Symptomatology and histopathology of fibrous roots of rough lemon (citrus limon) infected with Fusarium solani

1978 ◽  
Vol 63 (1) ◽  
pp. 35-40 ◽  
Author(s):  
S. Nemec
Keyword(s):  
Fusarium Solani ◽  
Citrus Limon ◽  
Rough Lemon ◽  
Fibrous Roots

Microscopy of Fusarium solani infected rough lemon citrus fibrous roots

1986 ◽  
Vol 64 (12) ◽  
pp. 2840-2847 ◽  
Author(s):  
S. Nemec ◽  
D. Stamper Achor ◽  
L. G. Albrigo
Keyword(s):  
Fusarium Solani ◽  
Cell Walls ◽  
Vessel Element ◽  
Primary Xylem ◽  
Root Hair Cell ◽  
Rough Lemon ◽  
Transmission Electron ◽  
Citrus Rootstock ◽  
Cortical Infection ◽  
Fibrous Roots

Mode of Fusarium solani penetration into rough lemon citrus rootstock seedling fibrous roots was determined and root symptomatology was evaluated using light, scanning, and transmission electron microscopy. Roots contained limited subepidermal infection 15 h after inoculation. Invasion of epidermal cells was principally through broken epidermal and root hair cell walls, but direct penetration also occurred. Cortical infection was primarily intracellular. Severe root rot was present 36–60 h after inoculation and in most cases infection after 60 h resulted in disruption of the phloem and endodermis around the still relatively intact primary xylem. Naturally infected roots from field trees were collected in an advanced stage of rot. In these, F. solani digestion of middle lamellae of primary xylem was common, and infection and erosion of secondary vessel element walls occurred frequently.

Carbon Dioxide Assimilation and Foliar Ion Concentrations in Leaves of Lemon (Citrus limon L.) Trees Irrigated With Nacl or Na2SO4

1993 ◽  
Vol 20 (2) ◽  
pp. 173 ◽  
Author(s):  
RR Walker ◽  
DH Blackmore ◽  
Q Sun
Keyword(s):  
Nutrient Solution ◽  
Osmotic Potential ◽  
Nitrogen Deficiency ◽  
Leaf Nitrogen ◽  
Citrus Limon ◽  
Assimilation Rate ◽  
Photosynthetic Rates ◽  
Rangpur Lime ◽  
Rough Lemon ◽  
Nitrogen Concentrations

An attempt was made to differentiate between the possible effects of high Cl- or Na+ ions on lemon leaf photosynthesis by treating grafted (Citrus limon (L.) Burm. f. cv. 'Taylor') plants with either NaCl or Na2SO4 to establish different foliar concentrations of Cl- or Na+. The rootstocks, Rangpur lime (C. reticulata var. austera hybrid?) and rough lemon (C. jambhiri), were chosen because Rangpur lime is known to be a good Cl- 'excluder' and rough lemon to be a poor Cl- 'excluder'. The grafted plants were initially treated for 7 weeks with nutrient solution (control) or nutrient solution containing 50 mol m-3 NaCl or 25 mol m-3 Na2SO4, after which time there were only marginal reductions in both photosynthetic rates and shoot growth, with the exception of 'Taylor' lemon on rough lemon roostock treated with NaCl where growth was affected more severely than the other treatments. Salinity levels were then doubled to 100 mol m-3 NaCl and 50 mol m-3 Na2SO4 and the plants treated for a further 8 weeks, causing significant increases in leaf Na+ and/or Cl- concentrations. Mature, 3-4-month-old leaves of 'Taylor' lemon on Rangpur lime rootstock treated with Na2SO4 for this period, contained c. 105 mol m-3 Na+ and c. 10 mol m-3 Cl- and had photosynthetic rates 60% lower than controls. Similar reductions in assimilation rate were seen in leaves on rough lemon roostock treated with NaCl containing c. 195 mol m-3 Cl- and c. 35 mol m-3 Na+. Smaller (35%) but significant reductions in assimilation rate were observed for trees on rough lemon roostock treated with Na2SO4, where the tagged leaves contained c. 40 mol m-3 Na+ and 50 mol m-3 SO42-. Leaf nitrogen concentrations were significantly reduced by treatment of trees with NaCl or Na2SO4 but, apart from small reductions in chlorophyll concentrations, there were no visible symptoms of nitrogen deficiency. Leaf turgor was not adversely affected. The data indicate that both Cl- and Na+ can reduce assimilation rates in salt-stressed lemon leaves, possibly because of poor compartmentation within leaves of either ion. Increases in leaf Na+ and Cl- accounted for 54-96% of the reduction in osmotic potential in 'Taylor' lemon leaves on trees treated with NaCl, whereas increases in Na+ and SO42- accounted for 33-71% of the reduction in osmotic potential in leaves on trees irrigated with Na2SO4. The greater increase in Cl- compared with the net increase of [Na+ + K+] in 'Taylor' leaves on rough lemon rootstocks was offset (65%) by reductions in malic and succinic acids. Proline increased significantly only in 'Taylor' leaves on Rangpur lime roostock treated with Na2SO4.

scholarly journals COPPER PHYTOTOXICITY TO YOUNG CITRUS TREES AS INFLUENCED BY SOIL pH

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 595c-595
Author(s):  
Ashok K. Alva
Keyword(s):  
Soil Ph ◽  
Tree Height ◽  
Fine Sand ◽  
Liquid Form ◽  
Trunk Diameter ◽  
Rough Lemon ◽  
Canopy Volume ◽  
Ph Increase ◽  
Fibrous Roots ◽  
Citrus Trees

The aim of this study was to investigate soil pH and copper (Cu) interactions affecting Cu phytotoxicity to young citrus trees on different rootstocks. Hamlin oranges on either Carrizo citrange, sour orange, or rough lemon rootstocks were grown on Candler fine sand at varying soil pH (5.0, 5.5, 6.0, 6.5) without additional Cu or soil applied Cu (liquid form; 240 kg Cu/ha; nine pre- and five post-planting applications over a period of 43 months). Increasing soil pH increased tree height, canopy volume and trunk diameter of trees on all three rootstocks, regardless of Cu treatments. Tree growth response to an increase in soil pH was greater in Cu amended as compared to unamended treatments. Response to pH increase above 6.0 was marginal as compared to that for pH increase from 5.0 to 6.0. Leaf Cu concentrations showed negligible differences in response to Cu treatments; however, Cu concentrations in fibrous roots increased by 126 to 152% in Cu amended as compared to unamended treatments.

Evaluation of rootstocks for Eureka and Lisbon lemons in replant ground in New South Wales

1992 ◽  
Vol 32 (2) ◽  
pp. 205
Author(s):  
RA Sarooshi ◽  
P Broadbent
Keyword(s):  
Fruit Quality ◽  
New South ◽  
New South Wales ◽  
Poncirus Trifoliata ◽  
Citrus Limon ◽  
Sour Orange ◽  
Rough Lemon ◽  
South Wales ◽  
Graft Compatibility ◽  
Large Flower

The yield, growth, fruit quality, and graft compatibility of 2 lemon cultivars Eureka and Lisbon [Citrus limon (L.) Bum. f.], budded onto several new rootstocks, were studied in replant ground.Promising rootstocks for Eureka lemon were 2 new hybrids bred at Gosford, New South Wales, 3798 (Scarlet mandarin x Poncirus trifoliata) and 4017 (Smooth Seville x P. trifoliata), and also Benton citrange and Nelspruit hybrid 639. Trees on the sour orange group of rootstocks including Xingshan, Dai Dai and Baggan yielded 44-63% less than trees on rough lemon rootstocks; but their fruit quality, as evidenced by juice per cent, OBrix, and citric acid (kg/t), was better. The performance of Lisbon lemon was tested on 10 selections of F'. trifoliata, and although trees on Flying Dragon were smaller and yielded about 50% less than on Swingle, Christiansen, Large Flower, and selection 22, results were not significantly (P<0.05) different.

Effect of soil temperature on root rot of rough lemon caused by Fusarium solani

1981 ◽  
Vol 76 (3) ◽  
pp. 185-190 ◽  
Author(s):  
S. Nemec ◽  
R. M. Zablotowicz
Keyword(s):  
Soil Temperature ◽  
Fusarium Solani ◽  
Root Rot ◽  
Rough Lemon

OXIDATIVE ENZYME RESPONSES OF SIX CITRUS ROOTSTOCKS INFECTED WITH PHOMA TRACHEIPHILA (PETRI) KANTSCHAVELI AND GIKASHVILI

2012 ◽  
Vol 48 (4) ◽  
pp. 563-572 ◽  
Author(s):  
AYDIN UZUN ◽  
UBEYIT SEDAY ◽  
ERCAN CANIHOS ◽  
OSMAN GULSEN
Keyword(s):  
Enzyme Activity ◽  
Antioxidant Enzyme Activity ◽  
Poncirus Trifoliata ◽  
Citrus Limon ◽  
Sour Orange ◽  
Trifoliate Orange ◽  
Rough Lemon ◽  
Phoma Tracheiphila ◽  
Cleopatra Mandarin ◽  
Mal Secco

SUMMARYCitrus trees are often exposed to severe infectious diseases. Mal secco caused by Phoma tracheiphila (Petri) Kantschaveli and Gikashvili is one of the most destructive fungal diseases of lemons (Citrus limon Burm. F.). In the present study, antioxidant enzyme activity in different mal secco-resistant and susceptible citrus rootstocks including Cleopatra mandarin (C. reshni Tan.), sour orange (C. aurantium L.), rough lemon (C. jambhiri Lush.), Volkameriana (C. volkameriana Tan. and Pasq.), Carrizo citrange (Poncirus trifoliata L. Raf. X C. sinensis L. Osbeck) and trifoliate orange (P. trifoliata) was investigated. Possible differences in constitutive levels of these antioxidant enzymes and correlations between enzyme levels and mal secco caused by P. tracheiphila were examined. Among the rootstocks, Cleopatra mandarin was found to be resistant to mal secco, whereas rough lemon, sour orange and trifoliate orange were highly susceptible. Total peroxidase (TPX; EC: 1.11.1.7) activity increased in all infected rootstocks. Ascorbate peroxidase (APX; EC: 1.11.1.11) activity increased in most of the rootstocks and no correlation was found between catalase (CAT; EC: 1.11.1.6) activity and mal secco resistance. This study indicates that overall TPX activity is upregulated and APX activity is up- and down-regulated depending on the type of rootstock in response to P. tracheiphila infection.

THE SUBLETHAL EFFECTS OF SELECTED INSECTICIDES ON LIFE TABLE PARAMETERS OF PANONYCHUS CITRI (ACARI: TETRANYCHIDAE)

1984 ◽  
Vol 116 (7) ◽  
pp. 1033-1040 ◽  
Author(s):  
Vincent P. Jones ◽  
Michael P. Parrella
Keyword(s):  
Life Table ◽  
Sublethal Effects ◽  
Reproductive Rate ◽  
Citrus Limon ◽  
Life Table Parameters ◽  
Panonychus Citri ◽  
Net Reproductive Rate ◽  
Citrus Red Mite ◽  
Rough Lemon

AbstractPopulations of the citrus red mite, Panonychus citri (McGregor), reared on “rough lemon” seedlings (Citrus limon (L.) Burm.) in a greenhouse and treated with malathion or permethrin were significantly higher than those on untreated seedlings. Significant increases were demonstrated in age-specific fecundity (mx), mortality corrected mx (lx mx), and net reproductive rate (Ro) values for mites reared in the laboratory on leaves treated with malathion or permethrin when compared with those reared on untreated leaves. Mites reared on oxamyl-treated leaves exhibited significant reductions in age-specific survivorship (% lx), mx, lxmx, and Ro values compared with those reared on untreated leaves. The importance of reproductive stimulation in relation to other causes of pest resurgence is discussed.

Deuterophoma tracheiphila. [Descriptions of Fungi and Bacteria].

1973 ◽  
Author(s):  
E. Punithalingam
Keyword(s):  
Geographical Distribution ◽  
Vascular Tissue ◽  
Citrus Limon ◽  
Citrus Aurantium ◽  
Specific Symptom ◽  
Rough Lemon ◽  
Orange Yellow ◽  
Aegean Islands ◽  
Mal Secco ◽  
Whole Tree

Abstract A description is provided for Deuterophoma tracheiphila. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Citrus limon; also Citrus aurantium, C. grandis, C. medica and rough lemon. DISEASE: Mal secco of Citrus spp., mainly lemon (C. limon). The first, although less specific, symptom of this vascular disease (tracheomycosis) is a sudden wilt and death of the leaves. If infection occurs towards the base of the tree or through the roots collapse is quick and the whole tree is eventually killed. Depending on the pattern of infection wilt may begin in one section or in several parts of the tree. If infection begins in the upper canopy spread of the leaf and branch collapse is much slower. Cuts into the wood (before wilt and death of the bark) reveal the characteristic orange-yellow to reddish discoloration of the vascular tissue. The host epidermal covering over the pycnidia assumes an ashy appearance. GEOGRAPHICAL DISTRIBUTION: Found in the Mediterranean and Black Sea areas: Algeria, Cyprus, France, Greece (including Crete and the Aegean Islands), Israel, Italy (including Sardinia), Lebanon, Syria, Tunisia, Turkey, USSR (Republic of Georgia and Caucasus). Countries in the region that appear free from mal secco are Morocco Portugal and Spain (43, 3223). A record from Colombia (Choco, 46, 3029) probably requires confirmation and one for Uganda should be deleted (CMI Map 155, Ed. 2, 1966). TRANSMISSION: Water-borne from host debris.

Histochemical characteristics of Glomus etunicatus infection of Citrus limon fibrous roots

1981 ◽  
Vol 59 (5) ◽  
pp. 609-617 ◽  
Author(s):  
S. Nemec
Keyword(s):  
Fatty Acid ◽  
Neutral Lipid ◽  
Catalase Activity ◽  
Laccase Activity ◽  
Basic Protein ◽  
Neutral Lipids ◽  
Acid Oxidation ◽  
Citrus Limon ◽  
Cortical Regions ◽  
Fibrous Roots

Lipid in vesicles and hyphae reacted positively to a variety of reagents that have an affinity for neutral lipids. In contrast, arbuscules did not appear to contain neutral lipid, but did react positively to phosphoglyceride tests and glycolipid. Walls of vesicles and hyphae contained chitin, but arbuscule walls appeared to contain mainly glycolipid. Young arbuscules, hyphae, and immature vesicles were rich in basic protein. Phenolics were detected in vesicle walls and hyphal attachments, but none accumulated around infected areas even though laccase activity was present in cortical regions occupied by young arbuscules. Dehydrogenases were present in young arbuscules, hyphae, and in immature vesicles still containing noticeable amounts of cytoplasm. Peroxidase and catalase activity in senescing arbuscules were probably associated with fatty acid oxidation in the fungus.

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