期刊名称：Revista Internacional de Contaminación Ambiental
印刷版ISSN：0188-4999
出版年度：2010
卷号：20
期号：4
页码：147-158
语种：Spanish
出版社：Centro de Ciencias de la Atmósfera
摘要：The effect of oneyear sequential and nonsequential fungal propagation, under polluted or nonpolluted conditions, on As and Cu fungal tolerance were studied. Germination, cell wall thickness, chitin and Cu content of spores were determined. Two arbuscular mycorrhizal fungi (AMF), isolated from As and Cu polluted soil, Glomus mosseae BEG132 (Nicolson and Gerdemann), G. caledonium BEG133 (Nicolson and Gerdemann), and one fungi from a non polluted soil G. claroideum Zac19 (Schenck and Smith) were used in this research. The treatments were: 1) WPWP; 2) WPP; 3) PWP and 4) PP, where WP=without pollution and P=polluted soil in the propagation substrate. In order to determine tolerance changes due to As and Cu exposure, spores were established under five As and Cu concentrations. Spores ofG. mosseae BEG132 and G. caledonium BEG133 had higher germination capacity than G. claroideum (Zac19), under all the As and Cu concentrations. The most negative effect on spore germination in BEG132 was related to the highest As and Cu concentration level tested. The propagation in polluted substrate in the second cycle (WPP; PP) significantly increased percentage of germination in spores of BEG132. After pollution exposure, Glomus claroideum Zac19 (WPP) increased its tolerance to the highest As and Cu concentration. Additionally, with this fungus, it was observed negative chemotropism in the germination tubes when spores germinated in polluted substrate. Spore cell wall thickness increased after propagation in polluted substrate. This was observed with BEG132 and BEG133 in the PP treatment; while in Zac19 this occurred in WPP. In Zac19, spore thickness increased from 5.4 mm to 7.4 mm after oneyear propagation in polluted substrate (WPP); however, this increment was not related to spore chitin content. This fungus showed the higher spore chitin content in comparison to the chitin content in spores of the other two fungi. Spores of BEG132 and 133 presented the highest chitin content in WPP treatment. Spores BEG132 sequestered Cu in a range from 470 to 680 μg g -1 (spore dry weight). Higher Cu sequestration corresponded to spores from WPP and PP treatments. Summarizing, in response to presence or not of polluted conditions during fungal propagation, germination percentage, cell wall thickness and chitin contents were modified. These responses were fungi straindependent. In conclusion, it was observed that AMF modified their tolerance to As and Cu as result of differences in fungal culture conditions and it may depend of interandintraspecific fungal variations.
