bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance of a Winter Wheat Hybrid, F2, F3, and Parent Varieties at Five Population Levels1
Authors: Briggle L. W. , Petersen H. D. , Hayes R. M. 
Published: July 2010

The F1 and parents involved in a winter wheat cross (‘Reed’ Χ ‘Gaines’) were grown at five population levels under irigation for 3 years at Aberdeen, Idaho. The F2 was grown in the same experiment for 2 years and the F3 for 1 year.A slight amount of heterosis was expressed in plant height.Heterosis was expressed by the hybrid in grain yield. When means over all five population levels were compared, the F1 produced more grain than either parent in all 3 years. Differences were significant except for that between the F1 and Gaines in 1965. The F1 produced significantly more grain than the F2 in 1964 and 1965, and the F3 in 1965. There was no significant difference between the F2 and F3 in 1965.No heterosis was evident in number of spikes per plant. Gaines produced more spikes per plant than the hybrid each year. Some degree of heterosis was expressed in number of kernels per spike and in kernel size 2 years out of 3.Reed (tall variety) was used as border around all plots in two replications and Gaines (short variety) was used as border in two replications in 1963 and 1964. The only significant competition effects measured were on height in 1964 and on grains of grain per plot in 1963. Each entry in 1965 was bordered by itself.F1 and parent plants were slightly taller when grown at the higher plant densities.Population level had an effect on grain yield. In 2 out of 3 years highest yields were produced by the hybrid and by Gaines at level 3. In no year were the F1 means at population levels 3, 4, or 5 significantly different. The same was true for both parents. On the basis of this test a producer could cut his seeding rate to that of population level 3 (approximately one plant per 2.5 cm (1 inch) or 0.9 hectoliter per hectare (3‐¼ pecks per acre). This could be important if hybrid wheat seed becomes available and is relatively costly. More tests at different population levels should be conducted before a general recommendation can be made.Plants grown at low population levels produced more spikes and more kernels per spike than those grown at high levels. Seed size was little influenced by plant density, although there was a trend toward smaller seed at the high population levels.
Selection for Increased Lint Yield and Correlated Responses in Upland Cotton, Gossypium hirsutum L.1
Authors: Miller P. A. , Rawlings J. O. 
Published: July 2010

Three cycles of recurrent selection for increased lint yield in Upland cotton (Gossypium hirsutum L) have been completed. Yield of the third cycle selections exceeded that of the base population by 29.7%. Response to selection was linear and is predicted to continue at approximately the same rate of gain for an additional cycle.Correlated responses to selection for yield were observed for the majority of the unselected traits measured. As selection increased lint yield, simultaneous increases were observed for lint percentage, number of seed per boll, earliness, fiber elongation, and fiber coarseness. Boll size, seed size, and fiber length and strength decreased. Weight of lint per seed showed little change.There was generally close agreement between predicted and observed responses to selection. This suggests that dominance effects were lacking or of relatively minor importance. Additive genetic effects would appear to predominate in this population, although additive ✕ additive effects cannot be excluded.
Seed Pod Dehiscence in Lotus and Interspecific Hybridization Involving L. corniculatus L.1
Authors: Phillips R. L. , Keim W. F. 
Published: July 2010

Whirty‐nine entries representing 16 Lotus species were tested for seed‐pod dehiscence at 38%, 33%, 25%, and 10.5% relative humidities. L. coimbrensis Willd. was the only species possessing completely indehiscent seed pods. L. angustissimus L. (Cyprus), L. tetragonolobus L., and two entries of L. ornithopodioides L. demonstrated a high degree of indehiscence.In the 34 entries where all pods dehisced, the mean number uf days for seed.pod dehiscence decreased as the relative hmnidity decreased.An interspecific‐hybridization study involving glabrous L. corniculatus (2n = 24) as the female parent and pubescent: L. coimbrensis (2n = 12) as the male parent was undertaken in an attempt to incorporate the indehiscent seed‐pod character of L. coimbrensis into the agronomically desirable L. corniculatus. The pollination of 2,498 flowers produced 13 putative hybrids exhibiting pubescence, a trait dominant in L. corniculatus. Also, pollen fertility was low in some of the hybrids. The somatic chromosome number of the putative hybrids was 24, general phenotypic appearance was similar to L. corniculatus except for the pubescence, and meiosis of the five offspring with the lowest pollen fertility was similar to that in L. corniculatus. Seed‐pod indehiscence was not observed. The four putative hybrids with the lowest pollen fertility were backcrossed to L. corniculatus. The presence of a high number of univalents in the backcross progenies supports the contention that interspecific hybridization was effected between L. corniculatus and L. coimbrensis.
Effect of Photoperiod and Temperature on Cold Hardening in Winter Wheat1
Authors: Paulsen Gary M. 
Published: July 2010

Changes in hardiness and plant constituents associated with hardening were observed in ‘Pawnee’ winter wheat under constant and under decreasing photoperiod and temperature treatments. Hardening occurred only when the temperature decreased, and was greater under a constant long photoperiod than under a decreasing photoperiod. Least hardening occurred when the photoperiod was decreased and the temperature remained constantly high.Changes in dry matter, reducing sugar, sucrose, and free amino acid contents of wheat crowns paralleled changes in hardiness. Soluble protein content of crowns was increased by decreasing photoperiod as well as by decreasing temperature.
Inheritance of Lint Quality Characteristics in Intraspecific Crosses Among Varieties of Gossypium hirsutum L. and of G. barbadense L.1
Authors: Marani A. 
Published: July 2010

Lint quality was tested in six trials which were conducted from 1959 to 1965 in Israel. These trials included varieties of G. hirsutum L. and G. barbadense L. and the F1 intraspecific crosses within each species. F2's of these crosses were included in two of these trials.A small effect of heterosis for upper‐half‐mean lint length was found in both species, with the magnitude of this heterosis larger in G. barbadense L. than in G. hirsutum L. The inheritance of this trait was found to be mostly additive, with small dominance effects in both species, and possibly also some epistatic effects in G. barbadense L. Results for mean lint length were similar.Lint strength (Pressley tester, 1/8” gauge) of G. hirsutum L. Fl's was very close to mid‐parental performance, whereas G. barbadense L. F1's were much closer to the parent having stronger lint. Inheritance of this trait was found to be mostly additive, with some dominance effects in G. barbadense L. Fineness of lint (Micronaire) of intraspecific crosses of both species was found to be intermediate between parental performance, with a slight tendency of F1 fibers to be coarser. Large interactions of fineness with environment were observed.
Root Elongation in the Preemergence Stage of Mediterranean Grasses and Legumes1
Authors: Tadmor Naphali H. , Cohen Yehezkel 
Published: July 2010

Rooting depth of seedlings at emergence was determined by radioisotope tracing (P32) for six range plants: Agropyron desertorum (Fisch.) Schult; Avena sterilis L.; Medicago hispida Gaertn.; Oryzopsis holciiormis (M. B.) Hack.; Phalaris tuberosa L.; and Vicia dasycarpa Ten.; with wheat and barley as controls.Seeds were planted from 2 to 18 cm deep in loess soil in a growth chamber at 20 C constant temperature. Except for the 2‐cm depth no interaction was found between root length and depth of planting. Seedling roots reached a certain length and no more before onset of photosynthesis. This length varied greatly with the species: 4 to 6 cm for the perennial grasses anl legumes; 6 to 8 cm for Avena; and 12 cm in wheat and barley. Root length was generally correlated with mean seed weight.The depth seedling roots have reached by the time of emergence is a sum of depth of planting and root length. The deepest root penetration occurred at the greatest planting depth from which seedlings emerge. Shallow planting may be suboptimal under arid conditions, and the deepest planting form which emergence is still satisfactory seems to be optimal. Root elongation in the preemergence stage may therefore become a useful criterion in breeding species for arid range.
Reciprocal Crosses and Their Influence on Wheat Quality1
Authors: McNeal F. H. , Berg M. A. , Watson C. A. 
Published: July 2010

Four crosses with their reciprocals and parents were evaluated for milling and baking quality and for agronomic characteristics in 1966 and 1967. The four parental varieties used in crosses represented a range in quality. Reciprocal crosses differed little in milling and baking quality, as indicated by significant differences in only 2 of 64 quality comparisons. Three of 28 agronomic comparisons differed significantly.Quality values for crosses were mostly intermediate between the two parents, with some values approaching those of the best parent and some significantly lower than the best parent. No quality value of the crosses exceeded the best parent significantly.
Yield Component Heritabilities and Interrelationships in Winter Wheat (Triticum aestivum L.)1
Authors: Fonseca Santiago , Patterson Fred L. 
Published: July 2010

A seven‐parent diallel cross of winter wheat was grown in the F1 generation in hills for 2 years and in the F2 generation in hills and in nursery yield plots the second year. Heritability estimates for earliness of flowering, height, number of spikes, kernels per spike, kernel weight, and grain yield were obtained from regression of F1 or F2 means on mid‐parent values. Simple correlations were calculated among all variables. The correlations were analyzed further by the path coefficient technique to determine direct and indirect effects.Heritability estimates from data from hills for earliness, height, number of spikes, and kernels per head were high and those for kernel weight and grain yield were intermediate or low. Estimates in the F1 and F2 generations from data obtained from hill plots were reasonably similar. Estimates of heritabilities for the six characters from the F2 generation, were very similar for hills and thick‐seeded nurseries.The three components of yield were highly correlated with grain yield. The path‐coefficient analysis indicated that each of the components had large direct effects on grain yield but important indirect effects resulting from negative correlations among yield components.
Toxicity of Tall Fescue to Rape and Birdsfoot Trefoil Seeds and Seedlings1
Authors: Peters Elroy J. 
Published: July 2010

Water extracts from roots and leaves of fescue (Festuca arundinacea elator Schreb.) reduced germination and growth of the roots of rape (Brassica nigra) and birdsfoot trefoil (Lotus corniculatus L.), but effects varied, depending upon how the extracts were prepared. Ethanol extracts of roots and leaves of fescue reduced growth of roots and tops of rape and birdsfoot trefoil seedlings grown in sand containing nutrient solution. Ethanol extract of root‐free soil in which fescue had been grown did not inhibit growth of rape or birdsfoot trefoil seedlings.Rape and fescue seeds germinated normally in sand with nutrient solution in which rescue was growing. Fescue growing in association with rape plants in nutrient solution or distilled water significantly reduced the growth of rape leaves. When half of the rape and rescue root systems were independently supplied with nutrient solution, and half of their root systems were grown together in distilled “water, rescue inhibited the growth of rape roots in the distilled water. This ruled out competition for nutrients as an explanation of the inhibitory effects of rescue on the growth of rape.
Inheritance of Lint Quality Characteristics in Interspecific Crosses of Cotton1
Authors: Marani A. 
Published: July 2010

In interspecific crosses between varieties of upland (Gossypium hirsutum L.) and Egyptian (G. barbadense L.) cotton, tested in Israel from 1959 through 1965, F1 performance for upper‐half‐mean and mean lint length exceeded that of either parent by 10 to 16% and 6 to 13%, respectively. The uniformity ratio of F1 plants was slightly lower than the parental mean. F2 performance for lint length was slightly above parental mean, but a significant F2 deviation was detected for this trait. There were indications that additive, dominance, and additive ✕ additive epistatic effects were operating in the inheritance of lint length.The tensile strength (1/8‐in. gauge, i.e. T1 of the F1's lint was almost as high as that of the stronger G. barbadense parental varieties. The magnitude of heterosis was 9 to 15% for this trait, with no F2 or backcross deviations. This indicated that only additive and dominance effects were operating in the inheritance of lint strength.Micronaire measurement of lint fineness was much lower in F1 hybrids than in either parent (a negative heterosis of 12 to 19%). Only the dominance effects were detected as operating significantly in the inheritance of this trait, but there were considerable deviations from the model with no epistasis.Significant effects of general combining ability were found for lint length and tensile strength. Additive gene‐action was predominant for these traits. Dominance effects were the main cause of heterosis for all the traits of lint quality examined.
Heterosis and Homeostasis in Secale montanum Guss ✕ S. cereale L. Hybrids I. Vegetative Growth and Development1
Authors: Pfahler P. L. 
Published: July 2010

F1 hybrids between Secale montanum (P1253956) and three varieties (‘Florida Black,’ ‘Gator,’ and ‘Wrens Abruzzi’) of S. cereale were made with S. montanum the female parent in each cross. F2 populations were produced by interpollination within each F1 population. Forage production and plant weight after final clipping were measured on plants from each population grown under space‐planted conditions in 1965–66 and 1966–67 winter seasons.or both characters, substantial heterosis was obtained in certain F1 populations with the amount depending on the S. cereale variety involved and the year tested. Heterosis for forage production in all hybrid populations was expressed late in the vegetative development of the plant. The response of the hybrid populations to yearly differences in environment was variable and associated with the character being measured. In comparison to the parents the variation within the hybrid populations was low. In general, the differences between the F1 and F2 populations were small.
Resistance to Brown Stem Rot in Soybeans1
Authors: Chamberlain D. W. , Bernard R. L. 
Published: July 2010

A total of 2,060 soybean strains, screened for resistance to brown stem rot, revealed no immune lines. However, PI 84946‐2, a strain of unknown origin selected from an introduction from Korea, had a very high proportion of disease‐free plants through 12 seasons. When crosses of PI 84946‐2 were made with several commercial varieties, the segregating generations averaged more healthy plants than did the commercial varieties. Lines with resistance similar to that of PI 84946‐2 have been selected from these populations.We observed that early‐maturing varieties tended to escape infection; locally adapted varieties planted in late June did likewise.Irradiating the seeds of six soybean varieties with thermal neutrons failed to induce resistant mutants in progeny tests.
Genetic Instability of Ottawa Wheat (Triticum aestivum L.)1
Authors: Urich Max A. , Heyne E. G. 
Published: July 2010

Spontaneously occurring off‐type plants susceptible to leaf rust race 9 were found at a high rate (2.61 per 1,000 seedlings tested) in the progeny of self‐pollinated (bagged) spikes of ‘Ottawa’ wheat. They appeared to originate from three different events in a normal, disomic Ottawa population: (1) mutation of the gene for leaf rust race 9 resistance, (2) breakage and loss of a terminal portion of chromosome 6B, which included the gene for resistance, and (3) nonpairing of the two 6B homologues, which resulted in mono‐6B and mono‐6B telo‐6BS aneuploids. A relatively high rate of 6B aneuploids occurred after one generation of self‐pollination (1.58 per 1,000 seedlings) and after two generations of self‐pollination (2.97 per 1,000 seedlings).Spontaneously occurring white‐glumed spikes ere found at the rate of 1.8 and 2.4 per 10,000 spikes in foundation and registered Ottawa, respectively. Those off‐types had either a ditelo or di‐iso constitution, indicating loss of an arm of chromosome lB. They probably originated from nonpairing of an 1B bivalent and subsequent misdivision and recombination of an 1B univalent.Nonhomology did not appear to cause nonpairing which was not random but affected chromosomes 1B and 6B more frequently than other chromosomes. This study suggests that Ottawa has some type of genetic malfunction that prevents chromosomes 1B and 6B from pairing in all meiotic cells.
Chromosome Stability in Some Hexaploid Strains of Triticale1
Authors: Tsuchiya T. , Larter E. N. 
Published: July 2010

In eight strains of hexaploid Triticale (2n = 42) which had undergone seven to eight generations of selection for improved agronomic characteristics, the mean frequency of aneuploid plants in bulk populations was 11.5%. Most aneuploids were monosomic and differences in the mean frequencies of aneuploids between lines were nonsignificant.In the immediate progeny of euploid plants, the average aneuploid frequency for eight lines was 8.8%, varying from a low of about 3% in those strains involving Triticum turgidum L. var. dicoccon as one parent, to approximately 11% in those strains with Triticum turgidum L. var. durum or Triticum turgidum L. var. carthlicum (persicum) as parents.
Influence of Supplemental Light on Apparent Photosynthesis, Yield, and Yield Components of Soybeans (Glycine max L.)1
Authors: Johnston T. J. , Pendleton J. W. , Peters D. B. , Hicks D. R. 
Published: July 2010

Experiments were conducted to determine the effect on soybean seed yields and yield components of increasing the amount of light available in the soybean leaf canopy and to evaluate the photosynthetic contribution of leaves at different levels in the canopy.Wide spectrum fluorescent lamps were placed at three levels in the canopies of ‘Amsoy’ and ‘Wayne’ varieties planted in rows 50‐cm and 100‐cm apart. White reflective polyethylene strips were placed between the rows. At harvest each plant was divided into top, middle, and bottom thirds corresponding to the levels of artificial lamps in the canopy.Measurements of apparent photosynthesis (AP) and respiration of individual soybean leaves were made with a plexiglass single leaf photosynthesis chamber. AP and respiration rates (rag CO2/dm2/hr) were determined by recording the change in CO2 concentration with time in a closed system.Adding light increased the yields of bottom, middle, and top canopy positions of plants 30, 20, and 2%, respectively. Light‐rich plants had more seeds, nodes, pods, branches, pods per node, seeds per pod, and a higher oil content than normal plants. Protein content and seed size were decreased by adding light.The rates of AP of bottom and middle soybean leaves were 13 and 60% of the 20.2 mg CO2/dm2/hr rate of top leaves under natural canopy conditions. When exposed to full sunlight, bottom and middle leaves fixed 258 and 50% more CO2, respectively, than when naturally shaded.Respiration rates decreased with depth in the canopy. Top, middle, and bottom leaves had respiration rates of 6.8, 4.3, and 2.8, mg CORespiration rates decreased with depth in the canopy. Top, middle, and bottom leaves had respiration rates of 6.8, 4.3, and 2.8, mg CO2/dm2/hr, respectively.
Leaf Area Relationships and Inheritance in Barley1
Authors: Fowler C. W. , Rasmusson D. C. 
Published: July 2010

Five barley, Hordeum vulgare L., populations were used in a study of leaf area. Information was obtained on estimation of leaf area, leaf area relationships on single plants and on inheritance and gain from selection. The formula, leaf width ✕ leaf length ✕ b, where b is the regression coefficient of actual leaf area on the width‐length product, provided a relatively good estimate of leaf area. Our results suggest that a coefficient of b = .69 would be satisfactory for most situations. However, the coefficients that were estimated differed significantly from one population to the other and for different leaves. Area per leaf increased progressively from the flag to the third leaf below the flag in the populations studied. Leaf area of adjacent leaves was highly correlated suggesting that it may be difficult to develop plants that have individual leaves of distinctly different size.Heritability estimates of leaf area, parent‐progeny method, ranged from .18 to .73 on the F3 and F4 plant basis, and from .24 to .49 on the family or plot basis, without replication. The mean estimates of gain from one generation of selection on the plant basis were 41 and 20% of the mean leaf area for the flag and the first leaf below the flag, respectively. Hence, the results should be encouraging to those who contemplate breeding programs in grass species aimed at altering leaf area.
Sources of Variation in Cynodon dactylon (L). Pers.1
Authors: Harlan Jack R. , de Wet J. M. J. 
Published: July 2010

SummaryThe species Cynodon dactylon is enormously variable and has become truly cosmopolitan as a weed of disturbed habitats. Six botanical varieties are recognized in our classification, but only one is the widespread weed; the others are either narrow endemics or have restricted distributions. The great variability within the cosmopolitan variety appears to have been generated internally by genetic interaction of three of the six varieties and by fragmentation of the gene pool by translocation races.
Viability and Leaching of Sugars from Germinating Barley1
Authors: Abdul‐Baki Aref A. , Anderson James D. 
Published: July 2010

The relationship of viability to leaching of sugars from germinating barley seeds has been studied with respect to age, accelerated aging, and mechanical injury of seeds. Sugar leaching increased with increased seed age and with increased mechanical injury of endosperm, but it was unchanged by accelerated aging except when viability was severely reduced.The amount of leached sugars, particularly glucose, even in seeds of high viability was a significant portion of total sugars found in the seed at 4, 8, and 12 hours of germination. Aging the seeds for 2, 5, and 8 years increased sugar leaching and reduced viability. Mechanical injury increased sugar leaching without affecting viability. Accelerated aging treatment up to 12 days did not affect sugar leaching but reduced viability. We conclude that sugar measurements are not a reliable index for seed viability. Furthermore, the leaching of sugars appears to be regulated primarily by the rate of utilization of such sugars during germination rather than by changes in membrane permeability of the dry seed.Eighty to 90% of the total glucose and sucrose of the seed was found in the endosperm. The remaining 10 to 20 % was found in the embryo. As germination progressed, the total amount of glucose in both embryo and endosperm increased while sucrose decreased. The depletion of sucrose was most pronounced in the embryo.