bluuebunny/crossref_metadata_2025 huggingface dataset:
Yield and Yield Components of Zea mays L. as Influenced by Artificially Induced Shade1
Authors: Schmidt W. H. , Colville W. L.
Published: July 2010

Studies were made to determine the effects upon grain yield of light reduction, leaf and stem removal, and thinning of corn (Zea mays L.) plant populations at ear silk emergence. Grain yields per hectare were significantly reduced when 75 to 100% of the solar energy available to leaves located below the ear was intercepted by black polyethylene shades. Restricting light penetration to these leaves by 25 to 50% had little effect on per hectare grain yields. Leaf or stem removal reduced grain yields by 22 to 44%. Leaves located either below or above the ear leaf, (other leaves removed) were equally efficient the production of grain on a per unit of leaf area basis. Artificially shaded leaf tissues continued contributing to grain yield although with greatly reduced efficiency per unit leaf area. Removal of all tissues above the ear reduced ear weight 45%. Weight per 100 kernels was reduced as a result of leaf tissue removal. The largest kernel size reduction occurred when all tissues above the ear were removed. Induced shading had little or no effect on the air temperature or relative humidity in these treatments. Soil temperatures at a depth of 12 cm were 2 C higher in the check treatment than under 100% shade. Weed growth increased as light reaching the soil surface was increased through defoliation or plant population reduction.
Linkage Between Two Traits Both Controlled By Duplicate Genes in Tobacco1
Authors: Wan Hsiung , Chang E. Y.
Published: July 2010

Linkage was detected between powdery mildew resistance and female sterility, both of which are controlled by recessive duplicate genes in tobacco. An F1 hybrid was obtained by crossing a resistant sterile line (pm1 st1/pm1 st1, pm2 st2/pm2 st2) with the susceptible fertile tobacco variety ‘Hicks.’ F2, F3, and testcross data were used for estimating linkage intensity by the method of maximum likelihood. A combined linkage intensity was estimated and heterogeneity of the linkage values was tested by using Fisher's scoring method. It was found that pm1 and st1 and pm2 and st2 were linked on both chromosomes with the same intensity of 89.81% ± 0.87% (or recombination value 10.19%). A heterogeneity test indicated that the linkage intensities estimated from varioats types of data were homogeneous. Assumptions used in the process of estimating linkage intensity were discussed.
Tiller Senescence and Grain Development in Barley1
Authors: Laude Horton M. , Ridley Jack R. , Suneson Coit A.
Published: July 2010

Two near‐isogenic barley cultivars segregating for male sterility were employed to study tiller senescence. This plant material made possible the simultaneous comparison of fruiting and nonfruiting plants without resort to debudding or mechanically removing flowers or fruits. The number of living tillers and tiller mortality was similar in fertile and sterile plants until some 10 days after awn emergence. Between jointing and awn emergence, extensive tiller senescence occurred in fertile and in sterile plants alike. This senescence is not attributable to the mobilization of nutrients into the developing fruit. The triggering mechanism for the preheading shoot senescence appears to be operative at initial stages of floral development and before mechanical debudding is feasible. Ten days to 2 weeks after awn emergence, new tillers arose rapidly on the male‐sterile plants. Renewed tillering on the fertile plants was delayed an additional 3 weeks.
Cytogenetic Effects and Responses of Agronomic Characters in Grain Sorghum (Sorghum vulgare Pers.) Following Atrazine Application1
Authors: Liang George H. L. , Feltner K. C. , Liang Y. T. S. , Morrill J. L.
Published: July 2010

Three varieties and two hybrids of grain sorghum were sprayed with atrazine at the rate of 2.7 kg a.i./ha (2.4 lb a.i./A). A single treatment was given to each plot and applications were made at weekly intervals, beginning 1 week after emergence. Pollen mother cells collected from each genotype treated at seven developmental stages were examined.

Many affected microsporocytes were observed. Abnormalities consisted of multinucleate cells, bridges, and increased chromosome numbers, some of which were not a multiple of the basic number. Dyads and quartets often contained micronuclei. Atrazine treatment apparently interfered with meiotic stability regardless of time of application. Statistical analyses of grain yield, head weight, kernel weight, fertility, stalk diameter, and germination percentage indicated that treated groups did not differ from the control group. Plant height, however, differed between control and treated groups. No consistent relationship was observed between content of protein, soluble and total carbohydrates, and date of treatment. Also, no apparent relationship existed between frequency of chromosomal aberrations and agronomic responses following atrazine application.
Influence of Environment on Stability of Corn During Vegetative Growth1
Authors: Andrew R. H.
Published: July 2010

Purpose of this study was to determine stability during vegetative growth for a diallel series of 10 corn hybrids (Zea mays L.) and their 5 inbred parents under greenhouse and field environments and to compare parenthybrid relationships in the two environments. Measurements were taken on fresh weight, adventitious root number, and leaf number at successive ages.

Analyses of variance within ages, across environments, and within environments across ages were completed for each character. Genetic variation in terms of other variability was expressed by ratios between genotype and environmental variance. Correlations between parents and hybrid progeny in each environment and between characters within and between environments were determined.

Growth was more rapid in the field. Leaf number was least variable and fresh weight most variable. For each character and type of germplasm there was greater variation between locations than between years. Environmental variance and ratios between field and greenhouse means for individual genotypes usually were higher for hybrids, while relative genetic variation in terms of other variability was higher for inbreds.

Respective variances were usually higher in the field. Age ✕ replicate and age ✕ genotype ✕ replicate interaction variances for both inbreds and hybrids were higher in the field where measurements were taken on different plants than in the greenhouse where successive measurements were taken on the same plants.

The association of inbred performance with general combining ability rating by diallel analysis was higher in the constant greenhouse environment. Also, hybrid performance was always more closely related to respective midparent values in the greenhouse. Associations between environments for fresh weight leaf number were usually significant by the third age of sampling at 650 thermal units. In all environments, associations between fresh weight and leaf number were most marked.
Inbreeding Medicago sativa L. by Sib‐mating I. Cross‐, Sib‐, and Self‐Fertility1
Authors: Aycock M. K. , Wilsie C. P.
Published: July 2010

Sib‐mating without selection was compared with selling as a method of inbreeding alfalfa. Through two generations, the drastic loss in fertility following self‐fertilization was reduced by approximately half through the slower form of inbreeding (sib‐mating).

In two populations, (a) a random population of noninbred ‘Vernal’ and (b) a composite S1 population derived from Vernal, self‐fertility was significantly correlated with sib‐ and cross‐fertility. Heritability estimates indicated that fertility was highly heritable.

Inbreeding coefficients were computed for the several levels of inbreeding attained and, in general, the reduction in fertility observed was much greater than that expected in an autotetraploid species. Reasons for the rapid loss in fertility following inbreeding and the possibilities for continuing sib‐mating for several more generations are discussed.
Photosynthesis in Plant Communities as Influenced by Leaf Angle1
Authors: Pearce R. B. , Brown R. H. , Blaser R. E.
Published: July 2010

Flats of barley were seeded at three different rates and tilted at 0°, 30°, and 60° from the horizontal. When the first leaf had developed the flats were returned to the horizontal for measurements of photosynthesis, light penetration, and leaf area index. This method produced flats with uniform leaf angles of 90°, 53°, and 18° at different leaf areas.

Results showed that differences in net photosynthesis, due to leaf angle, increased as leaf area index (ratio of leaf area to soil area) increased above two. The vertical leaves had a higher Pn and allowed more light to penetrate at high LAI's than horizontal leaves. Leaves at 90° required a leaf area index of 11 to intercept 95% of the light; 53° and 18° leaves intercepted 95% of the light at LAI's of 7 and 4.5, respectively. The mean extinction coefficients were 0.32, 0.45, and 0.60, respectively, for leaves 90°, 53° and 18° to the horizontal.

When data from these experiments were analyzed in equations proposed by Saeki to predict the net photosynthesis of a plant community, the predicted results closely approximated experimental results.
Changes in Weight, Germ Ratio, and Oil Content Kernel Development in High Oil Corn (Zea mays L.)1
Authors: Leng Earl R.
Published: July 2010

Changes in kernel and germ weight, germ percentage, oil percentage, and weight of oil were studied in the “Illinois High Oil” strain of corn during the 1962 and 1963 growing seasons. Dry weights of both whole kernels and germs (scutellum plus embryo axis) increased in linear manner from the first sampling date (19 to 21 days) until about the end of the 7th week of kernel development. The ratio of germ to whole kernel dry weight (germ percentage) continued to increase from the first sampling date until the kernel was nearly physiologically mature. Germ oil percentage rose rapidly from around 38% on the first sampling date to 54 to 56% by the end of the 4th week of kernel development, remaining nearly constant from then on. As a result, whole‐kernel oil percentage increased in about the same manner as germ proportion and did not reach maximum level until about the end of the 7th week after pollination.
Cross Pollination Studies with Male Sterile Wheats of Three Cytoplasms, Seed Size on F1 Plants, and Seed and Anther Size of 45 Pollinators1
Authors: Kherde Madhukar K. , Atkins I. M. , Merkle Owen G. , Porter K. B.
Published: July 2010

Forty‐five pollinators, including all market classes of wheat, were used to pollinate male sterile plants of three cytoplasms derived from Triticum timopheevi Zhuk., Aegilops caudata L., and Aegilops ovata L. Seed set ranged from 2 to 61% in 1964 and from 2 to 28% in 1965. The correlations between seed set on varieties for the two seasons were statistically significant but low. No relationship of seed set with any weather factor was evident. Pollinators varied significantly in anther length and width. Anthers of soft red winter wheats were longer and wider than those of other market classes. Weight of F1 seeds set on male sterile plants of all cytoplasms were larger and more angular and weighed more than pollinators. However, the influence of low seed set on size of F1 seed could not be separated from zenia effects. Seed set on fertile pollinators ranged from 95 to as low as 70% on lateral florets and 49% when all florets were considered.
Inheritance of Pod Maturity in a Phaseolus vulgaris L. Variety Cross1
Authors: Coyne Dermot P. , Mattson Richard
Published: July 2010

Time of green bean pod maturity in the cross between the early‐maturing day neutral ‘White Seeded Tendergreen’ and the late‐maturing photoperiodic responsive ‘Bush Blue Lake OSU 949‐1864’ was determined primarily by a single major gene with lateness being dominant.
Effects of Variable and Constant Storage Temperatures and Subsequent Room Storage on the Viability of Certain Seeds1
Authors: James Edwin , Bass Louis N. , Clark Dorris C.
Published: July 2010

Germinations of seeds of wheat, rye, soybeans, and safflower with approximate moisture contents of 4, 8, and 12%, stored at constant —12.2, —1.1, 10, 21.1, and 32.2 C were compared with seeds from the same lots stored at —12.2 C for 2 weeks and transferred, at biweekly intervals, progressively to the next highest temperature used in the constant series until the 32.2 C was reached. The sequence of transfer was then reversed from the highest to the lowest storage temperature through two complete sequences. Germination tests were made at the end of the constant and variable storages and again following 3‐month storage under room conditions (21.1 C and 30% relative humidity). Wheat seeds were not affected by any of the storage conditions, whereas incipient damage in rye seeds stored at 10 and 32.2 C became evident during 3 months' room storage. Soybean seeds with 11.4% moisture were dead at 34 weeks when stored at 32.2 C, and some damage was evident in seeds with 7.92% moisture under 32.2 C storage. Moisture content of 12.2% in safflower seeds was too high for storage at 21.1 and 32.2 C, and deterioration initiated at 21.1 C continued under room conditions. No adverse effects of room storage were evident following storage of seeds at —12.2, 10, or 21.1 C.
Effects of Self‐ and Cross‐Compatibility on the Frequency of Hybrids in Medicago sativa L.1
Authors: Carleton A. E. , Eslick R. F.
Published: July 2010

The influence of self‐ and cross‐compatibility of both parents on seed production potential and the percentage of crossed seed in. hybrids was studied. In separate studies a wide range in self‐ and cross‐compatibility of seven white flowered clones used as pistillate parents was found. Self‐ and cross‐compatibility were closely associated. In separate studies four of the five purple flowered clones used as male parents were rated as very low in selffertility. Cross‐compatibility as males of the five purple flowered clones varied; however, none rated high in crosscompatibility. In crosses between white flowered and purple flowered clones, pods per flower and seed per flower declined rapidly as self‐compatibility of the female parent decreased. Selection for low self‐compatibility resulted in low seed yield regardless of mating pattern. Pod and seed production were also influenced by the level of male cross‐compatibility of the male parent. The percentage of crossed seed in the hybrids was not closely associated with self‐compatibility of the female parent. Male cross‐compatibility was associated with the percentage of crossed seed in the hybrids. Specific combinations yielded 100% crossed seed, while other combinations within the same levels of self‐ and cross‐compatibilities yielded 0% crossed seed. A type of “specific combining ability” for the production of hybrids was suggested.
Effect of a Single Height Gene (Dw3) of Sorghum vulgare Pers. on Certain Culm and Leaf Blade Characteristics1
Authors: Casady A. J.
Published: July 2010

A 3‐year comparative study was made of isogenic lines of three sorghum varieties. The isogenic lines of each variety differed only in the dominant or recessive allele of the Dw3 height gene. The data showed that the Dw3 gene influenced culm diameter of the third, fourth, and fifth internodes from the top of the plant; peduncle length; and blade width, blade length, and blade area of the third, fourth, and fifth leaves from the top, aswell as culm height. There was no evidence that the Dw3 gene influenced maturity, as measured by number of nodes. Under environmental conditions that prevailed, effect of the dw3 allele resulted in greater culm diameters, longer peduncles, wider leaf blades, and shorter culms in all three varieties. The effect of the dw3 allele on leaf blade length and area was influenced by environment and variety, and its presence resulted in no effect, greater leaf blade length and area, or less leaf blade length and area, depending on environment or variety or both.
Heritability of Factors Affecting Malting Quality of Barley, Hordeum vulgate L., emend. Lam1
Authors: Foster A. E. , Peterson G. A. , Banasik O. J.
Published: July 2010

The feasibility of making selections in the F2 and F3 generation on the basis of prediction tests of barley quality was evaluated. Prediction tests made on F2 generation material were found to be unsatisfactory as a measure of quality of the F3 generation, based on heritability estimates and correlation coefficients. Heritability estimates obtained using variance components in the F3 generation were high and indicated that progress should be possible when selecting for nitrogen, extract, or diastatic power in this generation. Correlation coefticients among the three quality factors showed that extract was negatively associated with nitrogen and with diastatic power and that nitrogen and diastatic power were positively associated
Differential Seed Production of Alfalfa Clones at Two Diverse Locations1
Authors: Dade Eugene , Taylor Norman L. , Garrison C. S.
Published: July 2010

Twenty‐three alfalfa clones selected from the breeding program at the University of Kentucky were grown at Lexington, Ky., and at Prosser, Wash., in 1962 and 1963. Data were taken on date of bloom and seed yields. Flowering began later at Lexington than at Prosser in both years, but clipping at Lexington in 1963 prevented a direct comparison between locations. The range in days to first flower within the group was greater at Prosser but was considered slight in relation to the long pollination period at Prosser. Seed yields were higher at Prosser in both years. A substantial differential in seed yields of the clones at the two locations was revealed.

It was concluded that seed‐yield data from alfalfa clones grown in Kentucky could not be used to predict the reproductive capability of the clones in an environment which favors a more complete expression of seedyield potential. A correlation of r = .86 between the lst‐year and 2nd‐year seed yields indicates that clones could be screened for seed yields at Prosser in the 1st year.
Inheritance of Cytoplasmic Malesterility in Sudangrass1
Authors: Alam Sultanul , Sandal P. C.
Published: July 2010

Inheritance of cytoplasmic male‐sterility was studied in F2 and BC1 generations within crosses of male‐sterile Sorghum arundinaceum var. Rhodesian with six lines of sudangrass, Sorghum vulgare var. sudanense. All F1 progenies were male‐fertile indicating that the males carried dominant fertility restorer genes.

Based on the segregation of male‐fertile to male‐sterile plants in the F2 and BC1 generations, male‐sterility was conditioned by one gene pair in three crosses, two gene pairs in two crosses and by three gene pairs in one cross. Fertility was dependent on at least a single dominant fertility restorer gene at each of any two of the three gene loci identified.
Effects of a Suboptimal Temperature on the Free Amino Acid Composition of Bean Seedlings1
Authors: Knull H. R. , Kinbacher E. J.
Published: July 2010

Phaseolus vulgaris L. var. ‘Michelite’ was grown at an optimal temperature, 25 C, and a suboptimal temperature, 18 C. Seeds and seedlings were divided into different mmorphological sections at three stages of growth and analyzed for total nitrogen and 20 free amino acids. Significant differences in the free amino acid composition of seedlings at comparable stages of growth were observed between the two temperatures. Before the cotyledons emerged through the growth medium, the plants grown at 25 C were higher in free amino acids. At the time of their emergence through the growth medium, the seedlings grown at the suboptimnal temperature were higher in free amino acids. Asparagine was the most abundant free amino acid detected in all seedlings.
Somatic Chromosomal Irregularities in Nicotiana plumbaginifolia Viv.1
Authors: Collins G. B.
Published: July 2010

Nicotiana tabacum L. ✕ N. plumbaginifolia Viv. hybrids are characterized by somatic chromosomal irregularities involving chromosomes contributed by N. plumbaginifolia. Chromosomal irregularities were observed in smear preparations of root tips and corollas of N. plumbaginifolia; none were observed in similar tissue from N. tabacum. Irregularities in seedling root tips included; micronuclei, extra and missing chromosomes at metaphase, fragments, anaphase bridges, laggards, and extra long metaphase chromosomes suggestive of dicentrics. Two and four year old seeds produced a much higher frequency of these irregularities than seed that was 2‐3 months of age. Only corolla tissue from fresh seed was examined and aberrations were seldom observed. Chromsomal irregularities, detected in tissue of N. plumbaginifolia, may be associated with a seedling stress period marked by retarded growth and chromosome irregularities in a tabacum‐plumbaginifolia hybrid. In N. plumbaginifolia, the aberrations appear to be associated with aged seed whereas aberrancy in the tabacumplumbaginifolia hybrid may be partly a function of interspecific hybridity.
Natural Hybridization of Peanuts, Arachis hypogaea L., in Virginia1
Authors: Culp T. W. , Bailey W. K. , Hammons R. O.
Published: July 2010

Natural crossing in peanuts (Arachis hypogaea L.) averaged 0.27, 0.09, and 0.23% when measured by counting the hybrids with two marker varieties, at Holland, Va., from 1963 to 1965. Varietal as well as seasonal differences were noted. Highest natural crossing occurred in ‘Tennessee Red,’ 0.40% (range = 0.15 to 0.55%), and the lowest in ‘Virginia Bunch 67,’ 0.10% (range = 0.01 to 0.24%). Natural hybridization in peanuts at Holland is much less than that reported for other areas, but it is sufficient to account for 10 to 544 (4 to 220 plants/acre) “off type” plants/ha, and should be a consideration in maintaining varietal purity at this location.
Cyanogenesis in Lotus Species1
Authors: Phillips R. L.
Published: July 2010

The presence of hydrogen cyanide was determined in 60 entries of Lotus representing 28 species. Twelve entries were cyanogenetic, 40 were acyanogenetic, and 8 contained both cyanogenetic and acyanogenetic types. The planning of species‐hybridization studies in Lotus may be facilitated by utilizing cyanogenesis as a genetic marker.
Effects of Genotype and Heterozygosity of Pollen Source and Method of Application of Pollen on Seed Set and Seed and Fiber Development in Cotton1
Authors: Kohel R. J.
Published: July 2010

This paper reports results of a factorial experiment involving four methods of pollen application, four genotypes, and five levels of heterozygosity of pollen source from Upland cotton, Gossypium hirsutum L. Pollen was applied to a common female parent. Data obtained were seed number per boll, seed number per locule, seed index, lint index, grams of lint per boll, and staple length. Different methods of pollination caused varying degrees of physical damage to the young flowers, and this was reflected in all characters measured except staple length. Heterozygosity of the pollen source provided interesting results. Larger seeds developed when flowers of the female parent (F01) were pollinated with pollen of the same source than when pollinated with pollen from F1 or from genetically different parental sources (F02). Seed development (seed index) was less variable with F01 than F01 or F02 pollen; this indicated greater developmental stability and adaptation of self‐fertilization.
Exotic Germplasm Use in Grain Sorghum Improvement1
Authors: Malm N. R.
Published: July 2010

Eight fertility restorer lines developed from African introductions were crossed with four male sterile lines to produce 32 hybrids. Four check hybrids were included and the 36 hybrids were evaluated for yield, seed size, seed density, and various quality characteristics. The data reported indicates that large‐seeded parents produced the highest yielding hybrids, however, all sets of exotic hybrids produced larger seed than the checks. Some exotic hybrids produced 50% more protein than the checks. Considerable variations in starch, fat and fiber showed that a great potential exists for improving the quality of grain sorghum.
Estimates of Heterosis and Combining Ability in Winter Wheat1
Authors: Gyawali K. K. , Qualset C. O. , Yamazaki W. T.
Published: July 2010

From a seven‐parent diallel cross, using soft red, soft white, and hard red winter wheat varieties, 10 of the 21 F1 hybrids yielded significantly more grain than the better parent in a space‐planted experiment. The average yield of all hybrids was 24% greater than the better parent in each cross. Specific combining ability effects were significant for grain yield, kernel weight, pearling index, spike number, plant height in one year only, and heading date, but not significant for flour yield or micro‐alkaline water retention capacity (AWRC). General combining ability effects were significant for all of these characters. Tenn. 9 had good combining ability for grain yield but Morion did not. Soft red X soft red and soft red X hard red hybrids gave similar heterosis values, indicating that interclass diversity is not necessary for heterosis. Hybrids with early and late maturing parents produced greater heterosis for grain yield than hybrids with both early parents or both late parents. Milling and baking quality prediction tests indicated that hard X soft hybrids did not have desirable soft wheat quality. Pearling index, flour yield, and micro‐ AWRC were generally equal to the midparent values.
Characteristics of Rice Varieties in the U.S. Department of Agriculture Collection1
Authors: Webb B. D. , Bollich C. N. , Adair C. R. , Johnston T. H.
Published: July 2010

About 4,400 rice varieties from 57 countries were studied to determine length of growing period, kernel size and shape, and several physical and chemical endosperm characteristics associated with rice cooking and processing behavior. Days from seeding to heading was not highly correlated with the other characters studied. Correlation coefficients between kernel length, kernel width, and length/width ratio were significant. Amylose content, starchiodine‐blue values, and alkali reaction values were the best indicators of those stndied for predicting parboilingcanning stability. For long‐grain U.S. varieties, protein content also was an important component of the multiple regression equation of parboiling‐canning stability.
Mass Selection by Specific Gravity for Protein and Oil in Soybean Populations1
Authors: Smith R. R. , Weber C. R.
Published: July 2010

The effects of two cycles of mass selection by specific gravity were investigated in two hybrid soybean populations (Glycine max (L.) Merrill). Effects were measured on chemical composition and on six agronomic attributes. Selection was employed for high (Hi) and low (Lo) specific gravity within each population. A solution of glycerol and water was used to establish the desired specific gravity. Cycle 1 stratified the original populations into groups differing in chemical composition. Hi populations had a higher mean protein and lower mean oil content than the control populations. Lo populations were above average in oil and below average in protein content. Protein increased in the Hi populations and ranged from 0.3 to 1.2% and the decrease in protein in the Lo populations ranged from 0.6 to 1.5%. The increase in oil in the Lo populations ranged from 0.1 to 1.0% and thedecrease in oil in the Hi populations ranged from 0.0 to 0.9%.

The effects of continued selection (cycle 2) varied among and within populations. In general, selections in cycle 1 were more effective than in cycle 2 for protein and oil.

Specific gravity measures relative density; therefore, density of the seed was determined using a Bechman gaspycnometer. Average heritability for seed density was 69%. High seed density was associated with high protein, low oil and late maturity.
Differences in Response to Mineral Nutrients of Populations of Ryegrass, Lolium perenne L., and Orchardgrass, Dactylis glomerata L.1
Authors: Crossley G. K. , Bradshaw A. D.
Published: July 2010

The growth response to mineral nutrients of natural populations of Dactylis glomerata and Lolium perenne determined (a) in sand culture with varying levels of calcium and phosphate and (b) in calcareous, acidic, and ordinary soils showed considerable differences in response of populations from contrasting soil types, suggesting specific physiological adaptation to soil nutrient level. Cultivated varieties which were included usually performed best under ordinary nutrient conditions. But under extreme conditions they rarely performed as well as the specifically adapted natural populations. Seed/ tiller comparisons suggested a high heritability of response.

Material of cultivated varieties collected after seed multiplication, or from established awards, showed that genetic changes in physiological adaptation of varieties can occur when they are grown on extreme soils. In seed multiplication such changes are likely to be agriculturally disadvantageous. Edaphic differentiation and evolution in herbage plants may therefore be more widespread and Important than previously considered.
Mass Selection Systems for Sorghum, Sorghum bicolor (L.) Moench.1
Authors: Doggett H.
Published: July 2010

Alternate generations of female choice and selfed plant mass selection may be applied to sorghum composites. Selection of steriles for agronomic characters and yield alternates with intense selection of fertiles for yield. Cains are greater and seed set problems fewer. Composited collection entries using ms3 contribute to the breeding populations.
Inheritance of Tolerance in Flax (Linum usitatissimim L.) Treated with MCPS1
Authors: Stafford R. E. , Comstock V. E. , Ford J. H.
Published: July 2010

Progeny arising from crosses between 2‐methyl‐4‐chlorophenoxyacetic acid (MCPA)‐tolerant and MCPA‐susceptible flax varieties were evaluated for MCPA tolerance in F3, F4, BC(S2), and BC(S3) generations. Data were obtained on the change in anthocyanin production and stem curvature, delays to first bloom, full bloom, and maturity, and on the reduction of plant height andseed yield.

Based on heritability estimates, selection would be most effective for change in anthocyanin production, stem curvature, and reduction in plant height in the ‘Arrow’ ✕ ‘Dakota’ cross and most effective for stem curvature, and delays to first bloom and to maturity in the Arrow ✕ C.I. 1139 cross.
Inheritance of Small, Purple Flower Standard in Korean Lespedeza, Lespedeza Stipulacea1 Maxim.
Authors: Offutt Marion S.
Published: July 2010

The inheritance of small, purple flower standard in Korean Lespedeza (Lespedeza stipulacea Maxim.) was studied in two crosses. F1, F2, and F3 data indicate that the small, purple flower standard mutant character is controlled by a single recessive gene pair. Colorimetric and chromatographic analyses of flower standard extracts indicate that the mutant and normal standards contain equal quantities of the same anthocyanin pigments, which accounts for the darker purple color of the mutant standard. Thus, the only real difference detected between the mutant and normal standards was in size.
Early Generation Inheritance of Malting Quality Characters in a Barley Cross1
Authors: Baker R. J. , Bendelow V. M. , Buchannon K. W.
Published: July 2010

The inheritance of two qualitative and two quantitative characters was studied in the F3 and F4 generations of a cross between two varieties of barley (Hordeum vulgare L. emend. Lam.). It was shown that the two qualitative traits, aleurone color and level of free betaamylase, were each controlled by a single gene and that the two genes were independent. The two quantitative characters, nitrogen content and total beta‐amylase activity, were found to have high heritabilities and to be positively correlated. It was further discovered that nitrogen content and total beta‐amylase activity were both negatively correlated with level of free beta‐amylase. Progress from selection for these characters in F3 could be expected, and genetic variability would remain in the selected lines.
Second Phase in the Evaluation of Synthetic Varieties of Maize for Yield1
Authors: Hallauer Arnel R. , Sears J. H.
Published: July 2010

The second phase of a sequential synthetic variety testing program for yield in maize (Zea mays L.) is reported. Four varieties selected from the tests of the first phase and five previously untested varieties were crossed in a diallel series and evaluated at three locations in each of two years.

The yield level of the varieties included for the first time was generally higher than those selected from the first phase. Two‐ear Syn., Syn. AA, and Syn. BB were the highest‐yielding varieties, whereas S.S. Syn. and Purdue MJ yielded significantly lower than the other varieties. S.S. Syn. was outstanding in cross performance; it had the highest average yield in crosses and a significant, positive general combining ability effect. Two‐ear Syn. was high in both variety and cross performance and had the largest variety effect ( = 3.44**).

Relative to the midparent and high parent, average heterosis for all crosses was 9.8 and 4.2%, respectively. Relative to the high parent, S.S. Syn., L.E. Syn., and C.B. Syn. #3 exhibited the most heterosis in crosses. S.S. Syn. ✕ Pa. Int. Syn. had a significant, specific heterosis effect ( = 5.51**) and an observed heterosis of 24.1% relative to the midparent. Very little heterosis was observed for the crosses involving Syn. AA and Syn. BB. Specific heterosis (s.c.a.) was significant (P < .05) in the combined analysis. The specific effects for only three crosses were larger than the standard error: S.S. Syn. ✕ Pa. Int. Syn. had a positive effect, and Syn. AA ✕ Pa. Int. Syn. and Syn. BB ✕ S.S. Syn. significant, negative effects. The cross, S.S. Syn. ✕ Pa. Int. Syn., was the highest yielding in both phases of testing.
Growth and Carbohydrate Storage of Three Poa pratensis L. Strains as Influenced by Temperature1
Authors: Youngner V. B. , Nudge F. J.
Published: July 2010

To determine if Poa pratensis strains of different origins would respond differently to a series of temperatures, ‘Merion,’ ‘0217,’ and ‘Newport’ cultivars were grown in controlled environment growth chambers at four different temperature regimes.

Top growth, density, and total available carbohydrates in stem bases were determined after 8 weeks in the growth chambers. Plants were clipped to 4 cm at weekly intervals during the treatment period.

A differential response to temperature among the three strains was demonstrated. Merion and 0217 had the highest density at the higher temperatures and Newport had the highest density at the lower temperature regimes. The 0217 strain had significantly greater density at all temperatures than did Merion or Newport. All strains accumulated more carbohydrate reserves at the lower temperatures, but Newport had signficantly lower reserves at all temperatures than did Merion or 0217. Only Merion had a significantly greater carbohydrate reserve at the lowest temperature compared to the next warmer regime. Clipping yields were greater at the warm temperatures compared to the cool temperatures for all strains.
Germination of Oat (Avena Byzantina C. Koch) Pollen on Artificial Media1
Authors: Wallace A. T. , Karbassi P.
Published: July 2010

Freshly collected oat pollen was germinated in Petri dishes on media containing 13 g sucrose, 1.7 g raffinose, 20 mg boric acid, 25 mg calcium nitrate, 3 g bacto‐agar, and 85 ml double‐distilled water. Germination is improved if the dishes containing the media are “aged” 2 to 10 days in a refrigerator. The pollen germinates within 1 to 2 minutes after it comes in contact with the media. Within another 5 to 6 minutes the tubes usually have grown to their maximum length, 125 to 150 microns, at which time the ends burst and exude their contents. Modifying agents proved to be ineffective in preventing the bursting.
Differences in Free Amino Acids Between Stocks of the Same Long‐Time Inbred Line of Maize (Zea mays L.)1
Authors: El‐Eryani A. A. , Fleming A. A.
Published: July 2010

Qualitative analysis was made for free amino acids by two‐dimensional descending paper chromatography in four stocks of long‐time corn inbred CI 7 (Zea mays L.).

We detected eight amino acids in 60 lambdas of the North Carolina and Arkansas sources, whereas only four were found in the stocks from Athens and Beltsville. However, seven amino acids were detected in 100 lambdas of the Athens and Beltsville stocks. Apparently, the North Carolina and Arkansas stocks differ quantitatively, rather than qualitatively, from the Athens and Beltsville stocks with respect to the free amino acids—asparagine, glutamine, glycine, and probably arginine. These findings are in agreement with a previous report by us on variations between these stocks for seedling and quantitative biochemical characters.

Stocks within supposedly homozygous lines may differ in the number and/or amount of amino acids present in the seedlings. Thus biochemical analyses may become more useful as techniques in the identification and isolation of genotypes in breeding programs and in basic genetic and cytogenetic studies.

These variations may be due either to mutation or residual heterozygosis, or to both. The possibility of episomal systems or regulatory genes as a part of mutation or residual heterozygosis should not be overlooked.
Reciprocal Maintainer‐Restorer Relationship between A1 and A2 Sterile Cytoplasms Facilitates Millet Breeding1
Authors: Burton Glenn W. , Athwal D. S.
Published: July 2010

The reciprocal maintainer‐restorer relationship found to exist between the maintainers for A1 and A2 sterile cytoplasms in pearl millet, Pennisetum typhoides (Burm.) Stapf and C. E. Hubb., appears to be a new phenomenon in plants. Through this relationship, maintainer Tift 23DB1 for cytoplasmic male‐sterile Til't 23DA1 will restore fertility in cytoplasmic male‐sterile Tift 239DA2; and maintainer Tift 239DB2 will restore the fertility of Tift 23DA1. Population Y, containing plants with A1 cytoplasm and their maintainers, and population Z, containing plants with A2 cytoplasm and their maintainers, used in breeding systems such as reciprocal recurrent selection, will facilitate the development of superior F1 hybrids.
Inheritance and Differentiation of Semidwarf Culm Length of Wheat1
Authors: Allan R. E. , Vogel O. A. , Peterson C. J.
Published: July 2010

Information on the genetic control of culm length was obtained from a five‐parent diallel cross involving the standard height cultivar ‘Burt’ and semidwarf selections ‘Norin 10/Brevor 14,’ ‘Norin 10/Brevor 2238,’ ‘Seu Seun 27,’ and ‘Suwon 92.’ Culm length measurements of the F1 and F2 populations and their parents were recorded. All F1 populations expressed dominance or overdominance for tall culm length. Although Suwon 92 and Norin 10/Brevor 14 differ in height, they appear to have similar semidwarf genetic mechanisms. Each mechanism involves two independent major factors for semidwarfism, but Suwon 92 has one or more genes for tall culm length not present in Sel.14. Sel.2238 has a single gene for semidwarfism (one of the two genes of Sel.14 and Suwon 92). Limited evidence suggests that the semidwarf gene in Seu Seun 27 is different from that in Sel.2238 and may be the other gene carried by Sel.14 and Suwon 92. In addition to the two major semidwarfing genes, minor genes appear to modify the expression of semidwarf culm length.
Effects of Degree and Time of Defoliation on Yield and Related Attributes of Safflower1
Authors: Urie A. L. , Leininger L. N. , Zimmer D. E.
Published: July 2010

From 1960–1962 four agronomically diverse safflower entries were grown in replicated field plots at Logan, Utah. These entries were partially or totally hand defoliated at seven stages of growth. Removal of all leaves — when averaged over dates, entries, and years — reduced yield by 23.0%, weight per 100 seeds by 7.7%, test weight by 2.6%, hull percentage by 6.0%, and increased oil by 6.9% in relation to the check plot. The increase in oil percentage was negatively correlated with the decrease in hull percentage (r= —0.86). Removal of leaves from the top half of the plant had a similar but slighter effect. Removal of branches from the bottom half of the plant reduced yield at the later stages of plant development. Removal of leaves from the bottom half of the plant regardless of growth stage did not affect the attributes measured. There was a differential response of safflower entries to the severe defoliation treatments (removal of all leaves or removal of leaves from the top half of the plant).
Inheritance of White Stripe and Rolled‐Leaf Characteristics in Sorghum bicolor (L.) Moench
Authors: Miller F. R.
Published: July 2010

The inheritance of two previously unreported traits of Sorghum bicolor (L.) Moench was determined, and gene symbols were assigned. White stripe which develops on terminal leaves on a mutant in ‘Norkan’ (SA 357) was found to be controlled by a single recessive gene (ws ws). No striking indication of maternal cytoplasmic effects was detected. Rolled leaf, a condition typical of ‘Hoefling's Dwarf White Durra’ (SA 30), was also inherited as a single‐gene recessive (rl rl), in crosses to SA 5330. The trait is modified by other genes, as shown in crosses to Tx3197.
Differential Survival of Cool Season Turfgrass Species Overseeded on Different Selections of Bermudagrass1
Authors: Kneebone William R. , Major Gary L.
Published: July 2010

In a 2‐year study at Tucson, Ariz., marked reductions occurred from initial stands of four cool season grasses overseeded for winter turfgrass on certain varieties of bermudagrass (Cynodon dactylon (L.) Pers.) while stands were maintained on other bermudagrass varieties. The cool season grasses studied were Pennlawn fescue (Festuca rubra L.). annual ryegrass (Lolium multiflorum L,.), roughstalk bluegrass (Poa trivialis L.), and a mixture of highland bentgrass (Agrostis tenuis Sibth.), Kentucky bluegrass (Poa pratensis L.), and Pennlawn fescue. The stand reductions were most apparent with annual ryegrass and the grass mixture. Initial stands of all cool season grasses on all bermudagrasses were above 90%. These stands were maintained until the spring transition on seeded Arizona bermudagrass while stands of the ryegrass reduced to below 75% in late February and March on ‘Tiflawn,’ ‘Tifway,’ and ‘Ormond.’ Ryegrass stands on ‘Tufcote,’ ‘Beltsville #1,’ and ‘Midway’ averaged 89% in the spring compared to 94% on seeded Arizona bermudagrass.

Differentials in soil nitrogen levels could not be shown among the 16 bermudagrasses studied. No apparent disease affected cool season grass stands. Extracts from bermudagrasses with contrasting cool season grass stands were used to moisten annual ryegrass seeds in a germination study. There were no germination differentials. Ryegrass grown in the greenhouse and on an outdoor bench on plugs of Arizona bermudagrass maintained stand while ryegrass stands on plugs of Ormond were reduced.
Semi‐Vitro Methods in the Study of Compatibility in Birdsfoot Trefoil (Lotus corniculatus L.)1
Authors: Spiss Ludwik , Paolillo Dominick J.
Published: July 2010

In semi‐vitro cultures, there were no differences in emergence of pollen tubes from styles of birdsfoot trefoil (Lotus cornlculatus L.) after cross‐ and self‐pollinations. These findings support the hypothesis that compatibility of a mating in birdsfoot trefoil is not determined by differential growth rates of cross‐ and self‐pollen tubes through the style. The differential in performance of pollen tubes is presumed to be manifested in the ovary. However, preliminary tests for chemotropic responses of pollen tubes to ovarian tissues have failed to reveal how this differential performance is regulated.
Hybrid Performance of Maize Inbred Lines Selected by Testcross Performance in Low and High Plant Densities1
Authors: Russell W. A.
Published: July 2010

Nineteen S3 maize inbred lines (Zea mays L.) selected through three successive generations, S0, S1, and S2, on the basis of testcross performance in a low or a high plant density were evaluated further to determine the importance of plant density in iubred development. Two testers were used in the final study: the double‐double cross (DDC) used in the selection of the lines and a single cross (SC). The testcrosses were grown in low, medium, and high plant densities in five environments. With the DDC tester, the S3 lines as a group showed a significant yield gain when compared with a testcross of the source synthetic variety. Lines selected at low and high densities gave similar group testcross yields at low densities, but at medium and high densities, testcrosses of the highdensity group yielded better than those of the low‐density group. The difference in yield at medium and high densities was caused by a greater incidence of barren stalks for the low‐density selection group. With the SC tester, there was no gain in yield of the selections as a group over the source variety. Greater relative importance of nonadditive gene action as compared with additive gene action appears the only explanation for the results obtained.
Effect of Seed Source and Seedling Age on the Freezing Resistance of Winter Oats1
Authors: Marshall H. G.
Published: July 2010

Controlled freezing experiments were used to study the effect of the location where seed is produced on the freezing resistance of young winter oat plants (Avena byzantina K. Koch and A. saliva L.). Plants grown from Pennsylvania seed were significantly more resistant to freezing at early ages than those grown from Virginia seed, but seed source was not always important. Differences associated with location where the seed was grown disappeared as the plants aged, and the duration of the effect varied with the variety. The effect persisted as long as 26 days for the variety 'Ballard.' Seedling plants of the variety 'Wintok' had a moderate freezing resistance at 12 days of age, but this decreased to a first minimum at 19 days of age. The freezing resistance then rapidly rose to a maximum at 33 days of age, but a second decrease occurred after 33 days.

Limited data on chemical composition of the seed supported the hypothesis that the source effect was caused by differences in the nutrient reserves developed in the endosperm at different geographic locations. Freezing resistance was lowest when the N level in the seed was high, and highest when the P and K were high and the N level low.
Estimates of Genetic Variance in ‘Cherokee’ Alfalfa (Medicago sativa, L.)1
Authors: Dudley John W. , Busbice T. H. , Levings C. S.
Published: July 2010

Four blocks of clones (17, 18, 19, and 20 clones per block) taken at random from ‘Cherokee’ alfalfa (Medicago sativa L.) were evaluated in a partial diallel mating design. Vegetatively propagated clones and four cross progeny from each clone were evaluated in three replications at two locations for 2 years in the upper coastal plain of North Carolina. Variance components estimated were interpreted in terms of autotetraploid inheritance with alpha = 0. Significant estimates of total genetic variance (δ2c), general combining ability variance (δ2g), and covariance of parent‐offspring (δpo) were obtained for yield, recovery after cuts 1 and 2, spring growth, and fall growth. Estimates of specific combining ability variance (δ2s) were not significant for any character. However, estimates of δ2c were significantly larger than estimates of 2 δpo or 4 δ2g for forage yield, recovery after cut 1 and spring growth indicating that either trigenic, quadrigenic, or epistatic genetic variance was important.

Predicted gain in yield from selecting the upper 10% of the clones and recombining them into a synthetic was 9.3%. Because both additive and non‐additive genetic variance are important in Cherokee, additional gain might be made by producing hybrid varieties.