Two hundred and thirty-one isolates of P. nicotianae representing 14 populations fromdifferent host genera, including agricultural crops (Citrus, Nicotiana and Lycopersicon),potted ornamental species in nurseries (Lavandula, Convolvulus, Myrtus, Correa and Ruta)and other plant genera were characterized using SSR markers. A total of 99 multilocusgenotypes (MLGs) were identified revealing a strong association between genetic groupingand host of recovery with most MLGs being associated with a single host genus. Significantdifferences in the structure of populations were revealed, but clonality prevailed in allpopulations. Isolates from Citrus were found to be genetically related regardless of theirgeographic origin and were characterized by high genetic uniformity and high inbreedingcoefficients. Higher variability was observed for other populations and a significantgeographical structuring was determined for isolates from Nicotiana. Detected differenceswere related to the propagation and cultivation systems of different crops. Isolatesobtained from Citrus species are more likely to be distributed worldwide with infected plantmaterial while Nicotiana and Lycopersicon are propagated by seed, which would notcontribute to the spread of the pathogen and result in a greater chance for geographicisolation of lineages. With regards to ornamental species in nurseries, the high geneticvariation is likely the result of the admixture of diverse pathogen genotypes through thetrade of infected plant material from various geographic origins, the presence of severalhosts in the same nursery and genetic recombination through sexual reproduction of thisheterothallic species.
Genetic Analysis of Phytophthora nicotianae Populations from Different Hosts Using Microsatellite Markers
CACCIOLA, Santa Olga;
2016-01-01
Abstract
Two hundred and thirty-one isolates of P. nicotianae representing 14 populations fromdifferent host genera, including agricultural crops (Citrus, Nicotiana and Lycopersicon),potted ornamental species in nurseries (Lavandula, Convolvulus, Myrtus, Correa and Ruta)and other plant genera were characterized using SSR markers. A total of 99 multilocusgenotypes (MLGs) were identified revealing a strong association between genetic groupingand host of recovery with most MLGs being associated with a single host genus. Significantdifferences in the structure of populations were revealed, but clonality prevailed in allpopulations. Isolates from Citrus were found to be genetically related regardless of theirgeographic origin and were characterized by high genetic uniformity and high inbreedingcoefficients. Higher variability was observed for other populations and a significantgeographical structuring was determined for isolates from Nicotiana. Detected differenceswere related to the propagation and cultivation systems of different crops. Isolatesobtained from Citrus species are more likely to be distributed worldwide with infected plantmaterial while Nicotiana and Lycopersicon are propagated by seed, which would notcontribute to the spread of the pathogen and result in a greater chance for geographicisolation of lineages. With regards to ornamental species in nurseries, the high geneticvariation is likely the result of the admixture of diverse pathogen genotypes through thetrade of infected plant material from various geographic origins, the presence of severalhosts in the same nursery and genetic recombination through sexual reproduction of thisheterothallic species.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
