“Citrus exocortis viroid” (CEVd) has been long reported as responsible of bark cracking and shelling of trifoliate orange whereas its performance on citranges and other hybrids (citrumelo, C45, C35) is still unclear. For the purpose, investigations on Tarocco sweet orange and Clementine comune grafted on Troyer and Carrizo citranges, respectively inoculated 28 and 15 years ago with CEVd and/or different citrus viroids, have been conducted. Trees were monitored every year by field inspections for symptom observations, assays on Etrog citron, RT-PCR and real time RT-PCR analysis. CEVd-inoculated Clementine trees (2x3 m density planting) do not show any bark scaling but only a size reduction, likely related also to the density of planting, whereas those inoculated with a mixture of Citrus dwarfing viroid (CDVd), Hop stunt viroid (HSVd) and CEVd show reduction in size, bud union line indentation and bark gumming. Tarocco sweet orange nucellar lines perform very well in size and yield despite CEVd infection and are almost indistinguishable from clean sister trees. Due to the recent spreading of Citrus tristeza virus (CTV) in the Mediterranean area these results open the space for a re-evaluation of citrange as suitable candidate to the replacement of sour orange rootstock.
Long-term evaluation of citrange performance after Citrus exocortis viroid inoculation
LA ROSA, Rosa;TESSITORI, MATILDE;
2010-01-01
Abstract
“Citrus exocortis viroid” (CEVd) has been long reported as responsible of bark cracking and shelling of trifoliate orange whereas its performance on citranges and other hybrids (citrumelo, C45, C35) is still unclear. For the purpose, investigations on Tarocco sweet orange and Clementine comune grafted on Troyer and Carrizo citranges, respectively inoculated 28 and 15 years ago with CEVd and/or different citrus viroids, have been conducted. Trees were monitored every year by field inspections for symptom observations, assays on Etrog citron, RT-PCR and real time RT-PCR analysis. CEVd-inoculated Clementine trees (2x3 m density planting) do not show any bark scaling but only a size reduction, likely related also to the density of planting, whereas those inoculated with a mixture of Citrus dwarfing viroid (CDVd), Hop stunt viroid (HSVd) and CEVd show reduction in size, bud union line indentation and bark gumming. Tarocco sweet orange nucellar lines perform very well in size and yield despite CEVd infection and are almost indistinguishable from clean sister trees. Due to the recent spreading of Citrus tristeza virus (CTV) in the Mediterranean area these results open the space for a re-evaluation of citrange as suitable candidate to the replacement of sour orange rootstock.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
