caa a22 4500 475767322 CHVBK 20180406123609.0 cr unu---uuuuu 170329e20000201xx s 000 0 eng 10.1007/s007050050023 doi (NATIONALLICENCE)springer-10.1007/s007050050023 Inter- and intra-site genetic diversity of natural field populations of rice tungro bacilliform virus in the Philippines [Elektronische Daten] [M. Arboleda, O. Azzam] Summary.:  The genetic structure of rice tungro bacilliform virus (RTBV) populations within and between growing sites was analyzed in a collection of natural field isolates from different rice varieties grown in eight tungro-endemic sites of the Philippines. Total DNA extracts from 345 isolates were digested with EcoRV restriction enzyme and hybridized with a full-length probe of RTBV, a procedure shown in preliminary experiments capable of revealing high levels of polymorphism in RTBV field isolates. In the total population, 17 distinct EcoRV-based genome profiles (genotypes) were identified and used as indicators for virus diversity. Distinct sets of genotypes occurred in Isabela and North Cotabato provinces suggesting a geographic isolation of virus populations. However, among the sites in each province, there were few significant differences in the genotype compositions of virus populations. The number of genotypes detected at a site varied from two to nine with a few genotypes dominating. In general the isolates at a site persisted from season to season indicating a genetic stability for the local virus population. Over the sampling time, IRRI rice varieties, which have green leafhopper resistance genes, supported similar virus populations to those supported by other varieties, indicating that the variety of the host exerted no apparent selection pressures. Insect transmission experiments on selected RTBV field isolates showed that dramatic shifts in genotype and phenotype distributions can occur in response to host/environmental shifts. 2000 Springer-Verlag/, Wien Arboleda M. International Rice Research Institute, Makati City, Philippines, PH aut Azzam O. International Rice Research Institute, Makati City, Philippines, PH aut https://doi.org/10.1007/s007050050023 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s007050050023 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Arboleda M. International Rice Research Institute, Makati City, Philippines, PH aut NATIONALLICENCE 700 1- Azzam O. International Rice Research Institute, Makati City, Philippines, PH aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer