DROUGHT TOLERANCE IN MULBERRY (MORUS SPP.): A PHYSIOLOGICAL APPROACH WITH INSIGHTS INTO GROWTH DYNAMICS AND LEAF YIELD PRODUCTION

2010 ◽  
Vol 46 (4) ◽  
pp. 471-488 ◽  
Author(s):  
ANIRBAN GUHA ◽  
GIRISH KUMAR RASINENI ◽  
ATTIPALLI RAMACHANDRA REDDY

SUMMARYThe present study documents critical analysis of drought-induced physiological responses in mulberry (Morus spp.) with insights into growth dynamics and leaf productivity. The study was performed for two years in a two-phase experimental design combining both field (experiment no. 1) and glasshouse (experiment no. 2) observations. In field assays, we surveyed 15 mulberry genotypes under two irrigation regimes: well-watered (20 to 24 irrigations in each growing season) and water-limited (irrigated once in a fortnight in each growing season). The genotypes were assessed for variation in key leaf gas exchange characteristics: net photosynthetic rates (Pn), stomatal conductance of CO2 (gs), transpiration rates (E) and instantaneous water use efficiency (WUEi). Leaf yield/plant was considered to determine the tolerance index (TI). Drought stress severely down-regulated leaf-level physiological variables in the susceptible genotypes resulting in poor leaf yield. However, genotypes S-13 and V-1 performed better in terms of leaf gas exchange and proved their superiority over other genotypes in drought tolerance. Conversely, genotypes DD and Bogurai were highly susceptible to drought. Under glasshouse conditions, the combined leaf gas exchange/chlorophyll a fluorescence measurements further dissected out stomatal and non-stomatal restrictions to Pn. As internal/ambient CO2 ratio (Ci/Ca) decreased concurrently with gs in non-irrigated stands, it appeared that greater stomatal limitation to Pn was associated with decreased photo-assimilation and leaf yield production. Further, higher leaf temperature (TL) (>35 °C) and down-regulation of maximum quantum yield of photosystem II (Fv/Fm) were apparent in the susceptible compared to the tolerant genotypes, which indicated chronic photoinhibition due to photo-inactivation of photosystem II centres in the susceptible genotypes. Drought-induced trade-offs in biomass allocation were also highlighted. Overall, our results suggest that greater rooting vigour and leaf hydration status, minimal stomatal inhibition and stabilized photochemistry might play major roles in maintaining higher Pn and associated gas exchange functions in drought-tolerant mulberry genotypes under water stress conditions. The higher leaf yield production in tolerant than susceptible genotypes can be attributed to minimal plasticity in foliar gas exchange traits and better quantitative growth characteristics under low water regimes.

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 540a-540
Author(s):  
K.J. Prevete ◽  
R.T. Fernandez

Three species of herbaceous perennials were tested on their ability to withstand and recover from drought stress periods of 2, 4, and 6 days. Eupatorium rugosum and Boltonia asteroides `Snowbank' were chosen because of their reported drought intolerance, while Rudbeckia triloba was chosen based on its reported drought tolerance. Drought stress began on 19 Sept. 1997. Plants were transplanted into the field the day following the end of each stress period. The effects of drought on transpiration rate, stomatal conductance, and net photosynthetic rate were measured during the stress and throughout recovery using an infrared gas analysis system. Leaf gas exchange measurements were taken through recovery until there were no differences between the stressed plants and the control plants. Transpiration, stomatal conductance, and photosynthesis of Rudbeckia and Boltonia were not affected until 4 days after the start of stress. Transpiration of Eupatorium decreased after 3 days of stress. After rewatering, leaf gas exchange of Boltonia and Rudbeckia returned to non-stressed levels quicker than Eupatorium. Growth measurements were taken every other day during stress, and then weekly following transplanting. Measurements were taken until a killing frost that occurred on 3 Nov. There were no differences in the growth between the stressed and non-stressed plants in any of the species. Plants will be monitored throughout the winter, spring, and summer to determine the effects of drought on overwintering capability and regrowth.


OENO One ◽  
2017 ◽  
Vol 51 (1) ◽  
Author(s):  
Vivian Zufferey ◽  
Jean-Laurent Spring ◽  
Thibaut Verdenal ◽  
Agnès Dienes ◽  
Sandrine Belcher ◽  
...  

<p><strong>Aims : </strong>The aims of this study were to investigate the physiological behavior (plant hydraulics, gas exchange) of the cultivar Pinot Noir in the field under progressively increasing conditions of water stress and analyze the effects of drought on grape and wine quality.</p><p><strong>Methods and results : </strong>Grapevines of the variety <em>Vitis vinifera</em> L. cv. Pinot Noir (clone 9-18, grafted onto 5BB) were subjected to different water regimes (irrigation treatments) over the growing season. Physiological indicators were used to monitor plant water status (leaf and stem water potentials and relative carbon isotope composition (d<sup>13</sup>C) in must sugars). Leaf gas exchange (net photosynthesis A and transpiration E), leaf stomatal conductance (gs), specific hydraulic conductivity in petioles (K<sub>petiole</sub>), yield components, berry composition at harvest, and organoleptic quality of wines were analyzed over a 7-year period, between 2009 and 2015, under relatively dry conditions in the canton of Wallis, Switzerland. A progressively increasing water deficit, observed throughout the season, reduced the leaf gas exchange (A and E) and gs in non-irrigated vines. The intrinsic water use efficiency (WUE<sub>i</sub>, A/gs) increased during the growing season and was greater in water-stressed vines than in well-watered vines (irrigated vines). This rise in WUE<sub>i</sub> was correlated with an increase in d<sup>13</sup>C in must sugars at harvest. Drought led to decreases in K<sub>petiole</sub>, E and sap flow in stems. A decrease in vine plant vigor was observed in vines that had been subjected to water deficits year after year. Moderate water stress during ripening favored sugar accumulation in berries and caused a reduction in total acidic and malic contents in must and available nitrogen content (YAN). Wines produced from water-stressed vines had a deeper color and were richer in anthocyanins and phenol compounds compared with wines from well-watered vines with no water stress. The vine water status greatly influenced the organoleptic quality of the resulting wines. Wines made from non-irrigated vines with a water deficit presented more structure and higher-quality tannins. They were also judged to be more full-bodied and with blended tannins than those made from irrigated vines.</p><p><strong>Conclusions : </strong>Grape ripening and resulting Pinot Noir wines were found to be largely dependent on the water supply conditions of the vines during the growing season, which influenced gas exchange and plant hydraulics.</p><p><strong>Significance and impact of the study : </strong>Plant water status constitutes a key factor in leaf gas exchange, canopy water use efficiency, berry composition and wine quality.</p>


2017 ◽  
Vol 142 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Richard J. Heerema ◽  
Dawn VanLeeuwen ◽  
Marisa Y. Thompson ◽  
Joshua D. Sherman ◽  
Mary J. Comeau ◽  
...  

Zinc deficiency is common in pecan (Carya illinoinensis) grown in alkaline, calcareous soils. Zinc (Zn)-deficient pecan leaves exhibit interveinal chlorosis, decreased leaf thickness, and reduced photosynthetic capacity. Low photosynthesis (Pn) contributes to restricted vegetative growth, flowering, and fruiting of Zn-deficient pecan trees. Our objectives were to measure effects of soil-applied ethylenediaminetetraacetic acid (EDTA)-chelated Zn fertilizer on gas exchange of immature ‘Wichita’ pecan and characterize the relationship between leaf Zn concentration and Pn. The study orchard had alkaline and calcareous soils and was planted in Spring 2011. Zinc was applied throughout each growing season as Zn EDTA through microsprinklers at rates of 0 (Control), 2.2, or 4.4 kg·ha−1 Zn. Leaf gas exchange and SPAD were measured on one occasion in the 2012 growing season, four in 2013, and five in 2014. Soil Zn-EDTA applications significantly increased the leaf tissue Zn concentration throughout the study. On all measurement occasions, net Pn was significantly increased by soil-applied Zn EDTA compared with the control, but Pn was not different between the two soil-applied Zn-EDTA treatments. Leaf Pn in midseason did not increase at leaf tissue Zn concentrations above 14–22 mg·kg−1. Leaf SPAD consistently followed a similar pattern to Pn. Soil Zn-EDTA application increased leaf stomatal conductance (gS) compared with the Control early through midseason but not after August. Intercellular CO2 concentration was significantly lower for Zn-EDTA-treated trees than the Control even on dates when there was no significant difference in gs, which suggests that soil application of Zn-EDTA alleviated nonstomatal limitations to Pn caused by Zn deficiency.


Trees ◽  
2015 ◽  
Vol 30 (1) ◽  
pp. 203-214 ◽  
Author(s):  
Priscilla A. Silva ◽  
Igor V. Oliveira ◽  
Kátia C. B. Rodrigues ◽  
Vanessa S. Cosme ◽  
Abel J. R. Bastos ◽  
...  

Botany ◽  
2008 ◽  
Vol 86 (4) ◽  
pp. 435-441 ◽  
Author(s):  
Luca Vitale ◽  
Carmen Arena ◽  
Amalia Virzo De Santo ◽  
Nicola D’Ambrosio

Gas exchange and chlorophyll a fluorescence measurements were performed simultaneously on leaves of Phillyrea angustifolia L. to assess the effects of heat stress (30 min at 40 °C) on photosynthesis and photosystem II (PSII) photochemical efficiency of plants grown at ambient CO2 and exposed to an elevated CO2 concentration (800 µmol·mol–1) and 300 µmol photons·m–2·s–1. No significant difference was found in the heat-induced decreases of net photosynthesis (PN), quantum yield of PSII electron transport (ΦPSII), and maximum PSII photochemical efficiency (Fv/Fm) between plants exposed to ambient and elevated CO2 concentrations, showing that elevated CO2 was not able to reduce the potential for photoinhibition at high temperatures under moderate light conditions. The heat-induced decrease of PN was higher than that of ΦPSII indicating that reductive power was more utilized in non-assimilatory processes than in CO2 fixation at both CO2 treatments. This result suggested that impairment of the Calvin cycle rather than electron transport inhibition was the main cause of the limitation in CO2 fixation.


OENO One ◽  
2020 ◽  
Vol 54 (3) ◽  
pp. 553-568
Author(s):  
Vivian Zufferey ◽  
Thibaut Verdenal ◽  
Agnès Dienes ◽  
Sandrine Belcher ◽  
Fabrice Lorenzini ◽  
...  

Aims: The aim of the present study was to analyse the impact of different water regimes on the physiological and agronomical behavior of an aromatic white grapevine (cv. Arvine) by means of various levels of irrigation. The consequences of the plant water status were evaluated by carrying out a chemical (aromatic precursors) and sensorial analysis of the resulting wines.Methods and results: Adult vines of Vitis vinifera L. cv. Arvine grafted onto 5BB were subjected to different water regimes (various levels of irrigation) during the growing season. Physiological indicators were used to monitor the plant water status [pre-dawn leaf (ΨPD) and stem (ΨSTEM) water potentials and carbon isotope composition (d13C) in the must]. Gas exchange (net photosynthesis AN and transpiration E), stomatal conductance (gs), yield parameters, berry composition at harvest, analysis of potential grape aromatic properties (glycosyl-glucose G-G, precursor 3-mercaptohexanol P 3-MH) and the sensorial quality of wines were analysed over a period of 8 consecutive years (2009-2016) in the Agroscope experimental vineyard in Leytron under the relatively dry conditions of the Rhône valley in Wallis, Switzerland.In the non-irrigated vines, the progressively increasing water deficit observed over the season reduced the leaf gas exchange (AN and E) and gs. The intrinsic water use efficiency (WUEi, A/gs) increased over the season and was greater in the vines that had suffered water restriction than in the irrigated vines. The rise in WUEi was correlated with an increase in d13C in the must sugars at harvest. A decrease in plant vigor was observed in the water stressed vines over multiple years. Moderate to high water stress during fruit ripening lowered the contents of total and malic acidity in the musts and the content of yeast available nitrogen (YAN). On the other hand, contents in sugar and the aromatic precursor (P-3MH) in berries were not influenced by the vine water status. The G-G values for berries increased with rising water stress in the non-irrigated vines. The wines from the plants subjected to water stress and to yeast available nitrogen deficiency (non-irrigated vines during hot and dry seasons) had a less distinctive typicity, and developed a lower aromatic expression with a more bitter taste, than the wines from the non-stressed plants. Overall, and compared with the stressed vines, the organoleptic characteristics and quality of Arvine wines from vines which had not undergone restrictions in water and nitrogen during the growing season were appreciated more.Conclusions: The vine’s physiological behavior (leaf gas exchange, plant vigor) and agronomic parameters (yield, berry composition), together with the quality of white aromatic Arvine wines, were strongly influenced by vine water regimes during the growing season.Significance and impact of the study: Vine water status and must nitrogen contents are key factors in grape composition and in the sensorial quality of resulting aromatic white wines.


2012 ◽  
Vol 63 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Edward Borowski ◽  
Sławomir Michałek

In a pot experiment conducted in a phytotron, the effectiveness of foliar nutrition of spinach (Spinacia oleracea L.) with different magnesium salts with and without the addition of 0.5% CO(NH<sub>2</sub>)<sub>2</sub> was studied. Magnesium was applied 3 times in the form of solutions of MgSO<sub>4</sub> x 7H<sub>2</sub>O, Mg(NO<sub>3</sub>)<sub>2</sub> x 6H<sub>2</sub>O, MgCl<sub>2</sub> x 6H<sub>2</sub>O, C<sub>4</sub>H<sub>6</sub>O<sub>4</sub>Mg x 4H<sub>2</sub>O, compared to water as the control treatment. The obtained results showed that foliar feeding of spinach with inorganic magnesium salts was an efficient method for supplementing the Mg level in plants during the growing period. But the application of a metalo-organic complex in the form of magnesium acetate (C<sub>4</sub>H<sub>6</sub>O<sub>4</sub>Mg x 4H<sub>2</sub>O) at a concentration of 1.7%, in spite of a similar effect on leaf Mg content, induced phytotoxic symptoms in the form of chlorotic and necrotic spots on the leaves. The application of the solutions of inorganic magnesium salts had a significant effect, resulting in more intensive leaf gas exchange (stomatal conductance, transpiration and photosynthesis) and an increase in leaf yield. Magnesium sulphate affected the abovementioned processes in the most effective way, while magnesium acetate had a negative impact. Foliar feeding of spinach with the magnesium salts resulted in an increased leaf content of protein, chlorophyll, carotenoids, nitrates and proline, but a decrease in vitamin C content. The addition of urea to the applied magnesium salt solutions increased the plant gas exchange rates and the leaf content of protein, chlorophyll, carotenoids, nitrates and proline, but it decreased the content of vitamin C, potassium and magnesium.


Sign in / Sign up

Export Citation Format

Share Document