Potential of wild Solanum stramonifolium accesses as rootstock resistant to soilborne pathogens in tomato crops

ABSTRACT Resistant rootstocks is one of the most effective method to control soilborne pathogens in tomato crops. Thus, this study was installed to evaluate the reaction of Solanum stramonifolium accesses to Fusarium oxysporum f. sp. lycopersici (Fol) races 2 and 3 and to Meloidogyne enterolobii (Me). The seedlings were grown in trays and inoculated separately with Fol races 2 and 3 at 50 days after planting 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 second-stage juveniles in greenhouse conditions. The experiments were evaluated in the 34th day (Fol) and in the 64th day (Me) after inoculation. The experiment consisted of 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 the plants used as controls, susceptible to Fol races 2 and 3 and Me, presented 100% of incidence. All accesses were resistant to Fol race 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 accesses also presented resistance to nematode. 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 other accesses were resistance to Fol race 3 and susceptible to Me.

摘要 利用抗病砧木是防控番茄土传病原菌的最有效手段之一。本研究旨在评价类曼陀罗茄（Solanum stramonifolium）种质资源对尖孢镰刀菌番茄专化型（Fusarium oxysporum f. sp. lycopersici，简称Fol）2号、3号生理小种以及象耳豆根结线虫（Meloidogyne enterolobii，简称Me）的抗性反应。试验采用育苗盘培育幼苗，于播种后50 d通过将根系浸没于孢子悬浮液（1×10⁶ 微分生孢子·mL⁻¹）的方式，分别接种Fol 2号与3号生理小种；随后将幼苗移栽至装有灭菌土壤的花盆中，置于温室环境培养。针对线虫抗性评价试验，本研究选用27日龄幼苗，同样移栽至花盆后，于温室条件下接种6000个卵及2龄幼虫。两项试验分别于接种后第34天（Fol处理组）与第64天（Me处理组）完成调查。本试验采用随机区组设计，设置5次重复：其中Fol处理组每小区为1盆种植3株幼苗，Me处理组每小区为1盆种植1株幼苗。结果显示，对Fol 2号、3号生理小种及Me均感病的对照植株发病率达100%。所有供试种质均抗Fol 2号生理小种；其中CNPH-19、CNPH-22、CNPH-23、CNPH-25、CNPH-120、CNPH-122与CNPH-349对两种病原菌均表现为多抗，具备开发为抗病砧木的巨大应用潜力。CNPH-24、CNPH-119、CNPH-121及CNPH-336等种质对线虫表现出抗性，但接种Fol 3号生理小种后出现轻微维管束褐变症状；该症状同样出现在CNPH-21、CNPH-107与CNPH-117种质中。其余所有供试种质均抗Fol 3号生理小种，但对Me感病。