Differences In Photosynthetic Rates Research Articles

High canopy photosynthesis before anthesis explains the outstanding yield performance of rice cultivars with ideal plant architecture

ContextThe majority of investigations on mechanisms underlying yield difference between superior and conventional cultivars has focused on the grain-filling stage after anthesis. However, the physiological process before anthesis has been less explored. ObjectiveWe aimed to quantify the contribution of canopy photosynthesis at pre-anthesis stage to grain yield formation and clarify the mechanism underlying the yield advantage of the superior cultivars. MethodsThis study selected representative cultivars of indica and japonica rice, each type having a pair of cultivars with ideal plant architecture (IPA) and conventional architecture. Field experiments over four years (2019–2022) were conducted to compare the relevance of canopy photosynthesis to yield formation between the phases before and after anthesis. ResultsThe two IPA cultivars, JYZK-6 and ZZY-1, produced higher grain yield than the two conventional cultivars, NJ-5055 and HHZ. JYZK-6 and ZZY-1 also had good distribution of light interception inside the canopy, with the middle and lower part receiving more light than NJ-5055 and HHZ. At leaf level, there was no significant difference in photosynthetic rate between the two types of cultivars. At canopy level, the IPA cultivars had stronger photosynthetic activities before anthesis, outperforming NJ-5055 by 35.56% in averaged canopy photosynthesis, and by 46.65% in averaged daily net photosynthetic accumulation in 2021–2022. By contrast, canopy photosynthesis after anthesis was not significantly different between the two types. The IPA cultivars stored heavier biomass in internodes and sheaths before anthesis and remobilized more reserves to the developing grains, with the remobilization rate being 16.42% (internodes) and 35.34% (sheaths) higher than NJ-5055 and HHZ. ConclusionThe higher canopy productivity before anthesis is one of the main reasons accounting for the superior IPA cultivars, suggesting the necessity of optimizing plant growth and development during the vegetative and reproductive phases.

Controlling growth and carbohydrate utilization of tomato seedlings through day-night temperature difference and high light intensity under elevated CO2 conditions

Negative DIF, increasing nighttime temperature relative to daytime temperature, is widely used in the floral industry to reduce plant height. However, negative DIF can also reduce photosynthetic capacity in vegetative seedlings. We investigated the use of negative DIF combined with high light intensity under elevated CO2 and a long photoperiod to produce compact and well-developed tomato seedlings with reduced plant height. Seedlings were grown for 28 days under positive or negative DIF (with daytime/nighttime temperatures of 25 °C/19 °C or 21 °C/27 °C, respectively) combined with low or high light intensity [250 or 500 μmol m−2 s−1 photosynthetic photon flux density (PPFD), PPFD 250 or PPFD 500, respectively] at 1000 ppm CO2 (mean daily temperature: 23 °C across a photoperiod of 16 h d−1). Compared with positive DIF and PPFD 250, negative DIF with PPFD 500 significantly reduced plant height while tending to increase dry matter (DM) but decrease leaf area (LA). Relative growth rate was decreased under negative DIF despite the provision of PPFD 500, but there were no differences in photosynthetic rate and capacity parameters (e.g., total nitrogen and chlorophyll content at the LA level) between DIF treatments. Negative DIF and PPFD 500 might reduce DM by decreasing the amount of intercepted light in tomato seedlings. Negative DIF and PPFD 500 also increased respiration rate during nighttime and led to the consumption of more nonstructural carbohydrates (NSCs) at the LA level. Overall, our results indicate that negative DIF combined with high light intensity can maintain DM, photosynthetic capacity, and plant development while reducing plant height in tomato seedlings.

Glacial retreat and rising temperatures are limiting the expansion of temperate kelp species in the future Arctic

AbstractKelps act as ecosystem engineers on many polar rocky shore coastlines. The underwater light climate and temperature are the main drivers for their vertical and latitudinal distribution. With temperatures rising globally, an Arctic expansion of temperate kelp species and an accelerating glacial melt is predicted. It was our aim to investigate the effects of retreating glaciers and rising temperatures on the potential habitat of kelps in Arctic fjords. We analyzed the underwater light climate of areas being influenced by different stages of glacial retreat (sea‐terminating glacier, land‐terminating glacier, coastal water) in Arctic Kongsfjorden. We observed reduced light intensities and a changed spectral composition in glacial meltwater plumes, potentially resulting in an upward shift of the lower depth limit of kelp, counteracting the predicted biomass increase in the Arctic. Furthermore, we studied temperature‐related changes in light‐use characteristics in two kelp species (Alaria esculenta, Saccharina latissima) at 3°C, 7°C, and 11°C. Rising temperatures lead to a significant increase of the compensation irradiance of A. esculenta. The dark respiration of S. latissima increased significantly, correlating with a decreasing carbon content. We detected no differences in photosynthetic rates, although the chlorophyll a concentration of A. esculenta was ~ 78% higher compared to S. latissima. Ultimately, temperature‐induced changes in kelps light‐use characteristics might lead to a changed species composition, as we found A. esculenta better adapted to polar conditions. We conclude that the deterioration of the underwater light climate and the temperature increase may drive substantial changes of the future Arctic kelp forest structure.

Transcriptome analysis uncovering regulatory networks and hub genes of Populus photosynthesis and chlorophyll content

Photosynthesis plays vital role in plant growth and development throughout its life, and it is influenced by environmental signals and circadian rhythms. We analyzed the transcriptome landscape of the two poplars progeny with contrasting photosynthesis rates at three times point (ZT4, ZT16, ZT22), constructed gene regulatory network that related to circadian rhythm and photosynthesis. We suggest that the differences in photosynthetic rate between the progenies may originate from plant endogenous circadian oscillators prepare poplar plants for photosynthesis by regulating photosynthesis-associated nuclear genes and carotenoid metabolism genes before dawn, genes associated with plant hormone signal transduction and transcription factor increase leaf size and stomatal movement, the influence of other core regulatory factors on chlorophyll accumulation. Furthermore, overexpression of candidate regulatory gene, AP3 (Potri.007G017000), induced leaf senescence and reduced the content of chlorophyll. These results demonstrated that many potential key regulators are integrated closely with chlorophyll content and photosynthesis.

Comparison of water depth tolerance in two major wetland macrophytes, Phragmites australis and Typha angustifolia

Two major emergent macrophytes, Phragmites australis and Typha angustifolia, show a clear zonation with respect to water depth, i.e., P. australis occupies shallower water than T. angustifolia. However, the reasons for this interspecific difference is unclear. Therefore, this study focused on the features that enable T. angustifolia to survive at greater water depths than P. australis. In both outdoor and greenhouse experiments, P. australis did not survive at the deepest water depth and showed significantly lower biomass, nitrogen content, and photosynthesis in most deep and/or aerated water than T. angustifolia. Differences in tolerances to changes in the water depth and responses to root aeration may underlie the clear zonation of the two species. As T. angustifolia and P. australis are both very common in wetlands around the world, understanding the causal factors determining their depth distributions, such as differences in photosynthetic rate at different depths, will be of great importance for managing or controlling these species.

Modulation of photosynthesis in Synechocystis and Synechococcus grown with chromium (VI)

Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942 exhibit dissimilar tolerance to Cr(VI) with a tenfold difference in their EC50 value for Cr(VI). This contrasting tolerance was attributed to the difference in the ability to transport Cr(VI) and to detoxify ROS. The present study used biochemical assays and chlorophyll fluorescence to investigate the effect of growth with Cr(VI) on photosynthesis in the two cyanobacteria. In absence of Cr(VI), all the measured parameters viz., rates of CO2 fixation, PSII and PSI activities were higher in Synechocystis in comparison to Synechococcus, suggesting intrinsic differences in their photosynthesis. Growth in the presence of Cr(VI) reduced the pigment content and photosystems' activities in both cyanobacteria. It was further observed that photosynthetic functions were more adversely affected in Synechocystis in comparison to Synechococcus, in spite of exposure to tenfold lower Cr(VI) concentration. The effective quantumyield of PSII and PSI obtained by chlorophyll fluorescence measurements increased in the presence of Cr(VI) in Synechococcus whereas it decreased in Synechocystis. However, the overall CO2 fixation remained unchanged. These results indicated that, in addition to the intrinsic difference in photosynthetic rates, the two cyanobacteria exhibit differential modulation of photosynthetic machinery upon Cr(VI) exposure and Synechococcus could adapt better it's photosystems to counter the oxidative stress.

Photosynthesis and Related Physiological Parameters Differences Affected the Isoprene Emission Rate among 10 Typical Tree Species in Subtropical Metropolises.

Volatile organic compound (VOCs) emission is an important cause of photochemical smog and particulate pollution in urban areas, and urban vegetation has been presented as an important source. Different tree species have different emission levels, so adjusting greening species collocation is an effective way to control biogenic VOC pollution. However, there is a lack of measurements of tree species emission in subtropical metropolises, and the factors influencing the species-specific differences need to be further clarified. This study applied an in situ method to investigate the isoprene emission rates of 10 typical tree species in subtropical metropolises. Photosynthesis and related parameters including photosynthetic rate, intercellular CO2 concentration, stomatal conductance, and transpiration rate, which can influence the emission rate of a single species, were also measured. Results showed Salix babylonica always exhibited a high emission level, whereas Elaeocarpus decipiens and Ligustrum lucidum maintained a low level throughout the year. Differences in photosynthetic rate and stomatal CO2 conductance are the key parameters related to isoprene emission among different plants. Through the establishment of emission inventory and determination of key photosynthetic parameters, the results provide a reference for the selection of urban greening species, as well as seasonal pollution control, and help to alleviate VOC pollution caused by urban forests.

Calcium Nutrition in Coffee and Its Influence on Growth, Stress Tolerance, Cations Uptake, and Productivity

Calcium (Ca2+) is an important macronutrient in coffee and is involved in several physiological processes that influence crop growth, development, productivity, and stress response. This paper presents results from five experiments conducted on coffee under greenhouse and field conditions for over 5 years (2014–2018). The main objective of this study was to evaluate the influence of Ca+2 application on coffee growth, development, abiotic stress response, cation uptake, leaf cell structure, and productivity. The results show that Ca+2 directly influences the growth and development of plants and has a strong effect on root growth. Drought stress and low Ca+2 rates of 8 mg.L−1 showed no differences in photosynthetic rates (PN) and biomass accumulation; high Ca+2 rates between 75 and 150 mg.L−1 increased PN and biomass accumulation in plants under drought stress, with a positive correlation between Ca+2 content in the leaves and PN with and without drought stress. High air temperature (>30°C) reduced PN rates, and the treatment with proper Ca+2 application showed better PN compared to the treatments with low Ca+2. Ca+2 application showed a synergistic effect with potassium (K+) uptake and no influence on the magnesium (Mg+2) uptake but a reduction in the leaf concentration with the increase in Ca+2 application. Additionally, coffee plants with proper Ca+2 application showed thicker leaves, denser epidermis, and larger, more compact, and better-structured palisade parenchyma compared with the plants treated with Ca+2 at lower rates. After 5 years, the mean coffee yield showed a polynomial response with respect to the doses of Ca+2 applied, with optimum rate of 120 kg CaO ha−1year−1 and a peak of Ca+2 uptake by the coffee cherries during 110–220 days after flowering.

Detection of Defoliation Injury in Peanut with Hyperspectral Proximal Remote Sensing

Remote sensing can be applied to optimize efficiency in pest detection, as an insect sampling tool. This efficiency can result in more precise recommendations for decision making in pest management. Pest detection with remote sensing is often feasible because plant biotic stress caused by herbivory triggers a defensive physiological response in plants, which generally results in changes to leaf reflectance. Therefore, the key objective of this study was to use hyperspectral proximal remote sensing and gas exchange parameters to characterize peanut leaf responses to herbivory by Stegasta bosqueella (Lepidoptera: Gelechiidae) and Spodoptera cosmioides (Lepidoptera: Noctuidae), two major pests in South American peanut (Arachis hypogaea) production. The experiment was conducted in a randomized complete block design with a 2 × 3 factorial scheme (two lepidopterous species and 3 categories of injury). The injury treatments were: (1) natural infestation by third instars of S. bosqueella, (2) natural infestation by third instars of S. cosmioides, and (3) simulation of injury with scissors to mimic larval injury. We verified that peanut leaf reflectance is different between herbivory by the two larval species, but similar among real and simulated defoliation. Similarly, we observed differences in photosynthetic rate, stomatal conductance, transpiration, and photosynthetic water use efficiency only between species but not between real and simulated larval defoliation. Our results provide information that is essential for the development of sampling and economic thresholds of S. bosqueella and S. cosmioides on the peanut.

The Evolution of Functional Traits in Plants: Is the Giant Still Sleeping?

The Evolution of Functional Traits in Plants: Is the Giant Still Sleeping?

Seasonal gas exchange and resource-use efficiency in evergreen versus deciduous species from a tropical dry forest.

Tropical dry forests (TDFs) experience a long dry season in which plant species are subject to several months of water deficit. However, TDFs maintain a diverse group of plant life forms, growth forms and leaf phenology, and it is not clear how they vary in their mechanisms for coping with seasonal drought. We studied seasonal changes in leaf water potential (Ψleaf), gas exchange, photochemical activity and functional traits in evergreen and drought-deciduous species from a TDF to determine if leaf phenology mediates plant responses to drought. We found seasonal decreases in Ψleaf, stomatal conductance (gs) and transpiration rate (E), and increases in both intrinsic and instantaneous water-use efficiency. We did not find seasonal differences in photosynthetic rate (Aarea) and carbon isotope composition (δ13C); however, these traits differed between leaf phenology groups, with drought-deciduous plants having higher Aarea and δ13C than evergreen plants. We also found that plants with high leaf nitrogen concentration (Narea) also had low mass-based photosynthetic rate (Amass), photosynthetic-nitrogen-use efficiency and specific leaf area, contrary to the expected relationships given by the leaf economics spectrum. Despite higher Narea, sclerophyllous leaves maintained lower Amass, and this increased structural toughness of leaves may be imposing a stronger limitation for CO2 diffusion and hence photosynthesis. Overall, we found more water-conservative traits in deciduous than in evergreen plants, contrary to what is known about these two leaf phenology groups in other seasonal sites both at tropical and temperate latitudes.

Quantitation of oxalates in corms and shoots of Colocasia esculenta (L.) Schott under drought conditions

Oxalate (calcium oxalate) accumulation in taro plants (Colocasia esculenta (L.) Schott) impacts their nutritional quality, producing acridity, causing lips, mouth and throat tissues swelling if consumed fresh. The oxalate content is related to photosynthesis, through the glycolate–glyoxylate oxidation pathway. The plant’s photosynthetic rate usually increases in non-stressed conditions. Differences in photosynthetic rate are indirectly related to the chlorophyll content index. Protein accumulation and starch variation are also important traits to understand the taro oxalate synthesis caused by drought and how they affect corm quality. The purpose of this study was to quantitate oxalates in taro corms and shoots submitted to drought conditions and to evaluate how stress response can affect the nutritional quality of taro whole-plant. Seven taro genotypes from Madeira, Canaries and Pacific Community (SPC) collections were grown in greenhouse conditions and submitted to different watering regimes for drought tolerance screening. Corms and shoots were harvested and evaluated for oxalates (soluble, insoluble and total), chlorophyll content index (CCI), crude protein, starch, starch solubility in water and starch swelling power. All accessions had very high calcium oxalate content. Drought-tolerant genotypes showed good osmotic response by oxalate precipitation and mobilization through shoot to corm tissues, photosynthesis adaptation by increase of CCI, protein accumulation, and very low starch hydrolysis. Sensitive-drought genotypes showed less mobilization of calcium oxalate, decreased photosynthetic rate and protein synthesis, and slight increase of starch hydrolysis. Variation in taro oxalate content is consistent and significantly correlated with the photosynthetic rate, carbohydrate metabolism and protein synthesis.

A cost-effective and customizable automated irrigation system for precise high-throughput phenotyping in drought stress studies.

The development of high-yielding crops with drought tolerance is necessary to increase food, feed, fiber and fuel production. Methods that create similar environmental conditions for a large number of genotypes are essential to investigate plant responses to drought in gene discovery studies. Modern facilities that control water availability for each plant remain cost-prohibited to some sections of the research community. We present an alternative cost-effective automated irrigation system scalable for a high-throughput and controlled dry-down treatment of plants. This system was tested in sorghum using two experiments. First, four genotypes were subjected to ten days of dry-down to achieve three final Volumetric Water Content (VWC) levels: drought (0.10 and 0.20 m3 m-3) and control (0.30 m3 m-3). The final average VWC was 0.11, 0.22, and 0.31 m3 m-3, respectively, and significant differences in biomass accumulation were observed between control and drought treatments. Second, 42 diverse sorghum genotypes were subjected to a seven-day dry-down treatment for a final drought stress of 0.15 m3 m-3 VWC. The final average VWC was 0.17 m3 m-3, and plants presented significant differences in photosynthetic rate during the drought period. These results demonstrate that cost-effective automation systems can successfully control substrate water content for each plant, to accurately compare their phenotypic responses to drought, and be scaled up for high-throughput phenotyping studies.

Leaf transpiration plays a role in phosphorus acquisition among a large set of chickpea genotypes.

Low availability of inorganic phosphorus (P) is considered a major constraint for crop productivity worldwide. A unique set of 266 chickpea (Cicer arietinum L.) genotypes, originating from 29 countries and with diverse genetic background, were used to study P-use efficiency. Plants were grown in pots containing sterilized river sand supplied with P at a rate of 10μgPg-1 soil as FePO4 , a poorly soluble form of P. The results showed large genotypic variation in plant growth, shoot P content, physiological P-use efficiency, and P-utilization efficiency in response to low P supply. Further investigation of a subset of 100 chickpea genotypes with contrasting growth performance showed significant differences in photosynthetic rate and photosynthetic P-use efficiency. A positive correlation was found between leaf P concentration and transpiration rate of the young fully expanded leaves. For the first time, our study has suggested a role of leaf transpiration in P acquisition, consistent with transpiration-driven mass flow in chickpea grown in low-P sandy soils. The identification of 6 genotypes with high plant growth, P-acquisition, and P-utilization efficiency suggests that the chickpea reference set can be used in breeding programmes to improve both P-acquisition and P-utilization efficiency under low-P conditions.

Comparing growth and physiological responses of Globba schomburgkii Hook. f. and Globba marantina L. under hydroponic and soil conditions

Globba (Zingiberaceae) are attractive herbaceous plants widely used as ornamental plants. However, cultivation is limited because of low propagation rate and depends on the season only. This research aimed to compare growth and physiological responses of Globba schomburgkii Hook. f. and Globba marantina L. under both soil and hydroponic conditions. In vitro plantlets (8 cm in height) were transplanted to a hydroponic culture with the nutrient film technique (NFT). In soil culture, the plantlets were transplanted to small pots containing sand: burned rice husk: peat moss (1:1:1 by volume). Vegetative growth characteristics were measured at 15, 30, 45 and 60 days after transplanting (DAT), whereas reproductive growth and physiological characteristics were measured at 60 DAT. All there was 100% survival in both growth conditions. Plants of both species grown in hydroponic conditions had higher shoot length, leaf area and stem diameter, except number of shoots than when propagated in soil conditions. Moreover, both species grown in hydroponics had earlier inflorescences and more flowers, indicating that they can be flowering out of season. Additionally, in hydroponic conditions both species had significant higher stomatal conductivity, whereas there were no significant differences in photosynthetic rates, transpiration rates and leaf temperature when compared with soil conditions. Therefore, our study provides evidence that G. schomburgkii and G. marantina are capable of adapting to hydroponic conditions and that hydroponics may be a suitable method for propagating Globba and other ginger plant species into cut flower or potted plants all year round.

The Difference of Photosynthetic Responses to the Cadmium Stress Between a Wild Soybean (Glycine soja Sieb. et Zucc.) and a Cultivated Soybean.

The effects of Cd on a halophyte of Doingying wild soybean (DY-03262) were studied by comparing it with a cultivated soybean (SN-11) via investigating photosynthetic activity, chlorophyll fluorescence and Cd concentrations in leaves after treatment with different concentrations of Cd (0, 50, and 100μM) for 10 days. There were no significant differences in photosynthetic rate (PN), actual photochemical efficiency of PSII (ΦPSII), stomatal conductance (gs), and photochemical quenching (qP) between the both soybean species without Cd treatment, but they decreased greater in DY-03262 than that in SN-11 leaves after Cd treatment. The study demonstrated that the decrease in PN were significantly correlated with Cd concentrations in the leaves of both soybeans species. The greater decreases in photosynthetic activity of the DY-03262 were due to the higher Cd concentrations in its leaves.

Variations of water use efficiency and its relationship with leaf nutrients of different altitudes of Wuyi Mountains, China

We determined the water use efficiency and nitrogen and phosphorus concentrations of plants at different altitudes (600, 900, 1300, 1500, 1800, 2000, 2100 m) in Wuyi Mountains to understand the relationship of water use efficiency with foliar nutrients. The results showed that plant water use efficiency increased with altitude, and the leaf δ18O of tree showed no significant variance with altitude. On the whole, leaf nitrogen concentration showed no obvious trend, while leaf phosphorus concentration at high altitude was significantly higher than that at low altitude. No significant relationship between water use efficiency and foliar nitrogen concentration was found in this study, but water use efficiency had a positive correlation with foliar phosphorus concentration. In conclusion, the change of water use efficiency was mainly caused by the difference in photosynthetic rate. The effect of water status on plant water use efficiency was not significant. The variances of leaf phosphorus concentrations along the altitudinal gradient may affect photosynthetic rate and in turn the water use efficiency of plant in this area.

Succession in <i>Quercus gambelii</i> (Gambel’s Oak) Woodlands

Quercus gambelii (Gambel’s oak) communities are found in the mountains of the western United States from Wyoming, Colorado, and Utah south into northern Mexico. Leaf gas exchange rates were measured for potential successional species in Q. gambelii communities. Daily average light level below the canopy was 125 μmol/m2/sec. Light response curves indicated that Pinus ponderosa and Q. gambelii had high maximum photosynthetic rates (14.13 and 11.21 μmol/m2/sec) and were sun species. Abies concolor (white fir) is a shade species with the lowest photosynthetic rate (3.71 μmol/m2/sec). At low light levels few differences in photosynthetic rates were found between the species. Pinus ponderosa and Q. gambelii maximum photosynthetic rates were reduced 71% - 73% in shade and the shade species maximum photosynthetic rates were reduced by 50% - 57%. Comparing annual gas exchange rates for all species showed that A. concolor had higher gas exchange rates and could replace Q. gambelii. Growth in height of Q. gambelii was a second order quadratic function reaching a plateau of about ten meters between 80 and 95 years. Growth estimates of height of A. concolor in canopy shade were exponential, which would allow seedlings to reach the Q. gambelii canopy in approximately 35 years. Abies concolor wood specific gravity is 56% lower than Q. gambelii, which means more carbon is put into growth in height to reach the canopy at low light levels and low photosynthetic rates. The additional shading it causes would further reduce Q. gambelii photosynthesis rates and prevent self-replacement in these Q. gambelii communities, leading to an A. concolor dominated community.

Methane emission from irrigated rice ecosystem: relationship with carbon fixation, partitioning and soil carbon storage

Rice is a major agricultural crop and accounts for 40 % of the total food grain production of India. A field experiment was conducted for two successive seasons (December–June, 2012–13 and December–June, 2013–14) to assess the efficiency of rice varieties for methane (CH4) emission in relation to atmospheric carbon fixation, partitioning of carbon, and storage in the soil. Six high yielding rice varieties, Bahadur, Cauvery, Dinanath, Joymoti, Kanaklata, and Swarnabh were grown under irrigated condition. Results of the present investigation depicted differences in photosynthetic rate among the varieties accompanied by differential ability for plant biomass partitioning between the shoots and the roots. Stomatal frequency of flag leaf at panicle initiation stage was found to have strong influence on photosynthesis. Low CH4-emitting rice varieties, Bahadur and Dinanath, were found to have lower size of the xylem vessels than the high CH4-emitting rice varieties, Joymoti and Kanaklata, and found to influence the CH4 flux. Soil organic carbon storage of 0.505 Mg C ha−1 y−1 in the plough layer of soil (0–15 cm) confirmed that irrigated rice ecosystem is an effective sink of carbon. These findings suggest that selection of suitable rice varieties with higher photosynthetic efficiency and lower emission of CH4 can be a suitable biological mitigation of this greenhouse gas. Although an inverse relationship of CH4 with carbon dioxide (CO2) efflux was observed, irrigated rice ecosystem has a good potential to store substantial amount of carbon in the soil.

Pomegranate physiological responses to partial root drying under field conditions

The effects of different levels of Partial Root Drying (PRD) on pomegranate (Punica granatum L. cv. Wonderful) physiological and fruit quality parameters were studied under field conditions. Three irrigation treatments were applied: control (C) in which plants were irrigated at both parts of the rootzone to fully compensate evapotranspirational water losses; and partial root drying (PRD1 and PRD2) receiving 100% and 50% irrigation water of control plants, respectively. PRD plants exhibited lower stomatal conductance (Gs) and transpiration rate compared to the control plants. PRD1 maintained more favorable plant water status throughout the experimental period. On the contrary, no significant differences in photosynthetic rate (Pn) between PRD1 and control plants were observed. PRD2 plants exhibited significant lower values of all physiological parameters suggesting that the irrigation amount applied could not compensate water losses. Furthermore, higher level of water stress in PRD2 treatment resulted in a significant decrease in mean fruit weight and diameter. No significant effects of different irrigation methodologies on total titratable acidity and juice percentage were evident. Among all treatments, fruit cracking was significantly lower in PRD1 treatment, a fact that was associated with the maintenance of plant water status in this treatment throughout the experimental period.