ABSTRACT Anatomical, physiological, and biochemical analyses have been performed to predict graft compatibility. We analyzed if the concentrations of auxins, jasmonic acid, gibberellins, 1-aminocyclopropane-1-carboxylic acid, zeatin (cytokinin), salicylic acid, and abscisic acid could be used as predictors of compatibility between the rootstocks FOX1 and FOX4 (resistant to Fusarium wilt) and the scion of cherry tomatoes Sweet Heaven (SH). Self-grafted (SH/SH) and ungrafted SH plants (SH) were used as controls. Hormonal analyses were performed on leaves, at 20 and 70 days after grafting (DAG), and roots, at 20 DAG. No expressive concentrations of auxins, gibberellins, or jasmonic acid were detected. The concentrations of 1-aminocyclopropane-1-carboxylic acid, the immediate precursor of ethylene, and zeatin were altered at 20 DAG, but they stabilized at 70 DAG. Salicylic acid levels were reduced in the leaves of grafted plants at 70 DAG. The concentration of abscisic acid (ABA) in the leaves of SH grafted onto FOX1 was higher than in ungrafted and self-grafted plants at 70 DAG, suggesting some degree of incompatibility between these genotypes. The concentration of ABA in the combination FOX4/SH was similar to that in the self-grafted plants. Abscisic acid might be used as a reference phytohormone to predict graft compatibility among tomato genotypes.

Abstract Few commercial genotypes of tomato are resistant to Fusarium wilt (Fusarium oxysporum f. sp. lycopersici [FOL]), especially to race 3. We developed five intraspecific hybrids of Solanum lycopersicum (FOX1 to FOX5) and assessed them for agronomic traits and resistance to FOL races 1, 2, 3, and a mixture of these races. FOX1 and FOX4 were resistant to all races and the race mixture but did not have the desired agronomic traits. Next, FOX1 and FOX4 were assessed as rootstocks of the cherry tomato Sweet Heaven. The grafting of Sweet Heaven on FOX4 did not reduce growth, gas exchange, yield, or fruit quality. When FOX1 was used as a rootstock, the fruits exhibited a reduction in firmness, fruit pulp pH, and total soluble solids by 14.3%, 1.2%, and 6.75%, respectively. Thus, the hybrid FOX4 can be used as a rootstock for Sweet Heaven to manage Fusarium wilt.

RESUMO A aplicação de um bionematicida à base de clamidósporos de Pochonia chlamydosporia (Pc-10) pode se tornar uma importante estratégia para reduzir os danos causados por Meloidogyne incognita em cenoura. Baseado nessa perspectiva, o efeito nematicida de 0; 0,5; 1,0; 1,5; 2,0; 2.5 e 3,0 kg ha -1 de Pc-10 foi avaliado em área de produção de cenoura cv. Juliana em condições de campo. A produtividade de cenoura e a população do nematoide foram influenciados por doses crescentes de Pc-10. A aplicação de 3,0 kg ha-1 de Pc-10 aumentou a produção de raízes comerciais de cenoura em 41,7% comparada com aquela obtida na testemunha não tratada, enquanto que a produção de raízes não-comerciais e a população do nematoide no solo foram reduzidos em 48,7% e 61,4%, respectivamente. A aplicação de 3,0 kg ha -1 de Pc-10 reduz a população de M. incognita e aumenta a qualidade e a produtividade das raízes de cenoura.

ABSTRACT The application of a bionematicide based on chlamydospores of Pochonia chlamydosporia (Pc-10) can be an important strategy for reducing the damage caused by Meloidogyne incognita on carrot. Based on this perspective, the nematicidal effects of 0, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 kg ha -1 of Pc-10 were evaluated on carrot cv. Juliana under field conditions. Carrot yield and nematode population were influenced by increasing doses of Pc-10. The application of 3.0 kg ha-1 of Pc-10 increased the marketable production of carrot roots by 41.7% compared to the untreated control, whereas the production of unmarketable roots and the nematode population in the soil were reduced by 48.7% and 61.4%. The application of 3.0 kg ha -1 of Pc-10 reduces M. incognita population and improves carrot quality and yield.

Bacteria belonging to the genus Bacillus can promote plant growth and suppress plant-parasitic nematode populations. Based on this hypothesis, eight strains of the bacterium (SF 262, SF 264, SF 266, SF 267, SF 268, SF 271, SF 292 and SF 629) were formulated and applied as a seed treatment and/or sprayed on the soil surface with the aim of controlling Pratylenchys brachyurus in common bean under field conditions. The application of the bacterial isolates neither improved the grain yield and the root mass nor reduced the number of nematodes in the soil and in the roots of common bean. Thus none of the isolates of Bacillus spp. evaluated in this work are promising for the control of the lesion nematode on common bean.

Bacterias del género Bacillus pueden suprimirpoblaciones de nematodosfitoparásitos. Sobre la base de esta hipótesis, ocho cepas de Bacillus (SF262, SF264, SF266, SF267, SF268, SF271, SF292 y SF 629)fueronformuladas y aplicadas en el tratamiento de semillas y en la superficie de suelo para el control de Pratylenchus brachyurus en frijol. La aplicación de las cepas no aumentaron la producción de granos y la masa de las raíces, ni redujeron el número de nematodos en el suelo y en las raíces. Así, ninguna de las cepas de Bacillus es promisoria para el control del nematodo lesionador en frijol.