The levels of peroxidase activity in roots of non‐infected tomato plants resistant to Verticillium dahliae Kleb., were found to be considerably higher than those in the roots of susceptible plants. Similar differences were found in the leaves but were not significant as in the roots. Peroxidase activity increased in leaves, stems and roots of both susceptible and resistant plants after infection with V. dahliae. The ratio of the increase in leaves and roots of susceptible plants was greater than those of resistant plants. A positive correlation was found between the peroxidase activity in the roots of eleven cultivars/breeding lines and presence of Ve gene.

1989. Development of infection structures of Uromyces transversalis in leaves of the host and a nonhost. Can. J. Bot. 67: 429-433.Substomatal vesicle development of Uromyces transversalis on its host, gladiolus, was studied with a scanning electron microscope. Development after penetration occurred in distinct stages; the single infection peg developed into a globose immature substomatal vesicle, which initiated, singly or in pairs, primary hyphae that frequently developed asynchronously. One of the observed elongated primary hyphae delimited a haustorial mother cell. Observations on the orientation of the long axis of the substomatal vesicle in relation to the stomatal slit showed development of the primary hyphae at right angles rather than acute angles or parallel. A similar trend was observed in the substomatal vesicle formed in a nonhost, corn. FERREIRA, J. F., et RIJKENBERG, F. H. J. 1989. Development of infection structures of Urornyces transversalis in leaves of the host and a nonhost. Can. J. Bot. 67 : 429-433.A l'aide du microscope tlectronique par balayage, les auteurs ont ttudik le dkveloppement de la vtsicule sub-stomatale de 1'Uromyces transversalis sur son hBte, le gla'ieul. Apes la ptnktration, on reconnait plusieurs stades de dkveloppement; la pointe d'infection unique se dkveloppe en une vksicule sub-stomatale globulaire immature, laquelle donne naissance, isoltment ou en paires, B des hyphes primaires qui se dkveloppent de f a~o n asynchrone. Une des hyphes primaires allongtes observte dklimitait une cellule mbre des haustkries. Les observations sur l'orientation du long axe de la vtsicule sub-stomatale en relation avec celle de la fente ostiolaire montrent que les hyphes primaires se dtveloppent B des angles droits plutBt que des angles aigus ou de f a~o n parallble. On retrouve une tendance semblable chez le ma'is, une plante non-h6te.[Traduit par la revue] Introduction Scanning electron microscopy has been successfully used for the study of germination behavior of uredospores (Paliwal and Kim 1974;Staples et al. 1983Staples et al. , 1985Wynn 1976). Very little information (Davies and Butler 1986;Hughes and Rijkenberg 1985) is available on the initiation and formation of the substomatal vesicle (SSV) and its subsequent development. Hughes and Rijkenberg (1985) studied the initiation and formation of the infection peg, the development of the SSV, and the primary and secondary hyphae of Puccinia sorghi Schw. on corn. All observed substomatal vesicles were orientated with their long axes parallel to the stomatal slit and, therefore, to the leaf. In the present paper we report on the formation and orientation of the SSV of Uromyces transversalis (Thiim.) Winter, an important gladiolus pathogen (ViennottBourgin 1978), in the leaves of Gladiolus L. and a nonhost, Zea mays L. In this article we use the terminology of Hughes and Rijkenberg (1985).

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RESUMOA absorção do cálcio e do fósforo por raízes destacadas da soja var. IAC-2 foi estudada com ajuda de traçadores. Foram verificados os efeitos da concentração iônica externa do tempo, do pH, da temperatura, da aeração e de venenos respiratórios. Os dados sugerem que a absorção do cálcio tenha se dado passivamente, sendo ativa a do fósforo. A absorção cresceu com o pH e a temperatura. Os valores das constantes de Michaelis encontrados concordam com os da literatura. INTRODUÇÃOEntre as numerosas revisões da literatura sobre a absorção iônica pelas plantas destacam-se algumas mais recentes pelo seu aspecto didático e abrangente: HIGINBOTHAM (1973), HODGES 1973, GAUSH (1972, pp. 61-175), NISSEN (1974), HELLER (1974), HEWITT Ε SMITH (1974, pp. 72-104), EPSTEIN (1975, pp. 73-125). É pertinente ao presente trabalho o seguinte resumo que diz respeito à absorção do cálcio e fósforo e aos fatores que nela influem. * Com ajuda da FAPESP, CNEN, CAPES e BNDE.Entregue para publicação em 16/12/1976.