ISHS Acta Horticulturae 386: XVI International Symposium on Fruit Tree Virus diseases
DODDER TRANSMISSION OF TWO DIFFERENT MLOS FROM PLUM TREES AFFECTED BY "LEPTONECROSIS" |
| Authors: | N. Loi, L. Carraro, R. Musetti, I. Pertot, R. Osler |
| Abstract:
A graft transmissible disease khown as "Plum leptonecrosis" is described. It has been found in Italy since 1933 on Japanese plum (Prunus salicina Lindl.) and apricot. A mycoplasma-like organism (MLO) is thought to be the causal agent. In Udine, an effort was made to isolate the plum leptonecrosis agent (PLNa) from plum and peach to Catharanthus roseus L. A clone of Cuscuta campestris Younk was used as vector. Six different types of sources of inoculum were utilized: young shoots of Myrabolan (Prunus cerasifera Ehrh,); two-year-old plants of Ozark Premier; micropropagated Shiro plants; potted seedlings of peach GF 305 infected by chip-budding from plum; cut Ozark Premier shoots; field infected plum trees. In all 9 C. roseus plants were infected out of 176 inoculated: 4 reacted with typical small pale flowers; 5 with virescence. In sub-inoculated C. roseus the types of symptoms remained invariable. Both sources of inoculum and test plants were observed under electron and light fluorescence microscopes. The results indicate that plum can host different MLOs, at least two in the investigated area. The aetiological involvement of the two different MLOs is discussed as well as the possible occurrence of mixed infections. Analyses with PCR on naturally and artificially infected plants are in progress. | |
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