VIEW ARTICLE

Cytology and Histology

Light Microscopic Observation of Nuclei and Mitotic Chromosomes of Botrytis Species. N. Shirane, Aburahi Laboratories, Shionogi Research Laboratories, Shionogi & Co., Ltd., Koka-cho, Shiga 520-34, Japan; M. Masuko, and Y. Hayashi. Aburahi Laboratories, Shionogi Research Laboratories, Shionogi & Co., Ltd., Koka-cho, Shiga 520-34, Japan. Phytopathology 79:728-730. Accepted for publication 24 January 1989. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/Phyto-79-728.

Nuclei and mitotic chromosomes of five species of Botrytis that cause diseases in onion were observed with a light microscope. The mean number of nuclei in a conidium of B. allii (seven isolates), B. byssoidea (three isolates), and B. cinerea (five isolates) was 1.3–1.5, 5.0–5.1, and 4.0–5.1, respectively, whereas that of B. squamosa (one isolate) was 18.4. The chromosome number was found to be 16 in B. byssoidea, B. cinerea, B. squamosa, and B. tulipae. Seven isolates of B. allii were divided into two groups according to the chromosome number: three isolates had 32 chromosomes, whereas the other four had 16. In every species used, one of the chromosomes had a threadlike structure. These data indicate that the number of chromosomes in the Botrytis species is basically 16 but is 32 in some cases. The species of B. allii, B. squamosa, and B. byssoidea or B. cinerea could be distinguished from each other by counting the mean number of nuclei in the conidium.