caa a22 4500 467890854 CHVBK 20180406152748.0 cr unu---uuuuu 170328e20060801xx s 000 0 eng 10.1007/s10327-006-0276-x doi (NATIONALLICENCE)springer-10.1007/s10327-006-0276-x Colonization by two isolates of Plasmodiophora brassicae with differing pathogenicity on a clubroot-resistant cultivar of Chinese cabbage ( Brassica rapa L. subsp. pekinensis ) [Elektronische Daten] [Shuhei Tanaka, Hiroaki Mido, Shin-ichi Ito] A commercial clubroot-resistant F1 cultivar of Chinese cabbage (Brassica rapa L. subsp. pekinensis), Kukai 70, is resistant to an isolate of populations of Plasmodiophora brassicae from Hagi (HG) city and is susceptible to another from Yamaguchi (YMG) city. The degree and frequency of primary and secondary cycle colonization by the isolates in the root hairs and root tissues of cv. Kukai 70 were compared. Seedlings of cv. Kukai 70 were grown in soils amended with inoculum of either HG or YMG and harvested 10 days after inoculation to observe the primary cycle (number of root-hair infections) and 20, 30, and 40 days after inoculation to observe of the secondary cycle (frequency of infected cells and degree of plasmodial development based on the number of nuclei in infected cells). Although more root hairs were infected in HG than in YMG, fewer cells in root tissues including the cortex and medullary rays were infected in HG than in YMG. In addition, YMG developed plasmodia with many nuclei and formed resting spores, whereas plasmodia remained immature with a small number of nuclei in HG and did not form resting spores even by 40 days after inoculation. These results suggest that suppression of plasmodial development during secondary colonization is associated with resistance mechanisms to HG in cv. Kukai 70. Starch did not accumulate (i.e., development of amyloplasts) in HG-infected cells. This may be involved in the suppression of secondary colonization of P. brassicae in the cultivar. The Phytopathological Society of Japan and Springer-Verlag Tokyo, 2006 Clubroot-resistant cultivar nationallicence Cortical infection nationallicence Chinese cabbage nationallicence Plasmodial development nationallicence Plasmodiophora brassicae nationallicence Resistant mechanisms nationallicence Tanaka Shuhei Department of Biological and Environmental Sciences, Faculty of Agriculture, Yamaguchi University, Yoshida 1677-1, 753-8515, Yamaguchi, Japan aut Mido Hiroaki Department of Biological and Environmental Sciences, Faculty of Agriculture, Yamaguchi University, Yoshida 1677-1, 753-8515, Yamaguchi, Japan aut Ito Shin-ichi Department of Biological and Environmental Sciences, Faculty of Agriculture, Yamaguchi University, Yoshida 1677-1, 753-8515, Yamaguchi, Japan aut Journal of General Plant Pathology Springer-Verlag 72/4(2006-08-01), 205-209 1345-2630 72:4<205 2006 72 10327 https://doi.org/10.1007/s10327-006-0276-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10327-006-0276-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Tanaka Shuhei Department of Biological and Environmental Sciences, Faculty of Agriculture, Yamaguchi University, Yoshida 1677-1, 753-8515, Yamaguchi, Japan aut NATIONALLICENCE 700 1- Mido Hiroaki Department of Biological and Environmental Sciences, Faculty of Agriculture, Yamaguchi University, Yoshida 1677-1, 753-8515, Yamaguchi, Japan aut NATIONALLICENCE 700 1- Ito Shin-ichi Department of Biological and Environmental Sciences, Faculty of Agriculture, Yamaguchi University, Yoshida 1677-1, 753-8515, Yamaguchi, Japan aut NATIONALLICENCE 773 0- Journal of General Plant Pathology Springer-Verlag 72/4(2006-08-01), 205-209 1345-2630 72:4<205 2006 72 10327 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer