scholarly journals Phenotypic plasticity and genetic adaptation of functional traits influences intra-specific variation in hydraulic efficiency and safety

2019 ◽  
Vol 40 (2) ◽  
pp. 215-229 ◽  
Author(s):  
Carola Pritzkow ◽  
Virginia Williamson ◽  
Christopher Szota ◽  
Raphael Trouvé ◽  
Stefan K Arndt
Keyword(s):  
Phenotypic Plasticity ◽  
Water Potential ◽  
Genetic Control ◽  
Genetic Adaptation ◽  
Short Term ◽  
Huber Value ◽  
Turgor Loss Point ◽  
Hydraulic Vulnerability ◽  
Hydraulic Safety ◽  
Dry Conditions

Abstract Understanding which hydraulic traits are under genetic control and/or are phenotypically plastic is essential in understanding how tree species will respond to rapid shifts in climate. We quantified hydraulic traits in Eucalyptus obliqua L'Her. across a precipitation gradient in the field to describe (i) trait variation in relation to long-term climate and (ii) the short-term (seasonal) ability of traits to adjust (i.e., phenotypic plasticity). Seedlings from each field population were raised under controlled conditions to assess (iii) which traits are under strong genetic control. In the field, drier populations had smaller leaves with anatomically thicker xylem vessel walls, a lower leaf hydraulic vulnerability and a lower water potential at turgor loss point, which likely confers higher hydraulic safety. Traits such as the water potential at turgor loss point and ratio of sapwood to leaf area (Huber value) showed significant adjustment from wet to dry conditions in the field, indicating phenotypic plasticity and importantly, the ability to increase hydraulic safety in the short term. In the nursery, seedlings from drier populations had smaller leaves and a lower leaf hydraulic vulnerability, suggesting that key traits associated with hydraulic safety are under strong genetic control. Overall, our study suggests a strong genetic control over traits associated with hydraulic safety, which may compromise the survival of wet-origin populations in drier future climates. However, phenotypic plasticity in physiological and morphological traits may confer sufficient hydraulic safety to facilitate genetic adaptation.

scholarly journals Drought-Induced Mortality Is Related to Hydraulic Vulnerability Segmentation of Tree Species in a Savanna Ecosystem

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 697 ◽  
Author(s):  
Shubin Zhang ◽  
Guojing Wen ◽  
Daxin Yang
Keyword(s):  
Mortality Rate ◽  
Water Potential ◽  
Tree Species ◽  
Hydraulic Conductance ◽  
Recruitment Rate ◽  
Hydraulic Failure ◽  
Hydraulic Vulnerability ◽  
Hydraulic Safety ◽  
The Difference ◽  
Seasonal Droughts

Vulnerability segmentation (VS) has been widely suggested to protect stems and trunks from hydraulic failure during drought events. In many ecosystems, some species have been shown to be non-segmented (NS species). However, it is unclear whether drought-induced mortality is related to VS. To understand this, we surveyed the mortality and recruitment rate and measured the hydraulic traits of leaves and stems as well as the photosynthesis of six tree species over five years (2012–2017) in a savanna ecosystem in Southwest China. Our results showed that the NS species exhibited a higher mortality rate than the co-occurring VS species. Across species, the mortality rate was not correlated with xylem tension at 50% loss of stem hydraulic conductivity (P50stem), but was rather significantly correlated with leaf water potential at 50% loss of leaf hydraulic conductance (P50leaf) and the difference in water potential at 50% loss of hydraulic conductance between the leaves and terminal stems (P50leaf-stem). The NS species had higher Huber values and maximum net photosynthetic rates based on leaf area, which compensated for a higher mortality rate and promoted rapid regeneration under the conditions of dry–wet cycles. To our knowledge, this study is the first to identify the difference in drought-induced mortality between NS species and VS species. Our results emphasize the importance of VS in maintaining hydraulic safety in VS species. Furthermore, the high mortality rate and fast regeneration in NS species may be another hydraulic strategy in regions where severe seasonal droughts are frequent.

Seasonal Changes in the Water Relations of Eucalyptus behriana F. Muell. And E. microcarpa (Maiden) Maiden in the Field

1984 ◽  
Vol 32 (5) ◽  
pp. 495 ◽  
Author(s):  
BA Myers ◽  
TF Neales
Keyword(s):  
Water Potential ◽  
Water Relations ◽  
Rainfall Intensity ◽  
Field Measurements ◽  
Canopy Conductance ◽  
Laboratory Studies ◽  
Short Term ◽  
The Mean ◽  
Type Response ◽  
Vapour Pressure Difference

Field observations of some parameters of the water relations of the two eucalypt species E. behriana and E. microcarpa in dry sclerophyll, mallee and woodland vegetation were made at three sites from 1980 to 1983. The mean ( n = 519) water potential measured at dawn (Ψdawn) was -3.07± 0.01 MPa and fluctuated seasonally with rainfall intensity over the range -2.0 ± 0, 1 to -4.4 ± 0.1 MPa ( n = 30). Both species behaved similarly and some osmotic adjustment took place. Mean leaf conductance (gs) varied between 0.151 ± 0.006 and 0.003 ± 0.001 mol m-2 s-1 . Maximum daily values of gs were linearly related to Ψdawn as it fluctuated seasonally. The slope of this linear regression was not significantly different from that relating these values of gs and Ψ, when both were measured concurrently. There were thus no indications of a distinction between the responses of gs to long- and short-term fluctuations of Ψ or of a threshold-type response of gs to Ψ. Field measurements indicated that gs was decreased at high values of vapour pressure difference (Δe). In laboratory studies with seedlings of the two species gs decreased from 0.5 to 0.1 mol m-2 s-I as Δe increased from 0.5 to 3.0 kPa. Leaf and canopy conductance were the predominant plant determinants of transpiration rate (Er) in this type of vegetation which has the capacity to restrict Et via the effect of water potential (Ψ) on gs and also by the response of gs to Δe. Some of the water relations parameters of E. behriana indicated that this species was better able to withstand drought than was E microcarpa.

scholarly journals Vaccinium gaultherioides: Another insight into water relations of alpine dwarf shrubs

2015 ◽  
Vol 2 ◽  
pp. e004 ◽  
Author(s):  
Andrea Ganthaler ◽  
S. Mayr
Keyword(s):  
Growth Form ◽  
Current Knowledge ◽  
European Alps ◽  
Hydraulic Parameters ◽  
Turgor Loss Point ◽  
Dwarf Shrubs ◽  
Hydraulic Safety ◽  
Conductivity Cell ◽  
Osmotic Properties ◽  
Insight Into

Dwarf shrubs exhibit different requirements for a safe and efficient water supply compared to trees due their basitonic branching and low growth height. Though, only few studies dealt with the hydraulics of this growth form. Here we report key hydraulic parameters (vulnerability to drought-induced embolism, xylem hydraulic conductivity, cell osmotic potential, potential at turgor loss point) and related wood anatomical traits for Vaccinium gaultherioides, a wide-spread species in the European Alps. The results affirm the current knowledge, by indicating a relatively risky hydraulic strategy with low hydraulic safety compared to alpine trees and osmotic properties connected to the species’ soil humidity requirements.

scholarly journals Maternal effect determines drought resistance of eggs in the predatory mite Phytoseiulus persimilis

Oecologia ◽  
2019 ◽  
Vol 192 (1) ◽  
pp. 29-41 ◽  
Author(s):  
Sophie Le Hesran ◽  
Thomas Groot ◽  
Markus Knapp ◽  
Tibor Bukovinszky ◽  
Jovano Erris Nugroho ◽  
...  
Keyword(s):  
Phenotypic Plasticity ◽  
Maternal Effect ◽  
Environmental Changes ◽  
Biological Control Agent ◽  
Phytoseiulus Persimilis ◽  
Predatory Mite ◽  
Control Agent ◽  
Hatching Rate ◽  
Dry Conditions ◽  
Low Humidity

AbstractThe ability of an organism to adapt to short-term environmental changes within its lifetime is of fundamental importance. This adaptation may occur through phenotypic plasticity. Insects and mites, in particular, are sensitive to changes in temperature and humidity, especially during the juvenile stages. We studied the role of phenotypic plasticity in the adaptation of eggs to different relative humidity conditions, in the predatory mite Phytoseiulus persimilis, used worldwide as a biological control agent of the spider mite Tetranychus urticae. The biocontrol efficacy of P. persimilis decreases under dry conditions, partly because P. persimilis eggs are sensitive to drought. We exposed P. persimilis adult females from two different strains to constant and variable humidity regimes and evaluated the hatching rate of their eggs in dry conditions, as well as the survival and oviposition rates of these females. Whereas the eggs laid by P. persimilis females exposed to constant high humidity did not survive in dry conditions, females exposed to constant low humidity started laying drought-resistant eggs after 24 h of exposure. Survival and oviposition rates of the females were affected by humidity: females laid fewer eggs under constant low humidity and had a shorter lifespan under constant high and constant low humidity. The humidity regimes tested had similar effects across the two P. persimilis strains. Our results demonstrate that transgenerational phenotypic plasticity, called maternal effect, allows P. persimilis females to prepare their offspring for dry conditions.

scholarly journals Short‐term suppression of Aedes aegypti using genetic control does not facilitate Aedes albopictus

2015 ◽  
Vol 72 (3) ◽  
pp. 618-628 ◽  
Author(s):  
Kevin Gorman ◽  
Josué Young ◽  
Lleysa Pineda ◽  
Ricardo Márquez ◽  
Nestor Sosa ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Genetic Control ◽  
Aedes Albopictus ◽  
Short Term

Variation in water potential components among half-sib families of shortleaf pine (Pinusechinata) in response to soil drought

1992 ◽  
Vol 22 (1) ◽  
pp. 111-116 ◽  
Author(s):  
H.S. Choi
Keyword(s):  
Drought Stress ◽  
Water Potential ◽  
Drought Resistance ◽  
Water Volume ◽  
Soil Drought ◽  
Shortleaf Pine ◽  
Turgor Loss Point ◽  
Drought Conditions ◽  
Sib Families ◽  
Elastic Modules

To assess family differences in response to drought, various water potential components of seedlings from six half-sib families of shortleaf pine (Pinusechinata Mill.) were compared under control (well-watered) and drought conditions. Drought stress resulted in significant changes in water relations parameters of the seedlings between treatments and among families. Although both Montgomery (103) and Pope (322) families had a superior capacity to adjust osmotically to both treatments, Montgomery (103) family exhibited greater potential to adapt to droughty environments through having the lowest values of osmotic potential both at maximum turgor and at the turgor loss point and having the highest values of (i) mean volume of osmostic water at the turgor loss point per volume of symplasmic water, (ii) symplasmic water volume per total shoot water volume, (iii) maximum bulk elastic modules, and (iv) turgor potential. Families Polk (115) and Scott (202) showed intermediate responses to drought. Both Scott (219) and Yell (342) families showed the lowest ability for osmotic adjustment to both treatments, but Yell (342) family revealed even lower drought resistance responses. Results from this study may provide the means of screening families that have high drought resistance potential during the field establishment period.

A dynamic simulation of loblolly pine (Pinustaeda L.) seedling establishment based upon carbon and water balances

1988 ◽  
Vol 18 (7) ◽  
pp. 833-850 ◽  
Author(s):  
John I. Blake ◽  
Gerrit Hoogenboom
Keyword(s):  
Drought Stress ◽  
Water Potential ◽  
Loblolly Pine ◽  
Carbon Allocation ◽  
Weather Data ◽  
Soluble Carbohydrate ◽  
Plant Water ◽  
Short Term ◽  
Evaporative Demand ◽  
Plant Water Potential

A generalized simulation model, ROOTSIMU, which utilizes dynamic carbon and water balance algorithms, was modified to simulate loblolly pine (Pinustaeda L.) seedling growth and water uptake for a 100-day transplant period. The modifications included an allowance for time-dependent changes in photosynthesis and carbon allocation. Heat sums were used to control the initiation of growth. Additional compartments were added to separate the physiological functions of suberized and nonsuberized roots and secondary woody tissues. Values used to initialize the model were largely derived from the published literature. The predicted results of a simulation run using 1985 and 1986 weather data are reported. Changes in simulated plant water potential were closely related to periods of rainfall or high evaporative demand. Midday values were occasionally less than −7 MPa when evaporative demand was high. Simulated responses to the 1986 drought indicated that initial soil water potentials at planting affected survival at values of less than −0.064 MPa in a sandy soil. Simulated growth was very sensitive to the photosynthetic rate, less sensitive to initial soluble carbohydrate concentration, and insensitive to instantaneous carbon allocation in relation to drought stress. The predicted increase in total root length for 1985 corresponded to the responses reported in several controlled environmental studies, but these were generally higher than those reported under field conditions. The results suggest that the carbon balance algorithm represents potential root growth within the constraints imposed by the model assumptions. The extreme diurnal fluctuations in plant water potential indicate that one or more important components of the plant system used to regulate short-term drought stress are not represented. Both stem tissue capacitance and the hydraulic conductance of mycorrhizal mycelia at low soil moisture contents may be important in controlling short-term water deficits. Further advances in the application of similar models depend upon an evaluation of these variables and a better theoretical and experimental determination of the effects of the geometry of the transplanted root system.

Adaptation to heterogeneous environments. II.* Phenotypic plasticity in response to spacing in Linum

1976 ◽  
Vol 27 (4) ◽  
pp. 519 ◽  
Author(s):  
MA Khan ◽  
AD Bradshaw
Keyword(s):  
Natural Selection ◽  
Phenotypic Plasticity ◽  
Genetic Control ◽  
Linum Usitatissimum ◽  
Field Conditions ◽  
Heterogeneous Environments ◽  
Varietal Differences ◽  
Individual Character ◽  
Abundant Evidence ◽  
Epigenetic Processes

Six varieties of Linum usitatissimum, three of flax and three of linseed, were grown under field conditions at six different spacings, from 1 to 32 in. (2.5–81.3 cm) apart. There was abundant evidence of varietal differences in phenotypic plasticity in response to variation in spacing. This indicates that response to spacing is a genetically controlled and not an automatic phenomenon. The major differences were between the flax and linseed groups; linseed varieties were more responsive in branching. However, there were considerable differences between varieties within each group. Different characters showed very different patterns and degrees of response, which indicated that control of response operates on an individual character rather than on a whole organisms basis. Plausible explanations in terms of natural selection can be given for the origin of many of the differences in the response of varieties and in characters. Taken as a whole, the results suggest that there is precise genetic control of the epigenetic processes involved in the response of plants to spacing, and that evolution of different patterns of response can easily occur. _______________ *Part 1, Evolution, 22: 496-516 (1968).

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