bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors Affecting Resistance of Field‐Planted Alfalfa Clones to the Alfalfa Weevil1
Authors: Norwood B. L. , VanDenburgh R. S. , Hanson C. H. , Blickenstaff C. C.
Published: July 2010

Seventy alfalfa, Medicago sativa L., clones representing a range of observed reactions to the alfalfa weevil, Hypera postica (Gyllenhal), were evaluated in a field test for oviposition and larval feeding, and for interrelationships between plant resistance and growth characteristics.

Oviposition preference accounted for 26% of the variation among clones for larval feeding damage. Plants with decumbent growth, wide crown, little growth, and small stems tended to receive fewest eggs and suffer least larval feeding; they had many characteristics of Medicago falcata. Although weevils preferred to oviposit in plants with large stems, oviposition differences among clones were still significant after adjustment for stem size by covariance analysis. Weevils oviposited only sparingly in several of the clones with medium large stems. The following correlation coefficients were positive and significant: Number of egg masses and eggs per stem, stem diameter and eggs per stem, larval feeding and egg masses per stem, larval damage scores in different years, and number of egg masses in different years. Further study is needed to determine the kinds of resistance mechanisms involved and whether oviposition preference mechanisms reported here offer suitable control of alfalfa weevil damage.
Hot Water Immersion Effective for Scarifying Seeds of Tephrosia vogelii1
Authors: Ruppel E. G. , Freyre R. H. , Barnes D. K.
Published: July 2010

Immersion in hot water baths at 50 to 56 C for 5 to 30 minutes significantly increased the germination percentage of seeds of Tephrosia vogelii as compared to tapwater soaks and mechanical scarification. Immersion for 5 minutes at 54 C induced 96% germination with a minimum of seed swelling. Thiram fungicide, when added to the hot water bath, applied as a cool slurry after hot water immersion or applied as a dust to seeds cooled and dried after hot water immersion, had no deleterious effects on seed germination.
Hybrids Between Agropyron desertorum and Induced‐Tetraploid Agropyron cristatum1
Authors: Dewey Douglas R. , Pendse P. C.
Published: July 2010

Cross‐compatibility of Agropyron desertorum (Fisch. ex Link) Schult. and induced‐tetraploid A. cristatum (L.) Gaertn. was variable, and seed set ranged from 0 to 20 hybrid seeds per spike. Many hybrids were exceptionally large and leafy and compared favorably with the most vigorous crested wheatgrasses. The A. desertorum, 2n=31, and induced‐tetraploid A. cristatum, 2n=28, parents behaved cytologically as autoploids. The three extra A. desertorum chromosomes were believed to be supernumeraries. Chromosomes numbers of 42 hybrids ranged from 2n=28 to 2n=32. Chromosome associations in 28‐chromosome hybrids averaged 0.02 I, 8.54 II, 0.02 III, 2.25 IV, 0.22 VI, and 0.06 VIII in 180 cells at diakinesis. Hexavalent and octavalent associations at diakinesis and bridge‐fragment formations at anaphase I and II signified structural heterozygosity between A. cristatum and A. desertorum genomes. Seed set ranged trom 0.02 to 2.30 seeds per spikelet in 39 unselected hybrids and from 1.71 to 4.15 seeds per spikelet in 15 selected hybrids. The prospects of utilizing A. desertorum ✕ induced‐tetraploid A. cristatum hybrids in a breeding program appear favorable in spite of some parental cross‐incompatibility and reduced fertility of some hybrids. Taxonomic implications of the data are discussed.
Dehulling and Seed Germination in Vernonia Anthelmintica (L.) Willd.1
Authors: Berry C. D. , Lessman K. J.
Published: July 2010

Fresh seed of four Vernonia anthelmintica (L.) Willd. selections were (1) untreated (N), (2) water soaked overnight (S), (3) soaked overnight followed by removal of pericarp (SP), or (4) soaked overnight followed by removal of pericarp and seedcoat (SPS). The SP treatment increased germination, but many abnormal seedlings resulted, probably due to seedcoat damage during dehulling. A considerable increase in germination followed the SPS treatment. Average shoot length of resulting seedlings approached that of the few normal seedlings after N and S treatments. The factor(s) inhibitory to the germination of fresh vernonia seed is associated with the seedcoat.
Chromosome Interchanges of Spontaneous Origin in Pearl Millet, Pennisetum Typhoides1
Authors: Powell Jerrel B. , Burton Glenn W.
Published: July 2010

Two chromosome interchanges of spontaneous origin occurring in pearl millet, Pennisetum typhoides (Burm.) Stapf and C. E. Hubb., are described. One of domestic origin, first isolated from Inbred 13, also occurs in the inbred ‘Tift 239.’ A second, found in a plant introduction from Upper Volta, Africa, has one rearranged chromosome that is common to both interchanges, as evidenced by rings of six chromosomes that form at diakinesis in plants heterozygous for both. Pollen fertility is approximately 67% in heterozygous plants with the Tift T13 interchange and approximately 48% in plants heterozygous for both interchanges. Seed set in F2 plants segregating for the semisterility due to the Tift T13 interchange was 39% less than the fertile segregates in one population.
Genetic Variation in Maize Coleoptile Growth and its Relationship to the Auxin Regulatory System1
Authors: Moll R. H. , Levings C. S. , Stuber C. W.
Published: July 2010

Part of the variability of coleoptile elongation in a population of maize (Zea mays L.) was found to be due to genotypic differences. Genotypic differences were also found for five traits related to the auxin regulatory system. These five traits were (1) auxin production of corn coleoptile tips measured by Avena bioassay, (2) elongation of corn coleoptile sections without exogenous auxin, (3) elongation with exogenous auxin, (4) response to exogenous auxin measured by the differences between (3) and (2) above, and (5) peroxidase activity. Regression of coleoptile length after 5 days on the traits chosen to represent the auxin regulatory system resulted in a significant reduction in the sum of squares, and a coefficient of determination of 0.425.
Effect of Four Recurrent Selection Programs on Two Alfalfa Populations1
Authors: Hill R. R. , Hanson C. H. , Busbice T. H.
Published: July 2010

Two broad‐based germ plasm pools of alfalfa, Medicago sativa L, were each subjected to four separate programs of recurrent phenotypic selection for resistance to leafhopper yellowing, caused by Empoasca fabae (Harris); spotted alfalfa aphid, Therioaphis maculata (Buckton); bacterial wilt, caused by Corynebacterium insidiosum (McCull) Jens.; and common leafspot, caused by Pseudopeziza medicaginis (Lib.) Sacc. Selection for resistance to these pests was highly effective. A slight reduction in vigor in the aphid‐resistant populations was attributed to shifs resulting from selection of a small number of plants in the first cycle of that program. Generally, selection for resistance to a particular pest did not cause significant reduction in levels of resistance to other disease and insect pests developed in previous selection programs. Selection of 75 or more plants in each cycle was recommended.
Breeding Potential for Forage Yield and Seed Yield Tetraploid Versus Diploid Strains of Red Clover (Trifolium pratense)1
Authors: Thomas H. L.
Published: July 2010

In comparisons between tetraploid and related diploid red clover (Trifolium pratense) strains, the tetraploids averaged higher in forage but lower in seed yield. Wide genetic variability among and within the tetraploid strains indicated a good possibility for progress in selection.
Influence of Cutting Frequency, Species, and Nitrogen Fertilization on Forage Nutritional Value1
Authors: Allinson D. W. , Tesar M. B. , Thomas J. W.
Published: July 2010

The nutritive value of samples of forage taken every 2 weeks throughout the growing season was evaluated by a 6‐hour in vitro rumen fermentation technique, measuring percent dry matter disappearance (% DMD). Species subjected to four cutting systems ranked in the following order: alfalfa (Medicago sativa L.), birdsfoot trefoil (Lotus corniculatus L.), reed canarygrass (Phalaris arundinacea L.), bromegrass (Bromus inermis Leyss.), and orchardgrass (Dactylis glomerata L.). The overall mean DMD values of all forages cut one, two, three, or four times per season were 13.0, 21.6, 24.9, and 25.4%, respectively. Uncut forage lost nutritive value progressively thronghout the growing season but at a rate characteristic of the species. Morphological condition and moisture content of the forages were not adequate indicators of nutritive value except when the forages were not cut until the end of the growing season. Nitrogen fertilization in the period 1965–1966 did not consistently affect the nutritive value of either common or Siberian reed canarygrass. Common was superior to Siberian reed canarygrass in nutritive value. Considerable year‐to‐year and within season variation was evident for the nutritive value of the reed canarygrass types.
Factors Associated with Tiller Survival in Sorghum Varieties Resistant to the Sorghum Shoot Fly (Atherigona varia soccata)1
Authors: Blum A.
Published: July 2010

Five resistant sorghum (Sorghum sp.) varieties and two susceptible to the sorghum shoot fly (Atherigona varia soccata) were studied in order to evaluate the association between several plant traits and tiller survival after simulated damage in an insectarium and infestation in the field. Under insectarium conditions (non‐infested), tillering was simulated through a manual destruction of the growing apex: in seedlings.

The pattern of silica deposition in the abaxial epidermis at the base of the leaf sheaths of tillers differed markedly from that previously reported (3) for seedlings of the same varieties. However, in tillers of resistant varieties, the same lignification was found of the walls of cells which enclose the vascular bundles in the central leaf whorl, as in seedlings of resistant varieties. This was not found in tillers of the susceptible variety. Tillers of all resistant varieties grew faster than those of the susceptible ones. If tillers of resistant varieties were infested, infestation was delayed by two days, as compared with the susceptible one.

The results imply that tiller survival in shoot‐fly‐resistant sorghum varieties is associated with lignified tissues at the central leaf whorl and a fast growth rate of tillers
Resistance of Inheritance to Maize Dwarf Mosaic Virus in Maize (Zea mays L.)1
Authors: Dollinger E. J. , Findley W. R. , Williams L. E.
Published: July 2010

The inheritance of resistance of corn (Zea mays L.) to maize dwarf mosaic virus was studied under conditions of natural infection. Progenies evaluated were parents, F1, F2, BC(P1), and BC(P2). Parental inbred lines utilized were Oh07 (resistant) and C103 (susceptible), and Oh07 (resistant) and Oh43 (highly susceptible). Resistance was largely dominant. An estimate of two to three genes for resistance was obtained from the Oh07 and C103 data with he possibility that two dominant genes for resistance may be contributed by the Ohm parent. A gene or genes for susceptibility were postulated to be contributed by inbred line Oh43 which lowered the incidence of resistance in certain progenies and also reduced the estimated number of genes for resistance.
Identification of Diploid and Tetraploid Lolium Cultivars Grown Under Controlled Environmental Conditions1
Authors: Kranski B. , Bula R. J.
Published: July 2010

Seven cultivars of ryegrass, Lolium sps., were grown under controlled environmental conditions in an attempt to use the characters of leaf blade length or width, dry weight accumulations, and leaf blade proteins as a means of cultivar or ploidy identification.

Leaf width measurements after 2 weeks of growth at 20 C and 20‐hour photoperiods provided the most definitive statistical separation of cultivars. Dry weight measurements of plants grown at 20 C and 12‐, 16‐, or 20‐hour photoperiods for 4 weeks provided reasonable separation of cultivars but not to the degree noted for leaf blade width measurements. Leaf length measurements provided cultivar separations similar to those observed for the dry weight measurements. In all cases, cultivar separation was not specifically related to degree of ploidy (diploid vs. tetraploid).

Seed weights of four of the five tetraploid cultivars were statistically separate from the two diploid cultivars and the tetraploid cultivar, ‘Petra.’

Gel electrophoretic patterns of leaf blade proteins showed sufficient uniqueness to be potentially useful for cultivar identification.

Chromosome counts of root tip cells were time‐consuming and in some instances difficult to interpret as to degree of ploidy. The most satisfactory procedure for making chromosome counts may be unique for each cultivar.

These studies illustrate the feasibility of using growth characteristics of plants grown under controlled environment conditions for cultivar identification.
Quantification of Hydrocyanic Acid in Green Forage1
Authors: Burns J. C. , Smith L. H. , Moline W. J. , Wedin W. F. , Noller C. H. , Rhykerd C. L.
Published: July 2010

A procedure is presented for the quantification of potential hydrocyanic acid (HCN) released from green tissue. This procedure is suggested in preference to qualitative procedures because resulting data can be compared among both laboratories and regions. In addition, results from qualitative procedures frequently appear incorrectly on a quantitative basis.

The procedure was evaluated for its precision and recovery. An experiment was conducted to examine method (s) of sample preservation and period (s) of sample holding and incubation prior to analysis.

Forage sealed in a polyethylene bag and immediately frozen analyzed similarly in HCN to samples stored in the dark at 26 C. Once preserved, samples were held for 6 hr prior to analysis without significant reduction in HCN levels; however, a slight reduction was noted after 3 hr.

Maximum release of HCN was obtained after samples had been incubated in ethanol for 24 hr with no significant change through 96 hr.
Inter‐row Competitive Effects of Soybean Genotypes1
Authors: Lin Chi‐chen , Torrie James H.
Published: July 2010

Inter‐row competition among soybean (Glycine max L. Merrill) genotypes was studied separately for maturity groups I and II by comparing the performance of four genotypes in each group using bordered and nonbordered plots. Two spacings between rows, 46 and 91 cm, were used during 3 years, 1965, 1966, and 1967. Seed yield, plant height, weight of 100 seeds, maturity, and lodging index were the characters investigated to study competitive effects. Differences among genotypes for yield competitive effects were found with the narrow but not the wide row spacing. These differences were greater among group I then among group II genotypes. Specific and specific ✕ genotype interactions for competition effects involving yield were‐not significant. Adjusted average competitive effects for each character and the bias for yield of each genotype in each group for each row spacing were estimated. The magnitude of these effects for seed yield suggested the need for bordered plots at the narrow but not at the wide row spacing. Adjusted average competitive effects for characters other than yield, while statistically significant in certain tests, were too small to be of any practical consequence.
Persistence of Hard Seed in Vicia Lines Derived from Interspecific Hybridization1
Authors: Donnelly E. D.
Published: July 2010

Four advanced‐generation, hard‐seeded vetch lines (Vicia sativa type) from V. sativa L. × V. covdata Wulf. were studied for persistence of the hard seed characteristic in subsequent generations. Lines differed in persistence of hard seed. Two lines produced approximately 75% hard seed over a 3‐year period whether planted from successive generations of hard seed only or from hard and soft seed as produced. Two other lines that received these same treatments averaged over the 3‐year period 26 and 30% less hard seed when hard and soft seed were planted each generation than when hard seed only were planted. Data indicated that two lines were homozygous for the gene or genes conditioning hard seed and that two lines were segregating.
Growth of Red Clover Pollen. III. Free Amino Acid Composition in Grains and Supplements to Culture Media1
Authors: Kendall W. A. , Lowe R. H. , Taylor N. L.
Published: July 2010

Samples of red clover (Trifolium pratense L.) pollen were cultured in vitro or analyzed for 21 amino acids. Pollen rated at more than 50% in germination capacity had about twice as much gamma aminobutyric acid, glycine, isoleucine, leucine, ornithine, serine, tyrosine, glutamic acid, and phenylalanirie and less proline than pollen which germinated at less than 50%. Supplements of proline, glycine, and alpha aminobutyric acid to the medium enhanced germination of pollen from plants grown in the greenhouse but not from plants grown in the field. Tube elongation of pollen from plants in the greenhouse and field was enhanced by proline and alpha or gamma aminobutyric acid supplements to the medium.
Yield Components and Leaf Characteristics Associated with the Water Requirement of Alfalfa1
Authors: Dobrenz A. K. , Cole D. F. , Massengale M. A.
Published: July 2010

Five cultivars and two experimental lines of alfalfa (Medicago sativa L.) displayed significant differences in the grams of water required to produce a gram of dry matter under controlled environmental conditions. Stem and petiole weight, leaflet weight, total forage dry weight, and leaf area were all significantly associated with the water requirement of alfalfa. Leaf thickness and palisade cell density were not associated with water requirement or total transpired water, but did differ significantly among cultivars.
Comparisons of Three Scales of Measurement of Creeping in Alfalfa1
Authors: Gray Elmer , Anderson R. E.
Published: July 2010

Percentages of plants creeping, visual estimates of spread of individual creeping plants, and measurements of spread of both creeping and noncreeping plants were compared as scales of measurement of creeping‐root development in alfalfa. In Experiment I, the scales did not differ significantly in power to detect differences in creeping among the lines. In Experiment II, percentages of plants creeping and measurements of spread were equally sensitive, and both scales were more sensitive than visual estimates of spread.
An Application of Factor Analysis to Some Breadmaking Quality Data1
Authors: Briggs K. G. , Shebeski L. H.
Published: July 2010

A factor analysis of breadmaking quality data of the hard red spring wheat cultivar ‘Manitou’ (Tritieum aestivum L. em Thell) was conducted on samples grown in two different years. For the 13 quality parameters measured, the number of factors and their component structure was different from year to year. Seven factors in 1966 and five factors in 1967 were isolated, in contrast to the four factors for quality previously reported by Wrigley and Moss (7). Similarities were apparent between some of the factors isolated in this study and those described by Wrigley and Moss as “strength,” “stability,” “hardness,” and “stiffness.” A substantial contribution to the new factors of this study was made by the quality parameters 1,000 kernel weight, bushel weight, and flour ash, which are important criteria in Canadian wheat breeding programs, and which were not considered in previous factor analysis studies.
A Genetic Study of Flowering Time in Flax1
Authors: Baker R. J. , Pesek J. , McKenzie R. I. H.
Published: July 2010

The inheritance of flowering time was studied in five crosses of flax, Linum usitatissimum L. Genotype‐environment interaction, such that early or late‐flowering gentotypes were more variable than intermediate‐flowering genotypes, was important in determining flowering time. The genetic control of flowering time proved to be multigenic with epistasis playing an important part.
An Example of Increased Recombination in Gossypium1
Authors: Lee Joshua A.
Published: July 2010

A chromosome bearing a marked segment was transferred from the diploid species Gossypium raimondii Ulb. to the teraploid species, Gossypium hirsutum L. Upon mating with the homeologous G. hirsutum chromosome, the segment gave 2.4% recombination for the two markers used. When the genes were later recombined from the repulsion phase, the recombination value increased to an average of 20.2%. This increase was attributed to accelerated recombination in homologously paired segments that appeared in the intercalary region following initial breakage.
Intermediate and Pubescent Wheatgrass Complex in Native Collections from Eastern Turkey1
Authors: Mariam Emmanuel K. , Ross James G.
Published: July 2010

Agropyron intermedium (Host) Beauv. and A. trichophorum (Link) Richt. have been distinguished on the basis of the first species having smooth glumes and lemmas, and the second being pubescent. This separation has broken down because both characters occurred within original introductions from Russia and are found even within selected varieties. This study was conducted on herbarium specimens and on progenies from plants open pollinated under natural conditions. Collections were made at 11 sites in Erzurum Valley in the vicinity of Ataturk University in Eastern Turkey to obtain information on the distribution of smooth and pubescent plants in naturally occurring colonies where the plants are native. Similar proportions of smooth and pubescent plants occurred irrespective of the location of the colonies, and segregation for pubescence occurred in families from both pubescent and smooth parents. It was concluded that the original introductions containing smooth and pubescent plants truly represented the native material and that the two taxa should be combined into a single species, A. intermedium (Host) Beauv.
Inheritance of a Seedling Marker in Agropyron repens1
Authors: Dewey Douglas R.
Published: July 2010

Almost all seedlings of Agropyron repens (L.) Beauv. contain anthocyanin pigments, but a few are pure green. Pure green plants breed true far that trait when selfed or crossed with other green plants, and the green character is recessive. Six heterozygous colored A. repens clones segregated for colored vs green seedlings in ratios approximately 3:1, 15:1, or 63:l when selfed. Segregation in F2 and testcross progenies of the colored clones was consistent with the hypothesis that seedling coloration is controlled by triplicate dominant factors. Each of the three A. repens genomes apparently contains a locus controlling pigment formation, and the presence of any one of three dominant genes leads to seedling coloration. Plants homozygous for the green character should prove to be valuable genetic stocks. Their use as female parents permits early and accurate separation of selfs from hybrids in unemasculated crosses.
Correlation of Pith Cell Death with Various Stalk Quality Characteristics in Two Synthetic Populations of Maize1
Authors: Miller Terry L. , Myers Oval
Published: July 2010

Estimates of pith cell death in the first five elongated internodes of the stalk were obtained at midsilk and 3 weeks after midsilk in two synthetic maize (Zea mays L.) populations which had undergone three cycles of recurrent selection for high and low stalk quality. Significant correlations between rating periods and the first three successive internodes indicated that rating the first three internodes at midsilk accurately estimates pith cell death for these two populations.

Four components of stalk quality, crushing strength, rind thickness, rind puncture, and weight of a 5.1‐cm internode section, were determined for both populations. Significant negative correlations were obtained between pith cell death ratings and each of the stalk quality components. Thus, internodal cell death ratings could be successfully and practically utilized in predicting stalk quality.
Pollen Production Classification in Male‐Sterile Alfalfa: Location and Observer Effects1
Authors: Barnes D. K. , Pedersen M. W. , Elgin J. H. , Axtell J. D. , Garboucheva Rada A. , Smith D. M.
Published: July 2010

A system to evaluate the amount of pollen shedding in male‐sterile alfalfa (Medicago sativa L.) was tested by observers at different locations. Flowers were tripped and visually classified as: 1 = no pollen, 2 = trace of pollen, 3 = moderate amount of pollen, and 4 = much pollen. Populations segregating for degrees of male sterility were classified for amount of dehisced pollen by observers in Utah and Minnesota. The differences in mean scores between locations were small but significant. Differences among observers within locations and the populations × locations interaction were nonsignificant.

Dehisced‐pollen scores for 31 clones with varying degrees of male sterility were recorded during the summer at Presser, Wash.; Logan, Utah; St. Paul, Minn.; and Lafayette, Ind. Small but significant location differences were noted. There were no obvious associations between climatic conditions and pollen scores. Therefore, we as. sumed that the location differences primarily were due to variations in interpretations of class limitations by observers. At three locations, no significant differences existed among sampling dates within locations. At three locations, the clones ×; sampling dates interactions were significant.

A pictorial classification description is presented to help reduce variability among observers in future studies. We suggest that a 200‐plant sample is sufficient to determine accurately the level of dehisced pollen in an alfala population.
Differential Phosphorus Uptake by Phosphorus‐Stressed Corn Inbreds1
Authors: Clark R. B. , Brown J. C.
Published: July 2010

The corn (Zea mays L.) inbreds Pa36 and WH (reported to be high and low P accumulators, respectively, when grown in soils) were tested for differences in P uptake from nutrient solutions. Phosphorus efficiency for the two inbreds was tested by inducing P stresses in two ways: 1) by varying the amount of P added to the nutrient medium, and 2) by adding varied quantities of A1 to the nutrient medium at a given level of P. The more P‐efficient inbred Pa36 took up and accumulated higher amounts of P than WH when grown separately or together with WH in the same container. Dry matter yields for WH were comparable or higher than Pa36 when grown at various levels of P, but under Al‐induced P stress conditions, Pa36 yielded higher than WH. Regardless of the method of P stress, Pa36 yielded more dry matter than WH when both inbreds were grown together in the same container. WH roots decreased the solution pH faster than Pa36 roots under all P stress conditions. The increased amount of active A1 at the lower solution pH affected WH roots more adversely than Pa36 roots. Intact Pa36 roots exhibited higher phosphatase activity than WH roots when grown at various levels of P.
Alien Chromosome Substitution—A Cause of Instability for Leaf Rust Resistance in Oats1
Authors: Sharma D. C. , Forsberg R. A.
Published: July 2010

Monosomic alien chromosome substitution was discovered in F11 to F13 lines of the oat (Avena sp.) cross, derived‐tetraploid C.I. 7232 (2n=28) ✕ Avena sativa L. cv. ‘Clarion’ (2n=42). Transmission of 21‐chromosome alien substitution gametophytes through the male and female at differential frequencies of 0.0 and 39.0%, respectively, was responsible for lack of homogeneity for resistance to leaf rust (Puccinia coronata Cda. f. sp. avenae Fraser & Led.). Cytological examination of alien addition (21″ + 1′A), monosomic alien substitution (20″+1′+1′A), and monosomic susceptible plants revealed that the alien chromosome, which carries the gene(s) for resistance from the diploid progenitor, is submetacentric and the replaced A. sativa chromosome is metacentric.
Combining Ability for Eight Characters of a Four‐Parent Diallel Cross in Vernonia anthelmintica (L.) Willd.1
Authors: Lai W. Y. , Lessman K. J.
Published: July 2010

A diallel set consisting of all combinations of four parents, F1 and F2, and reciprocals of Vernonia anthelmintica (L.) Willd. showing diverse phenotypes were grown at West Lafayette, Indiana. The study was aimed at elucidating the inheritance of eight traits: days to first bloom, plant height, days to harvest, plant weight, primary branch number, heads per plant, clean seed weight, and percent oil.

Combining ability analyses showed that effects of general combining ability were highly significant for days to first bloom, plant height and days to harvest in F1 and F2, and significant for plant weight and percent oil in F2, suggesting the major portion of total genetic variation was additive in nature. Specific combining ability was highly significant only for days to first bloom and plant height in F1. General reciprocal effects were highly significant for days to first bloom in both F1 and F2, significant for plant height, days to harvest, and heads per plant in F2, while specific reciprocal effects were significant for primary branch number in F1, significant for days to first bloom, and highly significant for days to harvest in F2.
Variability in Leaf Anatomy in Primitive and Commercial Stocks of Cotton1
Authors: Morey P. R. , Quisenberry J. E. , Roark B.
Published: July 2010

The comparative anatomy of the uppermost leaf having near‐complete lamina expansion was studied in primitive and commercial stocks of Upland cotton (Gossypium hirsutum L.). Significant between‐stock variation for lamina thickness and palisade height occurred when plants were two months old and later when these same plants were six months old. Leaves formed when plants were six months old had a thicker lamina, a taller palisade layer, and wider palisade cells than leaves from twomonth‐old plants.
Stomatal Length, Frequency, and Distribution in Bromus inermis Leyss I1
Authors: Tan Geok‐Yong , Dunn G. M.
Published: July 2010

Octoploid (2n = 56) bromegrass (Bromus inermis Leyss.) had significantly larger but fewer stomata than tetraploid (2n = 28) plants at all leaf positions sampled and on both leaf surfaces. Both ploidies showed a similar pattern of stomatal length and frequency at four positions on the culm and three positions on the individual leaf. Stomatal length increased and frequency decreased progressively from the top (LI) to lower (IA) leaves. The tip of the leaf had the largest but fewest number of stomata with the reverse for the base of the leaf.

Seven bromegrass cultivars within the octoploid level differed significantly in stomatal length and frequency of adaxial and abaxial surfaces and at five different leaf positions on the culm. ‘Carlton’ and ‘Blair’ had consistently smaller stomata with greater frequency, whereas ‘Saratoga’ and ‘Red Patch’ had larger, but fewer, stomata. Stomatal length increased while frequency decreased from L1 to L3 and leveled off from L3 to L5 (fifth leaf below panicle). Varietal differences in stomatal length and frequency were mainly associated with the center position of a leaf surface.

Correlations between the adaxial and abaxial surfaces of L1 showed highly significant positive values for both stomatal length and frequency. Stomatal length and frequency were negatively associated at either surface of LI. The ratio length ✕ frequency was affected more by stomatal frequency than length on the same leaf surface. The interrelationships among stomatal and leaf characters and tiller dry weight suggested that a cultivar with lower stomatal frequency is likely to have larger stomata, longer and wider leaves, and greater dry weight/tiller.
Effect of Root Genotype on Shoot Water Relations in Soybeans1
Authors: Sullivan T. P. , Brun W. A.
Published: July 2010

The maintenance of adequate water relations in the above ground portions of plants is partially determined by the effectiveness of water absorption by the root system. The object of this study was to determine if reportedly different soybean [Glycine max (L.) Merr.] root types differ in ability to maintain leaf water potential, stomatal opening, the photosynthesis in a genetically common top. ‘Chippewa 64’ tops were grafted to rootstocks of four different genotypes (‘Aoda,’ PI 79648, ‘Chippewa 64,’ and ‘Harosoy 63‘) when in the seedling stage. Grafted plants were subjected to water stress at three stages of development. Symptoms of water stress were more severe in Chippewa 64 scions grafted on Aoda and PI 79648 rootstocks than in those grafted on Harosoy 63 and Chippewa 64 root stocks. These effects become increasingly evident during flowering and pod filling. When stressed during pod filling, Chippewa 64 tops grafted on Aoda and PI 79648 rootstocks snowed significantly higher stomatal resistances and lower leaf water potentials and photosynthetic rates than did Chippewa 64 tops grafted on Harosoy 63 and Chippewa 64 rootstocks.
Regeneration of Ryegrass Plants in Tissue Culture1
Authors: Ahloowalia B. S.
Published: July 2010

Ryegrass plants (Lolium spp.) were regenerated in callus cultures induced from triploid (2n = 21) embryos. Developing seeds from diploid Χ tetraploid and reciprocal crosses were cultured on i) Bacto‐Orchid agar and ii) modified medium of Niizeki and Oono containing 1.5 mg 2,4‐dichlorophenoxyacefic acid (2,4‐D); 6.5 mg indoleacetic acid (IAA); and 0.25 mg zeatin/liter.

Of the 219 seeds cultured, 10% formed triploid callus and 35% produced triploid and near‐triploid (2n = 19, 20, 22) plants. The calli differentiated root and shoot primordia on modified Murashige and Skoog RM medium containing 1.5 mg 2,4‐D; 6.5 mg IAA; and 2.15 mg kinetin/liter. Addition of 1 ml coconut milk, with or without 2 mg IAA and 2 mg zeatin/liter, to the medium stimulated chlorophyll development in the calli. Subsequent culture of these calli on half‐strength Murashige and Skoog RM medium containing 0.75 mg 2,4‐D; 3.25 mg IAA; and 1.075 mg kinetin/liter produced numerous normal and a few albino plants. The calli maintained for 18 months stayed totipotent through eight subcultures. Callus suspensions formed roots in liquid medium conraining 0.05 mg/liter each of IAA and kinetin. Cell suspensions plated on half‐strength RM medium with 2,4‐D; IAA; and kinetin, developed colonies which included elongate and spherical parenchymatous cells, cells with bipolar axis, vacuolated hair‐like cells, etc., of varying size.

The established procedures permitted a rapid regeneration of xyegrass plants in large numbers through tissue culture and hold potential for chromosome manipulation and selection at cell level.
Direct and Indirect Mass Selection for Grain Yield in Bulk Oat Populations1
Authors: Geadelmann J. L. , Frey K. J.
Published: July 2010

One cycle of direct mass selection was conducted separately for heading date, plant height, grain yield, width/seed, weight/seed, and spikelets/panicle of oats (Avena sativa L.). One cycle of indirect mass selection for grain yield was also conducted in each of the remaining five traits and weight/primary panicle. Selection was practiced among 1,500 random, nearly‐homozygous lines grown at two levels of interplant competition, and was bidirectional with selection intensities corresponding to 10 and 30%.

Variations of basic hill‐plot technique simulated the two selection environments, noncompetitive (one oat seed sown/hill) and competitive (1 oat seed plus 30 barley seeds sown/hill). Hill plots sown with 30 oat seeds/hill simulated planting arrangements common to commercial practice and provided a standard by which gains from mass selection were determined.

Direct mass selection was effective for each trait. Actual gains ranged from 15 to 83% of gains predicted from selection among line means in replicated trials. Selection for heavy primary panicles was the most effective method of indirect mass selection for grain yield. In general, the level of interplant competition had little effect on gains from mass selection. Considerations of technique and monetary costs seem of greater importance than interplant competition in the choice of an environment for mass selection in oats. Environmental effects on genotypic expression of grain yield were not sufficiently large to prevent improvement of this trait by mass selection at either level of interplant competition.
Genetic Nature of Resistance in Corn to Yellow Leaf Blight1
Authors: Mukunya D. M. , Boothroyd C. W. , Grogan C. O.
Published: July 2010

Different corn (Zea mays L.) inbreds and hybrids with normal cytoplasm (N) and similar inbreds with Texas (Terns) and other male sterile cytoplasms were compared for their reaction to Phyllosticta yellow leaf blight. Considerable resistance was found in some of the corn inbreds and hybrids tested. The resistance was found to be influenced by both cytoplasmic and nuclear factors. Plants with Tcms cytoplasm were the most susceptible, while C, J, and R types of cytoplasm seemed highly resistant. The reaction of offspring derived from a cross between susceptible and resistant normal inbreds indicated existence of at least one dominant gene pair for resistance to yellow leaf blight.
Herbicide Influence on Arrowleaf Clover Seedling Establishment1
Authors: Smith A. E.
Published: July 2010

The chlorophenoxy and benzoic acid herbicides are used extensively for the control of pasture weeds. The increasing importance of legumes to the pasture ecosystem has made it necessary to determine the influence of these herbicides on certain forage species. The purpose of this study was to determine the influence of chlorophenoxy and benzoic acid herbicides on ‘Amclo,’ ‘Yuchi,’ and ‘Meechi’ arrowleaf clover (Trifolium vesiculosum Savi.) germination and seedling development. The experiments were conducted in a programmed germinator and the greenhouse.

Increasing 2,4‐D [(2,4‐dichlorophenoxy)acetic acid] concentration decreased the percent germination of Yuchi. Whereas, 750 ppb 2,4,5‐T [(2,4,5‐trichlorophenoxy)acetic acid] and MCPA ([(4‐chloro‐v.tolyl)oxy]acetic acid) 500 ppb 2,4‐DB[4.(2,4‐dichlorophenoxy)butyric acid] adversely influenced the seed germination of Yuchi, Amclo, and Meechi, respectively.

The lowest concentration (63 ppb) of all herbicides except 2,4,5‐T reduced radicle development on all three cultivars. The 63 ppb treatment of 2,4,5‐T stimulated radicle development on Meechi and Yuchi. The order of increasing influence of these herbicides on seedling establishment was 2,4‐DB < 2,4,5‐T = 2,4‐D < MCPA = dicamba [3,6‐dichloro‐o‐anisic acid].
Relative Quantity and Biological Activity of Saponins in Germinated Seeds, Roots, and Foliage of Alfalfa1
Authors: Pedersen M. W.
Published: July 2010

Alfalfa (Medicago sativa L.) saponin was studied in germinated seeds, foliage and roots, and root fractions by bioassay with Trichoderma. Toxicity to Trichoderma increased rapidly for the first 48 hours and at a much slower rate up to 192‐hour germination and seedling growth. ‘DuPuits’ and ‘Lahontan’ were similar. Tests with Trichoderma showed that foliage saponin of DuPuits was more toxic than foliage saponin of Lahontan, but root saponins of the two cultivars were similar in toxicity and much more toxic than foliage saponin. Saponin was concentrated in the outermost layer of the cortex of the root and decreased inwardly without evidence of saponin in the stele.
Inheritance of a Chlorophyll Deficiency in Diploid Alsike Clover1
Authors: McConnell R. L. , Townsend C. E.
Published: July 2010

Inheritance of a variegated chlorophyll deficiency in diploid alsike clover (Trifolium hybridum L.), was determined under greenhouse conditions. The variegated character was first observed in the S2 progeny of a normal green S1 clone. The S2 progeny segregated 9 green: 7 variegated plants. Reciprocal F1 progenies of this S1 clone and another S1 clone whose S2 progeny was normal green in color, were green also. The F2 data fit phenotypic ratios of 9 green: 7 variegated plants or 3 green: 1 variegated plant depending upon the genotype of the F1 parent. F2 intercross progenies were grown to confirm the F2 segregations and to assign genotypes to several F2 plants.

Two recessive genes controlled the chlorophyll deficiency. The homozygous recessive conditions for either pair or both pairs of allcles produced the variegated character and the gene symbols v1 and v2 were suggested for the two loci.
Lattice Designs for Unreplicated Yield Trials of Maize Varieties at Several Plant Densities1
Authors: Cornelius P. L. , Byars J.
Published: July 2010

The analysis of lattice designs with varieties showing a linear response to levels of some factor confounded with replications is described and illustrated with a hypothetical example. The theory is applied to a 7✕7 quadruple lattice maize (Zea mays L.) variety trial with replications of the lattice planted at different plant densities. A linear regression model is used which assumes that the yield of each variety expressed as log (yield/plant) responds linearly to plant density. In a manner analogous to ordinary lattice designs, corrections for block differences to be applied Jo variety means and regression coefficients are obtained. Two methods of adjusting for variable stands, viz., covariance analysis with deviation from average stand at) a given plant density level as the covariable (Method I) and adjustment of the raw data using preliminary estimates of the variety regression coefficients (Method II), are suggested and compared with a generalized least squares solution (Method III). Method III is the theoretically correct procedure but we consider it impractical for large experiments. Both Methods I and II gave good approximations to the results for Metlfod III.

The experiment showed significant differences among variety means and among variety regression coefficients. Information on varietal response to plant density is obtained at the cost of very little loss of precision on variety means. It is suggested that for equivalent varietal replication more comprehensive yield trial data could be obtained by evaluation at more plant density levels with less (or possibly no) replication ot each density.
Cytological Characteristics and Nuclear DNA Bouyant Densities of Corn, Teosinte, Tripsacum, and Corn‐tripsacum Hybrids1
Authors: Levings C. S. , Timothy D. H. , Hu W. W. L.
Published: July 2010

This study assesses the variability in buoyant density of nuclear DNA (nDNA) of corn and its relatives and the effect of several cytological phenomena on the demity of nDNA. The nDNAs of four Tripsacum L. spp., corn (Zea mays L.), annual teosinte (Z. mexieana [Schrad.] Kuntze), perennial teosinte (Z. perennis [Hitchc.] Reeves and Manglesdorf), and corn‐tripsacum hybrids were characterized for buoyant densities. Corn and perennial teosinte nDNA densities were similar but were significantly greater than those of tripsacum and annual teosinte. The latter two did not differ in densities. The corntripsacum hybrid densities resembled those of the higher parent. However small significant differences in parental base composition did not preclude hybridization. In all cases, and typical of grasses, nDNAs were resolved as single bands without satellites and with relatively high guanine and cytosine contents.

Chromosome numbers of T. andersonii Gray, in ed., Guatemala grass, are reported for the first time (2n = 64). Chromosomal knob numbers of 12 Tripsocum accessions ranged from 0 to 40. One Tripsacum accession had 3 to 4 B chromosomes. The presence of chromosomal knobs and B chromosomes in tripsacums had no effect on the banding pattern and buoyant density of the nDNAs as determined by neutral CsCI analytical eentrifugation.

Although similarities and significant differences in buoyant densities of nDNA were found among corn and its relatives, the value of these results for establishing genetic relationships is not clear.
Anther Culture of Triticale1
Authors: Ono H. , Larter E. N.
Published: July 2010

Anthers from three strains of triticale (X Triticosecale Wittmack) were cultured on B5 and Blaydes' basic media containing various concentrations and combinations of sucrose, 2,4‐D indole‐3‐acetic acid (IAA), kinetin, amino acids, and coconut milk. The three strains of triticale reacted differentially in their development of callus in vitro although the percentages were low for each. The highest response (4.0%) was obtained with anthers of ‘Rosner’ cultured on B5 medium with 10% sucrose and supplemented with 2 rag/liter of IAA, kinetin, and 2,4‐D. Of a total of 9,246 anthers cultured from the three strains of triticale, 80 calluses were transplanted to differentiating medium. From this population, seven haploid (n = 21) albino plantlets developed.
Performance of Reciprocal Soybean Hybrids1
Authors: Wilcox J. R. , Simpson A. M.
Published: July 2010

Two high protein (51.3 to 52.6%), low oil (14.9 to 15.4%), poorly adapted soybean (Giycine max (L.) Merr.) strains were crossed reciprocally with three well adapted, high yielding soybean strains of average protein (39.3 to 41.2%) and oil (23.5 to 24.0%) contents. Data were corded on maturity date, mature plant weight, seed yield, harvest index, and seed protein and oil percentages of parents and reciprocal F1's. Maturity date, plant weight, seed yield, and seed protein and oil percentages of the Fl's were intermediate to the parental values. Even though the parents used in these crosses differed widely in all characteristics except harvest index, there was no evidence of cytoplasmic effects for any trait evaluated.
Light and Temperature Controls of Dormancy and Germination in Bentgrass Seeds1
Authors: Toole Vivian K. , Koch E. James
Published: July 2010

Germination on a two‐way thermogradient plate indicated a temperature range for intensive study of alternating temperatures in germination chambers for ‘Emerald’, ‘Penncrow’, and ‘Seaside’ cultivars of A. palustris and for ‘Astoria’ and ‘Bardot’, but not ‘Highland’ cultivars of A. tenuis. Studies of the seeds subjected to reciprocal periods on the low and high parts of daily temperature cycles showed that optimum temperature alternations depended on the length of exposure to the higher temperature of the cycle. Germination for all cultivars, except Highland, were not significantly different from maximum germination in an incubation regimen of 15 C for 16 hours alternated with 25 C for 8 hours daily. Emerald, Penncross, and Seaside required red light during the 25 C part of the cycles for optimum germination. For optimum germination, Highland required 1 to 2 hours at 30, 35, or 40 C alternated with 23 and 22 hours at 15 C and light.

Germination of all cultivars was under phytochrome control. Astoria and Bardot required a red light treatment at marginal temperatures, but not at the optimum temperatures. All other cultlvars required red light to germinate at the optimum temperatures. Response to light showed the typical reversible phytochrome reaction
Soybean Harvest Index in Hill‐Plots1
Authors: Buzzell R. I. , Buttery B. R.
Published: July 2010

Seed and plant weight of mature soybeans (Glycine max (L.) Merr.) were measured in hill‐plots to determine if the evaluation of harvest index (seed yield/mature plant dry weight) by a micro‐plot technique would be useful as a selection criterion. Harvest index did not change in response to increasing plant population within hills. Thus, screening can not be carried out in this manner to obtain cultivars which would maintain a high harvest index under high plant density in row culture. Furthermore, harvest index was negatively associated with yield and maturity, and appears to be of little value as an indicator of yielding ability.