Quantificação de esporos de fungosmicorrízicos em genótipos de mandioca com e sem inoculação de patógenos foliares

Abstract

Cassava is an important food source, due to its nutritional value, being consumed mainly in the countries of the tropics. The species has high mycorrhizal dependence, which directly influences the development, productivity and health of the crop. This work aimed to evaluate whether different cassava genotypes under inoculation of leaf pathogens influence the amount of mycorrhizal fungi spores. Soil samples (0-10 cm) were collected near the roots of ten genotypes, in the experimental area of the cassava breeding program for the selection of genotypes resistant to anthracnose, bacteriosis. Experiments inoculated with anthracnose, bacteriosis, control 1 and control 2 were considered as blocks. The experiment was implemented at the Fazenda Experimental de Ciências Agrárias of the Universidade Federal da Grande Dourados - UFGD, in a delineation of enlarged blocks, with plant material from germplasm bank of Embrapa Mandioca e Fruticultura. The spores of mycorrhizal fungi (FM) were extracted by the wet sifting method and subsequently quantified. The statistical analysis for the number of spores was performed using the mixed generalized linear model, with the Poisson family with log connection function (P≤0.05) and application of the Tukey test to compare means with α = 5%, a difference was found significant among the cassava genotypes in relation to the number of spores found, as well as significant difference was also verified for the source of variation blocks. Although there is a statistical difference in the chemical attributes of the soil in the different blocks and genotypes analyzed, there was no significant correlation with the amount of spores. It was concluded that the analyzed genotypes and blocks had an influence on the amount of mycorrhizal spores, in which BGM 0682 and BGM 0859 had a greater influence on the amount of mycorrhizal fungi spores present in the soil.