Phytopathology. 2002 Oct;92(10):1068-76. doi: 10.1094/PHYTO.2002.92.10.1068.
ABSTRACT The period of fruit susceptibility to Guignardia bidwellii (anamorph Phyllosticta ampelicida), the causal agent of grape black rot, was determined in the field. Intact fruit were inoculated weekly from bloom until 8 weeks later with a suspension containing 2 x 10(5) conidia per ml. Disease progress was monitored approximately every 2 days until 3 to 5 weeks after inoculation, depending on the year and variety. Fruit of Vitis x labruscana 'Concord' exhibited a period of maximum susceptibility from midbloom until 2 to 4 weeks later, although some berries became symptomatic when inoculated 4 to 5 weeks postbloom. Fruit of V. vinifera 'Chardonnay' and 'Riesling' exhibited a period of maximum susceptibility from midbloom until 3 to 5 weeks later, although some berries retained their susceptibility until 6 to 7 weeks postbloom. These susceptible periods were approximately 2 to 4 weeks shorter than previously assumed. Fruit age at the time of inoculation affected the length of the incubation period (time from inoculation until symptom appearance). When the incubation period was defined in terms of degree hours (base = 0 degrees C) accumulated after inoculation, DH(50) values (the number of degree hours required to reach 50% of final disease severity) increased by at least 50% as berries neared the end of their susceptible period. Newly symptomatic berries continued to appear for over 1 month after inoculation of older fruit. Thus, age-related or ontogenic, host resistance was manifested as both a decline in susceptibility and a significant increase in incubation period length. The control of black rot is likely to be improved by tailoring the intensity of fungicidal protection to the abbreviated period of fruit susceptibility defined in this study. Furthermore, the efficacy of management programs and the results of epidemiological studies are likely to be misinterpreted unless the variable effect of fruit age on incubation period length is recognized.
摘要 在田间条件下，测定了葡萄黑腐病菌（无性型为 Phyllosticta ampelicida）对浆果的感病期。从开花期开始，每周用含 2×10(5)个分生孢子/ml 的悬浮液对完整果实进行接种，直到 8 周后。根据年份和品种的不同，在接种后大约每 2 天监测一次病情进展，直到接种后 3 至 5 周。Vitis x labruscana 'Concord'果实的最大感病期从中花期持续到 2 至 4 周后，尽管有些浆果在开花后 4 至 5 周接种时就出现了症状。V. vinifera 'Chardonnay'和 'Riesling'果实的最大感病期从中花期持续到 3 至 5 周后，尽管有些浆果在开花后 6 至 7 周仍保持感病。这些易感期比以前假设的要短 2 至 4 周。接种时果实的年龄影响潜伏（从接种到症状出现的时间）期的长短。当潜伏期间用接种后累积的有效积温（以 0°C 为基数）来表示时，DH(50)值（达到最终病情严重程度 50%所需的有效积温数）随着浆果接近易感期末期至少增加了 50%。在对较老果实进行接种后，新出现症状的浆果仍在 1 个月以上的时间内继续出现。因此，与年龄相关或个体发育的宿主抗性表现为易感性下降和潜伏期间长度显著增加。通过使杀菌剂保护的强度适应本研究中定义的果实易感期的缩短，黑腐病的防治可能会得到改善。此外，如果不认识到果实年龄对潜伏期间长度的可变影响，那么管理计划的效果和流行病学研究的结果很可能会被误解。
