bluuebunny/crossref_metadata_2025 huggingface dataset:
Diallel Analysis of Ear Leaf Characteristics in Maize (Zea mays L.)1
Authors: Rutger J. N. , Francis C. A. , Grogan C. O.
Published: July 2010

Ear leaf characteristics and grain yield were measured on a 10‐parent early, a 12‐parent medium, and a 12‐parent late maturity set of diallel crosses of corn (Zea mays L.). Higlhly significant general combining ability and specific cumbining effects were obtained for all characters in all three diallels. General combining ability accounted for a larger proportion of the variation for leaf measurements than for grain yield.

Hybrids varied considerably in efficiency of grain production per unlit of leaf area. Grain production efficiencies may be useful in estimating optimum population levels for hybrids emerging from breeding programs.
Relationship of Fatty Acid Formation and Chlorophyll Content in Soybean Seed1
Authors: Fehr W. R. , Thorne J. C. , Hammond E. G.
Published: July 2010

We compared fatty acid formation in soybean (Glycine max (L.) Merrill) seeds with a normal level and low level of chlorophyll. A low level of chlorophyll in the seed of four genotypes was obtained by covering nodes with aluminum foil before pods were visible. Seeds of known age were harvested from covered and uncovered nodes at 4‐day intervals beginning 22 days after flowering and continuing until maturity. The percentage of palmitic, stearic, oleic, linoleic, and linolenic acid in the oil was determined by gas‐liquid chromatography.

Although fatty acid composition of the oil changed markedly during seed development, there were no large differences in the pattern of fatty acid formation among genotypes or between the covered and uncovered treatments. The similarity of linolenic acid percentage in seeds with a normal or low level of chlorophyll indicated that linolenic acid formation was not closely related to chlorophyll content in soybean seed.
Characterization of Alkaloids in Palatable and Unpalatable Clones of Phalaris arundinacea L1
Authors: Williams Martin , Barnes R. F. , Cassady John M.
Published: July 2010

We determined the types and amounts of alkaloids found in four reed canarygrass (Phalaris arundinacea L.) genotypes that differed in palatability. The palatability differences had been demonstrated previously in cafeteria grazing trials with lambs. The following alkaloids were identified in reed canarygrass by combinations of gas‐liquid chromatography, thin‐layer chromatography, and mass spectrometry: gramine, hordenine, N‐monomethyltryptamine, N,N‐dimethyltryptamine, 5‐methoxy‐N‐monomethyltryptamine, 5‐methoxy‐N,N‐dimethyltryptamine (5‐MeO‐DMT). Three additional peaks were detected by gas‐liquid chromatography, and work is in progress to determine their structures. The crude alkaloid content of the palatable and unpalatable clones averaged 0.26 and 0.78%, respectively, on a dry‐matter basis. The amount of 5‐MeO‐DMT in the unpalatable clones averaged 18 times the amount found in palatable clones.
Genetics of Host Reaction in Cowpea to Cowpea Yellow Mosaic Virus and Cowpea Mottle Virus1
Authors: Bliss F. A. , Robertson D.G.
Published: July 2010

Inheritance studies in cowpea (Vigna sinensis (L.) Savi ex Hassk.) showed that three additive loci were responsible for tolerance to cowpea yellow mosaic virus and that the tolerant variety ‘Alabunch’ was probably homozygous for the three genes. Resistance to cowpea yellow mosaic virus was isolated in a selection from the variety ‘Dixielee’ and was found to be dominant to susceptibility and due to a single gene segregating independently of the loci determining tolerance. Tolerant and several classes of susceptible phenotypes were observed when the gene for resistancewas homozygous recessive. Tolerance to cowpea mottle virus was dominant to susceptibility, with either one or two genes responsible for the observed segregation, depending on the parents studied.
Genetic Control of Starch Granule Morphology and Physical Structure in Developing Maize Endosperms1
Authors: Brown Richard P. , Creech Roy G. , Johnson Leon J.
Published: July 2010

Maize (Zea mays L.) starch granules in endosperms of 24 genotypes were studied during kernel development at 12, 18, and 24 days post pollination. Maximum and minimum granule dimensions, granule shapes expressed as the ratio of maximum to minimum granule dimensions, and differences in physical structure as measured by birefringence end‐point temperature (BEPT), X‐ray diffraction analyses, and infrared absorption spectra were determined. Mutant starch granule formation at 12 days after pollination was not different from normal for granule dimensions, granule shapes, and BEPT. Differences from normal were apparent for 18‐ and 24‐day granules for all factors studied except infrared absorption.
Chemotherapeutic Eradication of Ustilago striiformis and Uroeystis agropyri in Poa pratensis ‘Merion’ by Root Uptake of α‐ (2,4‐dichlorophenyl)‐α‐phenyl‐ 5‐pyrimidinemethanol (EL‐273)1
Authors: Hardison John R.
Published: July 2010

A new systemic fungicide, α‐(2,4‐dichlorophenyl)‐α‐phenyl‐5‐pyrimidinemethanol, supplied by Eli Lilly and Company3 under code EL‐273, has controlled and apparently eradicated Urocystis agropyri (flag smut) and Ustilago striiformis (stripe smut) in infected plants Poa pratensis ‘Merion’ after a single application to soil in the root zone. Effective dosages for eradication of U. agropyri and U. striiformis were 7 to 8 mg in 600 ml soil containing plants with 15 to 20 shoots or 7 to 8 mg on 92 cm2 of sod surface. Plants cured of both smuts remained smut‐free for 48 weeks. Shoots infected with U. striiformis became chlorotic and died within 8 to 10 weeks after application of effective dosages of EL‐273 and were replaced by healthy shoots arising from basal stem buds. Shoots infected with U. agropyri were not killed by minimum effective dosages and became smut‐free by development of healthy leaf tissue from basal meristems of existing shoots. Healthy plants were only slightly affected by EL‐273 at dosages effective for smut eradication. Applications of EL‐273 at 0.25 mg in 600 ml soil or 0.5 mg on 92 cm2 sod also controlled Erysiphe graminis (powdery mildew) in P. pratensis. EL‐273 is considered promising for control of stripe smut and flag smut, both in turf and in grasses grown for seed.
Genetic Parameters in Burley Populations of Nicotiana tabacum L. I. ‘Ky 10’ × ‘Burley 21’1
Authors: Legg Paul D. , Collins G. B.
Published: July 2010

In the F2 generation of a cross between two burley varieties of Nicotiana tabacum L., additive genetic variances were significant for days to flower, plant height, number of leaves, leaf length, leaf width, yield, and total alkaloids. All estimates of dominance and additive × additive epistatic variances were negative or nonsignificant. Heritabilities were low and estimates of additive genetic and phenotypic correlations between pairs of agronomic characters were positive. The six agronomic characters were negatively correlated with total alkaloids.
Analysis of Two Enzyme Proteins in Some Gcnotypes of Corn (Zea mays L.)1
Authors: Chatterjee N. K. , Gardner C. O.
Published: July 2010

Two enzyme proteins [alcohol dehydrogenase (ADH) and esterase] were analyzed electrophoretically; where possible, kinetic measurements for ADH were made in two exotic varieties of corn (Zea mays L.), some elite inbred lines and their hybrids, and two mutant lines developed by ethyl methane‐sulfonate (EMS) and thermal neutron treatments. Starch gel electrophoresis in a discontinuous buffer system for the two enzymes indicated their existence in multiple forms (isozymes) in the genotypes studied. All of the inbreds, except one, had two anode‐migrating isozymes of ADH, one of which was fast and the other slow moving. Of two mutants (EMS‐ and thermal neutron‐induced) from one inbred, only one (EMS) showed an isozyme pattern different from the original line. All single and double crosses showed the presence of hybrid enzyme in addition to the parental enzymes. Estimated specific activity values of ADH were lower in all the hybrids, except one, in comparison with the corresponding mid‐parent values. Km's for ethanol incrude enzyme preparations of the hybrids were lower than those of the mid‐parents of the hybrids. Km's of the two mutants were higher than that of the control.

Three of five anode‐migrating isozymes of esterase were found in the different genotypes. The EMS mutant showed an isozyme pattern different from the control. No hybrid enzyme for esterase was found in the hybrids. Possible use of isozyme studies in populations and sets of lines derived from them, and relating such studies to grain yield, are discussed.
Variations in Lignin and Other Structural Components of Brown Midrib Mutants of Maize1
Authors: Muller L. D. , Barnes R. F. , Bauman L. F. , Colenbrander V. F.
Published: July 2010

Three brown midrib (mutant) genotypes of maize (Zea mays L.) in inbred Tr background, bm1, bm3, and bm1/bm3 were harvested at 10, 35, and 55 days post‐silking and compared to the normal inbred line, Tr. Plants were separated into leaf blade, leaf sheath, stem, and a composite of husk, kernel, cob, and tassel tissue. Structural and nonstructural constituents were determined for component parts, and a weighted mean was obtained for the whole plant. Acid detergent lignin (ADL) values of the whole plant for normal, bm1, bm3, and bm1/bm3 were 6.08, 5.13, 4.37, and 4.60%, respectively, for plants harvested 35 days post‐silking. The leaf blade, stem, and leaf sheath tissue of the three brown midrib genotypes contained lower ADL (P < .05) than the normal maize. Similar differences existed at 10 and 55 days post‐silking. The brown midrib genotypes, bm3 and bm1/bm3, were consistently lower in ADL than was bm1 over harvests and plant parts. Other structural and nonstructural constituents measured were variable. The normal counterpart had higher ADL/acid‐detergent fiber (ADF) and ADL/cellulose ratios than the three brown midrib genotypes for leaf blade, stem, and leaf sheath tissue.
Heterosis in Spring Wheat1
Authors: Walton P. D.
Published: July 2010

Two complete diallel crosses, with eight and five parents, were used to study the expression of heterosis in spring wheat cultivars (Triticum aestlvum L.) of Canadian, Mexican and American origin. In both trials general combining ability was important for yield and yield components, as well as for certain morphological characters and for different stages of development. Only in the five‐parent diallel cross was specific combining ability measurahle for yield. Evidence indicated that season by F1 progeny interaction was associated with the expression of heterosis.
Isolation of Haploids of Tetraploid Alfalfa1
Authors: Bingham T.
Published: July 2010

Isolation of 178 haploids (2n=2x=16) of tetraploid alfalfa (2n=4x=32) by the 4x−2x cross method is described. Haploids were obtained from 28 out of 34 tetraploid seed parents, indicating most cultivated tetraploids are capable of haploid production. Seed parents varied in haploid frequency from 0 to 10 haploids per 1000 flowers pollinated with diploid pollen. The diploid pollinator also affected the frequency of haploids. Use of a seedling marker and distinctive morphological characteristics of haploids minimized the number of plants on which chromosome counts were required. Screening for spontaneously occurring haploids in breeding populations and in twin seedlings was inefficient. The potential use of haploids in alfalfa research was discussed.
Genetic Male Sterility as a Means of Developing Maintainer Lines and Restorer Parents of Hybrid Wheat1
Authors: Trupp C. R.
Published: July 2010

A proposed method now under investigation is presented for the development of improved maintainer lines of cytoplasmic male‐sterile parents and restorer parents of hybrid wheat (Triticum aestivum L. em. Thell.). A simply inherited recessive gene for male sterility is utilized to force cross pollination among otherwise self‐fertile plants in restoring and non‐restoring populations. Only open‐pollinated seed from genetic male‐sterile plants is harvested to maintain a population perpetuated entirely by cross‐pollination during the development phase. Any genetic factors enhancing the cross‐pollinating potential of the populations should have a natural selective advantage and thus accumulate. Lines developed from self‐fertile segregates in the non‐restoring population can be used as maintainer lines for cytoplasmic male‐sterile parents of hybrids or directly as conventional varieties.
Anatomical Changes in the Shoot Tip of Wheat After Exposure to Drought Stress1
Authors: Ridley Esther J. , Todd Glenn W.
Published: July 2010

Shoot apices of 3 to 4‐week‐old winter wheat (Triticum aestivum L.) seedlings of cultivars ‘Ponca’ and ‘Cheyenne’ were examined and described anatomically before and after exposure to drought stress. Drought caused the following changes: thickened cell walls in apical and subapical regions, abundant peri‐ and anti‐clinal divisions with granulation and absence of protoplasts of some cells in the sub‐apical region, plasmolysis of some cells, lack of distinct zonation, and increased lateral bud formation. Apex length in both cultivars was comparable in controls but length more than doubled in Cheyenne with drought stress while drought‐susceptible Ponca changed very little. The distance between the apex tip and the first differentiated procambial cells was greatest in control Cheyenne and decreased with drought to less than onehalf in plants droughted 8 days. This distance to procambium decreased in Ponca with slight drought, then increased with additional drought stress. It is suggested that several of these changes may be responsible for the eventual death of the plant from severe drought.
Effect of Plant Density on Yield of Inbred Lines and Single Crosses of Maize (Zea Mays L.)1
Authors: Rutger J. N.
Published: July 2010

Grain yields of seven single crosses and their component inbred lines were examined at populations of 37,000, 62,000, and 86,000 plants/ha. Inbreds as a group were more population‐responsive than hybrids. Thus, increasing the population from 37,000 to 86,000 plants/ha raised mean inbred yields 48% and mean hybrids yields 37% in one experiment, and 54 and 43%, respectively, in a second experiment. At 86,000 plants/ha one inbred in the first experiment yielded as much as the 37,000 rate of the single cross in which it appeared. The highest individual inbred yield observed in these studies was 62.2 q/ha at 62,000 plants/ha. The first population increment increased yields considerably more than did the second increment.

Grain yield heterosis was observed when hybrids and inbreds were compared at equivalent leaf area indexes at silking time. Large differences in grain‐producing efficiency per unit of leaf area were observed among the inbreds, but not even the highest.yielding inbreds were as efficient as any of the hybrids.
Population Response of Soybeans in Hill‐Plots1
Authors: Shannon J. G. , Wilcox J. R. , Probst A. H.
Published: July 2010

Hill populations of 3, 6, 9, and 12 plants of ‘Clark 63’ and ‘Harosoy 63’ soybeans [Glycine max (L.) Merr.] were evaluated in a systematic design. Response of yield and other characters were studied at 10 spacings from 30 to 122 cm to determine effects of populations on evaluating northern soybean genotypes in hill‐plots. Competition between different plant populations per hill also was assessed.

Yield was not significantly different among 3‐, 6‐, 9‐, and 12‐plant hills through spacings from 30 to 65 cm between hills for Harosoy 63 and from 30 to 104 cm for Clark 63. At spacings greater than these, yields of 6‐, 9‐, and 12‐plant hills tended to be greater than 3‐plant hills. Maturity was earlier in three‐plant hills than in higher populations at close spacings, but was similar for all populations per hill at spacings greater than 48 cm. Lodging generally increased as plants per hill increased at all spacings, and was moderately severe at close spacings especially in 9‐ and 12‐plant hills. There were no significant differences in plant height among different populations per hill at any spacing for Harosoy 63. Clark 63 plants were shorter at low populations per hill than at high populations. Seed weight differed significantly among varying plant numbers per hill at all spacings.

Competitive effects among hills differing by three plants were nonsignificant for all characters except seed weight.
Description and CO2 Metabolism of Aberrant and Normal Chloroplasts in Variegated Cotton, Gossypium hirsutum L.1
Authors: Kohel R. J. , Benedict C. R.
Published: July 2010

Mutant chloroplasts in variegated cotton leaves contained reduced amounts of pigments, were smaller, and lacked any well defined grana system when compared with normal green chloroplasts. Replication of the defective chloroplasts was not altered. Mutant leaves fixed reduced amounts of 14CO2 by photosynthesis, and the white leaves had a shift in the distribution of the products of 14CO2 fixation. Mutant leaves utilized 14C‐2‐acetate as effectively as green leaves.
Diallel Analyses of Kernal Carbohydrates in Sweet Corn (Zea mays L.)1
Authors: Rosenbrook R. W. , Andrew R. H.
Published: July 2010

Kernel samples from all possible F1 combinations among eight inbred lines of sweet corn, including reciprocals, were analyzed quantitatively for reducing sugars, sucrose, and water‐soluble polysaccharides. The F2 kernels produced on a diallel set of F1 plants involving five of the inbreds were analyzed also.

Analysis of covariance was used to remove the effects of maturity (percent moisture) on the carbohydrate fractions. Genotypic variability for reducing sugars, sucrose, and water‐soluble polysaccharides was partitioned into general and specific combining ability variances. Highly signiifcant GCA variances and nonsignificant SCA variances for each character indicate the inheritance of these carbohydrate fractions is highly additive. GCA effects corresponded closely in relative rank with inbred means.
Inheritance of Inflorescences in Main Stem Leaf Axils in Arachis hypogaea L.1
Authors: Hammons Ray O.
Published: July 2010

Fourteen F2 progenies of reciprocal crosses between peanut (Arachis hypogaea L.) cultivars ‘Argentine’ and ‘Early Runner’ were classified at full flowering for type of branch, vegetative or reproductive, in the leaf axils of the main stem axis. Chi‐squares for the seven progenies in each reciprocal, and the sum, pooled, and homogeneity chi‐square for both crosses, separately and combined, gave close fits to a phenotypic ratio of 225 plants with vegetative branches: 3l plants with reproductive branches on the main stem. The results indicate that flowering response is controlled by two sets of duplicate loci interacting with epistasis between loci. Gene symbols J1, J2, K1, and K2 are proposed to designate the sets of duplicate alleles. Either J1 or J2 and K1 or K2 interact to produce vegetative branches in main stem leaf axils. The implications of this genetic model are discussed with respect to the breeding development of new and hitherto unknown peanut types.
White Flagging of Stem Nemotode‐Infected Alfalfa1
Authors: Evans D. W. , Elgin J. H. , Faulkner L. R.
Published: July 2010

White shoots (flags) occur sporadically on occasional plants in alfalfa stands infected with stem nematode (Ditylenchus dipsaci, [Kuhn] Filipjev) in central Washington State. All plants showing white flagging were found to be infected. Attempts to induce this symptom consistently under controlled conditions were unsuccessful.
Induction of Male Sterility in Wheat with 2‐Chloroethylphosphonic Acid (Ethrel)1
Authors: Rowell P. L. , Miller D. G.
Published: July 2010

Male sterility was determined in greenhouse and fieldgrown wheat (Triticum aestivum L) sprayed with 2‐chloroethylphosphonic acid (Ethrel). Plants treated with 500 ppm in the pre‐boot and boot stages of development produced significantly fewer seeds per spike compared with untreated spikes. Plants treated with 1000 to 3,000 ppm Ethrel produced little or no seed set. The most usable level of male sterility occurred with rates ranging from 1000 to 2,000 ppm applied at the early, mid‐, and late boot stages. With increasing maturity, the concentration of Ethrel needed to approach 100% sterility also increased. The ovary, style, and stigma of treated plants appeared unaffected. In field‐grown ‘Nugaines’ winter wheat, significant differences between seeds per spike in those spikes allowed only to self‐pollinate and those allowed to cross‐pollinate with pollinators were shown for all concentrations in the early, mid‐ and late boot stages indicating ovary receptiveness. Side effects were minimal except at higher concentrations in which poor spike emergence and plant dwarfing were observed. Our results indicate that production of usable male sterility in wheat utilizing Ethrel appears feasible.
Estimation of Optimum Field Plot Shape and Size for Testing Yield in Crambe abyssinica Hochst.1
Authors: Meier V. D. , Lessman K. J.
Published: July 2010

A uniformity test using ‘Prophet’ crambe(Crambea abyssinica Hochst.) in a “solid seeding” of 1,296 basic units (one basic unit equaled 1.47 m2) was conducted to determine an appropriate plot shape and size for use in crambe yield testing.

In analyses using Smith's regression procedure, the soil heterogeneity index, b, was calculated as 0.5361 and the optimum plot size was estimated to be 6.70 m2.

Results of analyses using the modified maximum curvature technique developed by Lessman and Atkins (1963) indicated a plot size of 5.35 m2 as optimum.

Plot shape had an effect on plot‐to‐plot variability. Long, narrow plots arranged with their greatest length in the direction of greatest variation resulted in a lower estimate of among plot variance.
Inter‐Genotypic Competition in Soybeans. III. An Evaluation of Stability in Multiline Mixtures1
Authors: Schutz W. M. , Brim C. A.
Published: July 2010

Yield data from four soybean [Glycine max (L.) Merrill] varieties, six two‐component mixtures, and four three‐component mixtures were used to study the effect of intergenotypic competition on population stability. Yield tests were conducted in three‐row plots at four locations in each of four years. Stability was measured by estimating the relative contributions of pure lines and mixtures to the first and second order interactions of entries, locations, and years; by constructing frequency distributions of rank order; and by regression and deviations from regression of population performance on environmental productivity. Three of the six two‐component mixtures exceeded their component means by a significant amount and were arbitrarily classified as overcompensatory. Two‐component mixtures with yields similar to their component means were classified as complementary. Mixtures were generally more stable than the pure lines, with the degree of stability apparently dependent upon the type of competitive interaction involved. Variance component analysis indicated that overcompensatory mixtures made a very small contribution to the entry ✕ location component of variance while complementary mixtures contributed heavily to σ2 EL. However, overcompensatory mixtures produced a large entry ✕ location ✕ year interaction component in contrast to the small value obtained for the complementary group. The results suggest that overcompensatory competition effects are influenced by random environmental factors but that complementary effects are associated with environmental factors indigenous to a test location. Thus, both overcompensatory and complementary competition effects appear to be essential to obtain a high degree of stability in a heterogeneous population. Although complementary effects do not enhance reproductive output to any significant extent, their stabilizing influence may be an important factor in evolutionary population dynamics.
Relationship of Maize Characters with Yield in Testcrosses of Inbreds at Different Plant Densities1
Authors: El‐Lakany M. A. , Russell W. A.
Published: July 2010

The objective was to study the effects of different plant stand densities on the relationships of important plant and ear characters to grain yield for testcrosses of maize (Zea mays L.) inbred lines. The inbred lines, in the F5 generation and originating from M14xC103, were evaluated in two groups, based on high and low hybrid performance in an earlier study. Our study was done in six environments with low, intermediate, and high stand densities in each environment. At the low density only plant and ear heights were correlated significantly with yield; at the intermediate density ear diameter and shelling percentage, in addition to plant and ear heights, were correlated significantly with yield; at the high density all characters except 300‐kernel weights and dates of pollen shed and silk emergence were correlated significantly with yield.
Recovery from Partial Defoliation and Root Pruning in Sugar Beet1
Authors: Fick G. W. , Williams W. A. , Loomis R. S.
Published: July 2010

Removal of approximately half the leaf area or fibrous roots at either the 6‐ or 12‐leaf stage of growth in sugar beet (Beta vulgaris L.) was followed by restoration of the preclipping ratio of leaf blade weight to fibrous root weight. Leaf removal resulted in a rapid decrease in the fraction of new growth going to the fibrous roots, and in increase in the relative growth rate of the leaf blades. Root pruning caused the relative growth rate of the fibrous roots to increase for at least part of the recovery period. Root pruning further decreased the relative growth rate of the blades while restoration of the blade‐to‐root ratio was taking place. These responses support the hypothesis that a functional equilibrium controls leaf and root growth of sugar beet as a result of interactions among the several physiological processes involved.
Dormancy‐Related Growth Inhibitors in Seeds of Orchardgrass (Dactylis glomerata L.)1
Authors: Fendall R. K. , Canode C. L.
Published: July 2010

Greater amounts (concentrations) of growth inhibitors were extracted from seed of dormant ‘Latar’ orchardgrass (Dactylis glomerata L.) than from nondormant ‘S‐143’ orchardgrass. In Latar seed one‐third of the inhibitor was present in the lemma and palea and the remainder, in the caryopsis. On a per‐unit weight basis, however, the growth inhibitors are equally distributed between the hulls and the caryopsis. Storage of Latar seeds for 3 years did not significantly decrease the level of inhibitor. Chilling Latar seeds for 7 to 10 days at 5 C reduced the concentration (amount) of inhibitor to a level similar to that existing in nondormant S‐143 seed. Reduction of the inhibitor associated with Latar seeds by cold treatment of physical dehulling decreased their dormancy. Thus, the extent of dormancy appears to be regulated by the amount of growth inhibitors associated with the seed during germination.
Inheritance of an Albino Seedling Character in Arachis hypogaea L.1
Authors: Coffelt Terry A. , Hammons Ray O.
Published: July 2010

Twenty F2 progenies of reciprocal crosses between Arachis hypogaea L. cultivars ‘Argentine’ and ‘Early Runner’ were grown in greenhouse or field plantings. At 2 to 4 weeks of age 11,973 seedlings were classified for albino vs. normal green plant color. All chlorophyll‐deficient lethal seedlings were scored as albino. The results indicate that the two cultivars differ at three loci conditioning albinism. No differences occurred for the reciprocal cross. Results indicate that chlorophyll production is controlled by duplicate loci interacting in an epistatic manner with another locus. Gene symbols C1 and C2 are proposed for the duplicate alleles; L designates the third locus. Chi‐squares give good fits to a phenotypic ratio of 60 green:3 albino:1 zygotic lethal. A reexamination of results from earlier studies shows that those data are not incompatible with this new genetic model.
Effects of Ultra‐Low Volume and Conventional Spray Applications of In‐Covering‐Soil Fungicides on Cotton Stands1
Authors: Minton Earl B.
Published: July 2010

Ultra‐low volume (ULV) applications in covering soil over cotton (Gossypium hirsutum L.) seed at planting of emulsifiable concentrates of pentachloronitrobenzene + 5‐ethoxy‐3‐trichloromethyl‐1,2,4‐thizadiazole or 1‐chloro‐2‐nitropropane + pentachloronitrobenzene performed as well as, or better than, an equivalent dosage of the fungicides applied in 15.3 liters of water/ha. Phytotoxicity was not associated with ULV applications of fungicides. Only one fungicide treatment (l‐chloro‐2‐nitropropane + pentachloronitrobenzene) inceased final stand significantly when compared with the check. All fungicide treatments slightly reduced the rate of seedling emergence, as measured by the coefficient of velocity of emergence; conventional spray application was associated with the greatest reduction in emergence rate.
Cross‐Fertilization in Melilotus Alba1
Authors: Gorz H. J. , Haskins F. A.
Published: July 2010

Two simply inherited characters, o‐hydroxycinnamic acid (o‐HCA) content and β‐glucosidase activity, were used as genetic markers in studying the frequency of cross‐fertilization in Melilotus alba Desr. Based on the o‐HCA marker, the effective cross‐fertilization averaged 58% for two harvest years in a biennial population and 67% in a 1‐year study with an annual population. Use of the β‐glucosidase marker provided a cross‐pollination estimate of 72% in the biennial population. The extent of natural crossing in sweetclover appears to be sufficient to restore normal vigor in the production of varieties synthesized from selected inbred lines.
Self‐Compatibility Studies with Astragalus Cicer L.1
Authors: Townsend C. E.
Published: July 2010

Astragalus cicer L. is a predominantly self‐incompatible species, since 43% of a 424‐plant population did not set a single seed, and only 2% set in excess of 50 seeds per raceme following self‐pollination under field conditions. Air temperatures of 27 C day‐16 C and 21 C night, 27 C day‐21 C night, and 32 C day‐21 C night had no consistent effect on the self‐compatibility reaction of 16 clones. However, there was evidence of clone by temperature interaction. The average number of ovules per ovary was 11.5. The percentage of aborted pollen grains was generally very low. Three methods of measuring self‐compatibility (percentage of florets setting seed, average seed set per floret, and average seed set per raceme) were highly correlated.
Physiology and Field Performance of Wheat Infected with Barley Yellow Dwarf Virus1
Authors: Jensen S. G. , Fitzgerald P. J. , Thysell J. R.
Published: July 2010

The effect of barley yellow dwarf virus infection on agronomic and physiological responses was compared on 10 cultivars of hard red spring wheat (Triticum aestivum L.). The cultivars varied in their agronomic characteristics and in the effect of BYDV on some of these characteristics. The yield of diseased plants was only one‐fourth to one‐half of normal.

Healthy plants of all cultivars had essentially the same physiological patterns. Second, fourth, and flag leaf tissues differed in physiological characteristics. Changes in physiology caused by BYDV were greatest in the second Leaf and progressively less in the fourth and flag leaves. Virus infection induced both qualitative and quantitative changes in the interaction between physiological functions. The effect of BYDV infection on physiology was the same for all cultivars. Interrelationships between agronomic characteristics and between physiological functions are presented and discussed. No associations between physiological response and field performance were detected.
A Critical Period for Ear Development in Maize1
Authors: Prine G. M.
Published: July 2010

The environment of hybrid corn (Zea mays L.) was changed at intervals over the life cycle by removing every other plant of plants that were equispaced in rows 97 cm apart at a population of 44,500 plants/ha. Because the low plant population environment (LPE) resulting from these thinning treatments gave great improvement in the light environment over lower shoot and relatively small changes in other environmental factors, plant response was attributed mainly to changes in light environment. The number of ears per plant was 1.76, 1.57, and 1.70 during 1964, 1965, and 1966, respectively, for the 22,250 plants/ha check, which received LPE during the entire life cycle. The 44,500 plants/ha check, which received no LPE, had 1.10, 1.05, and 1.02 ears per plant, respectively. In the three seasons, changes in number of ears per plant in response to LPE imposed at different times indicated that 56, 79, and 78% of the above reduction in ears per plant between 22,250 and 44,500 plants/ha populations took place from the time the first plants silked until soon after all plants had silked — about 10 to 12 days. The rapid abortion of ears during silking and just afterward, under the unfavorable light environment of the 44,500 plants/ha population, establishes this as an important critical period for light competition in the plant community. Individual plants within the community began aborting ears under the unfavorable light environment as early as 3 or 4 days before silks emerged and continued until about 8 days after silks emerged.
Locating Genes for Resistance to Maize Dwarf Mosaic In Maize Seedlings by Using Chromosomal Translocations1
Authors: Scott Gene E. , Nelson Lloyd R.
Published: July 2010

F2 populations from crosses involving 28 reciprocal chromosomal translocations were used to identify the chromosome arms of corn (Zea mays L.) inbred GA209 that carry genes for resistance to maize dwarf mosaic (MDM). We found that both arms of chromosome 6 carried a gene(s) for resistance to this disease. However, GA209 probably lacks a gene for resistance on either the long arm of chromosome 1 or the short arm of chromosme 9.

The heterozygous genotype was nearly as susceptible as the homozygous susceptible genotype. Conclusions regarding type of gene action involved in resistance were dependent on when the notes for the presence or absence of the diease were taken.
Heterotic Response for Vegetative Growth and Fruiting Development in Grain Sorghum, Sorghum bicolor (L.) Moench1
Authors: Patanothai Aran , Atkins R. E.
Published: July 2010

Three sorghum (Sorghum bicolor L. Moench) hybrids that exhibited different levels of heterosis for grain yield were evaluated for vegetative and fruiting development over a 90‐day period of growth. Two‐year means showed that the high‐heterosis hybrid had greater vegetative weight, vegetative plant height, and more leaves/plant than its midparent at 30 days after planting. During the grand period of growth, the absolute rate of vegetative weight accumulation of the hybrid was greater than that of the midparent, but their relative growth rates were alike. The vegetative weight advantage of the hybrid continued to increase during the early stages of enlargement of the fruiting structure. The hybrid exceeded the midparent in rate and extent of fruiting development at all stages.

Similar heterotic response was observed for the med. ium‐heterosis hybrid, but the magnitude of heterosis was lower than that of the high‐heterosis hybrid. The low‐heterosis hybrid did not differ significantly from its midparent values for vegetative or fruiting weight at any of the stages of plant development.
Recurrent Selection for High Self‐Fertility in Vernal Alfalfa (Medicago Sativa L.)
Authors: Villegas C. T. , Wilsie C. P. , Frey K. J.
Published: July 2010

Three alfalfa (Medicago sativa L.) populations, each representing one cycle of phenotypic recurrent selection for high self‐fertility (seeds per tripped flower), and unselected Vernal (check) were evaluated. Progress from selection was measured via clones selected for high selffertility and single crosses from diallel intercrossing of the selected clones.

Self‐fertility in alfalfa was increased significantly in each cycle of recurrent selection. The gain per cycle for number of seeds per tripped flower was 0.83 when measured via the selected clones, and 0.36 when measured via the single crosses. Seeds per flower was increased 73% in three cycles.

Diallel analyses indicated that gain in seeds per flower from the first cycle of selection was due to additive gent action, whereas gains in cycles 2 and 3 were due to nonadditive gent action.
Effect of Reciprocal Recurrent Selection for Yield on Isozyme Polymorphisms in Maize (Zea mays L.)1
Authors: Brown A. H. D. , Allard R. W.
Published: July 2010

Nine isozyme polymorphisms were used to monitor the genetic effects of two cycles of reciprocal recurrent selection of a population of maize (Zea mays L.). The results indicate that RRS had little effect on gene or genotypic frequencies; the few changes that occurred could be ascribed to random genetic drift associated with restriction of population size (to about N = 30) at the time of selection of lines for advance to the next cycle of RRS. Studies of the joint distribution of alleles at pairs of loci revealed two further effects of random genetic drift at the time of selection: (i) generation of sporadic linkage disequilibrium or gametic unbalance; and (ii) loss of rare recombinants between closely‐linked loci, thereby restricting the release of variability through recombination. Thus, random events played a major role in the behavior of the linkage blocks marked by these isozyme loci. Implications concerning RRS as a scheme of maize improvement are discussed.
Nitrogen Translocation and the Role of Individual Leaves in Protein Accumulation in Wheat Grain1
Authors: Mikesell Merrel E. , Paulsen Gary M.
Published: July 2010

Translocation of 14C‐labe_lled amino acids from culms to grain of high‐ and low‐protein wheat (Triticum aestirum L.) lines during grain development was low initially after anthesis, increased at midmaturity, and decreased slightly at full maturity. Efficiency of translocation did not differ between high‐ and low‐protein lines.

Total N content was similar in flag leaves and greater in lower leaves removed at anthesis from high‐protein wheat lines than from low‐protein wheat lines. Grain N content at maturity was greater in high‐protein wheat lines when no leaves were removed at anthesis. Removing flag leaf blades at anthesis had little effect on grain N content of low‐protein wheat lines, but greatly decreased N content of high‐protein wheat lines. Removing lower leaves or all leaves at anthesis decreased grain N content markedly in all lines.

Nitrogen content in leaves at maturity did not differ consistently between high‐ and low‐protein lines when no leaves were removed at anthesis. Nitrogen content of mature lower leaves remaining after flag leaves were removed at anthesis was greater in low‐protein lines. When lower leaves were removed at anthesis, the remaining flag leaves contained similar amounts of N at maturity in all wheat lines.
An Asynaptic Character in Cotton Inherlted as a Double Recessive1
Authors: Weaver J. B.
Published: July 2010

An F2 population of cotton plants (Gossypium hirsutum L.) from ‘Atlas 66‐103’ ✕ ‘R2‐67, 26 N’ produced a ratio of 1 female‐sterile: 15 normal plants. F3 progeny from fertile F2’s provided further evidence that the femalesterile character was inherited as a double recessive. Cytological examination of megasporogenesis and microsporogenesis showed that female‐ and male‐sterility was due to asynapsis. The gene symbols as1 and as2 are proposed for this character.
Chlorophyll Mutations in Peanuts, Arachis bypogaea L.: I. Pigment Analysis1
Authors: Tai Y. P. , Todd G. W.
Published: July 2010

Six chloroplast pigments of leaves from both normal and mutant types of peanuts (Arachis hypogaea L.) and from their hybrids were separated and identified by twodimensional paper and sugar column chromatography. Chlorophylls a and b, neoxanthin, violaxanthin, lutein, and carotenes were determined in all normal and mutant plants. Quantities present in various mutants were different. Carotenoid contents of the lutescens mutants were much reduced with respect to those of normal or aureus leaves, especially in xanthophylls. Crosses of various mutants gave progeny having a variety of lowered carotenoid contents. Crosses between normal and mutant plants also were deficient in certain carotenoids. The aureus mutant did not retain the chlorophylls as long as normal plants, whereas the lutescens plants did not accumulate these pigments to the normal amount (especially chlorophyll b). The F1 plants from crosses between normal and lutescens plants and between aureus and lutescens plants appeared to be phenotypically normal and to have approximately the normal contents of chlorophylls a and b.
Recurrent Family Selection and Correlated Response in Nicotina tabacum L. I. ‘Dixie Bright 244’ ✕ ‘Coker 139’1
Authors: Matzinger D. F. , Wernsman E. A. , Cockerham C. Clark
Published: July 2010

Recurrent selection for increased alkaloids from a cross of two low alkaloid tobacco (Nicotiana tabacum L.) lines raised the population mean from the average of the two parents in the unselected population, to the high parent in one cycle of selection. Following two cycles of selection most families were above the high parent. A predicted decrease in yield of cured leaf in each cycle was obtained. The predominant genetic variance was additive, with little evidence of dominance or epistatic effects. The genetic variance following selection had not decreased from the initial population, and predictions were obtained for further continued progress from selection.
Kernel Phenotypes of Zea Mays L. Genotypes Possessing One to Four Mutated Genes1
Authors: Garwood D. L. , Creech R. G.
Published: July 2010

Kernel phenotypes of 12 maize (Zea mays L.) mutants and 82 two‐, three‐, and four‐gene combinations are presented. These gene mutations are amylose‐extender, brittle‐1, brittle‐2, dull, floury‐1, horny, opaque‐2, shrunken‐1, shrunken‐2, sugary‐1, sugary‐2, and waxy. Specific gene interactions are described. Knowledge of these interactions permits efficient development of multiple gene combinations.
Starch: Variation Associated with Location in Corn and Sorghum Plants1
Authors: Freeman J. E. , Bocan B. J. , Zobel H. F.
Published: July 2010

Starch granules from stems of mature corn (Zea mays L.) and sorghum (Sorghum bicolor L. Moench) plants were about a third as large as average granules from endosperm tissue of the same species and contained only 1/3 to 1/2 as much amylose. The stem starches had lower gelatinization temperatures and gave C X‐ray diagrams instead of the A diagram typical of normal cereal endosperm starches.
Inheritance of Crude Protein Percentage and Its Correlation with Seed Yield in Beans, Phaseolus vulgaris L.1
Authors: Leleji O. I. , Dickson M. H. , Crowder L. V. , Bourke J. B.
Published: July 2010

Five lines of dry beans (Phaseolus vulgaris L.) were selected for differences in protein content and were used as parents in crosses. The F1, F2, and F3 mean crude protein contents were generally between the parents, but slightly closer to the low‐protein parent. Reciprocal differences in protein of F1 seeds and its absence in F2 seeds showed that the maternal genotype controlled seed protein content.

Broad‐sense heritability estimates ranged from 30.7% to 63.7%. The narrow‐sense heritability estimates were 20.1% for backcrosses and 5.0% and 12% based on F3/F2 regression. These low values indicate high environmental influence on crude protein content and relatively low additive genetic variance.

Yield and crude protein percentage were generally negatively correlated in F2 and F3 plants from crosses between low and high percent crude protein bean lines. Seed yield and protein yield were highly correlated. The highest total seed protein was produced by plants average or below average in percent crude protein. In breeding for total protein production per unit area, progress appears more likely if efforts are directed toward increased seed yield while maintaining percent crude protein near average levels rather than by selecting for high protein in the seeds alone.

Generally, high‐yielding segregates tended to be relatively low in protein percentage. Among F2 and F3 progenies, however, there were plants that were high in seed yield and had above‐average percent crude protein.
A Simplified Classification of Cultivated Sorghum1
Authors: Harlan J. R. , de Wet J. M. J.
Published: July 2010

The simplified classification presented for Sorghum bicolor (Linn.) Moencihs is so easy that it requires no special knowledge of the crop to correctly identify mature heads and spikelets. Variation is partitioned into five basic races (bicolor, guinea, caudatum, kafir, and durra) and all combinations of their hybrid derivatives, for a total of 15 races. Intermediate races are designated, for example, as kafir‐caudatum, durra‐bicolor, etc. Subraces are the commonly used agronomic groups (feterita, kaura, sorgo, sudangrass, etc.) familiar to sorghum workers. None of these requires a formal Latin name.
Heritability of Oil Content in Oats, Avena sativa L.1
Authors: Baker R. J. , McKenzie R. I. H.
Published: July 2010

Fifty‐six random F4 lines from each of 13 crosses among high‐, medium‐, and low oil cultivars of oats (Arena sativa L.) were evaluated for oil content by nuclear magnetic resonance. Whole kernel oil content of the F4 lines ranged from 2.5 to 8.6%. Heritability of oil content was high in all crosses but one, a cross between sister cultivars. The greatest genetic variability was observed in crosses between high and low parents, but F4 lines derived from crosses between high‐oil parents had the highest oil content. Oil content was not significantly correlated with kernel weight, kernel density, or percent hull.
Integrating Exotic Germplasm into Corn Belt Maize Breeding Programs1
Authors: Hallauer Arnel R. , Sears J. H.
Published: July 2010

Two procedures were compared for integrating the Colombian ‘Eto Composite’ into our maize (Zea mays L.) breeding program: (i) mass selection for earlier silking and (ii) crossing Eto Composite with six early inbred lines and intermating to form ‘BS2.’ Both procedures were effective for adapting Eto Composite to the central Corn Belt.

Mass selection for early silking decreased the interval from planting to silking by 20 days, for an average decrease of 3.8 days per cycle of selection. A concomitant change with mass selection for early silking was an average decrease of 15 cm per cycle of selection for ear height. The simple correlation between early silking and lower ear height was r = 0.89.*

The (Eto Composite ✕ early lines) crosses averaged 10% heterosis for earlier silking, relative to the midparent. The intermated population (BS2) of the (Eto Composite ✕ early line) crosses showed nearly 50% silk emergence by August 1. The heritability (h2) estimates for silking date (h2 = 59%) and ear height (h2 = 58%), on an individual plant basis, verify that mass selection for early silking is effective for adapting Eto Composite to the Corn Belt.
Two Genes Affecting Stem Termination in Soybeans1
Authors: Bernard R. L.
Published: July 2010

Inheritance of the common determinate (abruptly terminated) stem type (dt1) vs indeterminate (tapered) stem (Dt1) in soybeans [Glycine max (L.) Merrill] was confirmed as monogenic. The heterozygote Dt1dt1 showed a distinct intermediate or semi‐determinate phenotype in the genetic backgrounds studied. A stem type resembling this Dt1dt1 heterozygote was found in a few true‐breeding varieties and was shown to be controlled by a single dominant gene designated Dt2. Crosses between the two types gave F2 ratios of 1 indeterminate:11 semi‐determinate:4 determinate, the expected ratio for independent segregation with dt1 epistatic to Dt2‐dt2.

The primary effect of both dt1 and Dt2 is to hasten the termination of apical stem growth, which decreases both plant height and number of nodes, but dt1 has a much greater effect. In tests at Urbana of dt1 and Dt2 BC5 isolines of the indeterminate (Dt1 dt2) commercial varieties ‘Harosoy’ and ‘Clark,’ plant height was reduced by 45 to 60% by dt1 and 12 to 15% by Dt2. Seed yield was only slightly reduced by dt1 and was unaffected by Dt2. Lodging resistance was consistently improved by dt1 and in some instances by Dt2. Time of maturity and seed size and composition were slightly affected in some cases.