Wegulo Stephen N, Vilchez Miguel
Department of Plant Pathology, University of California, Riverside 92521.
Plant Dis. 2007 Aug;91(8):997-1001. doi: 10.1094/PDIS-91-8-0997.
Lisianthus (Eustoma grandiflorum) is a high-value cut flower. However, major yield losses often result from gray mold caused by Botrytis cinerea. Various techniques were used to evaluate 12 lisianthus cultivars for resistance B. cinerea. Disease evaluations from detached leaf, leaf disc, cut stem, and in vivo growth chamber stem (GC) assays were correlated with those from an in vivo greenhouse stem (GH) assay, in which commercial greenhouse production of lisianthus was simulated. In all assays, stems or leaves were wounded before inoculation with spores or mycelia of B. cinerea. There was a significant (P ≤ 0.03) positive correlation between stem lesion length in the GH assay and disease incidence in the same assay (R = 0.74), stem lesion length from spore spray inoculation in the GC assay (R = 0.62), and percent necrosis from spore spray inoculation of detached leaves (R = 0.71). Correlations between stem lesion length in the GH assay and disease evaluations from spore drop and mycelial inoculation of detached leaves, leaf discs, and cut stems were not significant at P = 0.05. Considering only screening methods with significant correlations, 'Magic Champagne' was the most resistant cultivar (mean rank [mr] = 2 of 12). 'Echo White' and 'Echo Lavender' were the least resistant cultivars (mr = 11). The other cultivars were 'Magic White' (mr = 4); 'Avila Ivory', 'Balboa Yellow', 'Echo Pink', and 'Magic Rose' (mr = 5); 'Balboa Blue' (mr = 6); 'Avila Blue Rim' (mr = 8); and 'Avila Purple' and 'Catalina Purple' (mr = 9). The results from this study indicate that in vivo disease incidence, in vivo stem assays, and detached leaf assays, all initiated with wounding followed by spore spray inoculation, may be more reliable in evaluating lisianthus cultivars for resistance to B. cinerea than spore drop and mycelial inoculation of detached leaves, leaf discs, and cut stems. The results also indicate that lisianthus cultivars with moderate resistance to B. cinerea are commercially available. These cultivars have potential for use as germplasm in breeding lisianthus for resistance to the pathogen.
洋桔梗（Eustoma grandiflorum）是一种高价值的切花。然而，产量的重大损失往往是由灰葡萄孢菌引起的灰霉病导致的。采用了各种技术来评估12个洋桔梗品种对灰葡萄孢菌的抗性。离体叶片、叶盘、切茎以及活体生长室茎（GC）试验的病害评估结果与模拟洋桔梗商业温室生产的活体温室茎（GH）试验的结果相关。在所有试验中，在接种灰葡萄孢菌的孢子或菌丝体之前，先对茎或叶进行创伤处理。GH试验中的茎部病斑长度与同一试验中的发病率（R = 0.74）、GC试验中孢子喷雾接种后的茎部病斑长度（R = 0.62）以及离体叶片孢子喷雾接种后的坏死率（R = 0.71）之间存在显著（P≤0.03）正相关。GH试验中的茎部病斑长度与离体叶片、叶盘和切茎的孢子滴接种和菌丝体接种的病害评估结果之间在P = 0.05时无显著相关性。仅考虑具有显著相关性的筛选方法，‘Magic Champagne’是最抗病的品种（在12个品种中平均排名[mr]=2）。‘Echo White’和‘Echo Lavender’是最不抗病的品种（mr = 11）。其他品种依次为‘Magic White’（mr = 4）；‘Avila Ivory’、‘Balboa Yellow’、‘Echo Pink’和‘Magic Rose’（mr = 5）；‘Balboa Blue’（mr = 6）；‘Avila Blue Rim’（mr = 8）；以及‘Avila Purple’和‘Catalina Purple’（mr = 9）。本研究结果表明，活体发病率、活体茎试验和离体叶片试验，均先进行创伤处理然后进行孢子喷雾接种，在评估洋桔梗品种对灰葡萄孢菌的抗性方面可能比离体叶片、叶盘和切茎的孢子滴接种和菌丝体接种更可靠。结果还表明，对灰葡萄孢菌具有中等抗性的洋桔梗品种已可商业化获得。这些品种有潜力作为种质用于培育抗该病原菌的洋桔梗品种。
