1152 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



II. Inducing rosette formation characteristically, but not tattering of affected 

 foliage. 



2. Carpophthora rosettae. 



1. Carpophthora lacerans (Holmes) 

 McKinney. {Marmor lacerans Holmes, 

 Handb. Phytopath. Viruses, 1939, 82; 

 McKinney, Jour. Washington Acad. Sci., 

 34, 1944, 152.) From Latin lacerare, to 

 lacerate, in reference to characteristic 

 foliage injury. 



Common name : Peach X-disease virus ; 

 virus of peach yellow-red virosis. 



Hosts: ROSACE AE — Primus persica 

 (L.) Batsch, peach; P. virginiana L., 

 chokecherry. 



Geographical distribution : United 

 States, Canada. 



Induced disease : In peach, foliage nor- 

 mal each spring but yellowish areas ap- 

 pear in June at base of leaves ; affected 

 trees appear lighter green than neighbor- 

 ing healthy trees; discolored spots occur 

 at random on the leaf blade, becoming red 

 and yellow with remainder of leaf becom- 

 ing chlorotic ; the discolored areas usually 

 fall out, leaving the foliage tattered ; sub- 

 sequently, affected leaves drop except at 

 tips of branches; young trees may die, 

 older ones survive indefinitely. Fruit 

 either shrivels and falls or ripens prema- 

 turely, with bitter flavor and no viable 

 seed. In chokecherry, conspicuous pre- 

 mature reddening of foliage, development 

 of fruits with dead embryos in the pits ; 

 in the second and third seasons after 

 infection, duller colors of foliage, rosettes 

 of small leaves on terminals; death fol- 

 lows the advanced stage of disease. 



Transmission : By budding. Not bj' 

 inoculation of expressed juice. No insect 

 vector has been reported. 



Literature: Berkeley, Div. of Botany 

 and Plant Path., Science Service, Do- 

 minion Dept. Agr., Ottawa, Canada, Pub- 

 lication 678, 1941 ; Boyd, U.S. Dept. Agr., 

 Plant Dis. Rep., 22, 1938, 334; Hilde- 

 brand, Contrib. Boyce Thompson Inst., 

 11, 1941, 485-496; Hildebrand and Pal- 

 miter, U. S. Dept. Agr., Plant Dis. Rep., 



22, 1938, 394-396; Hildebrand et al.. 

 Handbook of virus diseases of stone fruits 

 in North America, Michigan Agr. Exp. 

 Sta., Misc. Publ., 1942, 21-24; Stoddard, 

 Connecticut Agr. Exp. Sta., Circ. 122, 

 1938, 54-60; Proc. Connecticut Pomol. 

 Soc, 48, 1938, 29-32. 



2. Carpophthora rosettae (Holmes) 

 comb. nov. {Cfdorogeniis rosettae H., 

 nomen nudum, Phytopath. 29, 1939, 434; 

 Nanus rosettae H., Handb. Phytopath. 

 Viruses, 1939, 125.) From rosette, com- 

 mon name of induced disease, from 

 French, diminutive of rose, a rose. 



Common name: Peach-rosette virus. 



Hosts: ROS ACE AE—Prunus persica 

 (L.) Batsch, peach; P. communis Fritsch, 

 almond; P. domestica L., plum. Experi- 

 mentally, SiXso—APOCYNACEAE— 

 Vinca rosea L., periwinkle. ROSA- 

 CEAE — P. am errcana Marsh., wild plum ; 

 P. armeniaca L., apricot; P. cerasus L., 

 cherry; P. pumila L., sand cherry. 

 SOLA NACEAE — Lycopersicon esculen- 

 tum Mill., tomato ; Nicotiana glvtinosa L. 



Geographical distribution : United 

 States (Georgia, Alabama, South Caro- 

 lina, Tennessee, West Virginia, Missouri, 

 Oklahoma). 



Induced disease : In peach, sudden 

 wilting and death, or growth of abnor- 

 mally short stems bearing dwarfed leaves 

 with clearing and thickening of veins, 

 followed by death in a few months. 



Transmission : By budding. By dod- 

 der, Cuscuta campestris Yuncker. Not 

 by inoculation of expressed juice. Not 

 through soil. No insect vector is known. 



Immunological relationships : No pro- 

 tection is afforded by previous infection 

 of peach trees with Chlorogenus persicae, 

 peach-yellows virus. 



Thermal inactivation : At 50° C in 10 

 minutes (in tissues of peach). Rosetted 

 trees are abnormally susceptible to heat 



