Pandey Madan, Amiri Achour
Washington State University, Department of Plant Pathology, Tree Fruit Research and Extension Center, 1100 N. Western Ave, Wenatchee, WA 98801, USA; University of Minnesota, Department of Horticulture, 1790 Folwell Ave, St. Paul, MN 55108, USA.
Washington State University, Department of Plant Pathology, Tree Fruit Research and Extension Center, 1100 N. Western Ave, Wenatchee, WA 98801, USA.
Pestic Biochem Physiol. 2024 Dec;206:106206. doi: 10.1016/j.pestbp.2024.106206. Epub 2024 Nov 5.
In this study, 162 Penicillium isolates, i.e., 31 P. expansum isolates and 131 isolates from 13 other Penicillium spp. referred to as "non-expansum" were collected from apples and pears from multiple packinghouses in Washington State and Oregon. The sensitivity of the isolates to the postharvest fungicides pyrimethanil (PYR) and fludioxonil (FDL) was assessed in vitro. The mean EC value for PYR was 0.75 μg/mL in P. expansum compared to 1.63, 3.47, 6.95, 7.06 and 32.21 μg/mL in P. solitum, P. palitans, P. commune, P. roqueforti and P. carneum, respectively. For FDL, the mean EC value was 0.04 μg/mL in P. expansum compared to >0.80, 1.00, 10.40, 13.99, and 158.10 μg/mL in P. commune, P. palitans, P. roqueforti, P. solitum, and P. paneum, respectively. Overall, > 40 % of isolates from five "non-expansum" species showed dual resistance to PYR and FDL versus 9.6 % in P. expansum. The recommended rates of PYR and FDL failed to control isolates of six Penicillium spp. on detached apples after five months at 1.5 °C. Sequencing of the Mdl1, NikA, and Os1 genes from different isolates of eight species revealed a high polymorphism in the Mdl1 and NikA of several "non-expansum" species. Three and two concurrent mutations, in addition to a G409R and S959, were detected in the Mdl1 and NikA, respectively, that potentially confer resistance to PYR and FDL. The high level of resistance and the control failure observed on fruits highlight the potential risk posed by several "non-expansum" Penicillium species to pome fruit packers.
在本研究中，从华盛顿州和俄勒冈州的多个包装厂的苹果和梨中收集了162株青霉菌株，即31株扩展青霉菌株和131株来自其他13种青霉属的菌株（称为“非扩展青霉”）。在体外评估了这些菌株对采后杀菌剂嘧霉胺（PYR）和咯菌腈（FDL）的敏感性。扩展青霉中PYR的平均EC值为0.75μg/mL，而在孤生青霉、苍白青霉、普通青霉、罗克福特青霉和肉色青霉中分别为1.63、3.47、6.95、7.06和32.21μg/mL。对于FDL，扩展青霉中的平均EC值为0.04μg/mL，而在普通青霉、苍白青霉、罗克福特青霉、孤生青霉和潘氏青霉中分别>0.80、1.00、10.40、13.99和158.10μg/mL。总体而言，来自五个“非扩展青霉”物种的>40%的菌株对PYR和FDL表现出双重抗性，而扩展青霉中这一比例为9.6%。在1.5°C下放置五个月后，推荐剂量的PYR和FDL未能控制离体苹果上六种青霉属的菌株。对八个物种的不同菌株的Mdl1、NikA和Os1基因进行测序发现，几种“非扩展青霉”物种的Mdl1和NikA存在高度多态性。在Mdl1和NikA中分别检测到三个和两个同时发生的突变，此外还有一个G409R和S959，这些突变可能赋予对PYR和FDL的抗性。在果实上观察到的高抗性水平和防治失败突出了几种“非扩展青霉”物种对梨果包装商构成的潜在风险。
