Kentia (Howea forsteriana) is worldwide grown as ornamental especially for inside decorations. Phytoplasmas have been associated with several diseases of palm trees with symptoms that are quite variable and consist of leaf yellowing, reduction in fruit and stalk size, stunting, wilting and severe or slow decline. Lethal yellowing, lethal decline, root wilt, white tip die-back and Al-Wijaam are some of the reported phytoplasmas-associated diseases associated with different species of palm in the world. Lethal yellowing is however a disease associated worldwide with phytoplasmas that affects at least 30 species of palm, among which the most relevant are Phoenix dactylifera, Veitchia merrilli, Caryota rumphiana, Phoenix canariensis and Elaeis guineensis. This disease has killed millions of palm trees such as coconut (Cocos nucifera) throughout the Caribbean, Florida, Mexico, and the Central American region. Kentia plants showing severe symptoms of decline quite similar to the lethal yellowing were observed in outside garden in some areas of Eastern Sicily. To study the disease ten potted plants were collected a few months after sprouting and maintained under insect-proof greenhouse. Total nucleic acids were extracted from 1 g of tissue from leaves and petioles with a chloroform/phenol-based method and direct and nested PCR assays were carried out in two different period of the year (Autumn and Spring). All the samples were negative to phytoplasma presence while in some cases RFLP profiles and sequences related to possible endophitic bacteria were detected. A second nested PCR assay with more specific primers allow to detect phytoplasmas that were identified as belonging to aster yellows (16SrI-B) and “stolbur” (16SrXII-A) ribosomal groups. The detection of these phytoplasmas in kentia with decline symptoms increases the number of plant species that can be infected by these prokaryotes. It is however necessary to further evaluate the possible presence of other microorganisms that may contribute to determine the severe disease detected in open field in order to devise the appropriate disease management to contain its spread.
Grave deperimento in kentia associato alla presenza di fitoplasmi
BERTACCINI, ASSUNTA;MEJIA DE LOS RIOS, JUAN FERNANDO;PALTRINIERI, SAMANTA;CONTALDO, NICOLETTA;
2013
Abstract
Kentia (Howea forsteriana) is worldwide grown as ornamental especially for inside decorations. Phytoplasmas have been associated with several diseases of palm trees with symptoms that are quite variable and consist of leaf yellowing, reduction in fruit and stalk size, stunting, wilting and severe or slow decline. Lethal yellowing, lethal decline, root wilt, white tip die-back and Al-Wijaam are some of the reported phytoplasmas-associated diseases associated with different species of palm in the world. Lethal yellowing is however a disease associated worldwide with phytoplasmas that affects at least 30 species of palm, among which the most relevant are Phoenix dactylifera, Veitchia merrilli, Caryota rumphiana, Phoenix canariensis and Elaeis guineensis. This disease has killed millions of palm trees such as coconut (Cocos nucifera) throughout the Caribbean, Florida, Mexico, and the Central American region. Kentia plants showing severe symptoms of decline quite similar to the lethal yellowing were observed in outside garden in some areas of Eastern Sicily. To study the disease ten potted plants were collected a few months after sprouting and maintained under insect-proof greenhouse. Total nucleic acids were extracted from 1 g of tissue from leaves and petioles with a chloroform/phenol-based method and direct and nested PCR assays were carried out in two different period of the year (Autumn and Spring). All the samples were negative to phytoplasma presence while in some cases RFLP profiles and sequences related to possible endophitic bacteria were detected. A second nested PCR assay with more specific primers allow to detect phytoplasmas that were identified as belonging to aster yellows (16SrI-B) and “stolbur” (16SrXII-A) ribosomal groups. The detection of these phytoplasmas in kentia with decline symptoms increases the number of plant species that can be infected by these prokaryotes. It is however necessary to further evaluate the possible presence of other microorganisms that may contribute to determine the severe disease detected in open field in order to devise the appropriate disease management to contain its spread.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
