Pomology
R. Fifaei; H. Taheri; Y. Tajvar; E. Gholamian
Abstract
Background and Objectives
Water is a main factor in agriculture activities and almost 70 percent of world water resources are consumed in agriculture. Drought consist the most important environmental restriction to plant growth and production. Drought stress is known to change a range of physiological ...
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Background and Objectives
Water is a main factor in agriculture activities and almost 70 percent of world water resources are consumed in agriculture. Drought consist the most important environmental restriction to plant growth and production. Drought stress is known to change a range of physiological processes such as photosynthesis, stomatal conductance and transpiration rate. Citrus are one of sub-tropical and tropical fruits and the most important horticultural products in the world that tolerate low temperature and weak drainage but as regards Citrus growing in sub-tropical and tropical regions that often expose drought. Drought is one the environment stress factors that is caused changes in plants morphological and physiological characteristics. Study of survival time in the three citrus rootstocks in sever stress circumstances showed that this time in rootstocks poncirus, cleopatra mandarine and former-alkaeid 5 were 11, 13 , 20 days, respectively while survival time in valencia on the rootstocks was 21, 26 and 29 days, respectively. This study was performed in order to study drought tolerant in natural genotypes with the poncirus and rough lemon. And so, morphological and physiological characteristics were investigated in this genotypes.
Materials and Methods
This research was performed in separately two tests in Citrus and subtropical fruits research center on 2016. In the first test, survival time and total transpiration and in the second test, organs fresh and dry weight, ion leackage and leaf relative water content were assessed in factorial experiment based on randomized completely design in nucellar seedlings of 8 Citrus natural genotypes (G10, G11, G12, G16, G18, G22, G23, G25) poncirus and rough lemon under glasshouse conditions (with temperature 26-28 degree centigrade in day and 20-22 degree centigrade in night and 80-85 percent relative humidity). Factors were 10 Citrus genotypes and two treatment of irrigation (optimum irrigation and withholding irrigation for six weeks) in the second test and 10 Citrus genotypes in the first test. In this study, medium weight moisture is calculated and due to the soil moisture characteristics curve was obtained medium matric potential. The matric potential rate was in control -0.03 megapascal and in sever stresss -1.5 megapascal. Organs fresh and dry weight were measured on digital balance with accuracy 0.01 gr. (model GM 6101, Germany). S amples were dried in oven (70 degree centigrade and for 48 hours). RWC is measured by using of fresh weight, dry weight and turgid weight in this formula: RWC= [(FW-DW) / (TW-DW)] × 100. Ion leackage was determined by use of 4 equal leaf segments and measuring of primary and secondary ion leackage in this fomula: EL (%) = (EL1/EL2) × 100. The first research was included of 10 treatment, six replication and one seedling in every plot and the second research was included of 20 treatment, three replication and two seedlings in every plot. SAS software (ver. 9.1) and Duncan test were used to variance analysis and mean comparison. Excel software was used to graphs drawing.
Results
The results showed that in first test, poncirus (with 125 days) and G11 (with 78 days) have longer survival time and are more tolerant and so rough lemon (with 38 days) and G12 (with 44 days) were more susceptible. Others were intermediate. Slowest of water consumption time in poncirus and the most quick in rough lemon, and so maximum of total transpiration in G25 and minimum in poncirus was observed. In second test, decrease maximum of leaf, shoot and total fresh weight in G22 (arranged by 0.37, 0.47 and 0.42) and decrease minimum in G11 (arranged by 0.48, 0.54 and 0.52), decrease maximum of root fresh weight in G22 (with 0.35 fold) and decrease minimum in G18 (with 0.52 fold), decrease maximum of root/shoot fresh weight in G18 (with 0.61 fold) and decrease minimum in G23 (with 0.65 fold) and increase maximum of root/shoot dry weight in G16 (with 1.56 fold) and increase minimum in poncirus (with 1.3 fold) was observed in compared with control. In stress, G18 (with 32.32 percent) and G12 (with 34.37 percent) had leaf relative water content minimum in compared with control. G12 (with 78.59 percent) and G18 (with 73.16 percent) had maximum and poncirus (with 31.85 percent) minimum ion leackage percent in compared with control. Therefore, rough lemon, G12 and G18 as susceptible and poncirus and G11 as tolerant to drought were introduced.
Discussion
In stress conditions, poncirus has longer survival time, slower water consumption time, minimum total transpiration and minimum ion leackage percent and is most tolerant. Rough lemon has shower survival time, more rapid water consumption time and is most susceptible. Other genotypes locate in after grades. Therefore poncirus and rough lemon can be used as rulers in tests of drought study.
Behrooz Golein; Vali Rabiei; Faezeh Mirabbasi; Reza Fifaei; Mohammad Fazel Halaji Sani
Abstract
Introduction: Citrus (L.) is a large genus that covers several major cultivatedspecies, including Citrussinensis (sweet orange), C.reticulata (tangerine and mandarin), C. limon (lemon), C.grandis (pummelo), and C. paradisi (grapefruit).Citrus is one of the world’s important fruit crops and grown inmost ...
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Introduction: Citrus (L.) is a large genus that covers several major cultivatedspecies, including Citrussinensis (sweet orange), C.reticulata (tangerine and mandarin), C. limon (lemon), C.grandis (pummelo), and C. paradisi (grapefruit).Citrus is one of the world’s important fruit crops and grown inmost areas with suitable climates between latitude 35◦N–35◦S. InIran, citrus industry is of paramount importance. Citrus species have been classified as salt-sensitive crops, although their relative tolerance can be influenced by climate, fertilization, soil type, irrigation method and rootstock. Citrus rootstocks differ in their ability to exclude Cl−and/or Na+from the scion. Many authors have contrasted the relative abilities of rootstocks to restrict movement of salts to the scions. The rootstocks Cleopatra mandarin (C. reshni), Rangpur lime (C. limonia) and Severiniabuxifolia (Poir) Tenore were relatively effective in restricting Cl−transport to scions, whereas the rootstocks Swingle citrumelo and Carrizo citrange were found to be less restrictive. Although the mechanism by which some rootstocks reduce concentrations of ions in the scion is still unknown, it seems to depend on the vigor of the scion and on water requirements. There are a number of reports demonstrating that both scion and rootstock may influence Cl−accumulation in leaves. Several papers reported that accumulation of Na+ in shoots seemed to be more dependent on rootstock–scion combinations. Since, citrus species are different in salt tolerance and use of tolerant rootstocks can decrease salinity damages, sothis study was conducted to identify tolerant genotypes among unknown types from the Kotra Citrus Research Station, Citrus and Sub-Tropical Fruits Research Center (Ramsar).
Materials and Methods: The experiment was –arrangedin afactorial, based on completely randomized design in three replications with two plantsin each experimental unit in Iran Citrus Research Institute.Treatment included 10 citrus natural genotypes along with two varieties of Cleopatra mandarin (tolerant plant) and Swinglecitrumelo (sensitive plant) with six-month old and four salinity levels of sodium chloride: 0(control), 2, 4 and 6 dsm-1, for 16 weeks in the greenhouse condition. Effect of salinity on fresh and dry weight of shoot and root, relative water content (using upper leaves), stomatal density (with counting of stomata using microscope), concentration ofCl (with titration method of silver nitrate) and Na (by flame photometry) in roots and leaves, content of total chlorophyll (using acetone 80%), proline (spectrophotometry at wavelength of 520 nm), lipid peroxidation (spectrophotometry at wavelength of 532 nm) and activity of peroxidase enzyme (spectrophotometry at wavelength of 470 nm)were investigated. Data analysis was done by SAS 9.1 software.
Results and Discussion: The results indicated that, the interaction of genotypes and salinity levels hadnot significant difference in relative water content, stomatal density and Na+concentration - in roots but, other traits except total chlorophyll content which was significant at 5% level, were significant at 1% level. Shoot fresh and dry weight of genotypes No. 4 and 6 were significantly (P
Ebrahim Abedi Gheshlaghi; Reza Fifaei; Davoud Javadi Mojaddad
Abstract
'Flying dragon' is one of the citrus rootstocks that are considered to be a promised dwarfing rootstock in the world. This experiment was conducted in the Astara research station for study of qualitative and quantitative characteristics of 4 mandarin cultivars (Unshiu, Clementine, Page, and Yunesi) budded ...
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'Flying dragon' is one of the citrus rootstocks that are considered to be a promised dwarfing rootstock in the world. This experiment was conducted in the Astara research station for study of qualitative and quantitative characteristics of 4 mandarin cultivars (Unshiu, Clementine, Page, and Yunesi) budded on 'Flying dragon'. This experiment was carried out with four cultivars in randomized complete bloke design (RCBD) with three replications. Qualitative and quantitative characteristics of fruits, as well as vegetative traits were recorded and analyzed for 3, 6 and 1 years, respectively. The highest yield was observed on Yunesi cultivar in the final year of experiments and the lowest yield was on Unshiu cultivar in the fifth year. TSS/TA and means of fruit weight were affected by interaction of year and cultivar. The highest means of fruit weight was on Yunesi in the years of 85 and the highest TSS/TA was in years of 88 on Clementine cultivar. The highest alternate bearing index obtained in years of 88 on the Unshiu cultivar and the lowest that was on the Page cultivar. The highest yield efficiency, cumulative yield and plant height were observed on Yunesi cultivar, and the highest width and canopy of tree were on Unshiu cultivar. The lowest yield and tree size were on Page cultivar.
