Submitted to: Journal of Sugarbeet Research
Publication Type: Abstract Only
Publication Acceptance Date: July 29, 1999
Publication Date: N/A
Technical Abstract: Co-culture of pathogen and host plant tissue in vitro offers prospects for studying host defense gene expression, and opportunities for identification and cell selection of resistant genotypes. Four important pathogens of sugarbeet were inoculated separately onto variations of a common plant tissue culture medium previously used in culture of several sugarbeet tissues, to determine mycelial growth capabilities and characteristics of each pathogen for a plant host tissue culture system. Both Rhizoctonia Solani (RZT) and Pythium ultimum (PYT) grew well (about 2 cm/day) from mycelial plugs on Murashige-Skoog agar medium with standard 60mM nitrogen from nitrate and ammonium. Cercospora beticula (CER) grew more slowly (about a tenth as fast), and Aphanomyces cochlioides (APH) spread rapidly but sparsely. In general, pathogen growth in liquid medium corresponded to expansion growth on comparable agar media, except for APH which grew negligibly in MS liquid medium. In subsequent co-culture tests, mycelia of each pathogen grew to, over, and into sugarbeet tissue cultured on the same plate, leading to tissue death. It was concluded that mycelium of CER (due to slow extension of growth) and APH (due to sparse growth) should be suitable for future co-culture research with sugarbeet tissue cultures.