cause serious diseases in many economi- PW isolate up to a dilution of 1:16. cally important crop plants around the BBWV serotype II had previously been world. Being perennial, periwinkle plants found only in the United States and can serve as reservoirs for these - Argentina (3,10). transmissible in Queensland. CMV has long been known to be present ACKNOWLEDGMENTS in Queensland (7) and also has been We are grateful to R. G. Garrett for the aphid transmission facilities and for providing the BB strain found in periwinkle in other countries (4), of BBWV and its antiserum. We are also grateful to J. but this is the first isolation of the K. Uyemoto for the gift of antisera to the two from this host in Queensland. This is also serotypes of BBWV. the first report of BBWV in periwinkle and of its presence in Queensland. LITERATURE CITED Our PW isolate differed from BB- 1. FINLAY, J. R. 1975. Cucumber mosaic virus in gerbera. Aust. Plant Pathol. Soc. Newsl. 4:14. BBWV (8) in host range, symptom- 2. GIBBS, A. J., and B. D. HARRISON. 1970. atology, and antigenic properties. Cucumber mosaic virus. No. 1. Descriptions of Although BBWV isolates with identical Plant Viruses. Commonw. Mycol. Inst., Kew, Fig. 1. Agar gel double diffusion test with or different antigenic properties have Surrey, England. 4 pp. 3. GRACIA, 0., and J. M. FELDMAN. 1976. antiserum to serotype II (As II, central well) previously been found to differ in host and the antigens of periwinkle (PW) and broad Studies of weed plants as sources of viruses. IV. range and symptomatology, the one Broad bean wilt virus bean (BB) strains of broad bean wilt virus in Sisymbrium irio and Plantago lanceolata in Argentina. Phytopathol. (peripheral wells). HS = healthy sap. common property has been their ability to infect different N. tabacum cultivars Z. 85:227-236. Chenopodium quinoa was the source of 4. RAO, D. R., and S. P. RAYCHAUDHURI. antigens. systemically, with ringspot symptoms in 1978. Chenopodium murale: A local lesion host most cases (3,6,9,10). In repeated for cucumber mosaic virus (CMV) isolated from inoculation tests, however, our PW Vinca rosea. Curr. Sci. 46:539. 5. REYNOLDS, Table 1. Reactivities between antisera and the isolate did not cause systemic infection in B., and D. S. TEAKLE. 1976. Viruses infecting commercial gladiolus cultivars periwinkle (PW) and broad bean (BB) strains this plant species. in Queensland. Aust. Plant Pathol. Soc. Newsl. of broad bean wilt virus in sap from infected The BB strain of BBWV commonly 5:22-23. plants found in some parts of Australia has been 6. SHUKLA, D. D., and K. SCHMELZER. 1972. placed in serotype I of the virus (10). Studies on viruses and virus diseases of Antibody titer cruciferous plants. III. Nasturtium ringspot virus Although the antibody titer obtained in Sinapis alba L. Acta Phytopathol. Acad. Sci. Homologous with antigens a with our PW isolate and antiserum to Hung. 7:147-156. Antiserum titer BB PW serotype II was 1:64 (Table 1), compared 7. SIMMONDS, J. H. 1966. Host index of plant BB strain 1:1024 (8) 1:1024 1:16 with a homologous titer of 1:128 (10), the diseases in Queensland. Queensland Dep. Serotypel1 1:128 (10) 1:128 1:32 Primary Industries. 111 pp. precipitin lines produced by this isolate 8. TAYLOR, R. H., P. Serotypel11 1:128 (10) R. SMITH, C. 1:16 1:64 and the BB strain in the immunodiffusion REINGANUM, and A. J. GIBBS. 1968. aLiterature citations in parentheses. plates indicated that the PW isolate is Purification and properties of broad bean wilt apparently more closely related serologi- virus. Aust. J. Biol. Sci. 21:929-935. 9. TAYLOR, R. H., and L. L. STUBBS. 1972. cally to serotype II than to serotype I. Broad bean wilt virus. No. 81. Descriptions of DISCUSSION Others have found that antiserum to BB Plant Viruses. Commonw. Mycol. Inst., Kew, Our results show that periwinkle is a strain (8) does not react with serotype II Surrey, England. 4 pp. host of CMV and BBWV in Queensland. isolates of the virus (3,10). In our 10. UYEMOTO, J. K., and R. PROVVIDENTI. 1974. Isolation and identification of Although the two viruses did not produce two experiments, however, this antiserum serotypes of broad bean wilt virus. Phyto- any visible symptoms in periwinkle, they produced visible precipitin lines with the pathology 64:1547-1548.

Maize Dwarf Mosaic Virus in Greece

P. C. PANAYOTOU, Plant Virologist, Plant Protection Research Institute, Ministry of Agriculture, Partas, Greece

(Sorghum bicolor L. 'Rio,' 'Atlas,' 'Sart,' ABSTRACT and 'MN 1056'), johnsongrass (S. PANAYOTOU, P. C. 1980. dwarf mosaic virus in Greece. Plant Disease 64:803-804. halepense (L.) Pers.), and wheat (Triticum Maize dwarf mosaic virus was isolated from nine corn and 27 johnsongrass plants in corn fields in aestivum L. 'Michigan Amber'). Seeds Achaia County in northwestern Peloponnese. All of the isolates were maize dwarf mosaic virus, treated with organomercurial fungicide strain A. Effects of the virus on height and stalk diameter of 10 commercial corn hybrids were were provided by the Institute of Cereals, determined. Thessaloniki, Greece, or by the National Seed Storage Laboratory of the U.S. Department of Agriculture. Plants were Maize dwarf mosaic virus (MDMV) This article concerns the first detection grown in steam-sterilized potting compost has worldwide distribution (8). It has of MDMV in Greece. The virus was (7:3:2 by volume of loam, peat, and fine been reported from Mediterranean identified by symptomatology, host sand) in 9-cm plastic pots. countries, Spain (1), Italy (5), Turkey (2), range, in vitro physical properties, and Inoculum was prepared by grinding Yugoslavia (6), and Bulgaria (7), all of aphid transmissibility. No viruses of corn leaves of virus-infected plants in 0.01 M which have weather conditions similar to have previously been reported in Greece. phosphate buffer, pH 7.0. Indicator those of Greece. plants were dusted with 600-mesh Celite, MATERIALS AND METHODS rubbed with inoculum, and rinsed with 0191-2917/80/08080302/$03.00/0 Indicator plants were corn (Zea mays distilled water. 01980 American Phytopathological Society L. 'Pioneer 3369A' and 'IC 228'), sorghum Aphid transmission tests were done

Plant Disease/August 1980 803 with Rhopalosiphum maydis Fitch and in 20 subplots. Each subplot consisted of These results indicate that wheat streak R. padi L. and two isolates of the virus, five 3-m rows of 10 plants, 0.75 cm apart. mosaic virus was not involved (4). MDMV-A(C) and MDMV-A(JG), from Treatment and hybrid plots were Aphid transmission. Both MDMV- corn and johnsongrass plants, respec- separated from adjacent plots and from A(C) and MDMV-A(JG) were tively. All were apterous, late the margins of the field by a 2-m passage. transmitted by R. maydis and R. padi in a instars, and were starved for about 1 hr All plants were sprayed twice a week nonpersistent manner (Table 1). In before acquisition feedings of 20 and 60 sec with pirimicarb to control disease spread. comparative transmission tests, R. on discolored areas of detached leaves. When most of the hybrids were at a maydis transmitted the virus after 20-sec Duration of the inoculation feeding was growth stage adequate for silage, plants acquisition feeding; R. padi requires 60 sec 24 hr, terminated by spraying with were cut at ground level, and plant for acquisition. Bancroft et al (3) and pirimicarb. heights and stalk diameters were Thongmeearkom et al (9) reported that The thermal inactivation point was determined. R. padi was a more efficient vector of determined in two tests: samples of crude MDMV than was R. maydis. The sap from infected IC 228 corn were RESULTS AND DISCUSSION transmission rates were consistent with exposed to 30-90 C temperatures at 100 MDMV was isolated from nine of 25 those reported previously (3,9). increments and 50-60 C at 20 increments. corn samples and 14 of 22 johnsongrass Physical properties. The thermal Subsequently, inocula were rubbed onto samples in 1979 and from 13 of 18 inactivation point and the dilution end end point was johnsongrass samples in 1980 collected point of both isolates in IC 228 corn sap IC 228 corn. The dilution - 3 - 4, found by diluting the crude sap in 0.01 M from cornfields in Achaia County. were 56 C and 10 to 10 respectively, phosphate buffer, pH 7.0, before Symptomatology. Isolates from corn and are consistent with those reported inoculation to IC 228 corn. and johnsongrass produced similar previously (5,7,8,10,11). Effects of MDMV-A(C) on plant symptoms on indicator plants. Effect of MDMV-A on growth of maize. height and stalk diameter were studied Corn hybrids 3369A and IC 228 and Height of Pioneer 3369A, IC 228, IC 962, under field conditions with commercial johnsongrass showed intense systemic IC 042, and IC 20 plants and stalk corn hybrids Pioneer 3369A, IC 228, IC mosaic 6-8 days after inoculation and diameter of Pioneer 3369A, IC 228, and 870, IC 080, IC 042, IC 962, IC 079, OH- noticeable dwarfing 2 wk after IC 962 plants were reduced by MDMV C-92, IC 20, and SC 46A. Plants were inoculation. infection (Table 2). individually sown in plastic pots in the On Atlas, Rio, Sart, and MN 1056, These results indicate that MDMV is glasshouse. chlorotic lines developed into fine whitish widely spread in corn in northwestern One-hundred uniform plants of each striae in older leaves, and later scattered Peloponnese and that it can be damaging hybrid were included in the test; 50 were necrotic spots on leaves progressively to some corn hybrids. manually inoculated and 50 were kept as coalesced to red stripes, followed by controls. After symptoms appeared, dwarfing of the plants. No symptoms developed on Michigan LITERATURE CITED seedlings were transplanted into the field. 1. ANONYMOUS. 1929. Work of the stations of The lots of 50 plants per hybrid and Amber wheat, and virus was not detected agricultural phytopathology. The advisory treatment were transplanted at random by back inoculations to IC 228 corn. service in connection with pests and diseases of cultivated plants in the year of 1927. Rev. Appl. Mycol. 8:152. 2. ANONYMOUS. 1956. Sugar cane diseases and Table 1. Efficiency of Rhopalosiphum maydis and R. padiin transmitting maize dwarf mosaic virus their world distribution. Rev. Appl. Mycol. (MDMV) isolates to corn 36:275. 3. BANCROFT, J. B., A. J. ULLSTRUP, M. Acquisition feedingb MESSIEHA, C. E. BRACKER, and T. E. SNAZELLE. 1966. Some biological and physical Virus isolate' Vector 20 sec 1 min properties of a midwestern isolate of maize dwarf mosaic virus. Phytopathology 56:474-478. R. maydis 4/20c 1/10 MDMV-A(C) 4. BRAKKE, M. K. 1971. Wheat streak mosaic R. padi 0/19 2/10 virus. Descriptions of Plant Viruses, No. 48. MDMV-A(JG) R. maydis 2/15 2/18 Commonw. Mycol. Inst., Kew, Surrey, England. R. padi 0/15 0/20 4 pp. 'MDMV-A(C) isolate from corn; MDMV-A(JG) isolate from johnsongrass. 5. LOVISOLO, 0. 1957. Contributo sperimentale bPreacquisition starving and inoculation access periods were constant, 1 and 24 hr, respectively. alla conoscenza ed alla determinazione del virus cInfected/infested plants; one aphid per plant. agente dell'arrossamento striato del sorgo e di un mosaico del mais. Boll. Staz. Patol. Veg. Roma 14:261-321. 6. LOVISOLO, 0., and M. ACIMOVIC. 1961. Table 2. Effect of maize dwarf mosaic virus infection on height and diameter of 10 commercial corn Sorghum red stripe disease in Yugoslavia. Rev. hybrids Appl. Mycol. 41:387. 7. MARKOV, M. 1964. Virus diseases of maize and b ' (cm) b Stalk diameter (cm)a sorghum in Bulgaria. Rastit. Zasht. 12:31-37. Height 8. PIRONE, T. P. 1972. . Hybrid Infected Control Infected Control Descriptions of Plant Viruses, No. 88. Commonw. Mycol. Inst., Kew, Surrey, Pioneer 3369A 183.7* 197.3 2.5* 2.7 England. 4 pp. IC 228 157.8* 201.5 2.1* 2.4 9. THONGMEEARKON, P., R. E. FORD, and H. IC 870 148.6 155.5 1.9 2.0 JEDLINSKI. 1976. Aphid transmission of maize IC 080 182.5 186.8 2.3 2.4 dwarf mosaic virus strains. Phytopathology IC 042 142.5* 153.8 2.5 2.4 66:332-335. IC 962 165.5* 193.0 2.4* 2.8 10. TOSIC, M., M. P. BENETTI, and M. CONTI. mosaic virus (SCMV) IC 079 209.8 211.8 2.3 2.4 1977. Studies on sugarcane isolates from northern and central Italy. Ann. OH-C-92 205.0 205.8 2.6 2.7 Phytopathol. 9:387-393. IC 20 130.9* 144.8 2.1 2.0 11. TOSIC, M., and R. E. FORD. 1974. Physical and SC 46A 197.2 205.1 3.0 2.9 serological properties of maize dwarf mosaic and ' Means from 50 infected plants and 50 control plants. sugarcane mosaic viruses. Phytopathology b* indicates significant difference (P = 0.05) between infected and corresponding control plants. 64:312-317.

804 Plant DiseaseNol. 64 No. 8