SURVIVAL and HOST RANGE OF ISOLATES OF Phytophthora capsici *
H.
PASANDI
نویسنده
author
text
article
2014
per
Phytophthora capsici was originally isolated from pepper in New Mexico and described by Leonian in 1922. Although the species have been isolated from different plant species in different parts of Iran, there is scanty information regarding its diversity, host range, survival structure and mating types. The present study was an attempt to determine host range of this pathogen especially among woody plants. The optimum temperature for growth, frequency of mating types and formation of chlamydospore in vitro and in vivo was also determined using 20 isolates from different plant species including squash, pepper and tomato. The results showed that both mating types of the pathogen with almost equal frequency were present among isolates. The pathogen abundantly formed chlamydospores on carrot agar and in crown and roots of squash . Among six woody plants inoculated, almond, apricot and pistachio cultivar Sarakhs were highly susceptible to P. capsici but hazelnut, kiwi and loquat were not infected. All isolates of P. capsici used were pathogenic to squash but pepper was resistant to most isolates.
Iranian Journal of Plant Pathology
انجمن بیماری شناسی گیاهی ایران
0006-2774
50
v.
2
no.
2014
109
122
https://ijpp.areeo.ac.ir/article_10991_5d04f2db371ab0a225461f75fffdbf83.pdf
MORPHOLOGICAL AND PHYLOGENETIC INVESTIGATION OF Bipolaris oryzae AND SOME SPECIES OF Bipolaris OBTAINED FROM RICE AND GRASS WEEDS *
A.
AHMADPOUR
نویسنده
author
text
article
2014
per
Brown spot disease is an important disease of rice in the world and Iran. A collection of 348 Bipolaris isolates was made from cultivated rice paddies and weeds in Mazandaran, Guilan, Golestan, Khuzistan and Fars provinces, during 2011 and 2012. Six species of Bipolaris viz. B. oryzae,B. cynodontis, B. spicifera, B. bicolor, B. sorokiniana and B. neergaardii were identified using morphological and molecular data. Bipolaris oryzae was known as dominant species and the causal agent of rice brown disease in Iran. Based on morphological characteristics, B. oryzae isolates were grouped into four different morphological groups. Maize, muse, Echinochloa colona, Paspalum scrobiculatum and an unknown grass are introduced new hosts for B. oryzae in Iran. Moreover, phylogenetic relationships of some Bipolaris species based on sequencing of rDNA-ITS region and gpd gene have been studied.
Iranian Journal of Plant Pathology
انجمن بیماری شناسی گیاهی ایران
0006-2774
50
v.
2
no.
2014
123
135
https://ijpp.areeo.ac.ir/article_10992_8a7575282b3cdb1e21ff45ed1bea4fb0.pdf
PARTIAL BIOLOGICAL AND MOLECULAR CHARACTERIZATION OF PHYTOPLASMAS ASSOCIATED WITH GRAPEVINE YELLOWS IN FARS AND LORESTAN PROVINCES OF IRAN*
E.
SALEHI
نویسنده
author
text
article
2014
per
Grapevine yellows (GY)-like symptoms were found widespread in vineyards of Fars and Lorestan provinces in Iran. To study the etiology of the diseases, cuttings from yellows affected vines were planted in pots and symptomatic vines developed from cuttings were used as the source of yellows agent. Agents of grapevine yellows from Fars (FGY) an Lorestan (LGY) were transmitted from symptomatic young grapevines to periwinkle via dodder inoculation and from periwinkle to periwinkle by grafting. Phytoplasmas were detected in symptomatic periwinkles by direct PCR using P1/P7 primer pair and in12 out of 20 symptomatic field vines, all symptomatic vines developed from cuttings and all inoculated periwinkles by nested PCR using P1/P7 and R16F2n/R16R2 universal primer pairs. Actual and virtual restriction fragment length polymorphism (RFLP) of nested PCR products (1.2 kbp), sequence homology and phylogenetic analysis of full length 16S rDNA classified FGY and LGY phytoplasmas in the 16SrXII-A. Comparison of virtual RFLP patterns indicated that FGY and LGY phytoplasmas are genetically different from the agent of grapevine declining disease previously reported from northeast of Iran as a stolbur related phytoplasma. This is the first report of GY disease in western and southern Iran. Presence of GY in widely separated regions in Iran indicates a long history for the disease in this country.
Iranian Journal of Plant Pathology
انجمن بیماری شناسی گیاهی ایران
0006-2774
50
v.
2
no.
2014
137
137
https://ijpp.areeo.ac.ir/article_10993_676c8e926d03aef63af32389e39d58cb.pdf
PHYLOGENETIC RELATIONSHIP OF Trichoderma ISOLATES FROM PADDY FIELDS OF MAZANDARAN PROVINCE BASED ON SEQUENCE ANALYSIS OF tef1α GENE *
SH.
NAEIMI
نوسنده
author
text
article
2014
per
Fungi belonging to genus Trichoderma are well known for their effectiveness in the biological control of different plant pathogenic fungi, inducing systemic resistance in crops and for promoting plant growth. Phylogeny of 81 Trichoderma isolates (with emphasis on some biocontrol strains) belonging to six species obtained from paddy fields in Mazandaran province, was studied by partial sequence analyses of the translation elongation factor 1-α (tef1α) gene. Data were analyzed by Neighbor-Joining, Maximum Parsimony and Minimum Evolution methods. For each analysis, one consensus tree was used out of all generated phylograms. Phylogenetic trees of the 41 Trichoderma isolates inferred by all methods and programs were similar. Results showed that 14 tef1α haplotypes can be recognized for T. harzianum (the most frequent species in rice fields) isolates grouped into five clades. Therefore, this complex species presented the highest intraspecific diversity when compared to other species in this study. In contrast, only two haplotypes were recognized for T. virens, the second most prevalent species. Furthermore, sequence analyses revealed three and two haplotypes for T. atroviride and T. hamatum, respectively. Results indicated that biological control strains represented various haplotypes and placed in different clades along with other native isolates. Consequently, a specific tef1α haplotype related to antagonism could not be distinguished. In addition, there was no correlation between tef1α haplotype and the geographic location and thus different species and haplotypes were isolated from the same sampling sites.
Iranian Journal of Plant Pathology
انجمن بیماری شناسی گیاهی ایران
0006-2774
50
v.
2
no.
2014
139
149
https://ijpp.areeo.ac.ir/article_10994_8987283eb6aaa72789596257bf965e2f.pdf
EFFECTIVENESS OF CELERY LEAF EXTRACT ON THE INDUCTION OF RESISTANCE AGAINST CUCUMBER POWDERY MILDEW *
A.
SIROUS
نویسنده
author
text
article
2014
per
Powdery mildew, caused by Podosphera fusca, is an important disease of cucumber, which is commonly controlled by fungicide application. The side effects of fungicides, however, necessitate searching for other control methods, including induction of disease resistance in the host plant. In this research, the effect of the celery leaf extract (CLE) on cucumber powdery mildew and possible induction of systemic resistance in the host plant was studied by greenhouse tests. The acetonic, methanolic, or water extracts of celery leaf tissues at concentrations of 1% and 5% (w/v) were sprayed on the host plants at either 1 day before, or 1 day after pathogen inoculation. The disease severity was evaluated based on the number of disease spots per leaf, ten days after inoculation. The effect of CLE on systemic control of the disease, germination of pathogen spores, and activity of β-1,3-glucanase (in the CLE -treated cucumber plants, with or without pathogen inoculation, and the non-treated control plants) were also studied. The results showed that CLE controlled the disease on the treated true leaf locally and the acetonic extract at a concentration of 5% showed higher efficacy in the disease control. Application of CLE was not effective on pathogen spore germination and it shows that control of cucumber powdery mildew by CLE was likely via resistance induction in the plant rather than its fungicidal effect. On the other hand, changes in β-1,3-glucanase specific activity in different treatments did not show any correlation with the disease control. Thus it seems that β-1,3-glucanase activity has not an specific role in this resistance induction, and it is necessary to investigate another probable mechanisms involved in inducing resistance.
Iranian Journal of Plant Pathology
انجمن بیماری شناسی گیاهی ایران
0006-2774
50
v.
2
no.
2014
151
161
https://ijpp.areeo.ac.ir/article_10997_c187777e9fd2f3fd27388078101ec064.pdf
INHERITANCE OF RESISTANCE TO STRIPE RUST IN SEVERAL COMMERCIAL CULTIVARS AND SELECTED ELITE GENOTYPES OF WHEAT FROM FARS PROVINCE *
A.
Zakeri
نویسنده
author
text
article
2014
per
This study was carried out to identify the number of resistance genes and mode of inheritance to yellow rust caused by Puccinia striiformis f. sp. tritici among selected elite genotypes of 2000-2002 and several commercial wheat cultivars. The wheat elite genotypes and cultivars were crossed to susceptible parent Avocet S. F1 populations were grown to produce F2 and F3 generations in the successive years. For genetic analysis, two F3 families from each cross at adult plant stage in the field and one F3 family of cross Bahar/Avocet S at seedling stage in the greenhouse along with parents, some of the commercial and control cultivars were examined to Puccinia striiformis f. sp. tritici pathotype 166E138A+ (that was the dominant yellow rust race in Fars province). Genetic analysis showed that elite genotypes including M-79-4, M-79-5, M-79-18, M-80-13, M-80-20, M-81-5, and the cultivar Darab 2, and elite genotypes S-78-11 and S-79-10 each had one adult plant resistance gene. The elite genotypes M-80-6, M-80-12, M-81-8, M-81-13 and M-81-15 were shown to confer two adult plant resistance genes. The resistance in elite genotypes M-79-17, M-81-18, M-80-4 and M-80-5 and cultivar NikNejad each was controlled by two dominant genes at least one of which operated at the seedling stage. The cultivar Bahar was shown to have one seedling and one adult plant resistance gene. The elite genotypes M-79-13 and M-81-3 and the cultivar Star were shown to lack any resistance genes at both seedling and adult plant stages. Past experiences with wheat rusts indicate that relying on single resistance genes particularly those with seedling resistance genes that were also identified in some of the cultivars and elite lines in the present research are usually short lived and mostly encounter with the danger of breaking of resistance in a short period (4-5 years) of time. Deployment of resistance genes of NikNejad cultivar and those elite lines that carried two adult plant resistance genes is recommended in breeding programs in order to produce resistant cultivars with more longevity.
Iranian Journal of Plant Pathology
انجمن بیماری شناسی گیاهی ایران
0006-2774
50
v.
2
no.
2014
163
174
https://ijpp.areeo.ac.ir/article_10998_f80ac81fcaee1a749d0f9420dc57048b.pdf
ASSOCIATION OF MEMBERS OF CLOVER PROLIFERATION (16SrVI) AND PIGEON PEA WITCHES’BROOM (16SrIX) PHYTOPLASMA GROUPS WITH TOMATO BIG BUD DISEASE IN IRAN
E.
JAMSHIDI
نویسنده
author
text
article
2014
per
Tomato plants with symptoms of big bud were observed in Khorasan Razavi, Khorasan Shomali, Azerbaijan Gharbi, Azerbaijan Sharghi, Kermanshah, Kurdistan and Fars provinces of Iran. Affected tomato plants showed proliferation of lateral shoots, small thickened and chlorotic leaves, purple coloration, hypertrophic calyxes, floral virescence, phyllody and failure of fruit setting. Agents of tomato big bud (TBB) disease from these provinces were transmitted from naturally symptomatic tomato plants to tomato by graft and from tomato to periwinkle via dodder inoculation. The presence of phytoplasma in affected plants was shown by direct and nested polymerase chain reaction (PCR) assays using the phytoplasma-specific primer pairs, P1/P7 and R16F2n/R2. Restriction fragment length polymorphism (RFLP) analysis of nested R16F2n/R2 primed PCR product (1.2 kbp) identified TBB phytoplasmas from Kurdistan and Khorasan Shomali provinces as members of the pigeon pea witches’broom (16SrIX) group, and TBB phytoplasmas from Khorasan Razavi, Azerbaijan Gharbi, Azerbaijan Sharghi, Kermanshah and Fars provinces as members of the clover proliferation (16SrVI) group. Phylogenetic analysis of 16S-23S spacer region and putative restriction site analysis of the R16F2n/R2 primed sequence also classified TBB phytoplasmas in the clover proliferation (16SrVI) and pigeon pea witches’broom (16SrIX) phytoplasma groups. The same analyses showed that TBB phytoplasmas related to clover proliferation group belong to subgroup 16SrVI-A and those related to pigeon pea witches’broom group belong to subgroup 16SrIX-E. To our knowledge this is the first report of tomato big bud disease in Khorasan Razavi, Khorasan Shomali, Azerbaijan Sharghi, Kermanshah and Kurdistan provinces and the first report of subgroup classification of associated phytoplasmas.
Iranian Journal of Plant Pathology
انجمن بیماری شناسی گیاهی ایران
0006-2774
50
v.
2
no.
2014
175
175
https://ijpp.areeo.ac.ir/article_10999_683b8a277aacc9d14d2362082419dab9.pdf
BIOCONTROL OF DISEASE AND INDUCTION OF CERTAIN DEFENCE COMPOUNDS IN TOMATO INFECTED WITH Meloidogyne javanica BY SEVERAL Trichoderma ISOLATES
H.
MOSTAFANEGHAD1MOSTAFANEZHAD
نویسنده
author
text
article
2014
per
Iranian Journal of Plant Pathology
انجمن بیماری شناسی گیاهی ایران
0006-2774
50
v.
2
no.
2014
177
181
https://ijpp.areeo.ac.ir/article_11000_bd7ab4000ec3079385c6e7183213b707.pdf
STUDY OF THE MECHANISM OF RESISTANCE TO POTATO LEAFROLL VIRUS (PLRV) ACCUMULATION IN POTATO CLONE G8107(1)
J.
NIKAN
نویسنده
author
text
article
2014
per
Post-transcriptional gene silencing (PTGS) has been proposed as a natural mechanism by which plants recognize and degrade foreign nucleic acids, such as virus genomes. It was thought that such a mechanism might underlie the resistance of potato clone G8107(1) to PLRV accumulation. The idea was examined by graft transmission experiment in which, stem segments of potato clone G8107(1) as test plant and those of the cultivar Maris Piper (MP) (susceptible to PLRV) as control, were grafted on top of the stems of a PLRV-infected root sock plant of the cultivar MP. The virus-free scions of the cultivar MP (as receptors) were also grafted on top of both test and control grafts. The results indicated that the amounts of PLRV antigen in the receptor scions grafted on top of either test or control intermediate grafts were not substantially different, indicating that the presence of stem segments of the clone G8107(1) as intermediate graft has not affected the accumulation of PLRV in the receptor scions, grafted on top of them. Apparently, no silencing factor capable of degrading PLRV-RNA has been transmitted from clone G8107(1) to the cultivar MP. Therefore, the putative silencing factors are either not present in this clone or if there are, they are not transmitted. However, because it has been demonstrated that silencing is transmissible, it is less likely that the virus RNA degradation due to a gene silencing mechanism is involved in the resistance of this potato clone to PLRV. It seems more plausible that the inhibition of PLRV replication underlies the resistance rather than virus degradation.
Iranian Journal of Plant Pathology
انجمن بیماری شناسی گیاهی ایران
0006-2774
50
v.
2
no.
2014
183
183
https://ijpp.areeo.ac.ir/article_11001_73bb72770ad917736fe0fe2fc859f921.pdf
Candidatus PHYTOPLASMA PRUNORUM ASSOCIATED WITH PLUM YELLOW LEAF STUNT IN IRAN
T.
ALLAHVERDI
نویسنده
author
text
article
2014
per
In Europe, chlorotic leaf roll of apricot (Prunus armeniaca L.), leptonecrosis of Japanese plum (P. salicina L.) and yellows and decline diseases of peach (P. persica L.), European plum (P. domestica L.) and almond (P. dulcis L.) have common aetiology and the single name 'European stone fruit yellows' (ESFY) is proposed for them (Seemülleret al. 1998a). European stone fruit yellows (EFSY), associated with ‘Candidatus Phytoplasma prunorum’ is an important disease of Prunus spp. Ca. P. prunorum is phylogenetically related to apple proliferation (AP), pear decline (PD) and peach yellow leaf roll (PYLR) phytoplasmas. Plum trees showing symptoms of yellowing and leaf stunt were observed in August 2012 in several orchards in Mazandaran province, the south coast of the Caspian Sea. Ten symptomatic and two symptomless plants were collected for the identification of the disease causal agent. Total DNA was extracted from 0.5 g of leaf midribs using the CTAB method (Murray & Thompson 1980). The dna samples were subjected to nested-PCR using primer pairs P1/P7 (Deng & Hiruki 1991), followed by R16F2n/R2 (Gundersen & Lee 1996) or fU5/rU3 (Lorenz et al. 1995). Following PCR with primer pairs R16F2n/R16R2 and fU5/rU3, amplified fragments of the expected size, 1200bp and 880bp, respectively were detected in symptomatic plants but not in symptomless plants. Two amplicons from each primer pair were purified and directly sequenced. The sequences were compared with those of the phytoplasma reference strains, using blast analysis. The sequences (GenBank Accession numbers KF739403, KF739404, KF739405 and KF739406) showed 99% similarity with those of ‘Ca. P. prunorum’ (Accession NOs. AJ575108, AJ542545, AJ575111). To our knowledge, this is the first report of a ‘Candidatus Phytoplasma prunorum’ (16SrX) strain associated with the yellowing and leaf stunt in plum trees in Iran.
Iranian Journal of Plant Pathology
انجمن بیماری شناسی گیاهی ایران
0006-2774
50
v.
2
no.
2014
185
185
https://ijpp.areeo.ac.ir/article_11002_98370dab3a92744e08160851ec53f582.pdf
FIRST REPORT OF PATHOGENICITY OF Alternaria interrupta ON CABBAGE (Brassica oleracea L. var. capitata) FROM IRAN
T.
RAHIMLOU
نویسنده
author
text
article
2014
per
In order to identify the Alternaria species involved in cabbage black spot disease, samples of infected leaves were collected from Urmia cabbage fields during the summer and autumn of 2012. Each sample was included in a separate paper bag and the samples were transferred to laboratory. Isolation of the fungi was carried out with culturing the samples on Potato Dextrose Agar (PDA), Potato Carrot Agar (PCA) and Water Agar (WA). The growing fungi with Alternaria characteristics were purified by single spore method. Identification to species levels was based on Simmons’ recommended method (Simmons 2007) under controlled conditions at 25°C, 8/16 light/dark cycle (cool white fluorescent) and PCA medium after 5-7 days. Alternaria interrupta was identified based on the followingcharacteristics. Colonies exhibit concentric rings of growth and sporulation. Vegetative mycelium grows on and within the culture medium. Primary conidiophores are relatively long and simple. Conidial chains on PCA are usually simple, with 8-17 conidia, of which 3-4 initial conidia are relatively large and the remainder abruptly smaller in size. Initial conidia are narrow ellipsoid, 30-45×7-8 µm, have 4-6 transepta and 1 longiseptum in the widest part. Conidia in the upper part are ovoid, 10-20×4-6 µm and have 0-3 transepta and rarely 1 longiseptum in a few conidia of a chain. Conidiophore color is light brown and conidium color is dark brown. The outer wall of conidia is smooth or punctuate (see Fig. 1 in Farsi section). Pathogenicity tests were done on detached, 3 month- old cabbage leaves. Healthy leaves were first washed under tap water, then surface sterilized with 70٪ ethanol and placed in a plastic container containing a wet filter paper. A 5 mm- diameter mycelial plug from the edge of actively growing, 4-5 day- old fungal colony was placed on the leaves. The treated leaves were kept in a growing chamber at 25°C for 1 week. Control leaves received agar plugs without fungus. Characteristic symptoms of the disease including chlorotic and necrotic areas around the inoculated sites developed only on the inoculated leaves (see Fig. 2 in Farsi section). Reisolation of inoculated fungus from infected leaves was done and Koch's postulates were fulfilled. Presence of Alternaria brassicicola, A. brassicae and A. raphani inassociation with infected cabbages has been previously reported in Iran (Ershad 2009), but this is the first report of isolation and pathogenicity test of A. interrupta on cabbage in this country.
Iranian Journal of Plant Pathology
انجمن بیماری شناسی گیاهی ایران
0006-2774
50
v.
2
no.
2014
187
188
https://ijpp.areeo.ac.ir/article_11003_41e584de9164fc2354473c255c2b32f6.pdf
FIRST REPORT OF Diplodia seriata, THE CAUSAL AGENT OF CANKER DISEASE OF APPLE TREES IN IRAN
S.
HANIFEH
نویسنده
author
text
article
2014
per
During the surveys of apple trunk and branch diseases in Urmia orchards, a pycnidial fungus was frequently isolated from Golden Delicious cultivar trees of over 15 years old with symptoms of stem and branch cankers, branch dieback, bark scaling and discoloration (Fig. 1-A in Farsi section). Purification of the isolated fungus was carried out by hyphal tip method. Formation of asexual fruiting bodies of the fungus was induced by the use of pine needles. The purified fungi were cultured on 2 percent water agar medium and then, sterilized pine needles were placed at different parts of the medium. Inoculated Petri plates were kept for four weeks at 25 °C under near-ultraviolet light (near-UV) with 12:12 h photoperiod (Pavlic et al. 2008). Different macro- and micro- morphological characters such as color and growth characteristics of the colony, color, shape and dimensions of conidia, conidiogenous cells and pycnidia were studied. Also, the ITS region of one selected isolate was amplified and sequenced using the ITS1 and NL-4 primers. Based on morphological and ITS sequence analysis, the fungus was identified as Diplodia seriata. The results of Blast search showed high similarity (100 percent) of the sequenced isolate with the isolates of D. seriata deposited in GeneBank. Descriptive characters of the species are: Colony diameter after four days at 25 °C is 75 to 80 mm; colony color is at first white, then turns olive green to olive gray and finally after two weeks becomes dark; colony with regular margins, aerial mycelium dense and thick; conidiomata pycnidial, 380 × 260 µm in diameter, solitary or aggregated, globose to ovoid, dark brown to black, immersed, partially erumpent when mature (Fig. 1-B in Farsi section); conidiogenous cells hyaline, smooth, cylindrical, swollen at the base, 7-12 × 3-5 µm, proliferating at the same level to produce periclinal thickening, or proliferating percurrently, giving rise to 2-3 annelations; conidia at first aseptate, thick-walled with smooth outer surface and verruculose inner surface clearly, ovoid to cylindrical, apex obtuse, base truncate or rarely rounded, hyaline, becoming pale brown and soon darkening before release from the pycnidia and becoming 1-septate (Fig. 1-C in Farsi section), rarely 2 or 3 septate after discharge, (12-) 20.6-22.02 (-31) × (7.5-) 9.6-10.05 (-12) µm, L/W = 2.2[H1] . Pathogenicity test was carried out on potted 2 years old seedlings and fruits of apple Golden Delicious cultivar based on completely randomized design. In seedlings, eight weeks postinoculation, symptoms of bark darkening and canker were seen in inoculated areas (Fig. 1-D in Farsi section). In fruits, six days after inoculation, the brown rot symptoms were seen around the inoculated area (Fig. 1-E in Farsi section), progressing into the fruit flesh. No symptoms were developed in the controls. Reisolation of the inoculated fungus were done from the newly infected tissues and Koch's postulates were fulfilled. All the tested isolates were pathogenic on fruits and seedlings. To our knowledge, this is the first report of isolation and pathogenicity confirmation of D. seriata from apple trees in Iran.
Iranian Journal of Plant Pathology
انجمن بیماری شناسی گیاهی ایران
0006-2774
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v.
2
no.
2014
189
190
https://ijpp.areeo.ac.ir/article_11004_adebdfd292cb7a41ccc549b3ad5f084c.pdf
DETECTION OF Hop stunt viroid IN LEMON, SWEET LIME, CLEMENTINE AND SATSUMA MANDARINS AND GRAPEFRUIT TREES IN MAZANDARAN
R.
VAMENANI
نویسنده
author
text
article
2014
per
Hop stunt viroid (HSVd) of the genus Hostuvirod, is mostly known around the world as the agent of cachexia-xyloporosis disease of mandarins (Citrus reticulata Blanco, C. unshiu Marco., and C. nobilis Lour.) and their hybrids, tangelos (C. reticulata × C. paradise Macf.) and tangors [C. reticulata × C. sinensis (L.) Osb.]. Sweet lime (C. limettioides Hort. ex Tanaka) is also susceptible, displaying stunted growth and stem pitting. Symptoms on mandarins and their hybrids include overall chlorosis of the trees, gum impregnation of the bark, formation of pits in the xylem and pegs on the cambial surface of the bark which fit in the pits on the wood. The severity of symptoms varies with the host species and cultivar and strain of the viroid. To estimate the prevalence of the viroid in some symptomatic and symptomless species of citrus commonly grown in Mazandaran province, samples were taken randomly from symptomatic Clementine mandarin (C. reticulata, Blanco), old line Wase Satsuma (C. unshiu) and sweet lime all of which displayed stem pitting and impregnation of gum in the bark tissue at and above the bud union and symptomless trees of lemon [(C. limon (L.) Burm. f., local cultivar)] and Duncan grapefruit (C. paradisi Macf.). RNA was extracted from the bark of one year old stems using TRIzol (Invitroge, Carlsbade, CA). Reverse transcription (RT) polymerase chain reaction (PCR) was performed using specific primers for HSVd and the products were electrophoresed on 2% agarose gels. The expected fragments of 300bp typical of HSVd, were detected in all Satsuma (20 out of 20) and 77% Clementine mandarin (19 out of 25), whereas 63% (14 out of 22), 100%(12 out of 12) and 33% (5 out of 15) of trees of sweet lime, lemon and grapefruit, respectively, were found to be infected with the HSVd. These symptomless trees are hidden sources of the viroid, contributing to maintenance and spread of HSVd and necessitate the use of sensitive molecular detection assays wherever eradication programs are in practice. This is the first report on infection of lemon and grapefruit with the HSVd in Iran.
Iranian Journal of Plant Pathology
انجمن بیماری شناسی گیاهی ایران
0006-2774
50
v.
2
no.
2014
191
191
https://ijpp.areeo.ac.ir/article_11005_451badff7b383ff6e9a190d6d216834e.pdf