Clonal variation in the incidence of Hypoxylon canker on trembling aspen

1974 ◽  
Vol 52 (7) ◽  
pp. 1475-1481 ◽  
Author(s):  
James A. Copony ◽  
Burton V. Barnes
Keyword(s):  
Genetic Control ◽  
Stand Density ◽  
Genetic Differences ◽  
Basic Unit ◽  
Clonal Variation ◽  
Biotic Factors ◽  
Clonal Structure ◽  
Trembling Aspen ◽  
Phenotypic Differences ◽  
Significant Difference

The incidence of Hypoxylon canker, caused by Hypoxylon mammatum (Whal.) Miller, on ramets of 80 pole-sized Populus iremuloides clones was determined on three sites near Pellston, Michigan, and two sites near Iron River, Michigan. Variation in the incidence of canker within clones was slight. No significant difference (P >.05) in canker incidence was found among NE, SE, SW, and NW quadrants of 47 clones on the Pellston Plain site. Significant differences (P <.005) were found among clones in the incidence of canker in four of the five sites studied. In some cases, nearby or adjacent pairs of clones showed significant and striking differences in the incidence of canker infection. The range in canker incidence (percentage of living and dead ramets with stem or branch cankers) for all clones was 9 to 90%; the range was wide on all sites. Low stand density and light bark color of ramets were both significantly (P <.01 and P <.05, respectively) correlated with high canker infection.Although genetic differences between clones in the incidence of canker were not proven, the marked phenotypic differences among clones and other findings suggested moderate genetic control on four of the five sites investigated. In studies relating the incidence of canker to site and biotic factors, the clonal structure of aspen stands should be recognized, and the clone should be used as the basic unit of sampling.

Evidence for genetic control of response to sulfur dioxide and ozone in Populustremuloides

1977 ◽  
Vol 7 (3) ◽  
pp. 437-440 ◽  
Author(s):  
David F. Karnosky
Keyword(s):  
Sulfur Dioxide ◽  
Genetic Control ◽  
Genetic Differences ◽  
Trembling Aspen ◽  
Rooted Cuttings ◽  
Clonal Repeatability

This study was designed to estimate the degree of genetic control of the response to sulfur dioxide (SO2) and ozone (O3), alone and in combination, in trembling aspen (Populustremuloides Michx.). Rooted cuttings from 11 randomly selected trees in central Wisconsin were used in the study. Significant interclonal variation was found in the response of the 11 clones to 3-h exposures to 0.50 ppm SO2, 0.20 ppm O3, and 0.35 ppm SO, plus 0.05 ppm O3. Clonal repeatability estimates of 0.464 for SO2 plus O3, 0.620 for O3, and 0.642 for SO2 suggest that much of this variation between clones can be attributed to genetic differences in response to SO2 and O3.

scholarly journals Do s genes or deleterious recessives control late-acting self-incompatibility in Handroanthus heptaphyllus (Bignoniaceae)? A diallel study with four full sib progeny arrays

2021 ◽  
Author(s):  
Marta B Bianchi ◽  
Thomas R Meagher ◽  
Peter E Gibbs
Keyword(s):  
Genetic Control ◽  
Inbreeding Depression ◽  
Fruit Set ◽  
Genetic Model ◽  
Pollen Tubes ◽  
Self Incompatibility ◽  
Significant Difference ◽  
Partial Embryo ◽  
Ovule Penetration ◽  
S Genes

Abstract Background and Aims Genetically controlled self-incompatibility (SI) mechanisms constrain selfing and thus have contributed to the evolutionary diversity of flowering plants. In homomorphic gametophytic SI (GSI) and homomorphic sporophytic SI (SSI), genetic control is usually by a single multi-allelic locus S. Both GSI and SSI prevent self pollen tubes reaching the ovary and so are pre-zygotic in action. In contrast, in taxa with late-acting self-incompatibility (LSI), rejection is often post-zygotic, since self-pollen tubes grow to the ovary where fertilization may occur prior to floral abscission. Alternatively, lack of self fruit set could be due to early-acting inbreeding depression (EID). The aim of our study was to investigate mechanisms underlying lack of selfed fruit set in Handroanthus heptaphyllus in order to assess the likelihood of LSI versus EID. Methods We employed four full sib diallels to study the genetic control of LSI in Handroanthus heptaphyllus using a precociously flowering variant. We also used fluorescence microscopy to study the incidence of ovule penetration by pollen tubes in pistils that abscised following pollination or initiated fruits. Key Results All diallels showed reciprocally cross-incompatible full-sibs (RCI), reciprocally cross compatible full-sibs (RCC), and non-reciprocally compatible full-sibs (NRC) in almost equal proportions. There was no significant difference between the incidence of ovule penetrations in abscised pistils following self- and cross-incompatible pollinations, but those in successful cross pollinations were around twofold greater. Conclusions A genetic model postulating a single S locus with four s alleles, one of which, in the maternal parent, is dominant to the other three, will produce RCI, RCC and NRC situations each at 33 %, consistent with our diallel results. We favour this simple genetic control over an early-acting inbreeding depression (EID) explanation since none of our pollinations, successful or unsuccessful, resulted in partial embryo development, as would be expected under a whole genome EID effect.

scholarly journals The Physical Nature of Velocity

2018 ◽  
Vol 10 (6) ◽  
pp. 15
Author(s):  
Zhonggang Li
Keyword(s):  
Mathematical Model ◽  
Total Mass ◽  
Maximum Velocity ◽  
Physical Nature ◽  
Added Mass ◽  
Basic Unit ◽  
Significant Difference ◽  
Moving Body ◽  
Basic Particle ◽  
The Universe

Matter and energy are made up of the same basic particles. Why, then, is there a significant difference between matter and energy? This is because their basic particle compositions differ. The basic particle is the basic unit of mass and energy. Mass and energy conservations are essentially basic particle conversions. The basic particle is a vector, moving at the maximum velocity of the universe; however, after a substance tangibly solidifies, this velocity becomes zero. The velocity of a moving object is, thus, the ratio between the basic particles contributing to energy and those contributing to mass, and the direction of its velocity is determined by the basic particle directions. Electrons, photons, neutrons, protons, neutrinos, and other microscopic particles consist of basic particles. The total mass of a moving body increases with increasing velocity. This added mass is composed of basic particles provided by an external system. As relativity is a mathematical model, its equations may satisfy mathematical principles even though some of them may not represent objective physical facts; instead, these may simply be mathematical solutions without physical meanings.

Behavioral archives link the chemistry and clonal structure of trembling aspen to the food choice of North American porcupine

Oecologia ◽  
2009 ◽  
Vol 160 (4) ◽  
pp. 687-695 ◽  
Author(s):  
Brandee Diner ◽  
Dominique Berteaux ◽  
Jim Fyles ◽  
Richard L. Lindroth
Keyword(s):  
North American ◽  
Food Choice ◽  
Clonal Structure ◽  
Trembling Aspen

Restoration of meiotic stability following artificial hybridisation and selection in Teleogryllus (Orth., Gryllidae)

1973 ◽  
Vol 62 (4) ◽  
pp. 557-563 ◽  
Author(s):  
T. W. Hogan ◽  
P. G. Fontana
Keyword(s):  
Sex Ratio ◽  
Genetic Control ◽  
Sibling Species ◽  
Parental Species ◽  
Genetic Differences ◽  
Hybrid Strain ◽  
Cytological Examination ◽  
Research Project ◽  
Meiotic Stability ◽  
Made In

As part of a research project directed at the genetic control of Teleogryllus commodus (Wlk.) in Australia, hybridisation studies have been carried out between T. commodus and the sibling species T. oceanicus (Le Guillou). A cytological examination of a hybrid strain (male progeny of T. commodus × T. oceanicus backcrossed to T. oceanicus) was made in the F4 generation when meiotic stability had been reached. The karyotype was very similar to that of T. oceanicus, suggesting that only those combinations in which the chromosomes were structurally homologous to T. oceanicus survived. But the stridulation pattern of the hybrid males, intermediate between that of the two parental species, and a consistent sex ratio of 2:1 in favour of the males, indicate profound genetic differences from T. oceanicus. These effects are attributed to introgression, with chromosomal material from T. commodus being incorporated in the T. oceanicus genome as an outcome of the initial hybridisation of the two species.

Clonal Structure of Some Weevil Species (Coleoptera, Curculionidae) From Central Ukraine

2018 ◽  
Vol 52 (4) ◽  
pp. 313-322
Author(s):  
V. Yu. Nazarenko ◽  
S. Yu. Morozov-Leonov
Keyword(s):  
Clonal Diversity ◽  
Hybrid Origin ◽  
Clonal Variation ◽  
Clonal Structure ◽  
Weevil Species ◽  
Electrophoretic Spectra

Abstract The clonal structure of the populations of nine weevil species (family Curculionidae) from central Ukraine was analyzed. Clonal diversity varied extensively among studied species. Th e level of clonal variation of some species (Otiorhynchus ligustici, O. raucus, Liophloeus tessulatus) is high, within some other species (O. tristis, Tropiphorus micans) it is low. Th e constant heterozygosity of lot of genes has been demonstrated that it may be a proof of the hybrid origin of the studied weevil populations. Th e asymmetry of some obtained electrophoretic spectra was observed. Th is can be a consequence of their polyploid nature. Th e signifi cant interpopulation diff erentiation of most of the species studied was demonstrated.

scholarly journals Genetic control of DNA specificity inPseudomonas aeruginosa

1968 ◽  
Vol 12 (1) ◽  
pp. 99-102 ◽  
Author(s):  
B. Rolfe ◽  
B. W. Holloway
Keyword(s):  
Genetic Control ◽  
Genetic Differences ◽  
Pleiotropic Effects ◽  
Direct Selection ◽  
Resistance Mutations ◽  
Phenotypic Changes ◽  
Dna Specificity

Genotypic and phenotypic changes of HCM inP. aeruginosaare due to a variety of causes. In addition to interstrain genetic differences and the semi-permanent effects of growth at 43°C, mutations affecting both restriction and modification have been isolated by direct selection and through the pleiotropic effects ofp–fluorophenylalanine resistance mutations. It is suggested that some of these changes affecting HCM may be taking place through alterations of the ribosomes.

Foliar bacterial communities of trembling aspen in a common garden

2015 ◽  
Vol 61 (2) ◽  
pp. 143-149 ◽  
Author(s):  
Charles J. Mason ◽  
Jesse A. Pfammatter ◽  
Liza M. Holeski ◽  
Kenneth F. Raffa
Keyword(s):  
Bacterial Community ◽  
Host Plant ◽  
Bacterial Communities ◽  
Common Garden ◽  
Clonal Variation ◽  
Physical Factors ◽  
Rrna Gene ◽  
Trembling Aspen ◽  
Plant Genotype ◽  
Microbe Interactions

Microbial associations with plants are widely distributed and are structured by a number of biotic and physical factors. Among biotic factors, the host plant genotype may be integral to these plant–microbe interactions. Trees in the genus Populus have become models for studies in scaling effects of host plant genetics and in plant–microbe interactions. Using 454 pyrosequencing of the 16S rRNA gene, we assessed the foliar bacterial community of 7 genotypes of mature trembling aspen trees (Populus tremuloides Michx.) grown in a common garden. Trees were selected based on prior analyses showing clonal variation in their concentration of chemicals conferring resistance against insect herbivores. At broad taxonomic designations, the bacterial community of trembling aspen was similar across all plant genotypes. At a finer taxonomic scale, the foliage of these trees varied in their community composition, but there was no distinct pattern to colonization or abundance related to plant genotype. The most abundant operational taxonomic units (OTUs) were classified as Ralstonia, Bradyrhizobium, Pseudomonas, and Brucella. These OTUs varied across the common garden, but there was no significant effect of host plant genotype or spatial position on the abundance of these members. Our results suggest that aspen genotype is less important in the structuring of its foliar bacterial communities than are other, poorly understood processes.

Weekly xylem production in trembling aspen (Populus tremuloides) in response to artificial defoliation

2004 ◽  
Vol 82 (5) ◽  
pp. 590-597 ◽  
Author(s):  
Brin Jones ◽  
Jacques Tardif ◽  
Richard Westwood
Keyword(s):  
Populus Tremuloides ◽  
Radial Growth ◽  
Regression Models ◽  
Wood Anatomy ◽  
Ring Width ◽  
Growing Season ◽  
Early Growth ◽  
Trembling Aspen ◽  
Forest Sites ◽  
Significant Difference

The present study investigated the effect of artificial defoliation on weekly radial xylem production in trembling aspen (Populus tremuloides Michx.). It was hypothesized that defoliated trees would show reduced xylem and vessel production and thinner secondary walls in fibres. Two adjacent natural forest sites were selected within Winnipeg, Manitoba. Microcores were extracted weekly from the stems of 30 aspen trees from May to October 2002. Ten aspen trees were defoliated using pole pruners between 22 June and 6 July. Measurements included weekly xylem increment, annual vessel characteristics, and late growing season fibre dimensions. No significant difference in overall ring width was observed; however, trees from both groups showed a significant reduction in ring width in 2002. The ratio of radial growth in 2002 / radial growth in 2001 was significantly less in defoliated trees, suggesting a higher reduction in radial growth due to defoliation. Sigmoidal regression models suggested early growth cessation in defoliated trees. No significant differences in vessel characteristics were observed between groups; however, the diameter and lumen width of fibres was significantly reduced in defoliated trees. It is speculated that a shorter radial growing season may have led to a reduced cell elongation period. An early cessation of the radial growing season associated with a reallocation of carbohydrates to produce a second flush of leaves could explain the reduced size of fibres from defoliated trees.Key words: wood anatomy, diffuse porous, image analysis, radial growth, cell dimension, dendrochronology.

scholarly journals Cryptococcus neoformans var.grubii: Separate Varietal Status for Cryptococcus neoformans Serotype A Isolates

1999 ◽  
Vol 37 (3) ◽  
pp. 838-840 ◽  
Author(s):  
Sarah P. Franzot ◽  
Ira F. Salkin ◽  
Arturo Casadevall
Keyword(s):  
Cryptococcus Neoformans ◽  
Dna Fingerprinting ◽  
Genetic Differences ◽  
Capsular Polysaccharides ◽  
New Variety ◽  
Serotype A ◽  
Phenotypic Differences ◽  
Immunologic Reactivity

Cryptococcus neoformans var. neoformanspresently includes isolates which have been determined by the immunologic reactivity of their capsular polysaccharides to be serotype A and those which have been determined to be serotype D. However, recent analyses of the URA5 sequences and DNA fingerprinting patterns suggest significant genetic differences between the two serotypes. Therefore, we propose to recognize these genotypic distinctions, as well as previously reported phenotypic differences, by restricting C. neoformans var. neoformans to isolates which are serotype D and describing a new variety, C. neoformans var. grubii, for serotype A isolates.

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