Schroeder B K, Waters T D, du Toit L J
Washington State University, Pullman 99164.
Washington State University, Franklin Co. Extension, Pasco 99301.
Plant Dis. 2010 Feb;94(2):236-243. doi: 10.1094/PDIS-94-2-0236.
Sixty-nine storage onion (Allium cepa) cultivars (seven white, five red, and 57 yellow cultivars) were evaluated in the Washington State University Onion Cultivar Trials in the semiarid Columbia Basin of central Washington in 2007-08 and/or 2008-09. Each cultivar was inoculated with Enterobacter cloacae, cured, stored under commercial storage conditions, and evaluated for bacterial storage rot symptoms approximately 4.5 months after storage. Noninoculated bulbs of each cultivar served as a control treatment in each experiment. In addition, bulbs injected with water served as a second control treatment in the 2008-09 experiment. Inoculation of onion bulbs with E. cloacae resulted in significantly higher incidence and severity of Enterobacter bulb decay compared to noninoculated bulbs and bulbs injected with sterile water. For bulbs inoculated with E. cloacae, mean severity of bacterial storage rot per cultivar ranged from 5 to 19% of the cross-section evaluated for each onion bulb in 2007-08 and from 9 to 29% in 2008-09. For noninoculated bulbs, mean severity ranged from 0 to 1% in 2007-08 and 0 to 3% in 2008-09. For bulbs injected with water in the 2008-09 experiment, severity of bulb rot ranged from 0 to 10% per cultivar, with four cultivars (OLYX05-26, RE-E, Redwing, and Talon) displaying bulb rot ratings significantly greater than 0%. For the 33 cultivars included in both experiments, a significant correlation in bulb rot severity ratings was detected for the 2007-08 versus 2008-09 experiments (r = 0.43 at P = 0.013). Redwing, Red Bull, T-433, Centerstone, and Salsa had low severity ratings in both experiments; whereas Montero, OLYS05N5, Caveat, and Granero had severe bulb rot ratings in both experiments. The results demonstrate that it should be possible to select for increased resistance to Enterobacter bulb decay in storage onion cultivars.
2007 - 2008年和/或2008 - 2009年，在华盛顿州中部半干旱的哥伦比亚盆地的华盛顿州立大学洋葱品种试验中，对69个贮藏洋葱（葱属）品种（7个白色、5个红色和57个黄色品种）进行了评估。每个品种都接种阴沟肠杆菌，进行晾晒处理，然后在商业贮藏条件下贮藏，并在贮藏约4.5个月后评估细菌性贮藏腐烂症状。每个品种未接种的鳞茎在每个试验中作为对照处理。此外，在2008 - 2009年的试验中，注射水的鳞茎作为第二个对照处理。与未接种的鳞茎和注射无菌水的鳞茎相比，用阴沟肠杆菌接种洋葱鳞茎导致阴沟肠杆菌引起的鳞茎腐烂发生率和严重程度显著更高。对于接种阴沟肠杆菌的鳞茎，每个品种细菌性贮藏腐烂的平均严重程度在2007 - 2008年为每个洋葱鳞茎评估横截面的5%至19%，在2008 - 2009年为9%至29%。对于未接种的鳞茎，平均严重程度在2007 - 2008年为0%至1%，在2008 - 2009年为0%至3%。在2008 - 2009年的试验中，对于注射水的鳞茎，每个品种的鳞茎腐烂严重程度为0%至10%，有4个品种（OLYX05 - 26、RE - E、Redwing和Talon）的鳞茎腐烂评级显著大于0%。对于两个试验中都包含的33个品种，在2007 - 2008年和2008 - 2009年的试验中检测到鳞茎腐烂严重程度评级之间存在显著相关性（r = 0.43，P = 0.013）。Redwing、Red Bull、T - 433、Centerstone和Salsa在两个试验中的严重程度评级都较低；而Montero、OLYS05N5、Caveat和Granero在两个试验中的鳞茎腐烂评级都很严重。结果表明，应该有可能在贮藏洋葱品种中选择提高对阴沟肠杆菌引起的鳞茎腐烂的抗性。
