AGRONOMIA: ELO DA CADEIA PRODUTIVA 3

Abstract

Associated with soybean seeds we can identify many biological imbalance relationships promoted by the highest frequency of the same fungal taxon. The objective of this work was to evaluate the diversity of fungi associated to seeds of soybean cultivars harvested in different harvests. Two experiments were carried out in which the cultivars of soybeans harvested in the 2015/2016 and 2016/2017 harvests were analyzed (83 cycles) and 13 (late cycle, stored for 6 months), both groups cultivated in Ipameri, GO. Using a “Blotter Test” method, 250 seeds of the different crops were plated for cultivation, incubated at 25 ± 3 ° C, after seven days the primary root emission (% ERP), incidence (% IM) (SH), Shannon index (ISh), Simpson index (ISi), and Fisher index (IF) were calculated for the following species: species abundance, species richness, for hypothesis testing and multivariate analysis. In the first experiment were identified 21 genera of fungi associated with the germplasm of the evaluated soybean represented by Colletotrichum sp., Pyricularia sp., Fusarium sp., Macrophomina phaseolina, Rhizoctonia sp., Pythium sp. and others. Of the 83 cultivars evaluated, the lowest germinability was statistically observed for the cultivars BG 4569©, CO 267 RR©, Felcha Ipro© and CG 67RR©. The cultivar G 850 RR© showed the lowest% IM (12.8%). The ISh statistically pointed out 20:83 cultivars with a higher diversity of associated fungi (biological equilibrium clue). In the second experiment, 19 taxa representing the microflora associated with seeds of stored cultivars / genotypes of soybean were detected. The highest ERP means were observed in cultivars / genotypes XI 791601 Ipro, Bonus 7.9©, XI 781616 Ipro, NS 7901 RR, XI 781654 Ipro, XI 811659 Ipro and lower ERP (physiological parameters) in cultivars NS 7901 RR©, NS 7901 RR© and NS 7901 RR©. The cultivars NS 7901 RR© and NS 7505 Ipro© presented the lowest incidence of microorganisms. There was no higher physiological activity in cultivars already established in the market in relation to unpublished genotypes. The storage of six months caused a reduction in the physiological activity of the seeds, however, in the same proportion the incidence of microorganisms did not increase Agronomia: Elo da Cadeia Produtiva Capítulo 15 112 to the point of reaching the totality of the seeds evaluated, leading to the belief that the low physiological activity does not result from the action of fungi on the seeds. Many agronomic performances of cultivars released on the market, many factors may explain its success however, the diversity of beneficial fungi associated with, and plant pathogenic can explain the maintenance of varietal behavior in the fields of production.