bluuebunny/crossref_metadata_2025 huggingface dataset:
Inheritance of Multifoliolate Leaves, Glabrous Leaves, and Petiolulate Leaflet Attachment in Crimson Clover, Trifolium incarnatum L.1
Authors: Knight W. E.
Published: July 2010

Inheritance of multifoliolate leaves, glabrous leaves, and petiolulate leaflet attachment was studied in the F1, F2, and F3 generations of crimson clover, Trifolium incarnatum L. Normal crimson clover has trifoliolate, pubescent leaves and sessile leaflet attachment. Inbred, recessive white‐flowered lines were used as the female parent in studying these mutants: glabrous leaves (g); petiolulate leaflets (p); and multifoliolate leaflets (mI). Segregation ratios for multifoliolate leaves, glabrous leaves, and petiolulate leaflets fit expected segregation ratios of 3:1. Each of the characteristics studied appears to be controlled by a single recessive gene pair. Intermediate forms were not observed, an indication that only a single gene pair was involved in each mutant. One mutant was a double recessive with glabrous leaves and petiolulate leaflet attachment. Heterozygous F2 and F3 populations from the double recessive segregated on the basis of a 9:3:3:1 ratios as expected; thus showing independent inheritance for these two characters.

The following genetic symbols are proposed: G for pubescence, and g for glabrous; P for sessile leaflet attachment and p for petiolulate leaflet attachment; and Ml for trifoliolate leaves and ml for multifoliolate leaves.

These characteristics should help determine effective hybridization in the crossing and breeding program. As more marker genes are accumulated, specific chromosomes and chromosomal regions can be identified. Some of these mutants will be of interest morphologically and of possible value as physiological indexes, e.g., multifoliolate leaves.
Virescent, a Temperature Sensitive Mutant in Alfalfa1
Authors: Stanford E. H.
Published: July 2010

A new chlorophyll mutant in alfalfa controlled by a single recessive tetrasomic gene was studied. Homozygous recessive plants were chlorotic at 10C but normal at 27C. Viability of the plants was good at temperatures of 18C or above and classification was easy at temperatures below 20C.
Relationship of Certain Stalk Characters with Grain Yield in Corn (Zea mays L.)1
Authors: Singh T. P. , Zuber M. S. , Krause G. F.
Published: July 2010

Previous studies have shown stalk quality in corn, Zea mays L., as measured by rind thickness and crushing strength, is highly correlated with field stalk lodging. Some corn researchers question if increasing rind thickness, weight of a 5.1‐cm section and crushing strength through breeding and selection might have an effect on grain yield. This study, employing the S0 and S1 progenies from the F2 and first and second backcross generation of two inbred lines, showed little, if any, genetic correlation between three stalk‐traits and yield. Since our study was limited to only two inbred parents additional studies should be conducted with larger randomly‐sampled populations tested over several environments to confirm whether a relationship exists. However, our results suggest to us that we would have little difficulty in developing high yielding lines with good stalk quality from the progenies of the two inbred parents, ‘Mo22’ and ‘Mo940.’
Delayed Flowering and Pollen Production in Male‐Sterile Sugarcane Subjected to Extended Day‐Length1
Authors: James Norman I.
Published: July 2010

Six early‐ to mid‐season flowering sugarcane clones (Saccharum officinarum L. ✕ S. sinense Roxb. ✕ S. spontaneum L.) that are highly male sterile were subjected to a 12‐5‐hour photoperiod for 2, 4, and 6 weeks between September 13 and October 25. The 2‐ and 4‐week treatments were applied at the beginning and toward the end of the period.

Longer durations of treatment caused greater delay of flowering, and a given duration caused greater delay of flowering when applied toward the end of the period. Maximum delay of flowering among clones ranged from 10 to 72 days. The earliest flowering clone could be crossed with all mid‐season flowering clones, and the midseason flowering clones could be crossed with most, if not all, late‐flowering clones of interest in the crossing program.

All clones produced pollen after flowering was delayed, and they were effective pollen parents. Delay of flowering to first pollen shedding ranged from 13 to 32 days among clones.
Effects of Seed Age and Preplanting Seed Treatment on Seedling Response in Crested Wheatgrass1
Authors: Bleak Alvin T. , Keller Wesley
Published: July 2010

Seed lots of Nordan crested wheatgrass, Agropyron desertorum (Fisch. ex Link) Schult., of six ages were subjected to presoaking treatments on moist blotter paper, for periods ranging from 40 to 90 hr at 17.2 C, prior to greenhouse planting in soil. Seeds given preplanting treatments, and planted wet, produced seedlings which emerged ahead of those from untreated seeds, the hours of advantage in direct relation to the length of pretreatmerit, but drying before planting reduced the advantage. At 4 days after planting, pretreated seeds produced seedlings with longer roots and shoots than those from untreated seeds. Older seeds required more tinie to produce seedlings but the advantage from treatment was not altered by age of seed.
Plant Differentiation from Callus Tissue of Saccharum Species1
Authors: Heinz Don J , Mee Grace W. P.
Published: July 2010

Callus tissue was induced on parenchyma tissue of shoot apices, leaves, and inflorescences of Saccharum sp. using a basal mineral medium supplemented with coconut water (10% by volume) and 2,4‐D. Transfer of callus tissue to a non‐2,4‐D basal medium induced the differentiation of plants. In all the plants studied, morphological variants from the parental clone were observed.
Inheritance of Peroxidase Activity in Soybean Seed Coats1
Authors: Buzzell R. I. , Buttery B. R.
Published: July 2010

Genetic analysis showed that high and low peroxidase activity in soybean (Glycine max (L.) Merrill) seed coats is controlled by a major gene. This gene, designated Ep, with complete dominance produces high activity and its recessive allele, ep, gives low activity. Control of activity resides in the maternal tissue and not in the endosperm nor in the embryo.
Use of Carbohydrate and Nitrogen Root Reserves in the Regrowth of Alfalfa from Greenhouse Experiments under Light and Dark Conditions1
Authors: Smith Dale , Silva Jorge P.
Published: July 2010

Alfalfa (Medicago sativa L.) plants were allowed to regrow 42 days in the dark and light with and without (roots only) intact crowns. A significant amount of new roots was produced only on actively photosynthesizing plants. No major change in fresh weight‐unit volume of the original roots was noted, except for an increase during the period of 21 to 42 days with plants grown undisturbed in the light which then were actively reaccumulating root reserves.

A small proportion of the root nonstructural carbohydrates, but none of the total nitrogen, was used in root respiration. Most of the nonstructural carbohydrates were translocated from the roots and used for the production of new tops and roots, and root carbohydrates were used in far greater amounts than root nitrogen. Even so, photosynthate from new leaves was an important factor in recovery growth. Current photosynthetic energy contributed 0, 52, 70, 83, 89, and 93% of the increase in total plant weight of plants grown undisturbed in the light at 7, 14, 21, 28, 35, and 42 days, respectively.
Inheritance of Yield, Forage Quality and Seed Characteristics in Sericea Lespedeza1
Authors: Cope W. A. , Moll R. H.
Published: July 2010

The inheritance of three forage quality characters, plant height, three yield characters, and two seed characters was studied in a cross between two inbred lines of sericea, Lespedeza cuneata (Dumont) G. Don. The design included F4 progenies from 3 F3 plants from each of 80 F2 plants and provided estimates of additive (σ2A), dominance (σ2D), and additive by additive (σ2AA) variances.

Progeny means for tannin content of forage were bimodally distributed, indicating tannin content to be largely controlled by a partially dominant allele at a single locus. The σ2A component was significantly large in eight of nine characters, σ2D in two, and σ2AA in none. For tannin and three yield traits σ2D was large relative to total genetic variance, and inbreeding depression was noted for these traits. Thus, although inbreeding may be employed to enhance the efficiency of selection for chemical characteristics, it may be necessary to intercross several selected lines in the final stages of the improvement program to restore productivity.

Heritability estimates ranged from 45 to 88%, indicating opportunity for progress through selection in all nine characters.
Improved Selling Techniques for Crested Wheatgrass1
Authors: Dewey Douglas R.
Published: July 2010

Daily manual agitation of the selling bag during anthesis more than doubled average self‐seed set of 162 crested wheatgrass clones in 1966 and more than tripled selling in 1967 and 1968. Increasing the number of spikes per bag from 5 to 10 only slightly decreased the number of seeds per spike. As spikes per bag were increased from 5 to 20, the number of seeds per bag increased 2.2 times; and the number of seeds per spike declined by 45%. Bag agitation was more essential to selfing in bags with 20 spikes than in bags with either 5 or 10 spikes. Daily agitation of bags with 10 spikes is recommended as an efficient method of selling crested wheatgrass
Mechanisms of Strontium Accumulation in Tissues of Wheat Spikes 1
Authors: Craker Lyle E. , Smith Lawrence H.
Published: July 2010

Studies of strontium accumulation in grain of excised wheat (Triticum aestivum L) spikes indicate that active mechanisms, analogous to those based upon the carrier concept in root absorption studies, mediate this process.

No evidence was found to suggest that Sr is passively accumulated in grain. No relationship, between transpiration rate and Sr accumulation in gram was found.
Influence of Fungus Isolate and Grass Variety on Sclerotinia Dollarspot Development1
Authors: Cole H. , Duich J. M. , Massie L. B. , Barber W. D.
Published: July 2010

Four isolates of Sclerotinia homoeocarpa from various geographic areas of the Eastern U. S. were utilized in inoculation experiments on 37 Kentucky bluegrass (Poapratensis) varieties and experimental selections and with 18 varieties and experimental selections of creeping bentgrass (Agrostis palustris). The grasses exhibited a wide range of resistance and susceptibility to the four isolates of S. homoeocarpa. The isolate which was most virulent against bentgrasses was least virulent against the bluegrasses. When isolates were ranked in order of virulence against individual varieties, changes in rankings were noted from variety to variety. These changes in some instances were complete reversals with the most virulent for one variety becoming the least virulent with another. It was concluded that considerable pathogenic variation is present within S. homoeocarpa and that a wide range of grass plant response is present hi turf type blue‐ and bentgrasses.
Effects of Loose Smut Infection and Vitavax Seed Treatment on Barley Yields1
Authors: Stoker G. L. , Dewey W. G.
Published: July 2010

The effect of loose smut caused by Ustilago nuda (Jens.) Rostr. on barley (Hordeum vulgare L.) yields, its control by Vitavax, and the possible direct effect of Vitavax on yields were studied with 10 seedlots of ‘Gem’ barley ranging in infection from .03 to 22%.

Yield losses were roughly proportional to percent infection; however, there was a tendency for percent infection to exceed percent yield loss at the higher smut levels. The percentage of loose smut in each of the 10 seedlots was determined by means of the embryo test, as well as by a corresponding field planting. The embryo test appeared to be a good, although a slightly conservative, predictor of field infection.

Seed treatment with Vitavax gave 100% control of loose smut over the range of infection tested. The beneficial effect of Vitavax in controlling loose smut was partially offset by an apparent direct adverse effect on yield. At very low levels of infection the yield reduction due to Vitavax treatment exceeded the benefit derived from the smut control. As infection levels rose above 5%, Vitavax treatment increased yields; however this increase did not reach statistical significance until loose smut levels approached 20%. Vitavax‐treated plots had significantly fewer tillers than did untreated plots.
Growth of Birdsfoot Trefoil and Alfalfa. IV. Carbohydrate Reserve Levels and Growth Analysis Under Two Temperature Regimes1
Authors: Nelson C. J. , Smith Dale
Published: July 2010

‘Empire’ birdsfoot trefoil (Lotus corniculatus L.) and ‘Vernal’ alfalfa (Medicago sativa L.) were grown in two growth chambers set at 32/24 C (day/night) and 18/10 Net assimilation rate (NAR) was highest for both species in the cool regime, but NAR values of trefoil were only 63% and 52% of those of alfalfa in the cool and warm regime, respectively. Alfalfa in both temperature regimes and trefoil in the cool regime exhibited typical carbohydrate root reserve cycles. However, trefoil grown at warm temperatures did not restore its reserve.

Alfalfa and birdsfoot trefoil flowered almost simultaneously in the cool regime (ca. 43 days). By comparison, the warm regime hastened flowering in alfalfa (24 days) and retarded it in trefoil (60 days). Delayed maturity of trefoil in the warm regime was attributed to a low NAR and to diseased roots and crowns which limited the energy supply. It was apparent that trefoil was not as adapted as alfalfa to warm temperatures.
Double‐Cross Sugarbeet Hybrids Utilizing Pollen Restorers1
Authors: Theurer J. C. , Ryser G. K.
Published: July 2010

Experimental studies in 1965 and 1966 indicated that double‐cross restored hybrid sugarbeets, Beta vulgaris L, have excellent potential for commercial use. In isolated seed plots, the female parental single crosses averaged about 100 g of double‐cross seed per plant. Forty‐six experimental double crosses showed favorable performance for gross sugar, root yield, sugar percentage, and quality in relation to that of two currently used commercial cultivars. A method for production of the double‐cross hybrid seed on a commercial scale is outlined.
Development of Resistance to Root‐Knot Nematode (Meloidogyne hapla Chitwood) in Alfalfa (Medicago sativa L.)1
Authors: Hunt O. J. , Peaden R. N. , Faulkner L. R. , Griffin G. D. , Jensen H. J.
Published: July 2010

Alfalfa (Medicago sativa L.) clones with dominant monogenic resistance to the Northern root‐knot nematode (Meloidogyne hapla Chitwood) were used in a backcross breeding procedure to develop resistance in adapted plant materials. Recurrent parents were some of the parent clones of the cultivars ‘Washoe’ and ‘Lahontan’ with resistance to pea aphid, spotted alfalfa aphid, stem nematode and bacterial wilt.

Results of these studies indicated that it was relatively easy to transfer a high level of M. hapla resistance into otherwise adapted germ plasm while maintaining resistance to several other pests. Eighty percent of the triplex and quadruplex M. hapla resistant clones were resistant to spotted alfalfa aphids and pea aphids and 65% of the polycross progeny of these clones were resistant to stem nematodes.
Effects of Leaf and Stem Diseases on Yield and Quality of Alfalfa Forage1
Authors: Willis W. G. , Stuteville D. L. , Sorensen E. L.
Published: July 2010

Field plots of alfalfa, Medicago sativa L., sprayed weekly with Dithane M‐45 during the 1965 growing season to control leaf and stem diseases yielded 2.8 MT/ha (18%) more hay than did unsprayed plots (Average of four varieties in four cuttings). Disease control increased carotene content 21% (third cutting) and decreased stem defoliation 18%. Increases in annual forage yields in MT/ha, for sprayed over unsprayed plots, respectively, were ‘Cody’ 1.57 (8.8%), ‘Lahontan’ 3.47 (21.1%), ‘Ranger’ 3.11 (19.4%), and ‘Vernal’ 3.11 (26.9%).

Phoma medicaginis and Leptosphaerulina briosiana were the major pathogens in the first and second cuttings. Their control increased yields of Cody 4%, Lahontan 14%, Ranger 19%, and Vernal 19% for the first two cuttings combined. Cercospora zebrina was the principal pathogen in the third and fourth cuttings. Control of C. zebrina increased yields of Cody 16%, Ranger 29%, Lahontan 30%, and Vernal 38% for the third and fourth cuttings combined. Corresponding increases in carotene content for the third cutting were 17, 20, 45, and 10%, respectively.

Defoliation was reduced by spray treatments. Protein percentage was not affected.
Seed Increase Problems in Synthetic Cultivars of Elymus junceus Fisch.1
Authors: Schaaf H. M.
Published: July 2010

Polycrosses and Syn‐ls, produced in 3 consecutive years (1959, 1960, and 1961) in a recombination block composed of the parent clones of ‘Vinall’ Russian wildrye (Elymus junceus Fisch.), were evaluated for seed yield in two replicated tests. The polycrosses were composed of equal weights of seed of 20 replications of each parent. The Syn‐ls were equal‐weight composites of five polycrosses. The 1959 polyerosses and the 1959 Syn‐1 were compared with their 1960 counterparts in 1962 and 1964.Counterparts for 1960 and 1961 were compared in 1966 and 1967.

In the first test, the 1960 Syn‐1 yielded significantly higher (P<.05) than the 1959 Syn‐1, demonstrating superiority of the 1960 seed. Differential performances of three polycrosses accounted for the difference. In the second test, yields of the 1960 and 1961 Syn‐ls, as well as combined averages for the 1960 and 1961 polycrosses, were closely similar. However, one 1961 polycross yielded significantly higher (P<.05) than its 1960 counterpart. The reverse was true of three other polycrosses, but the differences were not significant (P<.05). These opposing effects, although balanced in the Syn‐1, could cause divergence in later generations.

In the recombination block, large clone‐by‐year differentials were evident in seed production and seed size. if pollen production paralleled seed production, as seems likely, there were inequities of male parentage in all 3 years. Relative differences in seed size gave rise to both over‐ and under‐representation of females in the equalweight Syn‐I for each year. Inequalities of parentage were greatest in 1959.

Where these conditions exist, simple practices offering Where these conditions exist, simple practices offering Where these conditions exist, simple practices offering Where these conditions exist, simple practices offering more effective control of synthetic parentage are (a) imposing a uniform limit on number of spikes per plant to equalize male parentage, and (b) compositing on the basis of seed size to equalize female parentage. more effective control of synthetic parentage are (a) imposing a uniform limit on number of spikes per plant to equalize male parentage, and (b) compositing on the basis of seed size to equalize female parentage.
Radiation‐Induced Resistance to Root‐Knot Nematodes in Korean Lespedeza1
Authors: Offutt M. S. , Riggs R. D.
Published: July 2010

Eighty‐three cultivars and strains of annual lespedeza, Lespedeza stipulacea Maxim. and L. striata (Thunb.) H. & A., 77 of which were irradiated L. stipulacea strains, were evaluated for resistance to two of the most prevalent forms of root‐knot nematodes (Meloidogyne incognita “A” and M. incognita “B”).

‘Climax,’ ‘Kobe,’ ‘Korean,’ ‘Summit,’ and strain 29a were scored as susceptible, and ‘Rowan’ was scored as moderately resistant to each of these two forms of root‐knot nematodes. Seventeen percent of the 77 irradiated strains originating from strain 29a were scored as highly resistant to M. incognita “A”, 12% were scored as highly resistant to M. incognita “B”, and 9% were scored as highly resistant to both of these forms of root‐knot nematodes. In this study, 57% of the irradiated L. stipulacea strains had a significantly higher level of resistance to M. incognita “A” and 65% had a significantly higher level of resistance to M. incognita “B” than the check strain 29a. Approximately5 0% of the irradiated strains also were scored as either equal or superior in resistance to both M. incognita “A” and M. incognita “B” in comparison with the moderately resistant cultivar Rowan. Thus, through the use of irradiation, a new source of L. stipulacea germ plasm with a high level of resistance to these two forms of root‐knot nematodes is now available for improvemenotf this species.
Effect of Ploidy on Fertility and Heterosis in Pensacola Bahiagrass1
Authors: Burton Glenn W. , Forbes Ian , Jackson James
Published: July 2010

Diploid and tetraploid sectors isolated from seven mixoploid plants derived from Pensacola bahiagrass, Paspalum notatum var. saurae Parodi, seed treated with colchicine were selected to study the effect of ploidy on seed set and heterosis. Doubling the chromosome number did not improve the self‐fertility of the highly self‐incompatible diploid clones. Diploids set seed equally well in diploid or in diploid‐tetraploid polycrosses but tetraploids that set seed well in tetraploid polycrosses set less than half as much seed in etraploid‐diploid polycrosses. Single‐head diploid ✕ diploid and tetraploid ✕ tetraploid matings set nine and four times more seed, respectively, than diploid ✕ tetraploid or tetraploid ✕ diploid matings. Tetraploid ✕ tetraploid hybrids generally yielded less forage than diploid ✕ diploid hybrids involving the same genotypes. Otherwise, ploidy had little, if any, effect on the expression of heterosis.
Heritability Estimates of the Maturity of Fruit from Specific Growth Periods in Virginia Type Peanuts (Arachis hypogaea L.)1
Authors: Gupton C. L. , Emery D. A.
Published: July 2010

Components of variance and parent‐progeny regression techniques were utilized in Virginia type peanuts (Arachis hypogaea L.) to estimate the heritability of maturity as measured by the percent light transmittance through oil expressed from the kernels. Heritability coefficients were determined for early, intermediate, and late pegging groups in the F4 and F5 generations in the same year. The estimates were in remarkably close agreement for the two techniques and for the two generations. The coefficients ranged from .69 in the early pegging group to .95 in the late group. Predicted gains from hypothetical selection were similar to actual gains. The percent gain in maturity increased with successive pegging groups, resulting in more than twice as much gain from selection in the late as in the early group. These results indicate that greatest gain can be made by selecting for a rapid rate of fruit maturation at later‐appearing fruit positions.
Effect of Bacterial Pustule on Yield of Soybeans1
Authors: Laviolette F. A. , Athow K. L. , Probst A. H. , Wilcox J. R.
Published: July 2010

Nine pairs of susceptible and resistant lines of soybeans (Glycine max (L) Merr.) representing early, medium, and late maturity were compared for yield under heavy artificial infection with bacterial pustule caused by Xanthomonas phaseoli var. sojensis (Hedges) Starr and Burk. Comparisons were made for 1966 through 1968 at Worthington, Ind. All plots were inoculated three times and severe infection resulted on all susceptible lines. The susceptible lines yielded slightly but nonsignificantly higher than the resistant counterparts. Since infection was heavier than normally occurs in the midwest, the importance of bacterial pustule on yield in this area is questionable.
Importance of Hexaploid Wheat Germ Plasm in Hexaploid Triticale Breeding1
Authors: Sisodia N. S. , McGinnis R. C.
Published: July 2010

The original hexaploid (6x) Triticales were synthesized from crosses involving tetraploid (4x) wheat, Triticum sp. and rye, Secale sp. Recent evidence suggests that 6x wheat germ plasm is important in the improvement of 6x Triticale. Reasons for this are examined both at the nuclear and the cytoplasmic level.

By incorporating the 6x wheat genotype in 6x Triticale, one is recombining the AB genomes of the 4x and the 6x wheats and thereby making use of the evolutionary advantages of the 6x wheats. The C:N (cytoplasmicnuclear) ploidy ratio is 1:1 and 1:1.5 in 6x Triticale having 6x and 4x wheat cytoplasm, respectively. From this and other experimental evidence, 6x wheat cytoplasm appears of be more compatible than 4x wheat cytoplasm with the nucleus of the 6x Triticale. However, this relationship is not expected to be absolute since each genotype may be unique in its response.
Genetic Diversity Inherent in Vernonia anthelmintica (L.) Willd.1
Authors: Berry C. D. , Lessman K. J. , White G. A. , Earle F. R.
Published: July 2010

Forty selections were used to evaluate inherent genotypic diversity in Vernonia anthelmintica (L.) Willd. Materials were evaluated at two locations during 1966 and 1967 for 11 characters.

Analyses of variance indicated significant genotypic variation among lines for all characters except early vigor, days between one‐half and full bloom, and percent vernolic acid. Importance of years in a V. anthelmintica breeding and evaluation program was emphasized by large year × entry effects.

Genetic coefficient of variation (GCV) values suggested potential for genetic progress. Broad sense heritability estimates (H) varied from 0.92 to 0.01 for characters evaluated. GCV and H estimates were combined in estimates of expected gain from selection in percent of the mean (GS). Values suggested that substantial changes may be made in population means for most characters evaluated.

Phenotypic correlation coefficients indicated simultaneous selection might be practiced for several traits. Selection for good early vigor, early bloom dates, and increased seed number per head also should increase seed and oil yields.
Agronomic Significance and Genetic Variability of ATP Sulfurylase Activity in Soybeans [Glycine max (L.) Merr.]1
Authors: Adams C. A. , Rinne R. W.
Published: July 2010

The relationship between N/S ratios and ATP sulfurylase activity indicates that S content does not control enzyme activity once adequate sulfur is present. N metabolism may be the limiting factor. This is consistent with the known lack of response to sulfur fertilization once adequate levels have been attained. A survey of ATP sulfurylase activity in six commercial varieties and 20 soybean [Glycine max (L.) Merrill] lines indicated wide differences in activity. The activity is likely under genetic control. ATP sulfurylase activity did not correlate with seed protein content or with methionine content of the seed protein.
Genotype by Environment Interaction Study of Cotton in Oklahoma1
Authors: Murray Jay C. , Verhalen Laval M.
Published: July 2010

Eleven cotton (Gossypinm hirsutum L.) varieties were grown at three locations in Oklahoma over a three‐year period. Lint yield, fiber length, fiber coarseness, and two measures of fiber strength were studied using the analysis described by Comstock and Moll.

Significant varieties by years mean squares were obtained for fiber length and one measure of fiber strength. However, those mean squares were so small relative to their respective varietal mean squares that the evaluation of length and strength over years was considered unnecessary. A very large and significant varieties by locations mean square for yield suggested that the state should be subdivided in some manner for varietal testing and breeding purposes. A division into dryland and irrigated production may be adequate. The second‐order interaction mean squares for yield and fiber coarseness were large and significant. Therefore, a sizable proportion of the interactions exhibited by those two traits could not be attributed to locations or to years. Inferences made from comparisons of variance components were the same as those obtained from an examination of mean squares.
Hybrid Vigor in Hard Red Spring Wheat Crosses1
Authors: Wells Darrell. G. , Lay Charles L.
Published: July 2010

Yield and seed weight were studied in the F1 and F2 generations of 22 spring wheats, Triticum aestivum L. em Thell, crossed with ‘Lee’ and ‘Rushmore.’ Plots were grown in four‐replicate tests at Brookings, S. Dak., in 1965 and 1967.

Yields of crosses ranged from 14% less to 82% more than the high parent. Highly significant differences for F1 yields were found both years in general combining ability but only in 1965 in specific combining abilities. Yields of the F1 and of the high parent were not correlated. Yields were not correlated between years for Lee, Rushmore, tested lines, or F1s. F2 yields in relation to the high parent for Lee crosses ranged from 35% less to 15% more and for Rushmore crosses from 42% to 6% less than the high parent. Only three F.2S ranked higher in yield than the high parent and these were of Lee parentage. F1 and F2 yields were not correlated. The tested lines that consistently produced F1s higher in yield than the high parent were II54‐30, SD622, SD6310, and SD6332.

In relation to the high parent, Fxs of Lee crosses ranged in kernel weight from 13% less to 13% more. Highly significant differences in general combining ability were shown both years but differences in specific combining abilities were not found. Kernel weights and yields of F1s were correlated both years for Lee crosses and in 1965 for Rushmore crosses. The only correlation of significance between years was for kernel weights of the 22 tested lines. Kernel weights of F2s ranged from 9% less to 7% more.
Predicting Yields of Two Bunchgrass Species
Authors: Wright Henry A.
Published: July 2010

Four regression models were developed from various combinations of three plant characteristics (number of flowering culms, number of vegetative culms, and fourth longest leaf) to predict weights of individual plants of two bunchgrasses. The linear form of the three plant characteristics and one interaction (number of flowering culms times fourth longest leaf), together, were highly predictive for weights of needleandthread (Stipa comata Trin. and Rupr.), and for bottlebrush squirreltail (Sitanion hystrix (Nutt.) J. G. Smith) during 1962 and 1963.

Regression models 3 and 4, developed in this paper, may have high predictive value for other bunchgrass because they proved to be satisfactory on both a very leafy species and a very stemmy species. Except for the protected plants of squirreltail, both models had R2 values greater than 0.89 for weights of each species during each of 2 years. Moreover, except for one group of data, standard deviations from regression were within 25% of the mean.
Cytological and Morphological Investigations on the Grass Hemarthria altissima (Poir) Stapf et C.E. Hubb1
Authors: Wilms H. J. , Carmichael J. W. , Schank S. C.
Published: July 2010

Two introductions of Hemarthria altissima, limpograss, from South Africa were diploid (2n = 18), one was tetraploid (2n = 36), and one was hexaploid (2n = 54). Pollen and embryo sac development were studied. Each of the accessions produced a high percentage of viable pollen. Addition of gibberellic acid to the medium gave a significant increase in in vitro pollen germination. The four strains were interpollinated and the ovaries were killed after 1, 2, and 4 hours incubation. Double fertilization occurred in all four accessions. No apomictic development was detected. The polyploids set seed after self pollination under terylene bags, but the diploids did not. One diploid and both polyploids yielded some seed under open pollination. These results indicate that Hemarthria altissima can be included in a conventional plant breeding program.
Colorimetric Measurements of Purple Flower Color in Alfalfa as Affected by Variety, Soil pH, Soil Fertility, Light, and Seed Source1
Authors: Sheridan Kevin P. , McKee Guy W.
Published: July 2010

Measurements of the color of purple flowers from 10 varieties of alfalfa were made on two types of instruments. These were (1) reflection device using tristimulus filters for comparison of intact petals and (2) a grating type spectrophotometer for comparison of aqueous extracts. Alfalfa plants of the same variety grown under several field, greenhouse, and growth chamber conditions varied significantly in intensity of purple flower color. Flowers from field grown plants were lighter in color than plants produced in the greenhouse and growth chamber. Differences in flower color associated with soil pH, soil fertility, and seed lot were minor. When produced and measured under standardized conditions, purple flowers from different inflorescences on the same plant did not vary significantly nor did flowers produced on the same plant at different time periods. Either reflectance readings or colorimetric measurements were useful in characterizing varieties.
Variation in Carbohydrate Composition in the Endosperm of Sweet Corn (Zea mays L.) in Relation to Maturity1
Authors: Rosenbrook R. W. , Andrew R. H.
Published: July 2010

Reducing sugars, sucrose, and water‐soluble polysaccharides were quantitatively determined for kernels of eight inbred lines of sweet corn and their Fl combinations, including reciprocals, 25 days after pollination. A second harvest was taken from the inbred parents at 28 days. The inbreds differed significantly for percent moisture and for each carbohydrate fraction. Moisture content and carbohydrate composition changed at significantly different rates for the eight lines.

Analysis of covariance was used to remove effects of maturity on F1 kernels. There were highly significant differences among maternal half‐sib groups for percent moisture, reducing sugars, sucrose, and water‐soluble polysaccharides. Differences within half‐sib groups were significant for all variables except reducing sugars. Differences among reciprocal crosses were attributed to maternal effects and gene‐dosage relationships in the endosperm. Regression coefficients showed that content of reducing sugars and sucrose decreased, but content of water‐soluble polysaccharides rapidly increased with advancing maturity.
Effect of Variety, Seed Lot, Soil pH, Soil Fertility, and Light on Cotyledon and Plant Color in Alfalfa1
Authors: Sheridan Kevin P. , McKee Guy W.
Published: July 2010

Environmental conditions such as light intensity, temperature, soil pH, and fertility significantly affected the expression of alfalfa plant and cotyledon color. Soil pH and soil fertility had only minor effects on cotyledon color. Plant color was affected to a greater extent, plants grown on limed and fertilized soil being about 20% darker, i.e., acetone extracts of leaf tissue averaged about 20% less transmission than those grown on a relatively acid (pH 5.6) and infertile soil. Plants grown in growth chamber at alternating 18 and 9 C with light for 14 hours at the higher temperature were significantly darker than those grown in a warm greenhouse (25 to 20 C) and 24‐hour photoperiods. Differences in cotyledon and plant color associated with seed lot were relatively minor. When grown and sampled under standardized conditions, varieties derived in part from Medicago falcata such as ‘Vernal’ and ‘Narragansett’ were generally darker green than varieties derived from Medicago sativa. Measurements of cotyledon and plant color in 10 common varieties of alfalfa indicated the presence of significant varietal differences. Results of these studies indicate that colorimetric measurements of cotyledon and plant color can be used to separate alfalfa varieties into groups. Additional tests can then be applied to further characterize varieties within each group. Cotyledon color was of lesser value for this purpose than plant color.
Genetic Linkage in Soybeans: Linkage Group V and VI1
Authors: Weiss Martin G.
Published: July 2010

Genetic linkage between the soybean loci Dt1, dt1 (indeterminate, determinate stem growth) and L1, l1 (black, brown pod color) was verified in Linkage Group V and the combined recombination value was 39.4± 1.8%. Linkage Group VI was established as a new linkage group by discovery of linkage between the loci Y11, y1l (normal, deficient chlorophyll) and Df2, df2 (normal, dwarfness) with a combined recombination value of 12.1± 0.7%.
Inheritance of Stearic Acid in the Seed Oil of Safflower (Carthamus tinctorius L.)1
Authors: Ladd S. L. , Knowles P. F.
Published: July 2010

Differences in percentages of stearic acid in the seed oil of the safflower (Carthamus tinctorius L.) introductions, Israel 55‐46 (high), Russia 60‐110 (high) and the cultivar ‘US‐10’ (low), were determined principally by alleles at a single locus. Seeds of genotypes StSt, Stst, and stst have oils with respective stearic acid contents of 1.0 to 2.5, 2.5 to 5.0, and 5.0 to 12.0%. Increases in the percentage of stearic acid were accompanied by decreases in the relative amounts of linoleic acid, oleic acid, or both linoleic and oleic acids. Palmitic acid was usually reduced slightly as stearic acid increased.
Diallel Analyses of Potato Leafhopper Injury to Alfalfa1
Authors: Kehr W. R. , Ogden R. L. , Kindler S. D.
Published: July 2010

The objectives of this study were to obtain intormation on the genetic basis of leafhopper yellowing due to Empoasca fabae (Harris), and the interrelationships of yellowing with other characters in diallel crosses among six clones of alfalfa, Medicago sativa L., which differed in yellowing. Clones, S1 progeny, and diallel crosses, including reciprocals, were evaluated at two dates in the field. General combining ability effects were more important than specific combining ability effects for leafhopper yellowing, nymphs/gram of dry matter, and protein content in crosses. Reciprocal effects were non‐significant sources of variation. Amount of leafhopper yellowing was positively correlated with nymphs/gram of dry matter, but negatively correlated with protein, carotene, and fiber contents. Visually scoring breeding materials for leafhopper yellowing at one date per year is adequate for making progress, provided sufficient nymphs are present to give differential scores on materials of known performance.
Leaf Number ‐ An Index of Meiosis in Corn (Zea mays L.)1
Authors: Mock J. J. , Frey K. J.
Published: July 2010

An index to allow identification of meiotic stages in corn (Zen mays L.) without plant destruction was sought. Plants grown in growth chamber and field were dissected at several leaf‐number stages, and florets were sampled from four regions (tip, mid, butt, and branch) of each tassel. Anthers were prepared for microscope examination by the acetocarmine‐squash method, and the meiotic stage of each was assayed.

Correlations of meiotic stage with several plant traits showed expanded leaf number to be a better index of meiosis than days after emergence, plant height, or stem diameter. The leaf number associated with a given meiotic stage varied with genotypes and environments, but within genotype‐environment combinations the correlations ranged from 0.73 to 0.89. After genotypes and environments had been characterized, leaf nuinber was a reliable index of meiotic stage in corn. Use of the index is limited to genetically homogeneous populations.
Changes in Six Different Opaque‐2 Genotypes of Zea mays L. During Successive Generations of Backcrossing1
Authors: Feist W. A. , Lambert R. J.
Published: July 2010

Changes during backcrossing of six inbred lines of Zea mays for grams lysine per 100 g of protein and seed weight reduction during conversion to opaque‐2 were measured. Linear and quadratic regression coefficients were calculated for response of grams lysine per 100 protein. Although differences were found in the lines studied, the changes obtained were gradual and could not be attributed to interaction of the opaque‐2 gene with one or a few genes from the recurrent parents. The changes were probably due to genetically controlled differences that occur in the protein fractions of the kernel with backcrossing. These changes may enhance or reduce the effects of the opaque‐2 gene in different recurrent parent genotypes. The percent reduction in seed weight of opaque‐2 plants did not differ statistically among inbred backgrounds nor generations of backcrossing.
Recurrent Selection in Maize for Earworm Resistance1
Authors: Widstrom N. W. , Wiser W. J. , Bauman L. F.
Published: July 2010

Recurrent selection for resistance to corn earworm [Heliothis zea (Boddie)] injury in a population of maize (Zea mays L.) resulted in some progress during the first cycles of selection, but slowed considerably in later cycles. Progress of selection for specific combining ability in this population, derived from crosses among 34 inbred lines, seemed to plateau after approximately three or four generations of half‐sib selection with a moderately resistant tester. Realized heritability was estimated at 16.6% during five cycles of selection. It is suggested that either a change in the method of measuring earworm injury in this experiment or several cycles of random mating among the selected populations might make further selection progress possible. The use of a more susceptible tester or S1 progeny testing per se is also suggested to assist in identification of the more resistant genotypes. It was demonstrated that a population can be developed with a relatively high degree of resistance, or with a relatively high concentration of genes for resistance to corn earworm injury, while at the same time desirable agronomic traits, such as yield, are maintained.
A Recessive Gene for Male Sterility in Hexaploid Wheat1
Authors: Briggle L. W.
Published: July 2010

A recessive gene for male sterility in wheat (Triticum nestivum L. em Thell.) was transferred to ‘Chancellor’ from a heterogeneous stock commonly known as Pugsley Male‐sterile Wheat. Complete male sterility occurred at a relatively low frequency in the original stock. After the initial cross and four backcrosses to Chancellor, accompanied by rigid selection for single gene segregation for male sterility, some populations were obtained which segregated according to a ratio of three fertile plants to one malesterile plant. Intermediate types (partial sterility) did not occur in the most advanced and highly selected populations when grown in the greenhouse.

Transmission of the recessive allele for male sterility by the male gamete occurred at the same frequency as by the Ieniale gamete. Number of gametes tested, however, was small. Female fertility was normal.

Pollen produced by fertile plants was normal ‐ whether those plants were homozygous for the dominant allele or heterozygous. Pollen produced by male‐sterile plants was smaller than normal, irregular in shape, and did not stain in iodine solution.

Fertile plants with the dominant allele (homozygous or heterozygous) did not restore fertility to Triticum titmpheevi‐derived cytoplasmic male‐sterility.
Influence of Gibberellic Acid on the Winter Growth of Varieties of Tall Fescue (Festuca arundinacea Schreb.)1
Authors: Blacklow W. M. , McGuire W. S.
Published: July 2010

The winter growth of varieties of tall rescue (Festuca arundinacea Schreb.) that had originated from the Mediterranean region (‘Oregon 1000’ and ‘Tunisian’)and northern Europe (‘Alta’) were studied outdoors in the Mediterranean climate of western Oregon, and in controlled environment chambers.

Cubes of sod taken during the winter months from swards of Alta and Tunisian showed that Alta had a greater density of tillers and buds, and based on etiolated regrowth, a higher level of reserves. Monthly sowing of seed in pots from May through October showed that a preceding exposure to summer conditions was unnecessary to establish differences in winter growth.

During the winter, foliar growth of both Alta and Oregon 1000 was increased by a temperature of 15 to 20 C, a foliar spray of 0.1% gibberellie acid (GA), and possibly by a long photoperiod. Although chlorophyll concentration in the foliage was reduced by GA, the total chlorophyll per plant was increased by 10 to 30%.

Regrowth from reserves at 7/3.5 C (day/night) was described by a monomolecular function. The time taken for 63% of the total regrowth to be attained was 103 and 53 days for Alta and Tunisian respectively; these response times were halved for both varieties by GA.

Tunisian made more growth than Alta at 7/3.5 C, 19 langley per day (400 to 700 nm). The water soluble carbohydrates (WSC) were 6.4 and 7.9% of the total dry weight of Alta and Tunisian respectively, with greater concentrations in stems than leaves and roots; fructosans were the dominant WSC with sucrose, followed by reducing sugars of lesser concentrations. The level of WSC was increased by GA to 12.0 and 11.0% for Alta and Tunisian respectively. The greatest increase was that of sucrose.
Development of Two Alfalfa Populations with Resistance to Insect Pests, Nematodes, and Diseases. I. Aphid Resistance1
Authors: Hunt O. J. , Peaden R. N. , Nielson M. W. , Hanson C. H.
Published: July 2010

‘Turkistan’ alfalfa (Medicago saliva L.) is a good source of resistance to aphids, to organisms such as stem nematode associated with moist soil conditions, and diseases such as bacterial wilt and Phytophthora root rot. It is very susceptible to foliar pathogens.

In 1959, two germplasm pools, MSE and MSF, were initiated at Beltsville, Md., by intercrossing 50 plants of Turkistan origin with 50 foliar disease‐resistant plants of MSA‐9, MSB‐9, and ‘DuPuits’ alfalfa. After four cycles of intercrossing and recombination within pools, the two pools were sent to Reno, Nev., and later to Tucson, Ariz., to undergo two cycles of penotypic selection for resistance to spotted alfalfa aphid [Therioaphis maculata (Buckton)] and pea aphid, [Acyrthosiphon pisum (Harris)]. From 65 to 300 plants were intercrossed within each cycle and pool to initiate a new cycle.

Cycles 4, 5, and 6 were evaluated for seedling survival under severe aphid infestations. An average of 95 and 92% of the plants of MSE‐6 and MSF‐6, respectively, survived the spotted alfalfa aphid test, compared to 1% for ‘Caliverde’. An average of 60 and 42% of the plants of MSE‐6 and MSF‐6, respectively, survived the pea aphid test, compared to 0% for Caliverde. This form of mass selection was effective in developing resistance to spotted alfalfa aphids and pea aphids.
Increased Post‐Inductive Photoperiods for Delayed Flowering in Saccharum sp. Hybrids1
Authors: Moore Paul H. , Heinz Don J
Published: July 2010

Fifty‐nine clones, consisting of Saccharum sp. hybrids, S. spontaneum L., S. robustum Brandes and Jeswiet (✕ Grassl), and closely related genera hybridized with S. officinarum L., were subjected to combinations of preinductive and post‐inductive photoperiods to dday their flowering and thus synchronize the emergence of their inflorescences with later‐flowering Saccharum sp. hybrids.

The number of days delay in flowering varied among the clones tested and was correlated to the normal flowering dates. Early‐season flowering clones were delayed more than were late‐season flowering clones.

Most clones responded quantitatively to the illumination of the post‐inductive photoperiod. Greatest delay of flowering was seen as response to long post‐inductive photoperiods and highest supplementary illumination. A large number of days delay for flowering was often associated with low percentage flowering. Maximum percentage flowering and minimum days delay of flowering occurred in response to a combination of short postinductive photoperiods and low‐level supplementary illumination.
Preemergence Herbicidal Treatments for Small Grain Nurseries1
Authors: Schreiber M. M. , Patterson F. L. , Schafer J. F.
Published: July 2010

Several new herbicides, alone and in combination, have been tested for use as preemergence treatments in spring grains. The lnost consistent combination, for the control of grass and broadleaf weeds and no crop injury, has been 2‐chloro‐N‐isopropylacetanilide (propachlor) at 3.36 kg/ha and 3,6‐dichloro‐o‐anisic acid (dicamba) at .28 kg/ha.
Effect of Relative Humidity on Viability and Longevity of Wheat Pollen1
Authors: Khan Mir N. , Heyne E. G. , Goss James A.
Published: July 2010

Wheat (Triticum sp.) pollen stored in the spike at 4C and relative humidities varying from 75 to 95% showed highest viability when stored at 80% humidity; viability decreased at higher or lower humidities. In all treatments, viability declined during 4 days' storage, Benzidine‐hydrogen peroxide and seed set viability tests correlated closely.