Potential of wild solanum Stramonifolium accesses as rootstock resistant to soilborne pathogens in tomato crops

Resumo

Resistant rootstocks is one of the most effective method to control soilborne pathogens in tomato crops. Thus, this study was carried out to evaluate the reaction of Solanum stramonifolium accesses to Fusarium oxysporum f. sp. lycopersici (Fol) races 2 and 3 and to Meloidogyne enterolobii (Me). To study the reaction of S. stramonifolium accesses to F. oxysporum f. sp. lycopersici (Fol) races 2 and 3, seedlings were grown in trays and 50 days after planting, they were inoculated separately with (Fol) 2 and 3 by immersing the roots in the spore suspension (1×10⁶ microconidia mL^‑1). Then, seedlings were transplanted in pots containing sterilized soil and kept in greenhouse conditions. To study the reaction of S. stramonifolium accesses to nematodes, we used 27-day-old seedlings that were also planted in pots and inoculated with 6,000 eggs and juveniles in greenhouse conditions. The experiments were evaluated in the 34^th day (Fol) and in the 64^th day (Me) after inoculation. The experiment consisted in a randomized block design with five replications, where each plot consisted of one pot with three plants (Fol) and one pot with one plant (Me). We observed that plant used as controls susceptible to (Fol) 2 and 3 and (Me) presented 100% of incidence. All accesses were resistant to (Fol) 2 and the accesses CNPH-19, CNPH-22, CNPH-23, CNPH-25, CNPH-120, CNPH-122 and CNPH-349 presented multiple resistance to pathogens, indicating great potential for using as resistant rootstock. The CNPH-24, CNPH-119, CNPH-121 and CNPH-336 access also presented resistance to nematodes (Me). However, they presented slight browning symptoms of vascular tissues when they were inoculated with (Fol) race 3. This symptom was also observed in the CNPH-21, CNPH-107 and CNPH-117 accesses. All the others access were resistance to (Fol) race 3 and susceptibility to nematodes (Me).