%0 Journal Article %A Shaw, D. S. %A Elliott, C. G. %T Streptomycin Resistance and Morphological Variation in Phytophthora cactorum %D 1968 %J Microbiology, %V 51 %N 1 %P 75-84 %@ 1465-2080 %R https://doi.org/10.1099/00221287-51-1-75 %I Microbiology Society, %X SUMMARY: Strains of Phytophthora cactorum resistant to streptomycin were obtained by incubating zoospores in liquid medium containing the drug. One of the strains required streptomycin for growth. In this dependent strain and one of the resistant strains, the dependence or resistance was transmitted to both asexual and selfed sexual progeny without any segregation for sensitivity. Change from dependence to resistance occurred with low frequency. Some of the resistant and the dependent strains showed much greater morphological variation than the wild type. Continuing segregation for morphological characters was observed during vegetative growth and in the asexual progeny of single zoospores, and the ability to segregate was not lost following sexual reproduction (selfing). Cultures were more variable after storage at 3°. There was evidence suggesting a particulate nature for the determinants of these morphological differences, normal zoospores having one such determinant. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-51-1-75