Spotts Robert A, Wallis Kelly M, Serdani Maryna, O'Gorman Daniel T, Sholberg Peter L
Oregon State University Mid-Columbia Agricultural Research and Extension Center, Hood River 97031.
Department of Botany and Plant Pathology, Oregon State University, Corvallis 97331.
Plant Dis. 2008 Mar;92(3):451-455. doi: 10.1094/PDIS-92-3-0451.
The objective of this research was to determine quantitative relationships between incidence of stem end decay of pear fruit and inoculum concentration of Botrytis cinerea and Penicillium expansum using dry conidia applied to pear fruit in a settling tower. Five concentrations of conidia were applied to pear fruit, fruit were stored at -1°C for 8 months, and stem end decay was evaluated. In addition, conidia were washed from the surface of inoculated fruit, and DNA was extracted and quantified with real-time polymerase chain reaction (PCR). The linear regression relationships between percent stem end gray mold and B. cinerea conidia per liter of air or per square centimeter of fruit surface were significant (P = 0.01). At the highest inoculum dose introduced into the settling tower, conidia per liter of air, conidia per square centimeter, and percent stem end gray mold at 8 months after inoculation were 12, 31, and 39, respectively for 2000 and 6, 33, and 67, respectively for 2001. Similarly, the linear regression relationships between percent stem end blue mold and P. expansum conidia per liter of air or per square centimeter of fruit surface were significant (P = 0.01 and 0.05, respectively). At the highest inoculum dose introduced into the settling tower, conidia per square centimeter and percent stem end blue mold at 8 months after inoculation were 39 and 26, respectively for 2000 and 66 and 23, respectively for 2003. Real-time PCR provided a rapid, quantitative measure of B. cinerea and P. expansum DNA on pear fruit surfaces. Because of possible year-to-year shifts in susceptibility of fruit to decay, disease incidence:inoculum dose relationships may be of most value compared within years rather than across years. This would facilitate comparison of decay risk among orchards in order to determine which fruit is most suitable for long-term storage.
本研究的目的是通过在沉降塔中将干燥分生孢子接种到梨果实上，确定梨果实茎端腐烂发生率与灰葡萄孢和扩展青霉接种物浓度之间的定量关系。将五种浓度的分生孢子接种到梨果实上，果实于-1°C下储存8个月，并对茎端腐烂情况进行评估。此外，从接种果实表面洗下分生孢子，提取DNA并用实时聚合酶链反应（PCR）进行定量。每升空气或每平方厘米果实表面的茎端灰霉病百分率与灰葡萄孢分生孢子之间的线性回归关系显著（P = 0.01）。在引入沉降塔的最高接种剂量下，2000年接种后8个月每升空气的分生孢子数、每平方厘米的分生孢子数和茎端灰霉病百分率分别为12、31和39，2001年分别为6、33和67。同样，每升空气或每平方厘米果实表面的茎端青霉病百分率与扩展青霉分生孢子之间的线性回归关系显著（分别为P = 0.01和0.05）。在引入沉降塔的最高接种剂量下，2000年接种后8个月每平方厘米的分生孢子数和茎端青霉病百分率分别为39和26，2003年分别为66和2（此处原文可能有误，推测为23）。实时PCR提供了一种快速、定量测定梨果实表面灰葡萄孢和扩展青霉DNA的方法。由于果实对腐烂的易感性可能逐年变化，因此病害发生率与接种剂量的关系在同年内比较可能比跨年比较更有价值。这将有助于比较果园之间的腐烂风险，以确定哪种果实最适合长期储存。
