RESPONSE OF DIFFERENT POTATO CULTIVARS TO THE PRESENCE OF NACOBBUS ABERRANS

Nacobbus aberrans occurs in temperate and subtropical areas of South and North America. In Argentina, the species is widely distributed although accurate knowledge of the host range is unknown for many populations. In this work the reproductive capacity of three Argentine populations of different geographical origin was evaluated on four potato cultivars (Spunta, Kennebec, Colorada, and Asterix); histological studies were conducted on root tissues of inoculated plants from each cultivar. Two N. aberrans populations from Cordoba province were not able to reproduce on those cultivars; no evidence of the nematode presence was detected in root tissues. The remaining population, which was from Catamarca province, induced gall formation in all cultivars. Histological studies showed hyperplastic parenchymatous tissue occupying the central cylinder of invaded roots. In the same zone, syncytia developed closely associated with females of the nematode. The results showed different responses of potato cultivars to the presence of the N. aberrans populations. Nacobbus aberrans esta presente en areas templadas y subtropicales de America del Sur y del Norte. En Argentina posee una amplia distribucion y, por el momento, se desconoce el rango preciso de hospedadores de muchas poblaciones. En este trabajo se evaluo la capacidad de reproduccion de tres poblaciones argentinas de diferente origen geografico sobre cultivares de papa (Spunta, Kennebec, Colorada y Asterix) y se realizaron estudios histologicos en las raices de esas plantas. Dos poblaciones de la provincia de Cordoba no fueron capaces de multiplicarse en papa; en los tejidos radicales no se detectaron evidencias de la presencia del nematodo. La otra poblacion, proveniente de la provincia de Catamarca, indujo la formacion de agallas en todos los vegetales. Los estudios histologicos mostraron tejido hiperplasico con caracteristicas parenquimaticas ocupando el cilindro central de las raices infectadas. En la misma zona, se desarrollaron los sincitios en estrecha relacion con las hembras del nematodo. Los resultados mostraron diferencias entre cultivares de papa frente a las poblaciones de N. aberrans consideradas.