Abstract Fusarium wilt caused by Fusarium oxysporum f. sp. cubense (foc) is one of the main diseases affecting banana crops. Biological control emerges as an alternative technology to prevent the spread of the disease. The objective of this work was to evaluate the effects of endophytic bacteria isolated from banana Prata Anã challenged with the foc in pairing and volatile tests under in vitro conditions. Forty endophytic isolates of the genera Bacillus, Klebsiella, Paenibacillus, Stenotrophomonas, Lysinibacillus and Sporolactobacillus isolated from banana roots were challenged with foc. The principal component analysis showed that the spore germination variable in the presence of bacterial cells explained better the variance (29.88%). Spore germination in the presence of bacterial cells, number of spores/cm2 in paired and volatile tests, and colony area in volatile tests explained about 86.10% of the total variance observed. The isolate EB37 (Bacillus sp., JN215502.1) reduced 96% of the germination of Fusarium oxysporum f. sp. cubense spores. The UPMGA clustering method based on Euclidean distance divides the 40 endophytic bacteria isolates into eight groups. The autochthonous bacteria isolated from Musa sp. of the genera Bacillus, Lysinibacillus, Stenotrophomonas, Sporolactobacillus and Paenibacillus showed promising results in foc control under in vitro conditions.

The aim of this study was to evaluate the activity of elicitor, acibenzolar-S-methyl (ASM), in inducing resistance to Meloidogyne javanica in soybean and in enhancing plant development. Plantlets of the soybean susceptible cultivar BRSMT-Pintado and the resistant cultivar MG/BR 46 Conquista were treated with ASM (0.5 g/L) at three different times: seven days before, one day before and seven days after inoculation with 2000 eggs/plant. Untreated inoculated plants and untreated non-inoculated plants were used as controls. Sixty days after inoculation, the number of galls, eggs/g root and vegetative parameters (height, aerial part fresh and dry mass and root fresh mass) were evaluated. The experiments were conducted over two different periods (Experiments 1 and 2). Only in Experiment 2 treatment "seven days before inoculation" reduced the number of eggs/g root, irrespective of the cultivar evaluated, but the number of galls was not affected. Stronger plant development was observed in the susceptible soybean cultivar treated seven days before inoculation in Experiment 2.

Hospedeiros alternativos de fitonematoides podem causar restrição nutricional e afetar a capacidade de infecção e fertilidade dos nematoides. Nesse trabalho, avaliou-se o efeito da planta hospedeira na viabilidade do inóculo de H. glycines raça 3 e a sobrevivência desse inóculo no solo. O nematoide foi multiplicado em feijoeiro resistente (linhagem L2300), suscetível (cv. Ouro) e soja suscetível (cv. FT-Cristalina), e as suspensões de ovos foram preparadas a partir de fêmeas coletadas nesses hospedeiros. Para avaliar a penetração dos juvenis de segundo estádio e o desenvolvimento do nematóide até a fase adulta, suspensões de 2000 ovos foram colocadas em plantas de soja 'FT-Cristalina' (planta teste). Aos 10 dias após a inoculação, avaliou-se o número de juvenis que penetraram nas raízes. O número de fêmeas por sistema radicular foi avaliado aos 30 dias. O inóculo obtido a partir da linhagem L2300 resultou no menor número de juvenis e de fêmeas no interior das raízes da planta teste. O inóculo obtido na soja foi o que resultou na maior penetração e desenvolvimento do nematoide. Para avaliar a sobrevivência do inóculo, cistos de H. glycines produzidos nos diferentes hospedeiros permaneceram no solo, sem planta, por 18 meses. O menor percentual de ovos que sobreviveram no solo foi originário de cistos multiplicados em feijoeiro, da linhagem L2300 ou cv. Ouro. Conclui-se que o inóculo de H. glycines produzido em feijoeiro, resistente ou suscetível, apresenta menor viabilidade e sobrevivência no solo.

Alternative hosts of phytonematodes can cause nutritional restriction and affect infectivity and fertility of the nematode. In this study, we evaluated the effect of the host plant on inoculum viability of Heterodera glycines race 3 and survival of this inoculum in soil. The nematode was multiplied in resistant (line L2300) and susceptible (cv. Ouro) beans and susceptible soybeans (cv. FT-Cristalina), and the egg suspensions were prepared from females collected on these hosts. To evaluate penetration of second stage juveniles and development of the nematode to the adult phase, suspensions of 2,000 eggs were placed in soybean 'FT- Cristalina' plants (test plant). At ten days after inoculation, we evaluated the number of juveniles that penetrated the roots. The number of females per root system was evaluated at 30 days. The inoculum obtained from line L2300 resulted in fewer juveniles and females inside the roots of the test plant. The inoculum obtained from soybean resulted in higher penetration and development of the nematode. To evaluate the survival of the inoculum, cysts of H. glycines produced in the different hosts remained in the soil, without plants, for 18 months. The lower percentage of eggs that survived in the soil was originated from cysts multiplied in beans, line L2300 or cv. Ouro. It can be concluded that the inoculum of H. glycines produced in bean plants, resistant or susceptible, has lower viability and survival in the soil.