RELATIONSHIP OF SUPERCOOLING TO COLD HARDINESS AND THE NORTHERN DISTRIBUTION OF SEVERAL CULTIVATED AND NATIVE Prunus SPECIES AND HYBRIDS

1982 ◽  
Vol 62 (1) ◽  
pp. 137-148 ◽  
Author(s):  
H. A. QUAMME ◽  
R. E. C. LAYNE ◽  
W. G. RONALD
Keyword(s):  
Native Species ◽  
Interspecific Hybrids ◽  
Cold Hardiness ◽  
Prunus Species ◽  
Flower Buds ◽  
Freeze Injury ◽  
Northern Distribution ◽  
Deep Supercooling ◽  
Almost All ◽  
Relationship Of

Twig pieces from 13 Prunus species and seven interspecific hybrids were collected during mid-winter, preconditioned to induce maximum cold hardiness and subjected to freeze tests and exotherm analysis. The collection included representative cultivars of Prunus species cultivated in Canada for their fruit and/or ornamental value, i.e., apricot, cherry, peach and plum, and native Prunus. The flower buds were more susceptible to freeze injury than leaf buds, bark and xylem in almost all taxa. Leaf buds and stem xylem were the most susceptible of the vegetative tissues. A low temperature (LT) exotherm was detected in the stem of each taxon and was closely related to xylem injury. This suggested that freeze injury to the xylem is avoided by deep supercooling. Exotherm analysis and ice nucleation tests on seven taxa suggested that flower buds also avoid injury by deep supercooling. Bark and leaf bud injury were not consistantly related to the LT stem exotherm. The temperatures at which injury occurred to the most susceptible tissues were closely related to the average annual minimum isotherm temperature at the northern limit of distribution of those taxa for which the northern distribution was known. The degree of deep supercooling may be the factor limiting northern commercial production of the cultivated taxa or the northern geographical distribution of the native species in which flower buds and/or xylem were the most susceptible tissue. Interspecific hybrids of the hardy P. besseyi Bailey with more winter tender P. persica (L.) Batsch, P. armeniaca L., P. salicina Lindl. and P. tomentosa Thunb. appeared to be intermediate in hardiness between the parental species or equal to the hardiness of the more hardy parent. A second backcross of P. tenella Batsch to P. persica was considerably more hardy than any of the known peach cultivars.

scholarly journals VARIATIONS IN COLD HARDINESS CHARACTERISTICS AMONG PRUNUS SPECIES

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1081c-1081
Author(s):  
S. Kadir ◽  
E. L. Proebsting
Keyword(s):  
Cold Hardiness ◽  
Xylem Vessel ◽  
Chilling Requirement ◽  
Prunus Species ◽  
Flower Buds ◽  
Flower Primordia ◽  
Vessel Elements ◽  
Chill Unit

Flower buds of 20 Prunus species representing 4 subgenera were collected during winter and spring of 1989-90. Buds were preconditioned at +3° or 7°C to test their minimum hardiness level (MHL) or the rate of hardiness increase. DTA revealed that most of the prunus species have flower primordia that supercool. The subgenus Padus have racemose inflorescences and do not deep supercool during dormancy. P. besseyi, P. nigra and P. americana had small exotherms between -22° and -27°C while P. davidiana and P. subhirtella had larger exotherms at higher temperatures. Exposure of flower buds to -7°C shifted LTES to lower temperatures and/or reduced the size of LTE, which became undetectable for many species including P. nigra and P. americana. P. davidiana and P. subhirtella increased hardiness by 6°/day at -7° while dormant. Deacclimation coincided with an increase in LTE50 and the development of xylem vessel elements in the bud axis, calyx and filaments as indicated by dye movenent. P. davidiana was the least hardy species and required only 700 chill units to satisfy the chilling requirement, while P. nigra and P. americana had LTE average of -26°C at MHL and required over 1000 chill unit accumulation.

scholarly journals Low-temperature Exotherms and Cold Hardiness in Three Taxa of Deciduous Trees

1995 ◽  
Vol 120 (5) ◽  
pp. 830-834 ◽  
Author(s):  
Orville M. Lindstrom ◽  
Tomasz Anisko ◽  
Michael A. Dirr
Keyword(s):  
Low Temperature ◽  
Cold Hardiness ◽  
Acer Rubrum ◽  
Fraxinus Americana ◽  
Freeze Avoidance ◽  
Deep Supercooling ◽  
The Mean ◽  
Relationship Of ◽  
The Relationship ◽  
Zelkova Serrata

Although differential thermal analysis has been routinely used to evaluate cold hardiness, the relationship of deep supercooling ability and plant survival are not well understood. In this study, we compared the seasonal profiles of changes in low-temperature exotherm (LTE) occurrence with visually determined cold hardiness of Acer rubrum L. `Armstrong', Fraxinus americana L. `Autumn Purple' and Zelkova serrata (Thunh.) Mak. `Village Green' growing in three locations representing plant cold hardiness zones 8b, 7b, and 5a. Between December and February, LTEs in Acer rubrum `Armstrong' and Fraxinus americana `Autumn Purple' occurred at temperatures around 10 to 25C lower than the lowest survival temperatures. The mean difference between LTEs and lowest survival temperature was not significant for Zelkova serrata `Village Green' from January to April and for Acer rubrum `Armstrong' and Fraxinus americana `Autumn Purple' in March. Data indicated that LTEs could be used as an estimate of lowest survival temperature in Zelkova serrata `Green Village' but not in Acer rubrum `Armstrong' and Fraxinus americana `Autumn Purple'. This study demonstrated that LTEs may not reliably estimate cold hardiness in all species that deep supercool. Factors other than freeze avoidance ability of xylem may limit stem survival at temperatures above the LTE.

Supercooling Points of Adult Dermacentor variabilis (Acari: Ixodidae) From a Population Near the Northern Distribution Limit

2020 ◽  
Author(s):  
Matthew E M Yunik ◽  
Neil B Chilton
Keyword(s):  
Cold Hardiness ◽  
Dermacentor Variabilis ◽  
Subzero Temperatures ◽  
Host Seeking ◽  
Short Period ◽  
Significant Difference ◽  
Northern Distribution ◽  
Dog Tick ◽  
Provincial Park ◽  
Established Population

Abstract The northern distributional limit of Dermacentor variabilis Say, the American dog tick, is expanding in Saskatchewan and Manitoba (western Canada). The ability of D. variabilis to continue to expand its range northwards will depend upon the ability of individuals within populations at the species distributional edge to withstand very low temperatures during winter. One component of cold hardiness is the supercooling point (SCP), the temperature below 0°C at which an individual freezes. In this study, the SCP was determined for 94 questing D. variabilis adults (44 females and 50 males) from an established population near Blackstrap Provincial Park in Saskatchewan. SCP values ranged from −18.2 to −6.7°C, with a median of −13.3°C. This suggests that host-seeking D. variabilis adults differ in their ability to survive exposure to subzero temperatures, for at least a short period of time, without freezing. The distribution of SCPs was bimodal, but there was no significant difference in SCP values between female and male ticks, and no relationship between SCP and tick body weight. It remains to be determined what factors contribute to the variation in SCP values among questing D. variabilis adults.

scholarly journals Crayfish hemocytes develop along the granular cell lineage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fang Li ◽  
Zaichao Zheng ◽  
Hongyu Li ◽  
Rongrong Fu ◽  
Limei Xu ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Cell Lineage ◽  
Granular Cell ◽  
Marker Genes ◽  
Hematopoietic Tissue ◽  
Differentiated Cells ◽  
Stage Of Development ◽  
Almost All ◽  
Relationship Of

AbstractDespite the central role of hemocytes in crustacean immunity, the process of hemocyte differentiation and maturation remains unclear. In some decapods, it has been proposed that the two main types of hemocytes, granular cells (GCs) and semigranular cells (SGCs), differentiate along separate lineages. However, our current findings challenge this model. By tracking newly produced hemocytes and transplanted cells, we demonstrate that almost all the circulating hemocytes of crayfish belong to the GC lineage. SGCs and GCs may represent hemocytes of different developmental stages rather than two types of fully differentiated cells. Hemocyte precursors produced by progenitor cells differentiate in the hematopoietic tissue (HPT) for 3 ~ 4 days. Immature hemocytes are released from HPT in the form of SGCs and take 1 ~ 3 months to mature in the circulation. GCs represent the terminal stage of development. They can survive for as long as 2 months. The changes in the expression pattern of marker genes during GC differentiation support our conclusions. Further analysis of hemocyte phagocytosis indicates the existence of functionally different subpopulations. These findings may reshape our understanding of crustacean hematopoiesis and may lead to reconsideration of the roles and relationship of circulating hemocytes.

scholarly journals Predicting the potential distribution of the vase tunicate Ciona intestinalis in Canadian waters: informing a risk assessment

2008 ◽  
Vol 65 (5) ◽  
pp. 788-794 ◽  
Author(s):  
Thomas W. Therriault ◽  
Leif-Matthias Herborg
Keyword(s):  
Risk Assessment ◽  
Native Species ◽  
Potential Distribution ◽  
Negative Impact ◽  
Ciona Intestinalis ◽  
Environmental Niche ◽  
Environmental Models ◽  
Introduced Range ◽  
Negative Impacts ◽  
Almost All

Abstract Therriault, T. W., and Herborg, L-M. 2008. Predicting the potential distribution of the vase tunicate Ciona intestinalis in Canadian waters: informing a risk assessment. – ICES Journal of Marine Science, 65: 788–794. A crucial step in characterizing the potential risk posed by non-native species is determining whether a potential invader can establish in the introduced range and what its potential distribution could be. To this end, various environmental models ranging from simple to complex have been applied to predict the potential distribution of an invader, with varying levels of success. Recently, in marine waters, tunicates have received much attention, largely because of their negative impacts on shellfish aquaculture. One of these species is the vase tunicate Ciona intestinalis, which recently has had a negative impact on aquaculture operations in Atlantic Canada and could pose a risk in Pacific Canada. To inform the risk assessment of this species, we evaluated two different types of environmental model. Simple models based on reported temperature or salinity tolerances were relatively uninformative, because almost all waters were deemed suitable. In contrast, a more complex genetic algorithm for rule-set prediction (GARP) environmental niche model, based on documented Canadian occurrence points, provided informative projections of the potential distribution in Canadian waters. In addition to informing risk assessments, these predictions can be used to focus monitoring activities, particularly towards vectors that could transport C. intestinalis to these favourable environments.

scholarly journals Autonomy and Attachment in Relationships with Parents in the Context of Students’ Real Self-Determination

2021 ◽  
Vol 12 (1) ◽  
pp. 113-125
Author(s):  
D.A. Krasilo ◽  
T.A. Krassilo ◽  
A.N. Zalipaeva
Keyword(s):  
Inverse Relationship ◽  
Self Determination ◽  
Education Environment ◽  
Cognitive Autonomy ◽  
Positive Correlations ◽  
Almost All ◽  
Relationship Of ◽  
Real Self ◽  
The Relationship

Objectives. Studying the relationship of autonomy and attachment in relationships with parents with real self-determination in students. Background. The growing world globalization, intercultural contradictions, confrontation within society seriously complicate the path of self-determination of modern youth. At the same time, due to technical progress and digitalization of the communication and education environment, there are significant transformations in the interaction of people in almost all spheres, including in the family. Therefore, the question of studying the most important aspects in the relationship of young people with their parents for real self-determination is especially acute. Study design. The work studied the indicators of real self-determination, attachment to parents and autonomy among students. The presence of a relationship between these parameters was established by calculating the Spearman correlation coefficient. Participants. 60 college students aged 18 to 21. Measurements. Methodology “Scale of adult attachment for close relationships”; autonomy questionnaire (authors O.A. Karabanova and N.N. Poskrebysheva); questionnaire “ORS” (author D.A. Krasilo). Results. An inverse relationship of indicators of real self-determination of students with the level of intimacy and the level of anxiety (scales of attachment to parents) was established. A direct relationship was revealed between the indicators of real self-determination and the level of autonomy. Conclusions. Proximity and anxiety (components of attachment) have a significant inverse relationship with the level of real self-determination in students. There are no significant connections between reliability (a component of attachment) and real self-determination in the sample under study. Emotional autonomy, cognitive autonomy, behavioral autonomy, and value autonomy have significant positive correlations with the level of real self-determination in students.

scholarly journals Alien Species vs. Native Species: From Community Ecology to Eco-Evolutionary Dynamics

2019 ◽  
Author(s):  
Andersonn Silveira Prestes
Keyword(s):  
Alien Species ◽  
Exotic Species ◽  
Native Species ◽  
Evolutionary Dynamics ◽  
Evolutionary Processes ◽  
Native Communities ◽  
Individualized Approach ◽  
History Of ◽  
Relationship Of ◽  
The Relationship

The establishment and spread of exotic species is a contemporary major concern. Alien species may become invasive in their new habitat, leading to both/either environmental and/or economic impacts. I briefly reviewed the literature in the last decade about the relationship of exotic species and native communities. I identified that professionals usually approach the subject in two main points of view: (1) researchers tend to point out the impacts of alien species on entire communities, evaluating if the relationship is positive, negative or neutral; (2) they focus on the eco-evolutionary processes involved in the introductions, the dynamics of invasion, and individual study cases. When evaluating the response of introductions to entire communities, evidence seems to be ambiguous and may support positive, negative or neutral relationship, especially depending on the scale approached. The unique eco-evolutionary pathways of each introduction may be a great shortcoming in the searching for generalities. On the other hand, advances have been made in understanding the dynamics of invasion on different lineages through a more selective/individualized approach. I suggest that the dynamics of invasion might be studied through a perspective in which different eco-evolutionary processes, levels of organization (from gene to entire communities), the history of the organism(s) and time are taken into account. Individual cases might be compared in attempt to understand how the relationship exotic and native works and in the search for generalities.

Sign in / Sign up

Export Citation Format

Share Document