The hydraulic architecture of an arborescent monocot: ontogeny‐related adjustments in vessel size and leaf area compensate for increased resistance

2021 ◽  
Author(s):  
Dongmei Yang ◽  
Yinshuang Zhang ◽  
Dan Zhou ◽  
Yong‐Jiang Zhang ◽  
Guoquan Peng ◽  
...  
2019 ◽  
Vol 70 (21) ◽  
pp. 6195-6201 ◽  
Author(s):  
Silvia Lechthaler ◽  
Pierluigi Colangeli ◽  
Moira Gazzabin ◽  
Tommaso Anfodillo

Abstract The structure of leaf veins is typically described by a hierarchical scheme (e.g. midrib, 1st order, 2nd order), which is used to predict variation in conduit diameter from one order to another whilst overlooking possible variation within the same order. We examined whether xylem conduit diameter changes within the same vein order, with resulting consequences for resistance to embolism. We measured the hydraulic diameter (Dh), and number of vessels (VN) along the midrib and petioles of leaves of Acer pseudoplatanus, and estimated the leaf area supplied (Aleaf-sup) at different points of the midrib and how variation in anatomical traits affected embolism resistance. We found that Dh scales with distance from the midrib tip (path length, L) with a power of 0.42, and that VN scales with Aleaf-sup with a power of 0.66. Total conductive area scales isometrically with Aleaf-sup. Embolism events along the midrib occurred first in the basipetal part and then at the leaf tip where vessels are narrower. The distance from the midrib tip is a good predictor of the variation in vessel diameter along the 1st order veins in A. pseudoplatanus leaves and this anatomical pattern seems to have an effect on hydraulic integrity since wider vessels at the leaf base embolize first.


2015 ◽  
Vol 42 (9) ◽  
pp. 888 ◽  
Author(s):  
Sepideh Zolfaghar ◽  
Randol Villalobos-Vega ◽  
Melanie Zeppel ◽  
Derek Eamus

Heterogeneity in water availability acts as an important driver of variation in plant structure and function. Changes in hydraulic architecture represent a key mechanism by which adaptation to changes in water availability can be expressed in plants. The aim of this study was to investigate whether differences in depth-to-groundwater influence the hydraulic architecture of Eucalyptus trees in remnant woodlands within mesic environments. Hydraulic architecture of trees was examined in winter and summer by measuring the following traits: Huber value (HV: the ratio between sapwood area and leaf area), branch hydraulic conductivity (leaf and sapwood area specific), sapwood density, xylem vulnerability (P50 and Pe) and hydraulic safety margins across four sites where depth-to-groundwater ranged from 2.4 to 37.5 m. Huber value increased significantly as depth-to-groundwater increased. Neither sapwood density nor branch hydraulic conductivity (sapwood and leaf area specific) varied significantly across sites. Xylem vulnerability to embolism (represented by P50 and Pe) in both seasons was significantly and negatively correlated with depth-to-groundwater. Hydraulic safety margins increased with increasing depth-to-groundwater and therefore trees growing at sites with deeper water tables were less sensitive to drought induced embolism. These results showed plasticity in some, but not all, hydraulic traits (as reflected in HV, P50, Pe and hydraulic safety margin) in response to increase in depth-to-groundwater in a mesic environment.


1991 ◽  
Vol 69 (10) ◽  
pp. 2158-2164 ◽  
Author(s):  
Durland L. Shumway ◽  
Kim C. Steiner ◽  
Marc D. Abrams

Two-year-old seedlings of green ash, Fraxinus pennsylvanica Marsh., representing five native populations from an east to west precipitation gradient, were grown under contrasting moisture regimes in the greenhouse. At midsummer and the end of the growing season, leaf areas, earlywood and latewood transverse areas, and several structural attributes of the xylem hydraulic system were compared between well-watered and drought-stressed seedlings. Xylem hydraulic capacity was essentially fixed by midsummer. Drought significantly reduced both earlywood and latewood production but had no significant effect on potentially functional xylem area (Apf) or flow velocity (v). The principal effect of drought on hydraulic architecture was a significant reduction in leaf area and therefore the ratios of potentially functional xylem area to unit leaf area (Apf to A1) and leaf specific conductivity (LSC). In contrast, populations differed significantly in all measured parameters, especially under drought conditions. Path analysis of LSC and its component variables revealed that treatment differences in LSC arose primarily through differences in A1; contributions from variation in Apf and especially flow velocity were relatively minor. In contrast, population variation in LSC could be attributed in roughly equal measure to variation in Apf and A1, and to a lesser degree to variation in flow velocity. The covariance between A1 and Apf was important for both treatment and population variation in LSC, suggesting a fundamental physiological linkage between these two aspects of plant hydraulic architecture. Among populations, high flow velocity tended to be associated with low Apf to A1 values, thereby minimizing population differences in the composite character LSC. Populations differed significantly in all attributes studied, in one environment or another, but those at either end of the precipitation gradient did not differ in several presumably important structural attributes. Although plant hydraulic architecture is genetically controlled and variable in green ash seedlings, its adaptive significance cannot be considered in isolation from other factors that control plant response to water stress. Key words: leaf specific conductivity, ecotypic variation, xylem structure.


2021 ◽  
Vol 12 ◽  
Author(s):  
Irina Mozo ◽  
María E. Rodríguez ◽  
Silvia Monteoliva ◽  
Virginia M. C. Luquez

Willows are widely planted in areas under risk of flooding. The physiological responses of willows to flooding have been characterized, but little is known about their responses during the post-flooding period. After the end of the stress episode, plants may modify some traits to compensate for the biomass loss during flooding. The aim of this work was to analyze the post-flooding physiological responses of willow under two different depths of stagnant floodwater. Cuttings of Salix matsudana NZ692 clone were planted in pots in a greenhouse. The experiment started when the plants were 2 months old with the following treatments: Control plants (watered to field capacity); plants partially flooded 10 cm above soil level (F10) and plants partially flooded 40 cm above soil level (F40). The flooding episode lasted 35 days and was followed by a recovery period of 28 days (post-flooding period). After the flooding period, height, diameter and total biomass were higher in F10, while F40 plants showed an increase in plant adventitious root production and leaf nitrogen content. During the post-flooding period, the photosynthetic rate, nitrogen, chlorophyll and soluble sugar contents were significantly higher in leaves of F40 than in Control and F10 treatments. Stomatal conductance and specific leaf area were higher in the previously flooded plants compared to Control treatment. Plants from F10 treatments showed a higher growth in height, root-to-shoot ratio, and carbon isotope discrimination than F40, while the opposite occurred for growth in diameter, vessel size and leaf area. We conclude that depth of floodwater not only causes different responses during flooding, but that its effects are also present in the post-flooding recovery period, affecting the growth and physiology of willows once the stress episode has ended. Even when flooding impacted growth negatively in F40, in the post-flooding period these plants compensated by increasing the photosynthetic rate, plant leaf area and xylem vessel size. Willows endurance to flooding is the result of both responses during flooding, and plastic responses during post-flooding.


2018 ◽  
Vol 24 (2) ◽  
Author(s):  
SUPRIYA DIXIT ◽  
R. K. GUPTA

Currently, a real challenge for the workers in the agricultural research field is to stop or reduce the use of expensive agrochemicals/ chemical fertilizers which are hazardous to the environment as well as human health. Present study was aimed to improve the growth and obtain optimum yield of Vigna crop with eco-friendly, non-toxic way and to reduce the use of agrochemical/chemical fertilizer application in agricultural activities. A pot experiment was conducted to study the effect of chemical fertilizer (DAP) and biofertilizer ( Rhizobium strain) separately and in combination on seed germination and seedling growth (at 30 days) based on morphological parameters such as seedling length (cm), fresh weight (g), dry weight (g) and leaf area (cm)2 of Vigna radiata (L.) Wilczek. After one month (30 Days) observations, it was found that seedling length, fresh and dry weights and leaf area were maximum in T4 and minimum in T15, T7 and T8 favored improved seedling length and leaf area whereas T7, T8, and T9 favored improved fresh and dry weights as compared to control.


Efficiency of combination of soil herbicide Command (CE 0.02 ml/m2) and growth stimulators Melafen and Emistim S for tobacco seedling growing in sheltered ground has been studied. Before studies inhibition properties of herbicide on first stage of tobacco growing were found. For decreasing effect of herbicide ’s depression and increasing growing processes researches during greenhouse and field stages have been carried. It has been found that soaking seeds in solution of growth stimulator Melafen (concentration 0.05 %) and Emistim S (concentration 0.00001 %) during 3 hours in combination with further treatments on basic stages of seedling development (cotyledon and ready for transplanting before pulling out) led not only to decreasing toxic effect of herbicide but also increasing qualitative properties of tobacco plants. Growth stimulators led to increasing length of plants from collar to growing point by 46-62 %, to end of tips - by 20-35 %, above ground plant mass - by 42 - 86 %, root mass - by 32 %. It was also noticed 28 - 36 % increasing outcome of standard seedlings from m2 in time of transplanting. Due to prolonged effect of Melafen and Emistim S seedlings transplanted into field were with increased surviving properties. Later, due to increased growing rate it was noticed increasing leaf area by 9-18 % and productivity - by 16-24 %. Economic effect due to utilizing growth stimulators Melafen and Emistim S during seedling stage reaches 360 and 470 rubles/m2 and during field stage - 66 and 98 th.rubles/ha respectively. Offered elaboration can be utilized for protecting systems of different agricultural plants where utilizing soil herbicides is recommended. Also quality of cured tobacco grown with stimulators had been improved.


Sign in / Sign up

Export Citation Format

Share Document