozygous and heterozygous genotypes at the three loci. Highly significant differences were observed for all characters measured. Frequencies of significant comparison (P < .05) for the types of gene action were: additive, 63%; dominance, 37%; additive ✕ additive, 44%; dominant ✕ dominant, 56%; additive ✕ dominant, 20%; additive ✕ additive ✕ additive, 22%; additive ✕ additive ✕ dominant, 18%; additive ✕ dominant ✕ dominant, 37%; and dominant ✕ dominant ✕ dominant, 0%. Effects were greater for the rp1 and rf1 loci than for the wx locus. Overdominance was observed at two loci for yield and at one locus for each of ear row and ear length.
Comparison of Four Methods of Multiple Trait Selection for Five Traits in Alfalfa1
Authors: Elgin J. H. , Hill R. R. , Zeiders K. E.
Published: July 2010

Tandem, modified independent culling levels, estimated index, and base index methods of multiple trait selection were compared for improvement of alfalfa, Medicago sativa L., for resistance to Pseudopeziza medicaginis (Lib.) Sacc., Leptosphaerulina briosiana (Poll.) Graham & Luttrell, Ascochyta imperfecta Peck, and Uromyces striatus Schroet. vat. medicaginis (Pass.) Arth., and for increasing recovery after cutting in greenhouse and growth chamber facilities. Base index and estimated index methods were most effective, modified independent culling levels was intermediate, and tandem was least effective. Resistance to P. medicaginis and U. striatus, and recovery after cutting responded well to selection; there was little response for resistance to L. briosiana and A. imperfecta.
Effect of 2,3,5‐Triiodobenzoic Acid on Flax1
Authors: Vetter R. J. , Holden D. J. , Albrechtsen R. S.
Published: July 2010

Two varieties of flax (Linum usitatissimum L.), ‘Summit’ and ‘Nored,’ were treated with 2,3,5‐triiodobenzoic acid (TIBA) in an attempt to increase lateral branching and seed yield. Rates of 100 ppm to 300 ppm TIBA successfully inhibited apical dominance and broke lateral bud dormancy; however, timing of treatment was critical for maximum bud breakage with minimum injury to the flax plant. The only significant effects on seed yield were decreases, but indications are that TIBA has the potential of increasing yield in flax when certain critical environmental factors are present.
Covariance Analysis Involving Energy Production and Distribution Among Seed Fractions by Soybean Genotypes, Glycine max (L.) Merrill1
Authors: Shimura Eiji , Hanson W.D.
Published: July 2010

Genetic correlations and regressions between agronomic characters and the three principal agronomic characters in the soybean (yield, oil content, and protein content) were presented. These relationships were applicable to a general population of improved soybean genotypes and involved wide environmental sampling. The genetic control of energy distribution among the respective seed fractions was examined utilizing a carbon equivalent transformation. The high‐protein, high‐yield combination should be compatible if considered in terms of energy investment. A required commitment of energy to the residual fraction was noted. The genetic correlations and covariance partitions supported the alternate hypothesis that genotypes in this population (from high‐oil, improved parents) did not favor protein synthesis; rather, high energy production tended to favor oil synthesis. These observations suggested some physiological restriction for the production of high protein. The approximate nature of the energy transformation used was noted. To appreciate the problems involved in developing a high‐yielding, high‐protein genotype, one must first understand the energy requirements for the synthesis of protein and oil by soybean genotypes.
Seed Characteristics and Field Establishment in Indiangrass, Sorghastrum nutans (L.) Nash1
Authors: Rafii Zia E. , Barnett F. L.
Published: July 2010

Spikelets harvested in 2 successive years from 11 seed sources of indiangrass, Sorghastrum nutans (L.) Nash, were evaluated for seed set, caryopsis weight, germination at varying times following harvest, and ability to establish plants in the field under different conditions and at varying times following harvest. An appropriate level of seed‐source variation in the seed generation was considered assured by breeding background and management of seed sources. Correlation coefficients showed establishment capability to be closely associated with each of the other traits, although correlation of establishment and spikelet germination appeared to vary according to age and treatment of spikelets, in both germination and establishment tests. Four of five source F values for establishment declined to nonsignificance at .20 when establishment data were adjusted for multiple regression on caryopsis weight and some measure of spikelet germination. Adjustment seemed most effective when spikelets tested for germinability in the laboratory and those used in field establishment had undergone comparable dormancy reduction through either aging or laboratory treatment. Major seed‐source differences in establishment were attributed to laboratory‐evaluated differences in seed traits. Possibility of lesser differences not so attributable was noted. Findings agreed with those of a previous study having different breeding background and management of seed sources. Applications and limitations of laboratory seed analyses, as means of evaluating field establishment capability in breeding programs, were discussed.
Yield Components and Protein Quality of Opaque‐2 and Normal Diallels of Maize1
Authors: Sreeramulu C. , Bauman L. F.
Published: July 2010

Eight opaque‐2 lines of maize (Zea mays L.) were crossed in a diallel series and from opaque and normal pollinations, two phenotypes viz., opaque (o2o2o2) and normal (+o2o2), were compared and combining ability analysis was made. The opaque phenotypes were 11% lower in both 100‐kernel weight and yield of grain than their normal counterparts. Kernel number per ear was the same in both the opaque and normal. Opaque phenotypes had 11.4% protein as against 10.63% for the normal. Protein yield was 4% lower in opaque than the normal. In the opaque phenotypes, lysine as percent of protein was 4.70% and lysine as percent of sample 0.536. Correlation coefficients of protein and lysine percent with yield of grain were very low and not significant. Additive gene action was more important than nonadditive for kernel weight, kernel number, yield of grain, lysine as percent of sample, and lysine yield, while both additive and nonadditive gene action were important for protein percent and protein yield. Mass selection or recurrent selection for general combining ability is proposed to develop opaque‐2 lines of high productivity.
Accumulation of Strontium and other Cations by Plant Species Grown on Two Soil Types1
Authors: Collins H. A. , Burch H. E.
Published: July 2010

Concentrations of Sr, Ca, Mg, and K were determined in shoot tissues of 22 plant species representing six families and ranging from 51 to 88 days of age which grew on Crofton silty clay loam and Norfolk loamy sand. Crofton soil had a pH of 7.85 and a CEC of 20.27 meq/100 g, whereas Norfolk soil had a pH of 5.8 and a CEC of 4.4 meq/100 g.

A positive correlation of 0.84 existed between Ca and Sr concentrations among the plants tested.

There was approximately a five‐fold difference in Sr concentration between shoot tissue of mustard, Brassica alba (L.) Boiss., big bluestem, Andropogon gerardi Vitman, and grain sorghum, Sorghum bicolor (L.) Moench.
Gene Dosage Effects on Monogenic Resistance to Northern Corn Leaf Blight1
Authors: Dunn G.M. , Namm Ted
Published: July 2010

The Ht gene conditions chlorotic lesion resistance in maize (Zea mays L.) to northern corn leaf blight incited by Helminthosporium turcicum Pass.

Monoploid, diploid, triploid, and tetraploid seedlings of Zea mays were obtained for the Ht and ht alleles and inoculated at the 3‐ or 4‐leaf stage in a humid chamber at 19 to 21 C. Disease reaction was evaluated by determining the percentage of leaf area infected.

There was no difference in resistance between monoploid (Ht) and diploid (Ht Ht) or between triploid (Ht Ht Ht) and tetraploid (Ht Ht Ht Ht) seedlings; however, three and four doses of the Ht allele conferred a higher level of resistance on seedlings than did one or two doses. Heterozygous diploid (Ht ht) seedlings were always less resistant than any of the other levels of Ht used in this study.

Diploid, triploid, and tetraploid seedlings containing two, three, and four doses, respectively, of the ht allele did not differ in their degree of susceptibility. Monoploid (ht) seedlings were much more susceptible than seedlings of the other three dosage levels.
Effect of Bacterial Pustule and Frogeye Leafspot on Yield of Clark Soybean1
Authors: Laviolette F. A. , Athow K. L. , Probst A. H. , Wilcox J. R. , Abney T. S.
Published: July 2010

The effect of bacterial pustule (Xanthomonas phaseoli var. sojensis (Hedges) Starr and Burkh.) and frogeye leafspot (Cercospora sojina Hara) diseases on the seed yield of ‘Clark’ soybeans (Glycine max (L) Merrill) was studied with artificial inoculation at Lafayette, Ind., from 1966 to 1968. Good initial bacterial pustule infection resulted in only mild disease and no significant differences in yield between inoculated and noninoculated plots. Frogeye infection was. severe in 2 of the 3 years and the diseased plots were 17 and 21% lower in yield. We concluded that bacterial pustule resistance is nonessential in the area because of failure of the disease to develop sufficiently to affect yield even with good initial infection. Resistance to frogeye leafspot is desirable to prevent reestablishment of a potentially destructive disease.
Sweetclover Weevil Feeding Stimulants: Variation in Levels of Glucose, Fructose, and Sucrose in Melilotus Leaves1
Authors: Akeson W. R. , Gorz H. J. , Haskins F. A.
Published: July 2010

Youngest fully expanded leaves, from plants of M. officinalis (L.) Lam. seeded at weekly intervals but harvested on the same day, were approximately 1.5 to 2.0 times as high in content of glucose, fructose, and sucrose at all stages of growth as leaves from comparable plants of M. infesta Guss. These plants varied in age from 3 to 14 weeks. Levels of glucose and fructose increased with increasing plant age in both species. Sucrose content increased in M. officinalis but decreased in M. infesta as the plants matured. When plants of approximately the same age were sampled at six different dates, the level of each sugar again was higher in young leaves of M. officinalis than in corresponding leaves of.M. infesta at each sampling date. Evidence reported in this and preceding papers suggests that differences in sugar content may influence the degree of resistance or susceptibility of Melilotus leaves to feeding by the adult sweetclover weevil (Sitona cylindricollis Fahraeus), but that these differences apparently are not primarily responsible for the observed differences in resistance displayed by M. officinalis and M. infesta.
Location of Genes for Seed Coat Color in Hexaploid Wheat, Triticum aestivum L.1
Authors: Metzger R. J. , Silbaugh B. A.
Published: July 2010

Monosomic analysis was used to ascertain that red seed coat color in ‘Red Bobs’ wheat (Triticum aestivum L.) is controlled by one gene located on chromosome 3A. A second factor, tentatively located on chromosome 3B, and a third gene located on 3D governed seed coat color in ‘Kharkof’ wheat. One of the three genes that control seed coat color in PI 178383 wheat was associated with chromosome 3B. The gene located on chromosome 3B in Kharkof and PI 178383 was designated R3.
Sources of Immunity and Susceptibility to Downy Mildew of Soybeans1
Authors: Dunleavy John
Published: July 2010

The disease reaction of 14 races of Peronospora manshurica (Naum.) Syd. ex Gaum., the downy mildew fungus, was observed on 72 soybean (Glycine max (L.) Merr.) varieties. ‘Mendota,’ ‘Kanrich,’ and a portion of the ‘Kanro’ plants were resistant to all races studied. Only ‘Bansei’ was very susceptible to all races of the fungus to which it was tested. Varieties were rated for response to the fungus on a basis of 1 (immune) to (very susceptible). The distribution with respect to disease rating classes of the responses of the varieties to races of P. manshurica was determined. Nearly one‐third of the variety ratings for all race‐variety combinations were in class 5. The means for the other four disease rating classes were uniformly distributed in classes 1 through 4. Race 8 was most virulent, with 75% of the disease ratings occurring in classes 4 and 5. In contrast, race 10 was least virulent, with 26% of the ratings occurring in classes 4 and 5.
Yield Stability of Four Population Types of Grain Sorghum,1Sorghum bicolor (L.) Moench, in Different Environments
Authors: Reich V. H. , Atkins R. E.
Published: July 2010

Eight parental lines, 16 F1 hybrids, 16 2‐component blends of parental lines, and 16 2‐component hybrid blends of grain sorghum (Sorghum bicolor L. Moench) were grown in 9 environments over 2 years in Iowa.Standard analyses of variance and analyses for estimating stability parameters were made for grain yield and yield component data. A stable entry or population was defined as one with a regression coefficient close to 1.0 and deviations from regression near zero. A high mean yield also was deemed an essential attribute for an entry or population.

The parameters for grain yield indicated that hybrid blends were the most productive and stable population type, although none of the populations were distinctly superior for all parameters. Hybrid blends had the highest mean yield over all environments and were second among the population types in terms of low deviations from regression and an average regression coefficient near 1.0. Data for the components of yield tended collectively to support the conclusion that hybrid blends were the most stable population type.

A hybrid was the highest yielding individual entry in each environment, except one, where a hybrid blend was the most productive. Also, a hybrid had the highest mean yield among individual entries over all environments. Across all environments, 22 of the 32 blended populations yielded more than the pure‐stand mean of then: components. Yields for twelve of the 16 hybrid blends exceeded their mid‐component value. Collectively, the heterogeneous populations yielded 102% of the mean of their homogeneous components. Six of the blends exceeded the mean pure stand yield of their more productive component.
Effect of Planting Date on the Meiotic and Reproductive Behavior of Hexaploid Triticale (Triticale hexaploide Lart.)1
Authors: Sisodia N. S. , Larter E. N. , Boyd W. J. R.
Published: July 2010

Meiotic irregularities increased in each of five advanced generation hexaploid triticale (Triticale hexaploide Lart. (5)) with delayed planting. In addition, tillering capacity was reduced. Significant differences existed between genotypes, and a marked interaction occurred between genotype and planting date. Notwithstanding meiotic irregularities, production of normal pollen was reasonably good (70‐75%), and spikelet fertility was equivalent to that hexaploid wheat.
Meiotic Behavior and Preferential Pairing in Autotetraploid Barley1
Authors: Reinbergs E. , Kao K. N. , Harvey B. L. , Shebeski L. H.
Published: July 2010

Metaphase‐I pairing and anaphase‐I distribution were studied in four varieties and six hybrids of barley, Hordeum vulgare L. emend Lam. These data were compared with level of fertility. Multivalent formation was not related to fertility level, but the distribution of chromosomes at anaphase‐I was closely related to fertility. Preferential pairing for the genes orange lemma and smooth awns was found in autotetraploid barley hybrids. Progress in breeding for higher fertility in tetraploid barley might be attained by accumulation of small structural differences to enhancep referential pairing.
Fertility Relationships Among Interspecific Hybrid Progenies of Gossypium1
Authors: McKenzie W. H.
Published: July 2010

The two cultivated New World cottons, Gossypium Hirsulum L. and Gossypium barbadense L., together with four hybrid families comprising a representative range between them were studied to obtain a quantitative measure of the potential for and the realization of reproductivity.

Three of the four hybrid families possessed a greater number ot fertilized ovules per ovary than either of the parent strains. Heterosis was thought to be largely responsible. Hybrid families, however, made less efficient use of their reproductive potential. Families with the greatest mixture of germplasm which correspondingly possessed the greatest number of fertilized ovules per ovary, matured the smallest number of seeds per boll. Selfing brought about an even more drastic reduction in the number of seeds recovered per boll for all of the hybrid families. A smaller, but statistically significant, elimination of hybrid progeny accompanied germination.

Even though the majority of elimination was postzygotic, it was concluded that the relative amount of interspecific recombination occurring during gamete formation could adequately account for the observed reproductive breakdown.
Inheritance of a New Factor (Bt8) for Resistance to Common Bunt in Wheat1
Authors: Waud J. L. , Metzger R. J.
Published: July 2010

A previously unreported major dominant gene segregated for resistance to races T‐1, T‐15, T‐16, and L‐8 of common bunt (Tilletia caries and T. foetida) in a wheat (Triticum aestivum L.) cross of ‘Yayla 305’, P.I. 178210 (resistant) × ‘Elgin’ (susceptible). The gene, designated Bt8, determines resistance to all races of common bunt known to be present in the Pacific Northwest states.
Genetic Studies of Self‐Incompatibility in Carthamus flavescens Spreng1
Authors: Imrie B. C. , Knowles P. F.
Published: July 2010

The inheritance of self‐incompatibility was studied in Carthamus flavescens Spreng., a weedy relative of C. tinctorius L. (cultivated safflower). C. flavescens was found to have a single‐locus sporophytic system of selfincompatibility with at least six alleles at the locus. Data from intercrosses among C. flavescens plants and F2 and F3 generations of interspecific crosses supported the hypothesis of dominance in the pollen and independent action of alleles in the style. The allele for self‐compatibility, Sf, in C. tinctorius was intermediate in the dominance range of the self‐incompatibility alleles identified in C. flavescens. There was evidence that dominance relationships were temperature sensitive. Considerable nonhomology of S alleles in C. flavescens and C. oxyacantha M.B. was indicated.
Ethylene Production in the Cotton Plant (Gossypium hirsutum L.) Canopy and Its Effect on Fruit Abscission1
Authors: Heilman M. D. , Meredith F. I. , Gonzalez C. L.
Published: July 2010

Using gas solid chromatography, ethylene was determined in excised plant tissue and in the atmosphere at midpoint of the mature cotton (Gossypium hirsutum L.) canopy in the field. The ethylene produced from excised tissue was: leaves, 1,2 ✕ 10−9 moles/g; immature capsules, 0.35 ✕ 10−9 moles/g; bolls, 0.07 ✕ 10−9 moles/g; and pink blooms, 2 ✕ 10−9 moles/g. The ethylene in the atmosphere at the midpoint of the cotton canopy was 3.6 ✕ 10−12 moles/ml while the atmosphere surrounding an individual pink bloom contained 8 ✕ 10−12 moles/ml ethylene. Ethylene was applied at rates of 9.3 ✕ 10−12 and 18.6 ✕ 10−12 moles/ml to fruiting field‐grown cotton plants enclosed in plastic bags. A statistically significant increase in abscission of immature capsules and bolls was found for the 18.6 ✕ 10−12 moles/ml‐treated plants.
Photosynthesis and Photorespiration in Two Clones of Orchardgrass1
Authors: Carlson G. E. , Pearce R. B. , Lee D. R. , Hart R. H.
Published: July 2010

We measured photosynthesis and photorespiration of two selected clones of orchardgrass Dactylis glomerata L., at 1, 2, 5, 11, 32, and 52 klux of light. Clone A7 exceeded clone P3 by 50% in photosynthesis and 40% in photorespiration at saturating light intensity. The CO2 compensation point was identical for both clones. Photosynthesis and photorespiration increased with increasing light; however, no photorespiration was observed at a light intensity of 2 klux or lower, and saturation occurred at 11 klux. Clone P3, with the lowest photosynthetic rate, had the greatest amount of apparent photorespiratory substrate. Photosynthesis was not inversely related to photorespiration but was inversely related to photorespiratory substrate. Selecting orchardgrass for photosynthetic efficiency should be possible.
Effect of Phytophthora Rot on Yield and Chemical Composition of Soybean Seed1
Authors: Caviness C. E. , Walters H. J.
Published: July 2010

Three cultivars of soybeans (Glycine max (L.) Merr.), ‘Hill,’ ‘Hood,’ and ‘Lee,’ susceptible to phytophthora rot caused by Phytophthora megasperma Drecks. var. sojae Hildeb. and a resistant near‐isogenic line of each cultivat were evaluated for 3 years at three locations in Arkansas. Near‐isogenic lines were derived by crossing each cultivar to ‘Arksoy,’ which is resistant to this disease, and making five backcrosses to the recurrent parent. Yields of these resistant lines did not differ significantly from those produced by susceptible cultivars at Stuttgart where damage from phytophthora rot was negligible. At locations where damage from this disease was moderately severe, yields of Hood and Lee generally were significantly lower than their resistant near‐isogenic lines with yields of Hood reduced more than Lee. Yields of Hill generally were reduced less than other cultivars. Cultivars damaged by phytophthora rot produced seed with lower protein and higher oil content than nearisogenic lines resistant to this disease. Protein and oil content of seed of susceptible cultivars and their resistant near‐isogenic lines did not differ significantly at the location where damage from this disease was negligible.
Functional and Biochemical Changes in Maturing Barley. I. Changes in Malting and Brewing Characteristics1
Authors: Pomeranz Y. , Standridge N. N. , Shands H. L.
Published: July 2010

Samples of ‘Larker,’ ‘Dickson,’ and ‘Conquest’ barleys (Hordeum vulgate L.) were harvested at 2 to 5 day intervals between 7 to 37 days after heading, dried to about 12% moisture, and threshed. During development, the kernel (dry) weight increased from about 12.5 to 33.0mg, the test weight from 29 to 59 kg/hl (22 to 45 lb/bushel), and the hull color (Agtron) decreased from about 90 to 50. Moisture contents of the field‐harvested samples decreased almost linearly; net protein synthesis was apparently completed 10 to 13 days before field maturity. Maturation was accompanied by a percent decrease of ash, but increase of ash per kernel. Samples from early development stages imbibed more water in steeping, malted more slowly, and had higher malt losses. Malt modification, a‐amylase, and protein solubility increased with barley maturation. Diastatic power, β‐amylase, and α‐amylase were lowest in malts from barleys harvested about 12 to 17 days after heading. No consistent varietal effects on compositional and functional patterns during maturation were established. Whereas compositional maturity was attained in barleys harvested with a moisture content of 41 to 44%, optimal functional properties required harvesting of barley with lower moisture.
Relative Tolerance of Contemporary Oat Cultivars to Currently Prevalent Races of Crown Rust1
Authors: Michel L. J. , Simons M. D.
Published: July 2010

We tested about 100 contemporary oat (Avena sativa L.) cultivars, all visually rated as susceptible to crown rust (Puccinia coronata Cda. var. avenae Fraser and Led.) race 326, with severe field epiphytotics of this race. Eleven eultivars were then selected for more intensive testing with races 216 and 264, as well as with race 326. Yield and seed weight data showed that some cultivars (‘Clintland 64,’ ‘Jaycee,’ ‘Tippecanoe,’ and ‘Tyler’) were damaged as severely by race 326 as was the old highly susceptible ‘Clinton,’ while others (‘Kota,’ ‘Nodaway,’ and ‘Nodaway 70’) yielded almost as much as the resistant check.
Random‐Type Sterility in Sorghum1
Authors: Jaisani B. G. , Drolsom P. N.
Published: July 2010

Study of the S1, S2, and S3 generations of Sorghum bicolor (L.) Moench and S. sudanense Stapf. plants for the inheritance of random‐type (ra‐type) sterility revealed bimodal distributions when classified arbitrarily from 1 (excellent seed set) to 12 (no seed set). The first modal peak was observed at classes 2 or 3, while a second peak occurred at classes 8, 9, 10, or 11. Sterility classes 6 and 7 had the lowest frequency and appeared to be the break points. The distributions were very similar for classes 1 through 6, and 7 through 11. It appeared that the sterility observed in S. bicolor was quantitatively inherited and was different from that previously reported in sorghum. The narrow sense heritability estimate for this character was 0.43.

Pollen stainability decreased with an increase in sterility. It underestimated sterility among higher sterility classes, but was a good indicator of sterility among more fertile classes, suggesting that male‐sterility was primarily involved.

A negative association was observed between sterility and vigor during the same generation. Positive associations were observed for sterility between different generations and for vigor and height of the progeny in the same generation.

The study of progenies from individual panicles of the same plant revealed that S0, S1, and S2 plants had significant intra‐plant variation for ra‐type sterility. Plants with similar intra‐plant progenies suggested that the sterility trait followed mendelian inheritance. Variation in intra‐plant progenies suggested that within‐plant somatic variations were occurring.