TY - JOUR
T1 - Murraya paniculata and Swinglea glutinosa as short-term transient hosts of 'Candidatus Liberibacter asiaticus' and implications for spread of huanglongbing
AU - Cifuentes-Arenas, Juan Camilo
AU - Beattie, George Andrew Charles
AU - Pena, Leandro
AU - Lopes, Silvio Aparecido
PY - 2019
Y1 - 2019
N2 - Murraya paniculata (Mp) and Swinglea glutinosa (Sg) are aurantioid hosts of the Asian citrus psyllid (ACP) Diaphorina citri, the principal vector of ‘Candidatus Liberibacter asiaticus’ (Las), the pathogen associated with huanglongbing (HLB), the Asian form of which is the most devastating disease of species and cultivars of Citrus (Rutaceae: Aurantioideae). Mp is a common ornamental and Sg is grown as an ornamental, as a citrus rootstock, and as a hedgerow fence plant. Because of the uncertain status of these plants as reservoirs of Las, a series of cross-inoculation bioassays were carried out, in different environments, using infected ‘Valencia’ sweet orange (Citrus Ãaurantium) infected shoot tops as source of inoculum, and D. citri nymphs and adults, reared on Mp and Sg, to inoculate pathogen-free ‘Valencia’ orange plantlets. In contrast to sweet orange, Las was more unevenly distributed and reached much lower titers in Mp and Sg. Infections in Mp and Sg were also transient. Very few insects that successfully acquired Las from Mp and Sg were able to transmit the pathogen to healthy citrus. Transmission rates were low from Mp (1.0%) and Sg (2.0%) and occurred only in a controlled environment highly favorable to Las and ACP using 10-day-old adults that completed their life cycle on Las-positive plants. Our study showed that in areas where HLB is present Mp and Sg can be deemed as epidemiologically dead-end hosts for Las and not important alternative hosts of the pathogen for transmission to citrus. However, under a combination of highly favorable conditions to Las infection and transmission and in the absence of effective quarantine procedures, these plants could eventually serve as carriers of Las to regions currently free from HLB.
AB - Murraya paniculata (Mp) and Swinglea glutinosa (Sg) are aurantioid hosts of the Asian citrus psyllid (ACP) Diaphorina citri, the principal vector of ‘Candidatus Liberibacter asiaticus’ (Las), the pathogen associated with huanglongbing (HLB), the Asian form of which is the most devastating disease of species and cultivars of Citrus (Rutaceae: Aurantioideae). Mp is a common ornamental and Sg is grown as an ornamental, as a citrus rootstock, and as a hedgerow fence plant. Because of the uncertain status of these plants as reservoirs of Las, a series of cross-inoculation bioassays were carried out, in different environments, using infected ‘Valencia’ sweet orange (Citrus Ãaurantium) infected shoot tops as source of inoculum, and D. citri nymphs and adults, reared on Mp and Sg, to inoculate pathogen-free ‘Valencia’ orange plantlets. In contrast to sweet orange, Las was more unevenly distributed and reached much lower titers in Mp and Sg. Infections in Mp and Sg were also transient. Very few insects that successfully acquired Las from Mp and Sg were able to transmit the pathogen to healthy citrus. Transmission rates were low from Mp (1.0%) and Sg (2.0%) and occurred only in a controlled environment highly favorable to Las and ACP using 10-day-old adults that completed their life cycle on Las-positive plants. Our study showed that in areas where HLB is present Mp and Sg can be deemed as epidemiologically dead-end hosts for Las and not important alternative hosts of the pathogen for transmission to citrus. However, under a combination of highly favorable conditions to Las infection and transmission and in the absence of effective quarantine procedures, these plants could eventually serve as carriers of Las to regions currently free from HLB.
KW - Murraya
KW - citrus
KW - greening disease
KW - host plants
UR - http://handle.westernsydney.edu.au:8081/1959.7/uws:52657
U2 - 10.1094/PHYTO-06-19-0216-R
DO - 10.1094/PHYTO-06-19-0216-R
M3 - Article
SN - 0031-949X
VL - 109
SP - 2064
EP - 2073
JO - Phytopathology
JF - Phytopathology
IS - 12
ER -