bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Stand Geometry on Light Interception and Net Photosynthesis in Cotton1
Authors: Baker Donald N. , Meyer Raymond E.
Published: July 2010

The following geometric variables interact to determine the nature of shade patterns in row crops: solar altitude, the angle of the row with respect to the solar azimuth, plant size and planting pattern. Great change during the day was observed in the relative percent interception in all stands when the crop was young. In the early morning and late afternoon NS rows intercepted more light than EW rows. Percent interception began to level off at a leaf area index of about 3 in the conventionally planted cotton. Little or no convergence in the percent interception vs. LAI curves for noon and noon ± 5 hours was noted in the NS‐skip cotton up to an LAI of 4 on a per lanted acre basis. This indicates that expenditure of net photosynthate in the further elaboration of new leaf tissue would be a good investment as long as the fruit ltimately produced by the plant would have time to mature. Row direction had no significant effect on the total daily net photosynthesis by cotton conventionally planted in 40‐inch rows. On a per planted acre basis the NS‐skip planted cotton consistently outperformed the NSsolid stand and the EW‐skip planted stand. In all of the stands the daily time course of net photosynthesis parallelled very closely the course of interception of solar energy. The light data from a flat surface receiver may be adjusted for percent interception by any stand, regardless of geometry, to give an accurate prediction of net photosynthesis.
Heterosis and Combining Ability in a Diallel Cross in Sorghum vulgare Pers.1
Authors: Niehaus M. H. , Pickett R. C.
Published: July 2010

Combining ability analyses were computed on a diallel cross of eight inbred sorghum lines in the F1 and F2 generations. Five of the lines were standard combine height grain sorghums and three were widely diverse and relatively recent introductions differing for height and maturity genes. The objective of the study was to determine the usefulness of recent sorghum introductions in a hybrid sorghum breeding program and to determine the yield components responsible for any heterosis obtained. Heterosis was striking, but only if at least one of the parents was an introduction. General combining ability effects were high in the F1 and F2 but specific combining ability effects were high only in the F1. The correlation between the yield of the midparent and the yield of the F1 (r = .07) indicated that the superior parents could not have been selected phenotypically. Number of seeds per head was the most important component of yield in the F1 generation. From the available data it could not be ascertained whether the outstanding performance of the three introductions as parents was due to genetic diversity of many genes or to hybrid vigor associated with a relatively few height and maturity genes.
Stability Parameters for Comparing Varieties1
Authors: Eberhart S. A. , Russell W. A.
Published: July 2010

The model, Yij = μ1 + β1Ij + δij, defines stability parameters that may be used to describe the performance of a variety over a series of environments. Yij is the variety mean of the ith variety at the jth environment, µ1 is the ith variety mean over all environments, β1 is the regression coefficient that measures the response of the ith variety to varying environments, δij is the deviation from regression of the ith variety at the jth environment, and Ij is the environmental index.

The data from two single‐cross diallels and a set of 3‐way crosses were examined to see whether genetic differences could be detected. Genetic differences among lines were indicated for the regression of the lines on the environmental index with no evidence of nonadditive gene action. The estimates of the squared deviations from regression for many hybrids were near zero, whereas extremely large estimates were obtained for other hybrids.
Factors Affecting Oil Content and Oil Composition of Corn (Zea mays L.) Grain1
Authors: Jellum M. D. , Marion J. E.
Published: July 2010

Nine corn hybrids were grown at 5 locations in 1962 and at 6 locations in 1963 to study the factors which may influence the oil content and quality of the corn kernel. Three dates of planting were used at one location in each year. First and second ears were harvested separately and analyzed for oil content by nuclear magnetic resonance and for fatty acid composition of the oil by gas‐liquid chromatography. Oil content and quality were not greatly affected by different dates of planting. Ear position had no effect on palmitic, stearic, and linolenic acids. Although not always significant, the oil from the first ear was always higher in oleic acid and lower in linoleic acid than the second ear. The seeoml ear was lower than the first ear in oil content in 1963 but not in 1962. Year, location, and hybrid effects were highly significant for all characters. First and second order interactions were generally nonsignificant. Hybrids had a greater influence on the characters studied than any of the environmental factors.
Chlorophyll Relationships for Certain Sweet Corn Genotypes in Different Environments1
Authors: Oelke E. A. , Andrew R. H.
Published: July 2010

Five inbred lines of sweet corn and their l0 F, hybrids were used to investigate the relationships of chlorophyll concentration over successive sampling dates to phenotype, to ethanol soluble sugars and crude protein in the leaf tissue, to dry weight, and to ear weight at 70% moisture. The inbreds were dark green, medium green, pellucid, and fine striped in appearance. Phenotypic appearance was an indication of chlorophyll concentration when plants were grown in the field and growth chamber. Correlations for chlorophyll concentration between experiments were nearly always highly significant indicating little change in rank of the inbreds and hybrids between environments. Chlorophyll concentration decreased with age in all environments. Hybrids maintained their chlorophyll concentration longer during the growing season than the inbreds and also had higher concentrations than either parent. Estimates of general and specific combining abilities indicated that inbreds with high chlorophyll concentrations gave hybrids with high chlorophyll. Little correlation was found between chlorophyll concentration and ethanol soluble sugars, crude protein, dry weight production, and ear weight.
Inheritance of Stem Rust Resistance in Triticum aestivum ssp. vulgare ‘Reliance’ and P.I. 94701 of Triticum durum1
Authors: Rondon M. R. , Gough F. J. , Williams N. D.
Published: July 2010

Seedling resistance to physiologic race 111 (culture 111‐SS2) of Puccinia graminis f. sp. tritici was conditioned by two and three independent genes, respectively, in the durum wheat P.I. 94701 and the common wheat Reliance. The infection type was lower when P.I. 94701 genes for resistance were combined in a single plant than when they occurred singly. One of the P.I. 94701 genes also conditioned moderate resistance to physiologic race 15B (culture 15B‐SS1). Low infection types masked high infection types in plants carrying two or three genes for resistance from Reliance.
Diallel Analyses of Quantitatively Inherited Characters in Gossypium hirsutum L.
Authors: White Thomas G.
Published: July 2010

Diallel analyses were made on a 5‐parent complete diallel cross for 6 characters: yield, lint percent, boll size, seed index, lint index, and earliness. The objectives were: (1) To study epistasis for these characters, and (2) to evaluate further the fit of these parents to the assumptions necessary for the diallel analysis. Yield and boll size were the only characters for which dominance was significant. These same characters had shown dominance in an earlier experiment. Over‐all epistasis was barely significant for boll size and seed index, but no individual epistatic deviations were significant. Yield, seed index, and lint index apparently met all requirements for the diallel analysis. Multiple allelism appeared to be present in lint percent, boll size, and earliness.
A Major Gene for Resistance to Seed Coat Mottling in Soybean1
Authors: Cooper R. L.
Published: July 2010

Four soybean varieties were grown in a date‐of‐planting study (12 dates) at St. Paul, Minnesota, and the effect of planting date on seed coat mottling was observed. At the same location, segregation for seed coat mottling was recorded in the F2 and F3 generations of a cross between ‘Merit’ (nonmottled) and ‘Harosoy’ (mottled). Three of the four varieties, ‘Acme’, ‘Chippewa,’ and ‘Harosoy’ showed increased amounts of mottling as the planting date was delayed. Merit, however, remained completely free of mottling at all twelve planting dates, which suggested that Merit was immune to seed coat mottling. The F2 and F3 segregation for mottling in the Merit ✕ Harosoy cross indicated that resistance to mottling was controlled by a single gene, designated as Im, which exhibited partial to complete dominance when grown in an environment favoring the expression of this trait.
Effect of Height on Yield and Yield Components of Two Isogenic Lines of Sorghum vulgare Pers.1
Authors: Graham Doyce , Lessman K. J.
Published: July 2010

Reciprocal crosses between 3‐dwarf and 2‐dwarf lines of grain sorghum differing only at the Dw2 locus were grown in the summer of 1963. The effect of plant height on yield was studied to elucidate mechanisms or causes of superior yields of tall genotypes and to determine if higher yields might be achieved in combine height sorghums. It was concluded from light availability data that the taller 2‐dwarf parent and F1's were perhaps more efficient in utilization of available light due to spatial arrangement of leaves. The data suggested that the yield level of the taller 2‐dwarf line may not be recovered rapidly in the shorter 3‐dwarf line by manipulation of alleles at the Dw2 locus conditioning height.
Intra‐Plant Relationships in Reed Canarygrass1
Authors: Mittra M. K. , Wright M. J.
Published: July 2010

Vegetative shoots of reed canarygrass and the single tillers they bore were subjected to various defoliation regimes in the greenhouse to test the degree of interdependence of the two units. On some stems, only the three uppermost blades or the three lowermost blades were preserved, whereas on others all blades were preserved. These treatments were applied to main shoots and tillers in all nine possible combinations. Results measured in terms of stem elongation and yield of dry matter after 7 to 8 leaves had expanded indicated that the 2 units were largely independent. As in previous experiments, the removal of basal blades had little influence on stem elongation or dry matter accumulation above ground. Removing upper blades reduced elongation and, in some cases, yield of the treated stem, but did not much affect its companion.
Self‐Compatibility Response to Temperature and the Inheritance of the Response in Tetraploid Alsike Clover, Trifolium hybridum L.1
Authors: Townsend C. E.
Published: July 2010

The compatibility reaction of a self‐incompatible clone of tetraploid alsike clover was temperature sensitive in controlled environmental chambers. One to 2 days of constant 90 F or 90 day‐ 80 F night temperature treatments changed the incompatibility reaction; by the 4th day of treatments, approximately 50% of the selfed florets were setting seed. The 90 day‐ 70 F night and constant 80 F temperature treatments also affected the incompatibility reaction in 1 to 2 days, but no more than 20% of the selfed florets set seed. After the incompatibility reaction was changed at the 90 to 80 F treatment, propagules were removed and placed at constant 70 F. It took 24 hours to change the compatibility reaction from one of self‐compatibility to one of self‐incompatibility. S1 and F1 progeny data showed that the inheritance of the self‐compatibility response to temperature was due to a gene designated as T. The genotype of the temperature‐sensitive clone was TTtt, with sensitivity being dominant. The genotype of the nonsensitive parents of the F1 progenies was tttt. One dose of the T gene was sufficient to give the response. The S genotype of the clone was believed to be triallelic (S1S1S2S3). No association was observed between temperature sensitivity and S locus genotype.
Studies of the Physiological Basis for Yield Differences. II. Variations in Dry Matter Distribution Among Aerial Organs for Several Dry Bean Varieties1
Authors: Wallace D. H. , Munger H. M.
Published: July 2010

The extent of variation in distribution of accumulated dry matter among aerial organs at maturity was compared for 11 varieties of Phaseolus vulgaris L., representing marrow, red kidney, yelloweye, and pea types of dry bean. The lowest percentages of aerial dry weight present as fruit (seed and pod wall) were exhibited by the red kidney and pea bean varieties. ‘Charlottetown’ yelloweye exhibited the highest percentage as fruit and the highest harvest index (percentage of aerial dry weight as seed), but it had the lowest seed yield because of early maturity and accompanying low dry matter accumulation. The second highest harvest index was exhibited by ‘Cornell 7–16’ which regularly out‐yielded all other varieties. Harvest indices of the varieties varied from 53% to 67%. The high seed yield and harvest index of 7–16 were accompanied by the highest ratio for seed weight divided by pod wall weight. Harvest index was not correlated with time to maturity nor with determinate and indeterminate growth habits. In addition to harvest indices the varietal expressions of leaf‐area, leaf‐area ratio, relative growth rate, relative leaf growth rate, and net assimilation rate are discussed. This information on genetic variability and the inter‐relationships of these many factors provides improved understanding of the physiology of yield differences in beans. It also provides a physiological basis for formulating a program of breeding higher yielding dry bean varieties.
Morphological Measures of Earliness of Crop Maturity in Cotton1
Authors: Ray L. L. , Richmond T. R.
Published: July 2010

Certain features of the gross morphology of the cotton plant furnish clues to earliness of crop production. Three such features — (1) node of first fruiting branch (NFB), (2) number of vegetative branches (NVB), and (3) percentage of bolls on vegetative branches (PBV) — were used as morphological measures of earliness in the studies reported here. All of the morphological measures were significantly correlated but, because of its higher heritability and lower variability, NFB is considered the most reliable and the most practical one of the three. NFB and NVB were signficantly correlated, phenotypically, with product‐quantity measures of earliness. Mean maturity date (MMD), a product‐quantity measure, and NFB, a morphological measure, are separate estimates of the same phenomenon: i.e., earliness of crop maturity. Used together, they are mutually supporting and they form a reliable basis for estimating earliness in genetic studies and breeding programs.
On the Choice of Tester Parent for the Breeding of Synthetic Varieties of Maize (Zea mays L.)1
Authors: Allison J. C. S. , Curnow R. N.
Published: July 2010

The selection of genotypes (plants or first generation inbred lines) from an open‐pollinated variety to combine into a synthetic variety involves the choice of a suitable tester parent. A theoretical examination of a single locus shows that the recessive homozygote is the best tester for maximizing the expected mean yield of the synthetic variety.

In practice the gene frequency and the amount and direction of dominance will be unknown. With no dominance the mean yield of the synthetic variety is independent of the tester. With partial dominance any tester will give some increase in mean yield. With overdominance the choice of the ‘wrong’ homozygote as tester could cause a reduction in mean yield but if the parental variety is used as tester the yield will at least not decline. The parental variety may therefore be a safer choice as tester than other varieties with contrasting gene frequencies.

Criteria are derived for deciding which loci are most important in choosing a tester. It is argued that at these loci the parental variety is more likely than other available varieties to be near homozygous recessive. If positive dominance is important, a good tester may be produced by selecting for low yield within the parent variety.

Much of the theory and many of the conclusions presented in this paper are not new. The aim of the paper is to give a unified mathematical account of the known theory and to generalize and interpret it.
Linkage of Resistance to Erysiphe graminis f sp. tritici (Pm3) and Hairy Glume (Hg) on Chromosome 1A of Wheat1
Authors: Briggle L. W. , Sears E. R.
Published: July 2010

The gene Pm3 for resistance to Erysiphe graminis f. sp. tritici, in the wheat variety ‘Indian’, was located on the short arm of Chromosome 1A (XIV), 0.82 crossover units from Hg (hairy glume). This resistance gene is not fully effective until the host plants reach the three to five‐leaf stage, whereas what is believed to be an allele from certain other resistant varieties is fully expressed at the first leaf stage. Each of these alleles is dominant to the allele for susceptibility, and each has been transferred separately to the variety ‘Chancellor’.
Genetic Analyses of the Resistance to Mayetiola destructor (Say) in Hordeum vulgare L.1
Authors: Olembo J. R. , Patterson F. L. , Gallun R. L.
Published: July 2010

Resistance to Hessian fly (Mayetiola destructor Say) was studied in the F1, F2, and F3, generations following intercrosses among 3 barley varieties and crosses of the 3 to ‘Mars’ and ‘Gull’ translocation stocks. A common dominant factor (symbol proposed Hf hf) was found in ‘Delta’, ‘Nile’, and ‘Abusir’ which governed resistance at cool greenhouse temperatures. The factor was independent of 4 translocation breakpoints which tested one or more arms of chromosomes 1, 2, 3, 4, 6, and 7.

At higher greenhouse temperatures, two complementary dominant genes were necessary to explain resistance in Delta. The second factor pair which was ineffective alone was designated Hf2 hf2.
Free Amino Acid Composition of Flours Milled from Wheats Harvested at Various Stages of Maturity1
Authors: Hoseney R. C. , Finney K. F.
Published: July 2010

Flour milled from ‘Pawnee’ and ‘Kaw’ wheats harvested at various stages of maturity in 1961 and 1962 were analyzed for free amino acids by two‐dimensional paper chromatography. The number and concentration of free amino acids decreased strikingly during wheat maturation. However, the amount of free amino acids per kernel of wheat rose to a maximum at about physiological maturity and then declined to a minimum when combine ripe. Several nonprotein amino acids were found at the earliest stages of maturity. Little or no differences were found in the concentration of free amino acids between varieties or crop years.
Correlated Inheritance of Maturity and Quality Factors in a Hard Red Winter Wheat Cross1
Authors: Schlehuber A. M. , Abbott D. C. , Jackson B. R. , Curtis B. C.
Published: July 2010

Simple correlations between maturity and 14 quality characteristics were evaluated for F4 progeny of a hard red winter wheat cross between an early, mellow gluten variety with a late, strong gluten variety. Correlation coefficients were low and statistically nonsignificant except for those relationships between maturity and sedimentation and maturity and specific sedimentation. In 12 other correlations between maturity and quality characteristics, the values were low and statistically nonsignificant. For all 14 quality characteristics, the range of the F4 exceeded the 2 parents. Midparent values equaled the progeny means in 7 characteristics, exceeded the progeny means in 5 characteristics, and were less than the progeny means in 2 characteristics (sedimentation and specific sedimentation).

Genotypic and phenotypic correlations between heading date and eight quality characteristics tended to be small and indicated no strong genetic association which would impede selection for early maturity lines with good milling and baking quality characteristics. Heritabilities ranged from 25% for flour extraction to 78% for bake mixing time and to 87% for heading date. Results from lines selected for quality characteristics and early heading and grown continuously from F4 through F7 clearly indicated that selection was effective in improving mixograph mixing time, sedimentation, and protein content while maintaining maturity equal to the early parent.
Isogenic Lines in American Upland Cotton, Gossypium hirsutum L.: Preliminary valuation of Lint Measurements1
Authors: Kohel R. J. , Lewis C. F. , Richmond T. R.
Published: July 2010

We backcrossed plants of eight dominant markers recurrently to a highly inbred line to develop a series of isogenic lines. After backcrossing six generations, we evaluated eight agronomic and physical properties of the lint to determine the degree of isogenicity, and to characterize the pleiotropic effect of the individual marker genes. After separating the segregating material by genotype, we evaluated them by comparing the variability between and within genotypes. Analyses revealed residual variability in some lines but not in others after six generations of backcrossing, which indicated progress toward isogenicity but that additional backcrossing was needed. Some markers displayed apparent pleiotropic effects and one displayed linkage.
Diallel Analysis of Seven Economic Characters in Snap Beans1
Authors: Dickson M. H.
Published: July 2010

Seven varieties of snap beans (Phaseolui vulgaris L.) (‘Wade,’ ‘Earligreen,’ ‘Earliwax,’ ‘Streamliner,’ ‘Harvest King,’ ‘Slendergreen,’ and ‘Tendercrop’) and all possible F2's among them were evaluated. Number of seeds per plant, number of seeds in the best five pods, length of pod, number of pods per plant, days to flowering, plant height, and width were determined.

Additive genetic variance was predominant in the first five traits, but not for plant height and width. Pod number also showed some dominance, with recessive genes contributing to high pod number. Inheritance of seed number per plant and per pod resulted in interactions where Tendercrop and Streamliner were included, but without these two varieties a simple additive system is apparent. Pod length was under additive genetic control without dominance. Days to flowering was additive, but over‐dominance was expressed for earliness. The data indicate which parents would be the best for the characters studied, with Earligreen and Slendergreen appearing to be superior.
Growth of Birdsfoot Trefoil and Alfalfa. I. Responses to Height and Frequency of Cutting1
Authors: Smith Dale , Nelson C. J.
Published: July 2010

The responses of birdsfoot trefoil and alfalfa to frequency and height of cutting were studied. Single‐row plots were harvested 3, 4, 5, or 6 times before early September, leaving a stubble of 2.5, 7.6, or 15.2 cm. Responses of both legumes to cutting frequency were similar. Yields of forage and protein decreased as cutting frequency increased. The amount of stubble left at cutting was more important to trefoil than to alfalfa and was most clearly apparent in the the second harvest year. A leafy stubble was needed to maintain the yields at all cutting frequencies for trefoil, but only with the most frequent cutting schedule for alfalfa.
Growth Analysis Formulae ‐ Their Use and Abuse1
Authors: Radford P. J.
Published: July 2010

The ‘Growth Analysis’ formulae in most common use are derived and all the necessary assumptions involved in their derivation are explained. The dangers of the indiscriminate use of these formulae are highlighted and recommendations are given on the selection of appropriate ones in a given situation. A distinction is made between the traditional technique which involves the calculation of mean growth rates etc. over time periods and an alternative approach which enables a continuous trace of changes with time to be made. The relative merits of both methods are discussed.
Two Additional Sources of Cytoplasmic Male‐Sterility in Pearl Millet and Their Relationship to Tift 23A1
Authors: Burton Glenn W. , Athwal D. S.
Published: July 2010

Two new sources of cytoplasmic male‐sterility designated ‘L66A’ and ’L67A’ have been isolated. Genetic‐cytoplasmic interactions for restoration of fertility prove that these sources are different from ‘Tift 23A.’ The maintainers for these sources also maintain sterility in Tift 23A. ‘Tift 23B,’ maintainer for Tift 23A, is a good fertility restorer for L66A and L67A. Good fertility restorers for Tift 23A, such as ‘T239 and ‘L‐4,’ are excellent sterility maintainers for L66A and L67A. L66B, maintainer for L66A, restores fertility in L67A, while L67B is a partial fertility restorer for L66A. Genetic models suggesting the relationship between different sources are presented.
Effect of Common Leafspot on Coumestans and Flavones in Alfalfa1
Authors: Bickoff E. M. , Loper G. M. , Hanson C. H. , Graham J. H. , Witt S. C. , Spencer R. R.
Published: July 2010

The coumestan and flavone content of ‘Atlantic’ and ‘Cayuga’ alfalfa (Medicago sativa L.) was determined after infection with Pseudopeziza medicaginis (Lib.) Sacc., the common leafspot organism. A fluorometric assay on one‐ and two‐dimensional paper chromatograms was used to determine six phenolic compounds.

Uninoculated checks contained less than 2 ppm ofcoumestrol and trace amounts of medicagol + 4'‐Omethylcoumestrol and 7,4'‐dihydroxyflavone. Samples collected 12 days after infection had significant amounts of all compounds studied except 3'‐methoxycoumestrol. Samples collected 18 days after infection showed increases of from about 2 to over 11 times the concentrations found in the 12‐day samples. The greatest increase from the 12‐day to the 18‐day samples was of sativol in both alfalfa varieties. However, accumulation of the phenolics was greatest in the more disease‐susceptible variety Atlantic.

A similar set of samples infected with the alfalfa rust organism, Uromyces striatus Schroet, var. medicaginis (Pass.) Arth., was too low in coumestan and flavone content to obtain meaningful information. Rust urediospores contained large amounts of coumestrol and other coumestans, and the loss of urediospores by spore discharge before the late sampling date is assumed to have been the cause of the extremely low coumestan content in the rust samples.
A Positive Regression of Yield on Maturity in Sorghum1
Authors: Dalton L. G.
Published: July 2010

A positive regression between high yields and late maturity is demonstrated for grain sorghum. This regression should be considered when hybrid performance is tested. The use of this high yield‐late maturity relationship should assist in the detection of the more productive hybrids at all levels of maturity.
Variation and Covariation in Agronomic and Malting Quality Characters in Barley. II. Interrelationships of Characters.1
Authors: Rutger J. N. , Schaller C. W. , Dickson A. D.
Published: July 2010

Correlations between all possible pairs of 8 agronomic and 9 malting quality traits were calculated from a population of 102 random lines of the F4 generation from an intervarietal malting barley cross. A strong positive correlation between head erectness and lodging should prove useful for selection purposes, since head erectness can be determined in th absence of differential lodging. Plump barley was negatively correlated with barley color and positively with malt extract. Extract was positively correlated with bushel weight and the wort N/malt N ratio. Beta amylase was positively associated with diastatic power and the beta/alpha ratio. Diastatic power and beta/alpha ratio were positively correlated. Alpha amylase was positively correlated with the wort N/malt N ratio. Alpha and beta amylases were not correlated, indicating that these two traits are independently inherited.

Grain yield exhibited no really large correlations with any of the other traits, indicating that it should be possible to select for most quality traits without seriously reducing yield.

Correlations among three malting quality and two agronomic traits were compared with published reports by other workers.
Conversion of Alien Sorghums to Early Combine Genotypes1
Authors: Stephens J. C. , Miller F. R. , Rosenow D. T.
Published: July 2010

Alien sorghums from the world collection of sorghums are being converted to early, combine‐height strains adapted, to the United States and other temperate areas. Conversion is being accomplished by a crossing and backcrossing program in Puerto Rico under favorable shortday photoperiods during the winter, with selection for early, short genotypes within segregating populations in Texas under long‐day conditions during the regular growing season.

After 2½ years of work on the conversion program, the procedure has proved workable, with only minor changes in time of seeding. Data indicate that the majority of alien strains used segregate for three to four height or maturity genes when crossed to a 4‐dwarf early line.
Number of Leaves and Maturity Classification in Zea mays L.1
Authors: Chase Sherret S. , Nanda Devender K.
Published: July 2010

To test the constancy and predictive value for maturity classification of number of leaves developed on the main stalk in maize, 21 double crosses were studied in three replicated trials. The plantings were made on May 15, 1965, in Illinois and on September 10 and November 22, 1965, in lqorida. Eighteen of the hybrids were commercial dents selected to represent the range of kinds and maturities grown in the United States and Canada. Three later maturity experimental flint/dent double crosses were added to extend the range of maturities studied. Highly significant positive correlations were obtained between number of leaves per hybrid and days to anthesis in each planting. Leaves per plant were fewer in the winter plantings than in the summer. Fewer days were required for anthesis in the September planting than in the other two. Highly significant positive correlations were obtained among plantings for number of leaves per hybrid and for number of days from planting to anthesis. Number of leaves per hybrid was in these trials a highly reliable index of maturity class.
Effects of Light Intensity and Carbon Dioxide Concentration on Photosynthetic Rate of Soybean1
Authors: Brun W. A. , Cooper R. L.
Published: July 2010

Photosynthetic response curves to CO2 concentration and light intensity were determined for the soybean varieties ‘Hark’ and ‘Chippewa‐64’.

At light intensities above 5,380 lux, the photosynthetic rates of both varieties were limited by the CO2 concentration of the surrounding atmosphere within the range investigated (270 to 1670 ppm).

At normal atmospheric CO2 concentration (300 ppm), photosynthesis of both varieties was light saturated at about 21,530 lux. At a CO2 concentration of 1670 ppm, photosynthesis was not light saturated in either variety at the highest light intensity tested (75,350 lux).

The photosynthetic rate of the variety Hark was higher than that of the variety Chippewa‐64 at 45 of the 48 combinations of light intensity and CO2 concentration tested.
Relative Productivity of Homogeneous and Heterogeneous Oat Cultivars in Optimum and Suboptimum Environments1
Authors: Frey K. J. , Maldonado Uriel
Published: July 2010

We tested six oat cultivars and the 57 mixtures among them for yield at two sowing dates (early and late) for 3 years. The mean relative yield (actual yield of mixture divided by mean yield of component cultivars) of all mixtures was 100% at the first sowing date and 104% at the second. The advantage of heterogeneous oat populations increased as the environment became more stressed.

At the first date, the relative yield of only one mixture was significantly better than expected, whereas at the second date eight were significantly better. The interaction variances for “dates Χ cultivars” and “dates Χ mixtures of two cultivars” were highly significant, but none of the interactions of “date Χ mixtures of three, four, or five cultivars” was significant. This indicates that the mixtures of cultivars gave more stable production when tested across sowing dates than did cultivars. There was no association between the number of cultivars in mixtures and the grain yields of the mixtures. Several mixtures yielded more than the best cultivar when averaged across both environments.
Controlling Dehiscence with Plastic Bags for Hand Crosses in Sorghum1
Authors: Schertz K. F. , Clark L. E.
Published: July 2010

A technique is described for efficiently making hand crosses in sorghum. It involves covering the panicle of the female with a plastic bag to maintain high humidity and prevent dehiscence. This is followed the next day by removal of anthers by jarring and by pollination. The percentage crossing was usually high. The procedure has potential use with other species in which humidity prevents dehiscence and in which dominant marker genes can be used to detect F1 plants.
Effect of Natural Selection on Performance of a Barley Population1
Authors: Rasmusson D. C. , Beard B. H. , Johnson F. K.
Published: July 2010

A barley composite population obtained by mixing seed of 6,000 entries from the barley world collection was grown under severe stress, imposed by late planting, in Minnesota for 6 years. During this time the composite was advanced using a random lot of seed from the previous year's harvest. Remmant seed from each year ultimately was planted in yield trials to ascertain the change, if any, in the yield potential of the composite.

Yield of the population increased significantly indicating a substantial response to natural selection. The improvement amounted to 57% during the six years or an average of 9.5% for each year of natural selection.
Selecting for Stability of Yield in Maize1
Authors: Scott Gene E.
Published: July 2010

This study was conducted to determine if selected strains of maize differed for yield stability when grown in a number of environments. Selections were based on F2 topcross results and F1 crosses were grown to check selection effectiveness. Results indicated that selecting for yield stability, as defined, was effective.
Preliminary Wind Tunnel Studies of the Photosynthesis and Evapotranspiration of Forage Stands1
Authors: Hunt L. A. , Impens Ivan I. , Lemon E. R.
Published: July 2010

Surface characteristics, photosynthesis, and evapotranspiration of vegetative stands of alfalfa and orchardgrass, grown in flats in a glasshouse, were investigated in a small wind tunnel. The windspeed parameters of the crop surfaces were determined at low radiation intensity at each of two windspeeds, and the rates of net photosynthesis and evapotranspiration were measured at the two windspeeds at each of three radiation intensities.

The roughness length (zo) increased with windspeed and was greater in orchardgrass. Rate of net photosynthesis, but not evapotranspiration, also increased with windspeed. In consequence, water use was most efficient under the highest wind regime. The rate of net photosynthesis increased to the intermediate radiation intensity, whereas evapotranspiration increased and water use efficiency decreased to the highest radiation regime.

The work indicated that a small wind tunnel of the type described would be useful for further studies of the photosynthesis and evapotranspiration of forage stands.
Some Factors Affecting the Development of Northern Anthracnose of Red Clover1
Authors: Darunday Zenaida D. , Hanson E. W.
Published: July 2010

Only a trace of disease developed where spore concentration of the inoculum was as low as 2,000 spores per milliliter. Disease level increased with concentration up to 442,000 spores per milliliter on the more susceptible clone and up to 1,250,000 spores per milliliter on the less susceptible clone. The optimum temperature range for development of the disease was 20 to 24 C. No symptoms developed at 28 C. Low light intensity, especially during the first 4 days after inoculation, favored disease development. Red clover clones differed greatly in their reactions to different isolates of the pathogen. None of the clones was immune to all isolates, but one was immune to 7 of 18 isolates tested and resistant to the other 11. Isolates of Kabatiella caulivora differed in virulence as well as pathogenicity.
Nitrogen Relations During Spring Growth in Varieties of Triticum aestivum L. Differing in Grain Protein Content1
Authors: Johnson V. A. , Mattern P. J. , Schmidt J. W.
Published: July 2010

Field‐grown hard red winter wheat varieties harvested at weekly intervals differed in plant nitrogen content, but the differences were not associated with the protein content of their grain. Plants of ‘Warrior,’ a low grain protein variety, were consistently higher in nitrogen thanhigher grain protein varieties. High protein derivatives of ‘Atlas 66’ ✕ ‘Comanche’ were intermediate or comparatively low in plant nitrogen. Their grain was significantly higher in nitrogen content than the low protein varieties throughout the grain development period. Nitrogen content of the grain first decreased from an initially high level, then increased during the last 3 weeks of grain maturation. In the high protein varieties the decrease was less pronounced and the subsequent increase more rapid than in the low protein varieties.
Heritability Estimates and Gene Effects for Agronomic Traits in Grain Sorghum, Sorghum vulgate Pers.1
Authors: Liang George H. L. , Walter T. L.
Published: July 2010

Estimates of heritability and various gene effects were obtained for a number of agronomic traits in grain sorghum. The material studied included the parental lines and the F1, F2 B1 (P1 ✕ F1), and B2 (P2 ✕ F1), derivatives of the crosses ‘Redlan’ ✕ ‘Martin’, ‘Redlan’ ✕ ‘Combine 7078’, and ‘Plainsman’ ✕ ‘KS 7.’ It appeared that heritabilities of grain yield and kernel number were of lower magnitude than those of head weight, kernel weight, stalk diameter, and half blooming. Heritabilities of plant height and germination percentage were of a still higher order. The magnitude of heritability estimates varied greatly among crosses for some traits. Inadequacy of the original scale was indicated by a scaling test. Heritability estimates were also obtained based on logarithmically transformated data. Additive, dominance, and digenic epistatic gene effects were expressed in terms of parental, first and second filial, and backcrosses population means. Additive gene effects seemed to have a minor contribution to the inheritance for grain yield, head weight, kernel weight, and kernel number but appeared to be more important for other traits. Dominance gene effects seem to be important in the inheritance of most of the traits. Among the 3 types of epistatic gene effects it appeared additive ✕ additive and dominance ✕ dominance were important types of epistasis. Additive ✕ dominance gene effects were of minor importance, in general, except for germination percentage. The magnitude of additive ✕ additive gene effects was comparable to that of dominance gene effect and greater than additive gene effect. Dominance ✕ dominance gene effects were also of large magnitude. The effect of epistasis perhaps cannot be considered as negligible. Genetic models assuming negligible epistasis may be somewhat biased.
Gelatinization of Starches From Corn (Zea mays L.) and Sorghum (Sorghum bicolor (L.) Moench): Effects of Genetic and Environmental Factors1
Authors: Freeman J. E. , Kramer N. W. , Watson S. A.
Published: July 2010

The gelatinization temperatures of starches from 85 samples of sorghum grain of diverse origin and type were determined by a standard microscopic procedure. In general, waxy starches had higher gelatinization temperatures than regular starches. The sweet, juicy stalk characteristic of forage sorghums seemed to depress gelatinization temperature of both waxy and regular starch types.

Two commercial grain sorghums and two commercial waxy grain sorghums were grown in each of three locations in the warm, humid Coastal Bend region of South Texas and at a single location in the cooler and less humid High Plains of North Texas. Starch synthesized by plants grown in North Texas consistently gelatinized at a lower temperature (average, 4 C) than starch from the same variety grown in South Texas. Gelatinization end‐point temperatures of the waxy starches were 2 to 3 C higher than those of the regular starches.

A 6‐year breeding program to transfer the property of low starch gelatinization temperature from the forage varieties ‘Atlas’ and ‘Hoti’ to acceptable grain types was unsuccessful. Waxy derivatives from this program had a higher starch gelatinization temperature than derivatives with regular starch.

Two commercial maize hybrids and their waxy counterparts were grown in central Illinois. In each case the waxy starch had a gelatinization temperature higher than that of the regular starch counterpart. Waxy starch from another corn hybrid had a 3 C higher gelatinization temperature when the grain was produced in Texas than when it was grown in central Illinois.
Inheritance of a Lutescens Mutant in Sugarbeets, Beta vulgaris L.1
Authors: Theurer J. C.
Published: July 2010

A seedling graft technique was used to study the inheritance and linkage of a lethal chlorophyll mutant in sugarbeets, Beta vulgaris L. This lutescens (lu2) was inherited as a single recessive character and is independent of monogermness, Mendelian‐male‐sterility or genes in the well‐known Y‐R‐B linkage group.
Effect of Tropical Photoperiods on the Growth of Sorghum When Grown in 12 Monthly Plantings1
Authors: Miller F. R. , Barnes D. K. , Cruzado H. J.
Published: July 2010

Effects of day length on number of days to anthesis and plant height were observed on 15 tropical sorghums (Sorghum bicolor (L.) Moench) and compared with 7 U.S. sorghums and a set of 8 maturity genotype testers. Plantings were made for 12 consecutive months in 1964 and 1965. Plantings made as much as 230 days apart flowered within a 17‐day period in November while plantings separated by only 30 days reached anthesis as much as 200 days apart. Tropical sorghums appeared to have a lower critical photoperiod than the U.S. sorghums. It was possible, however, to bring all types into flower at about the same time in Puerto Rico by planting in mid‐September through mid‐November when day lengths were below the critical level for the varieties.

Data indicated that photoperiodic thresholds varied because the sorghums could be separated into five general response classes. Variation in floral induction time was strongly suggested. Among the eight maturity genotype testers, photoperiodic response was observed only in 100‐ day Milo and 90‐day Milo, varieties containing both dominant genes, Ma1 and Ma2. None of the other genotypes were significantly affected by the Puerto Rico environment. This indicated that their critical photoperiod must be above 13 hours.

Significant correlation was observed between days from planting to anthesis and plant height in most of the tropical sorghums, but not for the U.S. sorghums which were unaffected by changes in the photoperiod.
An Inheritance Study of Tolerance to Atrazine in a Cross of Flax (Linum Usitatissimum L.)1
Authors: Cornstock V. E. , Andersen Robert N.
Published: July 2010

A selection of flax, C. I. 2484, having relatively high tolerance to atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine) was crossed with ‘Koto,’ a susceptible variety. The F3 and backcross populations were tested for tolerance to atrazine. The atrazine tolerance exhibited by C. I. 2484 behaved as a quantitive character.

Heritability (broad sense) of atrazine tolerance in F3 and BC1F2 populations was estimated to be 29 and 34%, respectively. This relatively low heritability indicates that selection for atrazine tolerance in flax populations will be difficult, at least with the procedures and the criterion used in this study.
Stomatal Chloroplasts in Alfalfa at Four Ploidy Levels1
Authors: Bingham E. T.
Published: July 2010

Diploid, triploid, tetraploid, and hexaploid alfalfa plants had 9.2, 9.4, 12.8. and 15.2 chloroplasts per pair of stomatul guard cells, respectively. Plants at the four ploidy levels could be separated into three groups as early as the seedling stage of growth. The technique could be used to screen alfalfa populations for plants with desired ploidy levels, and restrict chromosome counting to verification of selected plants.
Maternal Effect on Fatty Acid Composition and Oil Content of Soybeans, Glycine max (L.) Merrill1
Authors: Brim C. A. , Schutz W. M. , Collins F. I.
Published: July 2010

Fatty acid composition and oil content of seeds were determined by gas‐liquid chromatography and nuclear magnetic resonance spectrometry, respectively, for parents and reciprocal crosses of soybeans. It was found that oil content and the fatty acids (oleic, linoleic, and linolenic) of the oil are determined primarily by the genotype of the maternal parent. The pollen parent had little influence on oleic and linoleic acids of seed oil, but in certain crosses the genotype of the male parent influenced the linolenic acid fraction. In these crosses linolenic acid was intermediate between the two parents. The results indicate that selection for oil content or for unsaturated fatty acids based on individual F2 seed analysis would be ineffective in soybeans, with the possible exception of linolenic acid.
Mass Selection by Seed Size and Specific Gravity in Soybean Populations1
Authors: Fehr W. R. , Weber C. R.
Published: July 2010

Three cycles of mass selection for seed size and specific gravity were evaluated for their effect on the protein and oil composition of F6‐F8 heterogeneous soybean populations from two crosses. An approximately linear change in seed size was observed with each selection cycle. Effective progress was obtained for protein content in cycle 1 of both crosses, but the effectiveness of subsequent cycles differed between crosses. Selection was effective for oil content in cycle 1, but progress in subsequent cycles differed between large and small seed populations of both crosses. Maximum progress for high protein and low oil was obtained by selecting for large seed and high specific gravity. Selection for small seed and low specific gravity resulted in maximum progress for high oil and low protein. Heritability was .93, .87, .77, and .73 for seed size, specific gravity, protein, and oil, respectively.
Genetic Variability in Forage Yield, Crude Protein Percentage, and Palatability in Reed Canarygrass, Phalaris arundinacea L.1
Authors: Asay K. H. , Carlson I. T. , Wilsie C. P.
Published: July 2010

Twenty clonal lines of reed canarygrass, Phalaris arundinacea L., and their topcross progenies were evaluated under two clipping management systems designed primarily to compare forage harvested in the fall after two‐month and three‐month regrowth periods. Objectives were to investigate the genetic variability in forage yield, crude protein percentage, and palatability to rabbits and sheep.

The differences among the clonal and progeny lines in forage yield and crude protein percentage were similar under the two management systems; however, the entry ✕ year and entry ✕ cutting interactions generally were statistically significant. Broad‐sense heritabilities (mean basis) ranged from .77 to .88 for forage yield and from .44 to .70 for percentage crude protein. Narrow‐sense heritabilities ranged from .33 to .44 for forage yield and from .19 to .41 for crude protein. The additive genetic variance (2CovPC) constituted from 40 to 59% of the total genetic variance.

Significant differences among clones and among topcross progenies in palatability of dried fall‐cut forage were obtained in most cafeteria trials. When differences among the lines were significant, the parent‐progeny correlations and the correlations between rabbit and sheep trials were usually significant.