1218 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



FAMILY IV. RUGACEAE HOLMES. 



(Handb. Phytopath. Viruses, 1939, 114) 



Viruses of the Leaf -Curl Group, causing diseases characterized by suddenly arrested 

 development of invaded tissues, resulting in leaf curl, enations, and other deformities. 

 Vectors, typically white-flies (ALEYRODIDAE). There is a single genus. 



Gentis I. Ruga Holmes. 



{Loc. cit., 114.) 



Characters those of the family. Generic name from Latin ruga, a wrinkle. 

 The type species is Ruga tabaci Holmes. 



Keij to the species of genus Ruga. 



I. Infecting tobacco. 

 II. Infecting cotton. 



III. Infecting cassava (Manihot). 



IV. Infecting sugar-beet. 



1. Ruga tabaci Holmes. (Handb. Phy- 

 topath. Viruses, 1939, 115.) From New 

 Latin Tabacum, former generic name of 

 tobacco. 



Common names : Tobacco leaf -curl 

 virus, kroepoek virus, curl-disease virus, 

 crinkle-disease virus. 



Hosts: SOLAN ACE AE—Nicotiana 

 tabacum L., tobacco. COMPOSITAE— 

 Vernonia iodocalyx, V. cineria, Ageratum 

 conyzoides L., Synedrella nodi flora Gaertn . 

 Experimentally, also other solanaceous 

 plants. 



Insusceptible species: MALVACEAE 

 — Gossypium hirsutum L., cotton. 



Geographical distribution : Tanganyika, 

 Southern Rhodesia, Southern Nigeria, 

 Nyasaland, India, Sumatra, Formosa. 



Induced disease : In tobacco, leaves 

 curled and crinkled, with occasional leafy 

 outgrowths or enations. Veins greened 

 and thickened. No chlorosis nor necro- 

 sis. Plant stunted. 



Transmission: By white-fly, Bemisia 

 gossypiperda Misra and Lamba (ALEY- 

 RODIDAE). By grafting. Not by in- 

 oculation of expressed juice. 



Literature : Kerling, Phytopath., £3, 

 1933, 175-190; Mathur, Indian Jour. Agr. 



1. Ruga tabaci. 



2. Ruga gossypii. 



3. Ruga bemisiae. 



I 



4. Ruga verriicosans . 



Sci., 3, 1933, 89-96; Matsumoto and 

 Tateoko, Trans. Nat. Hist. Soc. Formosa, 

 30, 1940, 31-33; Pal and Tandon, Indian 

 Jour. Agr. Sci., 7, 1937, 363-393; Pruthi 

 and Samuel, ibid., 7, 1937, 659-670; 

 Storey, Nature, 128, 1931, 187-188; East 

 African Agr. Jour., 1, 1935, 148-153; 

 Thung, Meded. Proefsta. Vorstenl. Ta- 

 bak Java, 72, 1932; 78, 1934. 



2. Ruga gossypii H. (loc. cit., 116). 

 From Latin gossypium, cotton. 



Common names : Cotton leaf -curl virus, 

 cotton leaf -crinkle virus. 



Hosts: MALVACEAE— Gossypium 

 hirsutum L., cotton ; G. peruvianum Cav. ; 

 G. vitifolium Lam.; Hibiscus cannabinus 

 L. ; H. esculentus L. ; //. sabdariffa L. ; 

 Althaea rosea Cav., hollyhock; Sakel 

 (hybrid) cotton. 



Geographical distribution : The Sudan 

 and Nigeria, in Africa. 



Induced disease : In cotton, clearing of 

 veins, blistering and pale spotting of 

 leaves ; leaves puckered at edge and un- 

 symmetrical. Internodes shortened, 

 producing bunchy growth. 



Transmission : By white-fly, Bemisia 

 gossypiperda Misra and Lamba (ALEY- 



