Atributos fisiológicos e sanitários de sementes de espécies olerícolas

Abstract

The objectives of this research were to evaluate the physiological and sanitary quality of vegetable seeds such as lettuce, rocket, kale, radish, coriander and cucumber and study route of infection Xanthomonas campestris pv. campestris (Xcc) in seeds and peduncles of cauliflower. The experiments were performed at the Laboratory of Seed Analysis and greenhouse Department of Plants of the Federal University of Pelotas (UFPel) and at the Laboratory of Plant Pathology of the Wageningen University and at greenhouses in two different regions of Netherlands. In the assessment of physiological and sanitary quality four seed lots of lettuce, coriander, kale, cucumber, radish and rocket were used. The following tests were performed: germination, first count of germination, electrical conductivity, seedling emergence, speed of emergence index , shoot length and root, seedlings dry mass of shoots and roots, accelerated aging with saline solution and sanity. To study the infection route of Xcc were used seeds and peduncles of cauliflower. The experimental design was completely randomized design and the means were compared by Tukey test (P ≤ 0.05). All vigor tests used in this study were effective in separating rocket seed lots in vigor levels. The germination test using high temperature classified lettuce seed lots in vigor levels in a manner similar to seedling emergence. The incidence of fungi in seeds of lettuce, cucumber, kale and rocket negatively affected seed vigor. The first count germination test and accelerated aging allow ranking of kale seed lots with a similar trend to seedling emergence. The accelerated aging tests and seedling emergence were the most appropriated to assess the quality of radish and coriander seed lots. The cold test with evaluation at 3 and 5 days and accelerated aging test were efficient to evaluate the physiological quality of cucumber seeds. Growing plants of cauliflower under organic management resulted in a high incidence of black rot and a high incidence of seed infection. The results suggest that bees are not responsible for the transmission of Xcc. In severely infected plants cannot be excluded that seed become infected via translocation of Xcc from leaves, stems, peduncles and through pedicels for seed.