scholarly journals Evaluation of Three New Citrus Rootstocks under Boron Toxicity Conditions

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2490
Author(s):  
Lidia Aparicio-Durán ◽  
Frederick G. Gmitter ◽  
Juan M. Arjona-López ◽  
Jude W. Grosser ◽  
Rocío Calero-Velázquez ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Mediterranean Basin ◽  
Negative Impact ◽  
Boron Toxicity ◽  
Limiting Factor ◽  
Carrizo Citrange ◽  
Visual Damage ◽  
Citrus Rootstock ◽  
Relative Water ◽  
Chlorophyll Index

Boron (B) toxicity is a common limiting factor both in arid and semiarid regions, such as the Mediterranean Basin. Citrus trees are sensitive to B-toxicity, which generates a negative impact in citrus orchards. In this work, two promising citrus rootstocks (UFR-6 and 2247 x 6070-02-2) have been assessed against B-toxicity and compared with Carrizo citrange, a common commercial citrus rootstock in Mediterranean Basin. Three B concentration treatments (Control, 1 and 2.5 mM H3BO3) were established, irrigating the plants three times per week for 21 days under greenhouse conditions. During the assay, above-ground symptoms, and chlorophyll index (SPAD) were recorded. At the end of the experiment, stomatal conductance, relative water content, and B concentration in leaves and roots were determined. The increasing B concentration in plants generates visual damage in leaves for all citrus rootstocks assayed. Carrizo citrange displayed the greatest visual symptoms, decreased its chlorophyll index (SPAD), and stomatal conductance throughout the B-treatment. However, UFR-6 and 2247 x 6070-02-2 displayed less symptoms than Carrizo citrange and only reduced its parameters under the 2.5 mM H3BO3 treatment. These results can aid citrus grower rootstock planting decisions with under B-toxicity conditions.

scholarly journals Salinity Effect on Plant Physiological and Nutritional Parameters of New Huanglongbing Disease-Tolerant Citrus Rootstocks

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 653
Author(s):  
Lidia Aparicio-Durán ◽  
Aurea Hervalejo-García ◽  
Rocío Calero-Velázquez ◽  
Juan M. Arjona-López ◽  
Francisco J. Arenas-Arenas
Keyword(s):  
Mediterranean Basin ◽  
Plant Material ◽  
Mineral Content ◽  
Emerging Diseases ◽  
Carrizo Citrange ◽  
Salinity Response ◽  
Chlorophyll Index ◽  
Damage Symptoms ◽  
Mediterranean Conditions ◽  
The Mediterranean Basin

Salinity is a major agriculture problem for citrus in the Mediterranean basin, which is a major global producer region. Citrus crops are also threatened by emerging diseases such as Huanglongbing (HLB). The use of different rootstocks increases the variability of citrus plant material in orchards, thus preventing extensive damage caused by abiotic and/or biotic diseases. In this work, we have evaluated the salinity response of five citrus rootstocks (US942, US897, X639, Forner Alcaide No. 5 and Carrizo citrange) some of which have known tolerance to HLB, under Mediterranean conditions. Four treatments with different salt concentrations (0, 25, 50 and 75 mM of NaCl) were applied by watering the plants three times per week for eleven weeks. Chlorophyll index (SPAD), growth and plant symptom parameters were recorded on a biweekly basis. At the end of the trial, roots, stem and leaves biomass and plant mineral content were obtained. The increasing concentration of NaCl resulted in visible leave damage symptoms for all citrus rootstocks assayed, hindering plant growth in all citrus rootstocks assayed, except for X639. The highest concentration of toxic ions in leaves was detected in Carrizo citrange and US897 for Cl−, while the lowest concentration of Na+ was obtained in X639. These results provide growers with information about the sensitivity to salinity of different citrus rootstocks.

scholarly journals Water-Stress Influences on Three New Promising HLB-Tolerant Citrus Rootstocks

Horticulturae ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 336
Author(s):  
Lidia Aparicio-Durán ◽  
Frederick G. Gmitter ◽  
Juan M. Arjona-López ◽  
Rocío Calero-Velázquez ◽  
Áurea Hervalejo ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Status ◽  
Abiotic Factors ◽  
Dry Weight ◽  
Emerging Diseases ◽  
Carrizo Citrange ◽  
Citrus Rootstock ◽  
Chlorophyll Index ◽  
Stress Influences ◽  
Water Treatments

Drought and flooding conditions are increasingly common abiotic factors that affect citrus crops in both the Mediterranean Basin and Florida. Furthermore, emerging diseases, such as Huanglongbing (HLB), are a potential risk for these crops in those producing areas. This study aimed to evaluate the behavior under water-stress treatments of three new citrus rootstocks (UFR-6, B11R5T60, and 2247 x 6070-02-2) with reported tolerance of HLB, comparing them with a common commercial citrus rootstock (Carrizo citrange). Four water conditions were established: Control, Medium Water Stress (MWS), Drought, and Flooding. Chlorophyll index (SPAD), growth in height, relative growth rate, biomass (fresh and dry weight) and plant water status were evaluated. Citru rootstock response were different for each genotype; Carrizo citrange was negatively affected by all water treatments in the chlorophyll index (SPAD) and biomass production. By contrast, UFR-6 showed a positive response in SPAD and growth under MWS and Drought, B11R5T60 displayed similar behavior to Control under all water stresses, and the response of 2247 x 6070-02-2 under MWS treatment was adequate but was not under Drought or Flooding conditions. Our study describes the behavior of these promising new citrus rootstocks against water stress; B11R5T60 exhibiting the best performance. These results can be useful for the citrus industry to address water-stress problems in these crops.

scholarly journals Effects of soil water depletion on the water relations in tropical kudzu

1999 ◽  
Vol 34 (7) ◽  
pp. 1151-1157
Author(s):  
Adaucto Bellarmino de Pereira-Netto ◽  
Antonio Celso Novaes de Magalhães ◽  
Hilton Silveira Pinto
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Water Content ◽  
Soil Water ◽  
Cover Crop ◽  
Soil Water Depletion ◽  
Pueraria Phaseoloides ◽  
Water Depletion ◽  
Relative Water ◽  
Dry Soil

Tropical kudzu (Pueraria phaseoloides (Roxb.) Benth., Leguminosae: Faboideae) is native to the humid Southeastern Asia. Tropical kudzu has potential as a cover crop in regions subjected to dryness. The objective of this paper was to evaluate the effect of soil water depletion on leaflet relative water content (RWC), stomatal conductance (g) and temperature (T L) in tropical kudzu. RWC of waterstressed plants dropped from 96 to 78%, following a reduction in SWC from 0.25 to 0.17 g (H2O).g (dry soil)-1.Stomatal conductance of stressed plants decreased from 221 to 98 mmol.m-2.s-1, following the reduction in soil water content (SWC). The day after re-irrigation, g of water stressed plants was 15% lower than g of unstressed plants. Differences in T L between waterstressed and unstressed plants (deltaT L) rose linearly from 0.1 to 2.2ºC following progressive water deficit. RWC and T L of waterstressed plants paralled RWC and T L of unstressed plants the day after reirrigation. The strong decrease in SWC found in this study only induced moderate water stress in tropical kudzu. In addition, tropical kudzu recover rapidly from the induced water stress after the re-irrigation.

scholarly journals Growth and physiological response of two biomass sorghum (Sorghum bicolor (L.) Moench) genotypes bred for different environments, to contrasting levels of soil moisture

2015 ◽  
Vol 10 (4) ◽  
pp. 208 ◽  
Author(s):  
Lorenzo Barbanti ◽  
Ahmad Sher ◽  
Giuseppe Di Girolamo ◽  
Elio Cirillo ◽  
Muhammad Ansar
Keyword(s):  
Soil Moisture ◽  
Stomatal Conductance ◽  
Water Potential ◽  
Water Content ◽  
Aboveground Biomass ◽  
Relative Water Content ◽  
Physiological Response ◽  
Field Capacity ◽  
Biomass Sorghum ◽  
Relative Water

A better understanding of plant mechanisms in response to drought is a strong premise to achieving high yields while saving unnecessary water. This is especially true in the case of biomass crops for non-food uses (energy, fibre and forage), grown with limited water supply. In this frame, we investigated growth and physiological response of two genotypes of biomass sorghum (<em>Sorghum bicolor</em> (L.) Moench) to contrasting levels of soil moisture in a pot experiment carried out in a greenhouse. Two water regimes (high and low water, corresponding to 70% and 30% field capacity) were applied to JS-2002 and Trudan-8 sorghum genotypes, respectively bred for dry sub-tropical and mild temperate conditions. Two harvests were carried out at 73 and 105 days after seeding. Physiological traits (transpiration, photosynthesis and stomatal conductance) were assessed in four dates during growth. Leaf water potential, its components and relative water content were determined at the two harvests. Low watering curbed plant height and aboveground biomass to a similar extent (ca. 􀀀70%) in both genotypes. JS-2002 exhibited a higher proportion of belowground to aboveground biomass, <em>i.e</em>., a morphology better suited to withstand drought. Despite this, JS-2002 was more affected by low water in terms of physiology: during the growing season, the average ratio in transpiration, photosynthesis and stomatal conductance between droughty and well watered plants was, respectively, 0.82, 0.80 and 0.79 in JS-2002; 1.05, 1.08 and 1.03 in Trudan-8. Hence Trudan-8 evidenced a ca. 20% advantage in the three traits. In addition, Trudan-8 could better exploit abundant moisture (70% field capacity), increasing aboveground biomass and water use efficiency. In both genotypes, drought led to very low levels of leaf water potential and relative water content, still supporting photosynthesis. Hence, both morphological and physiological characteristics of sorghum were involved in plant adaptation to drought, in accordance with previous results. Conversely, the common assumption that genotypes best performing under wet conditions are less suited to face drought was contradicted by the results of the two genotypes in our experiment. This discloses a potential to be further exploited in programmes of biomass utilization for various end uses, although further evidence at greenhouse and field level is needed to corroborate this finding.

scholarly journals Physiological Responses to the Foliar Application of Synthetic Resistance Elicitors in Cape Gooseberry Seedlings Infected with Fusarium oxysporum f. sp. physali

Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 176
Author(s):  
Cristhian C. Chávez-Arias ◽  
Sandra Gómez-Caro ◽  
Hermann Restrepo-Díaz
Keyword(s):  
Stomatal Conductance ◽  
Fusarium Oxysporum ◽  
Foliar Application ◽  
Dry Weight ◽  
Carotenoid Content ◽  
Limiting Factor ◽  
Vascular Wilt ◽  
Potential Growth ◽  
Disease Progress ◽  
Cape Gooseberry

Vascular wilt caused by Fusarium oxysporum is the most limiting disease that affects cape gooseberry (Physalis peruviana L.) crops in Colombia. The use of synthetic elicitors for vascular wilt management is still scarce in Andean fruit species. The objective of the present study was to evaluate the effect and number of foliar applications of synthetic elicitors such as jasmonic acid (JA), salicylic acid (SA), brassinosteroids (BR), or a commercial resistance elicitor based on botanical extracts (BE) on disease progress and their effect on the physiology of cape gooseberry plants inoculated with F. oxysporum f. sp. physali. Groups of ten plants were separately sprayed once, twice, or three times with a foliar synthetic elicitor, respectively. Elicitor applications were performed at the following concentrations: JA (10 mL L−1), SA (100 mg L−1), BR (1 mL L−1) and BE (2.5 mL of commercial product (Loker®) L−1). The results showed that three foliar BR, SA, or BE applications reduced the area under the disease progress, severity index, and vascular browning in comparison to inoculated plants without any elicitor spray. Three BR, SA, or BE sprays also favored stomatal conductance, water potential, growth (total dry weight and leaf area) and fluorescence parameters of chlorophyll compared with inoculated and untreated plants with no elicitor sprays. Three foliar sprays of SA, BR, or BE enhanced photosynthetic pigments (leaf total chlorophyll and carotenoid content) and proline synthesis and decreased oxidative stress in Foph-inoculated plants. In addition, the effectiveness of three foliar BR, SA, or BE sprays was corroborated by three-dimensional plot and biplot analysis, in which it can evidence that stomatal conductance, proline synthesis, and efficacy percentage were accurate parameters to predict Foph management. On the hand, JA showed the lowest level of amelioration of the negative effects of Foph inoculation. In conclusion, the use of the synthetic elicitors BR, SA, or BE can be considered as a tool complementary for the commercial management of vascular wilt in areas where this disease is a limiting factor.

scholarly journals Physiological responses of two halophytic grass species under drought stress environment

2016 ◽  
Vol 75 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Zamin Shaheed Siddiqui ◽  
Huda Shahid ◽  
Jung-Il Cho ◽  
Sung-Han Park ◽  
Tae-Hun Ryu ◽  
...  
Keyword(s):  
Drought Stress ◽  
Stomatal Conductance ◽  
Water Deficit ◽  
Physiological Responses ◽  
Biomass Accumulation ◽  
Photosynthetic Performance ◽  
Grass Species ◽  
Free Proline ◽  
Relative Water ◽  
Halophytic Grasses

AbstractThe physiological responses of two halophytic grass species, Halopyrum mucronatum (L.) Staph. and Cenchrus ciliaris (L.), under drought stress were evaluated. Biomass accumulation, relative water content, free proline, H2O2content, stomatal conductance, photosynthetic performance and quantum yield (Fv/Fmratio) were studied. Under drought conditions, these halophytic plants expressed differential responses to water deficit. Stomatal conductance and free proline content were higher in H. mucronatum than in C. ciliaris, while H2O2content in H. mucronatum was substantially lower than in C. ciliaris. Performance index showed considerable sensitivity to a water deficit condition, more so in C. ciliaris than in H. mucronatum. Results were discussed in relation to comparative physiological performance and antioxidant enzymes activity of both halophytic grasses under drought stress.

scholarly journals Cross-Protection as Control Strategy Against Grapevine fanleaf virus in Naturally Infected Vineyards

Plant Disease ◽  
2008 ◽  
Vol 92 (12) ◽  
pp. 1689-1694 ◽  
Author(s):  
Véronique Komar ◽  
Emmanuelle Vigne ◽  
Gérard Demangeat ◽  
Olivier Lemaire ◽  
Marc Fuchs
Keyword(s):  
Protein Gene ◽  
Negative Impact ◽  
Cross Protection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Limiting Factor ◽  
Grapevine Fanleaf Virus ◽  
Limited Effect ◽  
Arabis Mosaic Virus ◽  
Polymerase Chain ◽  
The Impact

The efficacy of cross-protection at mitigating the impact of Grapevine fanleaf virus (GFLV) on grapevines (Vitis vinifera) was assessed in two naturally infected vineyard sites. Test vines consisted of scions grafted onto rootstocks that were healthy or infected by mild protective strains GFLV-GHu or Arabis mosaic virus (ArMV)-Ta. Challenge GFLV infection via the nematode Xiphinema index was monitored over nine consecutive years in control and ArMV-Ta cross-protected vines by double-antibody sandwich–enzyme-linked immunosorbent assay using GFLV-specific antibodies, and in GFLV-GHu cross-protected vines by characterizing the coat protein gene of superinfecting isolates by immunocapture–reverse transcription–polymerase chain reaction–restriction fragment length polymorphism. Results were consistent with a significantly reduced challenge infection rate in cross-protected vines compared with control vines, more so in those protected with GFLV-GHu (19 versus 90%) than with ArMV-Ta (40 versus 65% in field A and 63 versus 90% in field B). However, the two mild strains significantly reduced fruit yield by 9% (ArMV-Ta) and 17% (GFLV-GHu) over 8 years and had a limited effect on fruit quality. Therefore, in spite of a great potential at reducing the incidence of challenge field isolates, cross-protection with natural mild protective strains GFLV-GHu and ArMV-Ta is not attractive to control GFLV because the negative impact on yield is a limiting factor for its deployment.

scholarly journals Using trophic flows and ecosystem structure to model the effects of fishing in the Jurien Bay Marine Park, temperate Western Australia

2011 ◽  
Vol 62 (5) ◽  
pp. 421 ◽  
Author(s):  
Hector M. Lozano-Montes ◽  
Neil R. Loneragan ◽  
Russell C. Babcock ◽  
Kelsie Jackson
Keyword(s):  
Western Australia ◽  
Negative Impact ◽  
Limiting Factor ◽  
Commercial Fishing ◽  
Ecosystem Structure ◽  
Fishing Mortality ◽  
Benthic Primary Production ◽  
Cascading Effects ◽  
Marine Park ◽  
The Impact

Understanding the impacts of fishing on the trophic structure of systems has become increasingly important because of the introduction of Ecosystem Based Fisheries Management and the legislative requirements of fisheries to demonstrate that they are not having a negative impact on other species. A biomass-based dynamic model of Jurien Bay Marine Park (∼30°S) was constructed using Ecopath to investigate the ecosystem impacts of fishing (mainly commercial rock lobster, Panulirus cygnus) in the park, as an example of the potential responses of temperate marine ecosystems in Western Australia to commercial fishing. A simulated 50% reduction in fishing mortality for commercial finfish predicted that after 20 years, the biomass of important fished species (i.e. Pagrus auratus and Choerodon rubescens) would increase by up to 30%. A simulated total fishing closure resulted in much larger (2.5–8 fold) increases in targeted populations, but did not result in any predicted cascading effects on grazing invertebrates and benthic primary producers. The simulations suggest that the structure of this ecosystem is characterised more by bottom-up than top-down processes; i.e. benthic primary production is a major limiting factor. The present study identified trophic linkages and ecosystem processes such as the role of both low and high trophic-level groups and the impact of fishing mortality in the marine park, an essential step towards distinguishing the impacts of fishing from those attributable to natural or other human-induced changes.

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