bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epistatic and Other Genetic Variances in Two Varieties of Maize1
Authors: Eberhart S. A. , Moll R. H. , Robinson H. F. , Cockerham C. C. 
Published: July 2010

We obtained full‐sib and half‐sib covariances in two open‐pollinated varieties of maize, ‘Jarvis’ and ‘Indian Chief,’ from families derived from both inbred and noninbred parents. These covariances provide estimates of additive, dominance, and certain estimable functions of epistatic variances, and are useful to investigate the relative importance of the different types of genetic variation in these varieties.Seven characters were studied in both varieties, and no evidence of epistatic variance was noted except possibly for yield in Indian Chief. During development of the random inbred lines natural selection increased ear number and yield in both varieties. It may also have reduced the total genetic variance for characters that showed no change in the mean.Both the observed and “expected” standard errors were smaller for estimates of variance components obtained from the Design II than from the Design I experiments. Observed standard errors of the experimental error variances were larger than “expected standard errors” for both Designs.Additive variance appeared to account for the largest proportion of the total genetic variance for all characters in both varieties. Hence, recurrent selection should be effective in improving these varieties.
Mass Selection for Plant Height in Oat Populations1
Authors: Romero G. E. , Frey K. J. 
Published: July 2010

The effectiveness of mass selection for uniform plant heights in a heterogeneous and segregating oat population was evaluated.The mass‐selection procedure consisted of clipping the panicles of the bulk population of plants to a uniform height equivalent to the height of the panicle tips of ‘Cherokee’ oat variety. At maturity, only the top 4 inches of the clipped plots were harvested. The procedure was repeated for 4 consecutive generations (F3 ‐ F0). Check populations originating from the same material, but receiving no artificial selection pressure, were grown each year. Remnant seeds of each generation of the check and mass selected populations were kept in cold storage for future studies.In 1962, 500 randomly selected seeds from each of the 5 check populations (F2 ‐ F6), from each of the 4 mass‐selected populations, (F3 ‐ F6) and from a pure line, were space planted in the field. At maturity, the surviving plants were harvested individually. In 1963, the progenies from 75 random lines (a line was derived from a spaced plant in 1962) from each of the 10 populations were sown in a randomized block experiment with 4 replications. The attributes measured were plant height, heading date, and grain yield.The mass‐selection procedure was successful in reducing the mean plant height and the genetic variance of the oat population. In the check population the plant height increased. Mean heading date of the mass selected population was shifted earlier and the mean grain yield higher by the mass selection procedure.Positive phenotypic and genetic correlations were found between plant height and heading date and between heading date and grain yield, whereas, the corresponding correlations between plant height and grain yield were negative.
Genetics of Medicago sativa L. I. Inheritance of Dwarf Character, Dw11
Authors: Busbice Thad H. , Wilsie C. P. 
Published: July 2010

Cytological studies have indicated that alfalfa is a tetraploid. Recent reports have suggested that it behaves genetically and cytologically as an autotetraploid. The hypothesis, that meiosis in alfalfa is identical to that expected of an autotetraploid displaying random chromosome segregation, was tested by observing the segregation for dwarf plants in a source of plant material from Medicago sativa L.Dwarf phenotype was found to be controlled by a single recessive gene, inherited tetrasomically. The symbols Dw1 and dw1 were proposed for dominant and recessive forms of the gene at this locus.The conclusion was based upon a positive test for tetrasomic inheritance. Fifty‐three normal plants, from the self progeny of a plant that segregated 3 normal:l dwarf upon selfing, were analyzed genetically by test crossing. Dwarf plants were homozygous recessive and were used as male testcross parents. Upon testcrossing, 52 of the 53 normal plants segregated with ratios that could likely occur only under tetrasomic inheritance.There were significant deviations from the expected 5:1 ratio in testcross progenies of plants assumed to be duplex. Preferential pairing of chromosomes was considered the most likely cause of these deviations, but differential transmission of gametes could not be ruled out. If preferential pairing occurred, this would indicate that alfalfa deviates from true autotetraploid behavior in the direction of allotetraploid behavior.
Rate of Change of Lodging Resistance, Yield, and Test Weight in Varietal Mixtures of Oats, Avena sativa L.1
Authors: Grafius J. E. 
Published: July 2010

Two varieties of oats (Arena sativa L.) ‘Simcoe’ and ‘Rodney’ were mixed in 10% incremeuts with ‘Garry’ and planted at two locations in Michigan. The resulting curves relate percentage mixture with percent lodging, yield, and test weight. On the basis of these curves both the slope and the shape of the curve relating percentage mixture to the response to stress are shown to be important factors in determining the success of a multi‐line variety. The slopes and the shapes of the curves for the three traits examined indicate that a 40:60 percent mixture of Rodney and Garry would be advantageous. Some mixtures are detrimental as witnessed by the curve for yield for the Simcoe mixture which dropped off rapidly in a nonlinear fashion when quite small amounts of Simcoe were added to Garry.In general, some mixtures may tend to inhibit pathogens and favorable mixtures can be found for lodging, test weight, and yield in oats. It is worth noting that the proportions of each line in a mixture may be quite important. In all probability, the success of a multi‐line variety will depend upon how carefully the varieties going into the mixture are chosen and how much consideration is given to the optimum proportions of each line. The random mixing of pure line varieties is likely to produce multi‐line varieties having expected values which are estimates of the mean values of the pure line varieties.
Genetics of Medicago sativa L. II. Inheritance of Dwarf Character, DW21
Authors: Busbice Thad. H. , Wilsie C. P. 
Published: July 2010

A previous report described the inheritance of a dwarf mutant in a source of Medicago sativa L. designated source A. A second source of dwarf mutants was discovered in the ‘DuPuits’ variety and was designated source B. The expression of dwarf phenotype was found to be controlled by nonallelic genes in the two sources. The mode of inheritance of dwarf phenotype in source B was investigated.A recessive gene inherited tetrasomically was found to condition dwarf phenotype in source B. A positive test for tetrasomic inheritance was made through the genetic analysis of the self‐progeny of a simplex plant. The self‐progeny of the simplex plant contained 1/4 duplex plants + 1/2 simplex plants + 1/4 nulliplex plants. This zygotic array could occur only under tetrasomic inheritance. Some evidence of preferential pairing of chromosomes was found.The symbols, Dw2, and dw2, were suggested for the dominant and recessive alleles, respectively, for this gene conditioning dwarf phenotype.
Cross‐Pollination in Sericea Lespedeza1
Authors: Cope Will A. 
Published: July 2010

Percent crossing was determined in two populations of Lespedeza cuneata for 3 years and in one population for 2 years. A simply inherited, partially recessive, low tannin character served as the genetic marker for identifying hybrids.Chasmogamous seed production ranged from 10 to 38% of the total among populations and years. Percent crossing in chasmogamous flowers ranged from 16 to 43%, and percent crossing for total seed ranged from 2 to 13%.Plant to plant variation in percent crossing was highly significant, but the crossing percent of individual plants was not consistent from year to year, indicating a large environmental effect relative to genetic. The nature of the environmental effect is unknown, but may be related to the size and activity of the natural pollinator bee populations.Crossing percent in sericea may often be too low for one generation of crossing inbred lines to be effective to utilize heterosis. A breeding program should be designed for several consecutive generations of intercrossing for seed production.
Ash and Energy Content of Material From Seven Forage Grasses1
Authors: Hunt L. A. 
Published: July 2010

Ash and energy determinations were carried out on material from vegetative stands of seven species of temperate forage grasses grown in boxes in a glasshouse.The mean ash content of the young leaf laminae (9.7%) was less than that of the mature laminae (11.1%) and sheaths (11.8%). Additionally, there was a significant variation among species in the ash content of the mature laminae. The energy content of the young laminae (4,415 cal/g) was greater than that of the mature laminae (4,290 cal/g) and sheaths (3,935 cal/g). There were no differences in the energy content of leaf material from the various species.A factor of 4,300 cal/g dry weight is suggested as suitable for converting data from well fertilized vegetative stands of temperate forage species to an energy basis. With material from soils of different fertility, however, the conversion should be based on ash‐free material. for such purposes, a factor of 4,900 cal/g ash‐free dry weight is suggested as suitable.
Managerial and Physiological Factors Influencing the Winter Hardiness of Barley in Wyoming1
Authors: Young A. L. , Feltner K. C. 
Published: July 2010

The environmental factors air and soil temperature and soil moisture were monitored as they influenced the crown sugars glucose, fructose, and sucrose in three varieties of winter barley planted on two fall dates.‘Dicktoo’ (winter hardy), ‘Reno’ (intermediate), and ‘Tennessee Winter’ (nonhardy) were planted on August 25 and September 10, 1964, at Laramie, Wyoming. Crown tissue was periodically collected (from October 17, 1964, to May 1, 1965) and analyzed for sugar content.Later planting enhanced winter survival of Dicktoo and Tennessee Winter, but did not appreciably influence Reno. In Dicktoo, fructose was the major alcohol‐soluble sugar during the fall and early winter, decreased during the late winter, and disappeared at time of spring regrowth. Glucose and sucrose content increased in the late winter and decreased at time of spring regrowth. Fructose content in crowns of Tennessee Winter was significantly lower than in the other varieties, although the trend with time was similar in all varieties. Only small amounts of glucose and sucrose were present in the Tennessee Winter variety at any given collection date.The important factor in survival of the nonhardy Tennessee Winter variety was apparently soil moisture at the 3‐inch depth and fructose content, while in Dicktoo it was low soil and air temperature and its influence upon the synthesis of total alcohol‐soluble sugars.
Effect of Metal Cations on Aldolase from Leaves of Zea mays L. Seedlings1
Authors: Clark Ralph B. 
Published: July 2010

Aldolase prepared from 7‐ to 10‐day‐old Zea mays L. leaves was assayed for its response to metal cations. Monovalent cations at concentrations up to 0.2 M and divalent cations at concentrations up to 0.04 M had no stimulatory effect on aldolase activity. Aldolase was completely inhibited by Zn++ and Co++ at 0.04 M, 60% by Fe++ 20% by Mn++, and 0% by Ca++ or Mg++. It was inhibited slightly by NH4+ above 0.1 M, but not by K+ Rb+, Cs+, Li+, or Na+. Cyanide and a,á‐dipyridyl were inhibitory to aldolase above 5 × 10−3 M, but ethylenediaminetetraacetic acid, 2,3‐dimercapto‐l‐propanol, and pyrophosphate were not. ο‐Phenanthroline inhibited aldolase below as well as above 5 × 10−3 M.Aldolase was also prepared from corn seedlings grown 14 days in complete, minus‐K, and minus‐Zn nutrient solutions. Aldolase activity was lower in preparations from K‐ and Zn‐deficient plants than in preparations from nondeficient plants. K+ and Zn++ added in vitro to aldolase from K‐ and Zn‐deficient plants did not stimulate the enzyme. The reduced aldolase activity found in mineral‐deficient plants was attributed to reduced protein synthesis rather than to a requirement for metal cations for aldolase activity.
Change in Carbohydrates in Alfalfa (Medicago sativa L.) Roots During the Period of Floral Initiation and Seed Development1
Authors: Dobrenz A. K. , Massengale M. A. 
Published: July 2010

Alfalfa plants grown under field conditions at Tucson, Arizona, were used to investigate the change in acidhydrolyzable carbohydrates, glucose, fructose, sucrose, and starch stored in the roots during the time of floral initiation and seed development at three different seasons of the year.Acid‐hydrolyzable carbohydrates and starch reached their lowest level in the roots more rapidly in plants that were cut in June and August as compared with plants that were cut in April to begin growth for seed production. Floral initiation and development also occurred earlier during the June and August growth periods. This early reduction in stored reserves coincided with early floral initiation and development. The concentration of glucose, fructose, and sucrose was quite low in alfalfa roots during all growth periods. Positive and significant association existed between the concentration of specific carbohydrate fractions in alfalfa roots during the first three weeks after forage removal and seed production, number of pods per stem, number of seeds per pod, and percentage pod set.
Heritabilities of Quantitative Attributes of Oats (Avena sp.) at Varying Levels of Environmental Stress1
Authors: Johnson G. R. , Frey K. J. 
Published: July 2010

We grew 27 oat cultivars at 3 levels of soil nitrogen, 4 levels of soil phosphorus, and 3 planting dates to examine the reactions of several agronomic characters to degrees of environmental stress. Each environmental factor was varied in a separate experiment. The experiments were grown in split‐plot designs in which wholeplots were levels of the environmental variables and subplots the cultivars planted in hills spaced 1 foot apart in perpendicular directions.The degree of stress imposed by a certain level of environmental factor was measured by the relative productivity of the attribute in question. For most attributes, stress was reduced with increasing increments of nitrogen and phosphorus and with earlier plantings. However, adding nitrogen increments increased the stress for 100‐seed weights, and early planting increased stress for number of spikelets per panicles and 100‐seed weights. Intraplant competitive, caused by the increased numbers of panicles produced per plot when nitrogen was applied or the oats were planted earlier, may have induced stress on spikelet and seed development.In general, genotypic variances among the oat cultivars increased as the environmental stresses were reduced. Environmental variance, however, also tended to increase so that heritabilities did not always increase with reduced environmental stress.
Sunflower Development at Latitudes Ranging from 31 to 49 Degrees1
Authors: Robinson R. G. , Bernat L. A. , Geise H. A. , Johnson F. K. , Kinman M. L. , Mader E. L. , Oswalt R. M. , Putt E. D. , Swallers C. M. , Williams J. H. 
Published: July 2010

Sunflower (Helianthus annuus, L.) varieties were planted May 14, 1965, at nine locations in central North America ranging from 31 to 49° north latitude. Second plantings were made at four locations to study the effect of planting date.Seed was soaked before planting and irrigation and fertilizer were used where needed to minimize location differences in water imbibition by seed, soll moisture, and soil fertility.In plantings made May 14, the growth periods ‐ planting to emergence, emergence to ray flowers, and planting to ray flowers ‐ increased greatly from south to north each degree of latitude northward, days from planting to ray flowers increased on the average nearly 2 days. Whether growing degree‐days from planting to ray flowers decreased, varied about an average, or increased from south to north was dependent upon the temperature base chosen. Heights and leaves per plant showed no trend associated with latitude. The lengthening of the three periods of growth from south to north may have been due to temperature gradient rather than photoperiod, since leaves per plant showed no trend associated with latitude. However, daylight durations for the northern and southern locations were only about 16 and 14 hours, respectively, when photoperiod effects occurred.When practical dates of planting for the locations were compared, i.e., April 5 at 31° latitude and May 14 at 49° latitude, daylight duration when photoperiod effects occurred was about 13 hours in the south and 16 in the north. Under this range of photoperiod, three closely related inbreds ‐ ‘HA6,’ ‘HA7,’ and ‘HA43’ ‐ responded morphologically like short‐day plants. Therefore, when such inbreds are used for hybrid seed production, latitude and planting date are important considerations.
Effects of Freezing and Mechanical Injury on Viability of Sorghum Seed1
Authors: Kantor D. J. , Webster O. J. 
Published: July 2010

Our purpose was to determine the effect of freezing temperatures on the viability of sorghum seed at different moisture levels and the damage to seed which may result from threshing.Viability of sorghum seed with a moisture content of less than 40% was not reduced when the seed was frozen for 12 hours at 1.7 or 0 C (29 or 32 F). The damage to seed with 35% moisture or higher increased with the duration of the freezing period when frozen at 3.3 C (26 F). The results from the two years indicate that the mid‐twenties is a critical temperature for causing injury to seed with an excess of 20% moisture.Increased cylinder speeds of the thresher not only increased, the percentage of cracked seed, but also reduced the germinability of ‘sound’ seed and increased the percentage of abnormal seedlings. Injury also increased as the moisture content of the seed increased. Abnormal seedlings are probably due to injury to the radicle and plumule in the dormant embryo.
A Bioassay for Alfalfa Saponins Using the Fungus, Trichoderma viride Pers. ex Fr.1
Authors: Zimmer D. E. , Pedersen M. W. , McGuire C. F. 
Published: July 2010

Extracted alfalfa saponins and leaf meal extracts from alfalfa influenced the growth rate of some fungi more than others. Of seven fungi whose growth rate was studied on media to which different concentrations of extracted alfalfa saponins or Leeben, a commercial saponin, were added, only Trichoderma viride was fonnd highly sensitive at concentrations below 1 mg of saponin per milliliter of medium.A correlation coefficient of —0.952** was found between the growth of T. viride on 2% potato‐dextrose‐agar containing leaf meal extracts from 36 F1 and S1 plant families and saponin percentage. This, together with a correlation coefficient of —0.922** between the growth of T. viride on media containing leaf meal extracts from individual alfalfa plants and saponin percentage, suggests the use of T. viride for bioassays for saponins.
Effect of Second‐Brood European Corn Borer Infestation on 45 Single‐Cross Hybrids1
Authors: Scott Gene E. , Guthrie W. D. , Pesho G. R. 
Published: July 2010

Plots of corn artificially infested with second‐brood corn borer egg masses were compared with plots treated with an insecticide to prevent infestation. Our studies were conducted to determine if the resistance of inbreds would be expressed in hybrids and if the present level of resistance was sufficient to prevent serious yield losses.Resistant ✕ resistant crosses were reduced in yield by second‐brood corn borer damage on the average slightly less than 4%, but the susceptible ✕ susceptible crosses were reduced in yield by 12%. Corn borer infestation decreased yield and the moisture content of the grain, but increased stalk lodging and ear droppage. The number of cavities per plant, which we used as a direct measure of resistance, increased with the susceptibility of the inbreds in the single crosses.
Cytogenetics of Crested Wheatgrass Triploids1
Authors: Dewey Douglas R. , Pendse P. C. 
Published: July 2010

Meiosis and fertility were studied in triploids derived from diploid Agropyron cristatum, 2n=14; tetraploid A. desertorum, 2n=28; and A. cristatum ✕ A. desertorum crosses. Chromosome associations in autotriploid A. cristatum averaged 4.39 I. 4.51 II, and 2.53 III in 278 meta phase‐I cells. Trivalent associations were less common in autotriploid A. cristatum than in other known Gramineae autotriploids. Triploid A. desertorum averaged 3.88 I, 4.20 II, and 2.91 III in 116 cells at metaphase I. The A. desertorum genomes appeared to be essentially homologous except for a possible inverted segment in one chromosome and cryptic structural differences. The A. cristatum ✕ A. desertorum triploid averaged 2.43 I, 3.50 II, 3.10 III, 0.53 IV, and 0.03 V in 70 metaphase‐I cells. The A. cristatum and A. desertorum genomes apparently differ from one another by several structural chromosome rearrangements including interchanges and inversions.Diploid A. cristatum, triploid A. cristatum, tetraploid A. desertorum, triploid A. desertorum, and A. cristatum ✕ A. desertorum triploids were represented by genome formulas of CC, CCC, C1C1C1C1, C1C1C1 and C1C1C1, respectively. Although A. desertorum is an apparent autotetraploid, it appears doubtful that it originated directly from the only known form of diploid A. cristatum.Although A. cristatum and A. desertorum differ in ploidy level and morphology, they contain the same basic genome and do not appear to be distinctly different species. It is suggested that A. desertorum and all other crested wheatgrass be designated as subspecies and varieties of A. cristatum. Grass breeders are advised to consider all crested wheatgrasses, regardless of ploidy level, as a single breeding population.
Effects of Different Gene‐Cytoplasm Systems on Quantitative Characters in Reciprocal F2 Crosses of Maize (Zea mays L.)1
Authors: Crane Paul L. , Nyquist W. E. 
Published: July 2010

The inbred WF9 genotype was incorporated into 41 diverse cytoplasms by backcrossing 4 times. Cytoplasmic donor lines were thus formed with largely WF9 genotype in cytoplasms of diverse origins. Seventeen of 60 reciprocal plant‐to‐plant F1 crosses between donor lines and 2 inbred testers gave significantly different yields in 1962. Subsequent experiments utilized reciprocal F2 pairs to eliminate maternal seed effects. Six of 16 reciprocal F2 pairs gave significant differences in yield in one experiment. In a more extensive study with 11 cytoplasmic donor lines plus the original WF9 crossed with 4 tester inbreds, the F2 pairs were tested 2 years at 2 locations. Fed reciprocal differences and interactions with reciprocals were significant for yield of grain, percent moisture at harvest or lodged plants at harvest. Only 2 of 48 differences between reciprocal crosses were significant for yield. However, 2 of the 4 overall mean reciprocal differences for testers were significant, and in these cases exotic cytoplasms were superior.Cytoplasmic and genotype ✕ cytoplasmic interaction effects on the three characters as measured in reciprocal F2 hybrids were of low magnitude and probably interacted with years and locations. The results give little encouragement to the breeder to select cytoplasms with superior performance over years for even a limited region.