Viruses affecting lentil in Jordan

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1 / Indian Phytopath. 51 (1) : 1-9 (1998) Viruses affecting lentil in Jordan O. AL- MABROUK and A.N. MANSOUR Department of Plant Protection, University of Jordan, Amman-Jordan ABSTRACT: A study was initiated to identify the viruses causing diseases in lentil, their incidence and yield loss caused by the most prevalent one. Three viruses were identified from four hundred leaf samples collected from the main growing regions of lentil during 1995 and 1996 and fourth isolate from lentil seeds. Identification of the viruses was based on host range, symptomatology, physical properties, insect, and serological tests. The viruses identified were AMV, BYMV, BBSV and PSBMV. Growing on test had indicated that BBSV and PSBMV were seed transmitted up to 2.1% and 0.8%, respectively in all the tested commercial cultivars of lentil. The highest viral disease incidence was 16.5% in Rabba at the end of the growing season. BBSV was the most prevalent virus followed by PSBMV in lentil growing in Jordan. This is the first report of lentil viruses in Jordan. Key words : AMV, BYMV, BBSV, PSBMV, Lentil, Jordan Lentil is a leguminous food crop which provides a valuable protein. The residues form threshing have a good livestock feeding value (Webb and Hawtin, 1981). In Jordan lentil is planted in 2424 hectars (Anonymous, 1994). Several viruses were reproted to naturally infect lentil in different parts of the world (Bos, et ai., 1988; Makkouk et al., 1992). Some of these viruses such as broad bean stain virus (BBSV), pea seed borne mosaic virus (PSBMV) and bean yellow mosaic virus (BYMV) are transmitted through lentil seeds (Kumari et al., 1994; Hampton and Muehlbauer, 1977; Goodbell and Hampton, 1983; Makkouk and Azzam, 1986; Makkouk et al., 1987). Since no work had been done on viruses affecting lentil, this work was carried out to identify virus (es) involved in virus disease complex, their incidence and prevalence in the main growing areas of lentil crop. MATERIALS Sample collection AND METHODS Four hundred lentil leaf samples showing viruslike symptoms were collected from the areas of M'shagar, Maru, Rabba, Jordan Valley and Amman. The survey was conducted at weekly intervals for each location starting from February until June of Virus isolation All samples were biologically assayed on diagnostic hosts, Chenopodium amaranticolor, C. quinoa, Lens culinaris, Nicotiana glutinosa, N. tabaccum Havana 423, Phaseolus vulgaris cv. Strike Pisum sativum cv. Onward, Vicia faba cv. Local and Vigna unguiculata cv. Black eye. Inocula were prepared by grinding th tissue in O.OIM neutral phosphate buffer (Ig tissue/ Iml buffer) containing O.OIM sodium diethyl dithiocarbamate (Na-DIECA) and O.OIM cysteine (C-HCI) using sterilized mortar and pestle. Sap inoculation was done using carborundum (160 mesh) dusted plants on cotyledonary or 3rd-4th leaf stage. Inoculated plants were observed for 4-6 weeks for symptoms development under glasshouse conditions (25 C). The preliminary assay suggested the presence of three virus isolates (16/95, 145/95 and 223/95). Another virus isolate (Se/95) was isolated from commercial lentil seeds during seed test. Pure culture of each isolate was obtained by a single lesion transfer and multiplication on Nicotiana tabacum H 423 (isolate 16/95), Vicia faba (isolate 145/95) and Pisum sativum (isolates 223/95 and Se/ 95) for further studies. Host range Thirty six plant species of different families (Table 3) were grown in 10 em pots filled with methyl bromide fumigated soil and inoculated at the cotyledonary or 2nd and 3rd leaf stage. The inoculum of each isolate was prepared by grinding the fresh young infected of propagative host in neutral phosphate buffer (O.OlM) containing O.OlM Na-DIECA and O.OlM C-HCI. Five healthy plants of each species were inoculated. Five weeks later, inoculated and non inoculated top of test plant were back in-

2 2 indian Phytopathology [Vol. 51(1) 1998] Table 1. Dilution of antigen and antisera used in I-ELISA Antigen Antisera Isolate Buffer Dilution Incubation Dilution Dilution Incubation time buffer time 16/95 CEP 1:20 overnight at PEP 1: hour at 37 C 4 C 145/95 PEP 1:10 1 hour at PEP 1: hour at 37 C 37 C 223/95 PEP 1:10 3 hour at PBS 1:1000 overnight at 37 C 4 C Se/95 PEP 1:10 I hour at PEP 1: hour at 37 C 37 C CEP : Coating buffer, ph 9.6 containing 2% PVP and 0.2% ovalbumin. PEP: Phosphate buffer saline (PBS), ph 7.4 containing 0.05% Tween- 20, 2% PVP and 0.2% ovalbumin. dexed on Vigna unguiculata (isolate 16/95), C. amarnticolor (isolates 145/95 and Se/95) and on Vicia faba (isolate 223/95). Transmission Aphid Apterous adults of Myzus persicae from the rearing host (Capsicum frutescens) were given one hour starvation, 5 minutes acquisition access on the propagative hosts; Nicotiana glutinosa H 423 (isolate 16/ 95) Vicia faba (isolate 145/95) and Pisum sativum (isolates 223/95 and Se/95). Five aphids per plant were transferred to each of 10 healthy plants. After 5 minutes inoculation access, aphids were killed with Anthio 33EC at a rate of 25 mv20 L. Beetle Weevils (Sitona Iineatus) collected form lentil fields were allowed to feed on healthy lentil plants, which were changed daily for one week to enable the weevils to lose the virus, if present (Gibbs and Smith, 1970; Cockbain et ai., 1975). They were then allowed to feed on the propagative host for 24 hours using small plastic cages (Mansour and Al-Musa, 1992). Ten weevils on each plant were transferred to group of 10 healthy seedlings of propagative plants for an inoculation access period of 24 hours. Seed Six hundred seeds of each of the three lentil cultivars namely, Jordan 1,2 and 3 kindly provided by Dr. Ababneh (National Centre of Agriculture Research and Technology Transfer- Amman) were sown in polystyrene seedling trays containing sterilized peatmoss. Plants showing abnormal growth such as stunting, yellowing and leaf curling were tested by indirect ELISA (I-ELISA) against antisera specific to broad bean stain virus (BBSY), bean yellow mosaic virus (BYMY) and pea seed borne mosaic virus (PSBMV). Abnromal plants were also tested biologically on the diagnostic plants. Physical properties The thermal inactivation point (TIP), dilution end point (DEP) and longevity in vitro CLIY) of each isolate were studied using plant sap extracted form systemically infected young (Walkey, 1985). Serology Antiserum against AMY was a gift by T.Z. Scot (Clemson Universty, North Carolina) and antisera of BBSY, BYMY and PSBMY were kindly supplied by K. Makkouk (ICARDA, Aleppo, Syria). The virus isolates were tested serologically against AMY, BBSY, BYMY and PSBMY antisera by agar gel double diffusion test and I-ELISA. Agar gel double-diffusion test This test was performed in plastic dishes in 0.85% purifed agar dissolved in distilled water containing 0.58% NaCI and 0.2% NaN0 3 with or without 0.5% SDS. Yirus antigens were prepared by grinding systemically infected tissue with neutral phosphate buffer (lgmllml) with or without equal dilution of 3% SDS. Healthy saps of the same plant species were included as control. Indirect ELISA For I-ELISA buffers were the same as described /

3 [Vol. 51(1) 1998] Indian Phytopathology J Table 2. Reaction of virus isolates 16/95, 145/95, 223/95 and Se/95 on diagnostic hosts Plant Species 16/95 145/95 223/95 Se/95 Inoculated Terminal Inoculated Terminal Inoculated Terminal Inoculated Terminal Chenopodium amaranticolor - Y.M. C.L.L. N.L.L. Chenopodium quinoa C.L.L. Y.M. C.L.L. C.L.L. Lens culinaris CUR. ST., CL. CUR Mo., T.T. CUR Y.M., ST. CUR. T.T. Nicotiana glutinosa V.C. Nicotiana tabacum cv. V.C. H423 CH.M. Phaseolus vulgaris cv. N.L.L. S.G.M. Strike Pisum sativum cv. Onward WIL. M.M. WIL. CH.M. WIL. ST., N. Vicia faba cv. Local N.L.L. M.M. S.G.M. H.M. M.MO. Vigna unguiculata cv. N.L.L. SC Black eye Y.M. : YelIow Mosaic C.L.L. : Cholrotic Local Lesions N.L.L. : Necrotic Local Lesions CUR : Curling ST : Stunting V.C. : Vein Clearing CH.M. : Cholrotic Mottling M.M. : Mild Mottle M.M.O. : Mild Mosaic MO. : Mottling S.G.M. : Systemic Green Mosaic L.N. : Leaf Narrowing N. : Necrosis WIL. : Wilting CL. : Chlorosis T.T. : Tip Twisting SC : Symptomless Carrier : No Infection by Koenig (1981). Antigen, antisera and conjagate dilution that gave the best reaction were selected for further tests as given in Table 1. ELISA plates (Dynatech Immulon, U.S.A.) were charged with 0.2 ml of the extracted sap from propagative host. Healthy sap and the buffer used were the negative control. After incubation, crude sap was discarded and the plate washed three times with phosphate buffer saline - Tween 20 (PBS-T). The wells were then loaded with 0.2 ml of specific antisera. At the end of incubation, wells were washed three times with PBS-T, then 0.2 ml of goat anti-rabbit (GAR) diluted at 1:3000 in phosphate buffer saline (PHS) at ph 7.4, containing 0.05% Tween-20, 2% polyvinyl pyrrolidone (PVP, M.W. 40,000) and 0.2% ovalbumin was added to each well. The plate was then incubated for 3 hours at 37 C (isolate 16/95 and 223/95) and one hour (isolates 145/95 and Se/95). After the conjugate removal, wells were washed with PBS-T and 0.2 ml of substrate, (0.1 gm p-nitrophenyl phosphate disodium in 100 ml of substate buffer) was added. Optical density was measured 20 minutes later using ELISA reader Denley WellScann model. Incidence of lentil viruses The disease incidence study was initiated during late February 1996 and continued until late May 1996 in the main growing locations of lentils in Jordan (M'shagar, Maru and Rabba). From each field, 500 plants were chosen randomly in five different rows and visually observed weekly. The number of plants showing virus-like symptoms were counted each time. A portion of tip of suspected plants was collected and tested serologically using antisera specific to BBSV, BYMV and PSBMV. Positive ELISA samples were biologically assayed on diagnostic assay plants. Detection of the lentil viruses in other crops and weeds Leaf samples of economic crops showing viruslike symptoms form fields adjacent to lentil in Ghor, M'shagar, Maru and Rabba locations and weeds from lentil fields were collected during the growing season of lentil crop. Each sample was tested for the presence or absence of AMV, BBSV, BYMV and PSBMV using I-ELISA and biological assay.

4 4 Indian Phytopathology [Vol. 51(1) 1998] Table 3. Host range of the four lentil virus isolates Plant species Reaction of virus isolates Amaranthus retroflexus 16/95 145/95 223/95 Se/95 Chenopodium amaranticolor NT NT NT NT Chenopodium murale SM CLL NT NIL Chenopodium quinoa NI NI NT CLL Cicer arietinum CLL & SM CLL NI CLL Cucumis sativus SC SMMt NI SMMt Cucurbita pepo NT NI NI NI Datura strammonium SMMt NI NT NI Gomphrena globosa NI NI NI NI Lathyrus cicera SMMt NT NI NI Lathyrus ochrus SC SMMt SMMt St Lupinus alb'us SC SMMt SMMt St Lycopersicon esculentum SC SC NI SC, St Medicago polymorpha SMMt NI NT NI Medicago sativa SMMt SC SMMt SMMt Medicago rotata SMMt SC LC&SC SMMt Nicotiana clevelandii SVC SMMt NI NI Nicotiana glutinosa SVC NI NI NI Nicotiana tabacum cv. H423 VC&Mt NI NI NI Phaseolus vulgaris cv. Bronco NLL NI NI NI Phaseolus vulgaris cv. Helda NLL SGMt NI NI Phaseolus vulgaris cv. Lavict NLL SGMt NI NI Phaseolus vulgaris cv. Lolita NLL SGMt NI NI Phaseolus vulgaris cv. Seville NLL SGMt NT NI Phaseolus vulgaris cv. Strike NLL GMt NI NI Phaseolus vulgaris cv. Sutter pink NLL SGMt NI NI Pisum sativum cv. Alderman, Onward W SGMt SMMt SMMt, LC Ocimum basilicum SC SGMt NI NI Spinaceae oleareaceae NI NI NT NI Trifolium tementosum SMMt NI SC SNC, LC Trifolium alexandrium SMM SC SMMt SC Vicia ervilia SMMt SC S&LC SNC,LC Vicia faba cv. Cyptiote, local SMMt SMMt SNC SMMt, St Vicia sativa SMMt SGMt SNC SMMt Vicia narbonensis SMMt NI LC&St NT Vigna unguiculata cv. Blackeye NLL SC NI NI NI : Not infected Mt : Mottle CLL : Cholorotic local lesion NLL : Necrotic local lesion SM : Systemic chlorosis W : Wilt SC : Systemic chlorosis SGMt : Systemic green mottle SMMt : Systemic mild mottle SLC : Systemic leaf curling SVC : Systemic vein clearing SNC : Systemic necrosis RESULTS Virus isolation Sixty three virus samples were recovered form diseased lentil plants during the growing seasons of According to their reaction on the diagnostic hosts (Table 2), they were grouped into three distinct isolates 16/95, 145/95 and 223/95. A fourth isolate Set 95 was obtained from seedlings raised from commercial lentil seeds collected.

5 [Vol. 51(1) 1998) Host range Host range studies indicated that the isolates 16/ 95, 145/95 and Se/95 are not restricted to leguminosae while the isolate 223/95 was restricted to leguminosae. The response of different plants species mechanically inoculated with the four isolates are given in Table 3. Insect The isolates 16/95, 145/95 and Se/95 were readily transmitted by the green peach aphid Myzus persicae after an aquisition and inoculation access period of 5 minutes. No symptoms were observe on tested plants when the weevil Sitona lineal us was used as viurs vector for the isolates 16/95, 145/95 and Se/95. Isolate 223/95 was transmitted successfully by Sitona lineatus after an acquisition and inoculation Indian Phytopathology :; access period of 24 hour. This isolate was not transmitted through Myzus persicae. Seed Seed test indicated that BBSV and PSBMV could be transmitted through lentil seeds (Table 4). The rate of of BBSV in lentil seeds was higher than that of PSBMV. Physical properties All isolates had a TIP of C and DEP of 10' J _ LlV of isolates 16/95, 145/95 and Se/95 was 2-3 days and 8 days of 223/95 isolate. Serology In agar double diffusion test, the isolates 16/95, 145/95, 223/95 and Se/95 reacted strongly with anti- Table 4. Seed test of BBSV, BYMV and PSBMV in seeds of lentil Diagnostic method Cultivar I-ELISA Diagnostic host BBSV PSBMV BYMV BBSV PSBMV BYMV Jordan 1* 0.6% 0.0% 0.0% 0.6% 0.0% 0.0% Jordan 2* 2.1% 0.3% 0.0% 2.1% 0.3% 0.0% Jordan 3* 1.8% 0.8% 0.0% 1.8% 0.8% 0.0% *600 seeds were tested 20 "i!l"t{nljbil 18 - ~..l\jal u & 1\1lshagar' C 12 c: 14 - ~ Q. "0 ~ "~c: 12 i,~ ClJ ell 8 - 'c'" " u.. 6.., Feb. March April May Fig. 1. Incidence of viral diseases on lentil fields of Rabba, Maru and M'shagar during the winter of 1996.

6 6 Indian Phytopathology [Vol. 51(1) 1998] Table 5. Crop and weed samples tested for natural infection by four viruses infecting lentil Diagnostic method BBSV PSBMV BYMV AMY S B S B S B S B Crops Capsicum frutescens + + Cicer arietinum + + Medicago sativa Pisum sativum Vicia faba Weeds Asperula arvensis + Caucalis tenella + + Euphorbia sp. + + Malva sylvestris + + Medicago obicularis Polygnum aviculare Silene conoidea + Tetragonolobus palaestinus " + '+ Vaccaria parviflora + S : Serological assay - : Negative result B : Biological assay + : Positive result sera specific to AMV, BYMV, BBSV and PSBMV, respectively, by forming a sharp precipit line; such reaction was not observed against buffer and healthy sap (plate 1). Indirect-ELISA showed that the isolates 16/95, 145/95, 223/95 and Se/95 reacted positively with antisera specific to AMV, BYMV, BBSV and PSBMV, respectively. Wells charged with buffer and healthy sap extract did not show any specific reaction. The O.D. values at absorbance 405 nm of of wells charged with virus isolates were three times more than the negative control. Incidence of lentil viral disease The disease developed slowly until late April when the maximum incidence (16.5%) was in Rabba fields while the minimum disease incidence (3.5%) was in M'shagar fields (Fig. 1). The result of the virus survey during 1995 and 1996 by using serological and biological tests indicated maximum incidence of BBSV (23.2%) followed by PSBMV (10.6%) while only 3.3% and 0.4% infection of BYMV and AMV, respectively, was recorded. Detection of the identified viruses in other crops and weeds Broad bean stain virus (BBSV) was detected serologically and biologically only in pea and faba bean plants whereas PSBMV was found in most of the pea fields grown near or far from lentil fields and faba bean fields of the Jordan Valley (Table 5). Bean yellow mosaic virus (BYMV) was detected serologically and biologically from chickpea, pea, faba bean plants grown near or far from fields and serologically only in only in Medicago sativa (Table 5). Alfalfa mosaic virus (AMV) was detected from pepper, alfalfa, pea and faba bean plants grown in the Jordan Valley, but -not from any sample collected from Rabba, Maru and M'shagar locations (Table 5). Weed samples from several plant families were collected from lentil fields in Rabba, Maru M'shagar and Agricultural Research Station (ARS) during and at the end of the growing season of lentil crop (Table 5). Broad bean stain virus (BBSV) was shown to be present in Medicago obicularis and Tetragonolobus palaestinus of families

7 [Vol. 51(1) 1998] Indian Phytopathology 7 Fig. 2. Agar gel double deffusion test: Central wells contain antisera (I) AMV; (2) BYMV; (3) BBSV; (4) PSBMV. Peripheral wells contain : A = Antigen; B = Negative control; (C) = control. Papilionaceae and in Polygonum aviculare, a member of Polygonaceae but not in other weeds collected (Table 5). Serological-and biological tests showed the presence of PSBMV in Tetragonolobus palaestinus, Polygonum aviculare of families Papilionaceae and Polygonaceae in Caucalis tene/la of family Umbelliferae. However, serological results indicated the presence ofpsbmv in Asperula arvensis, Medicago obicularis, Silene conoidea and Vaccaria parviflora, respectively of families Rubiacease, Papilionaceae, Caryophyllaceae and Caryophyllacea, while this was not confirmed by biological assay (Table 5). Bean yellow mosaic virus (BYMV) was present in Euphorbia sp., Polygonum aviculare and Tetragonolobus palaetinus of families Euphorbiaceae, Polygonaceae and Papilionaceae, respectively (Table 5). Alfalfa mosaic virus (AMV) was detected only in Malva sylvestris of family Malvaceae collected fram the Jordon Valley (Table 5). DISCUSSION On the basis of host range, mode of, properties in crude sap and serological tests, the isolates 16/95 145/95 and Se/95 were identified as AMV, BYMV and PSBMV, respectively (Makkouk et al., 1993; Bos et al.,1988; Mink et al.,1969; Hampton et al., 1978; Hampton and Mink, 1975; Kasier, 1973; Al-Musa et al., 1987; Swalha and Mansour, 1996; Japser and Bos, 1980). The isolate 16/95 differs form the other isolates by producing systemic symptoms on C. amaranticolor and N. glutinosa and local lesions on Phaseolus vulgaris, Vigna ungiculata and Vicia faba. Such reaction on these hosts is considered as a good indicator for AMV identification (Swalha and Mansour), 1996; Jasper and Bos, 1980). The host range of the isolate 145/95 was similar to that of pea mosaic strain of BYMV of producing chlorotic local lesions on C amaranticolor and systemic symptoms on Phaseolus vulgaris (Al-Musa et al., 1987; Bos, 1970).

8 8 Indian Phytopathology The isolate Se/95 identified as PSBMV reacted with necrotic local lesions on C. amaranticolor but failed to infect P. vulgaris (Hampton and Mink, 1975). With regard to the isolate 223/95, host range study, beetle and properties in crude sap suggested a close resemblance to BBSV described by Gibbs and Smith, (1970). This was substantiated by positive serological tests. The growing on test suggested that BBSV and PSBMV could be transmitted through seeds of lentil. BYMV was not transmitted through seeds of lentil. Similar results were obtained by other (Bos et al., 1988; Makkouk et al., 1993; Varma et al., 1991). The presence of viral disease with low percent in lentil field at the begining of the lentil growing season was due to the seed (Makkouk et al., 1988). The development of the disease was very slow and did not reach more than 16.5% at the end of the growing season. This may be attributed to the low temperature prevailed during the study which prevented the build up of the vector population and inhibited the vector activity. The survey indicated the prevalence ofbbsv and PSBMV followed by BYMV whereas AMV was deteced only from the Jordan Valley. The prevalence of BBSV and PSBMV may be explained by the presence of these viruses at early stages through seed and subsequent dissemination by insect vector. Detection of the lentil viruses in crops and weeds in the vicinity of lentil fields suggested importance of these species as a source of inoculum during the growing season, that contribute in the spreading the viruses with the presence of vector (Bos et al., 1988). REFERENCES Anonymous. Annual Report, Department of Agriculture Economics and Planning. Ministry of Agriculture, Amman, Al-Musa, A.M., AI-Haja, H., Mansour, A. and Jankat, S. (1987). Properties of bean yellow mosaic virus occuring on broad beans in the Jordan Valley, Dirasat, 14(11): Bos, L. (1970). Bean yellow mosaic virus, CMIIAAB Description of Plant Viruses No. 40. Bos, L.,Hampton, R.O. and Makkouk, K.M. (1988). Viruses and virus diseases of pea, lentil, faba bean, and chickpea, In : Summerfield, R.O., World Crops: Cool Season Food Legumes, kluwer Academic Publishers, Dordrecht, pp Cockbain, A.J., Cook, S.M. and Bowen, R. (1975). Transmission of broad bean stain virus and Echtes Ackerbohnenmoaik virus to field beans (Vidafaba) by weevils. Ann. Appl. Biol. 81: [Vol.51(1) 1998] Gibbs, A.J. and Smoth, H.G. (1970). Broad bean stain virus, CMIIAAB Description of Plant Viruses No. 29. Goodel, J.J. and Hampton, R.O. (1983). Seed and aphid of the lentil strain of pea seed born mosaic virus (PSBMV-L) in Lens culinaris. Phytopathology 73(6): 959. Hampton, R.O. and Mink, G.I. (1975). Pea seed borne mosaic virus, CMIlAAB. Description of Plant Viruses No Hampton, R.O. and Muelbauer, F.J. (1977). Seed of the pea seed borne mosaic virus in lentils. Plant Dis. Reptr. 61(3): Hampton, R.L., Beczner, D., Hagedorn, Bos, L., Inouye, T., Barnett, 0., Musil, M. and Meiners, J. (1978). Host of reactions of mechanically transmissible legume viruses of the northern temperate zone. Phytopathology 68(12): Japser, E. and Bos, L. (1980). Alfalfa Mosaic Virus, CMII AAB Description of Plant Viruses. No Kaiser, W.J. (1973). Etiology and biology of viruses affecting lentil (Lens esculenta Moench) in Iran. Phytopathologica Mediterranea 12(9): Koenig, R. (1981). Indirect ELISA methods for the broad -specifity detection of plant viruses, J Gen. Virol. 55: Kumari, S.G., Makkouk, KM. and Ismail, I.D. (1994). Seed and yield loss induced in lentil by bean yellow mosaic virus. Lens Newsletter 21(1): 42. Makkouk, K.M. and Azzam, 0.1. (1986). Detection of broad bean stain virus in lentil seed groups. Lens Newsletter 13(2): Makkouk, KM., Bos, L., Azzam, 0.1., Katul, L. and Rizkallah, A. (1987). Broad bean stain virus: identification, detectiability with ELISA in faba bean and seeds, occurrence in West Asia and North Africa, and possible wild hosts. Neth. J Plant Path. 93: Makkouk, KM., Bos, L., Azzam, 0.1., Kumari, S. and Rizkallah, A. (1988). Survey of viruses affecting faba bean in six arab countrues. Arab Journal of Plant Protection 6( 1): Makkouk, K.M., Kumari, S.G. and AI-Daoud, R. (1992). Survey of viruses affecting lentil (Lens culinaris Med.) in Syria. Phytopathologica Mediterranea 31: Makkouk, KM., Kumari, S.G. and Bos, L. (1993). Pea seed-borne mosaic virus: Occurrence in faba bean (Vida faba L.) and lentil (Lens culinaris Med) in West Asia and North Africa, and further information on host range, characteristic, and purification. Neth. J Plant Path. 99:

9 [Vol. 51(1) 1998] Mansour, A. and AI-Musa, A. (1992). Tomato yellow leaf curl virus: host range and virus vector relationships. Plant Pathology, 41: Mink, G.L., Kraft, J., Knesek, J. and Jafri, A. (1969). A seed-borne virus of peas. Phytopathology 59(10): Swalha, H.D. and Mansour, A.N. (1996). Incidence of alfalfa mosaic virus in alfalfa fields in Jordan. Dirasat, 23(2): Varma, A., Khetarpal, R.K., Vishwanath, S.M., Kumar, Indian Phytopathology 9 D., Maury, Y., Sharma, B. and Tyagi, M.C. (1991). Detection of pea seed borne mosaic virus in commercial seeds of pea, and germplams of pea and lentil. Indian Phytopath. 44: Walkey, D.G. (1985). Applied Plant Virology. John Willey and Sons, New York, pp 337. Webb, C. and Hawtin, G. (1988). Lentils. Second Edition, Page Bros (Norwich/Ltd), England, pp Received for publication October 10, 1996.