台灣瓜類病毒病害流行病學之時空分析

Abstract

在台灣瓜類在種植期間植株易受各種病毒危害，感染結果造成植株不同程度的病徵，罹病較輕的植株出現輕微斑駁或嵌紋，嚴重者葉片及果實畸型，有時多種病毒複合感染造成植株矮化及生長停止甚至死亡，不但影響品質也影響產量，目前尚無可防治病毒病的藥劑，因此探究病毒感染瓜類的流行病學時空分析，將有助於釐清發病之因素，以提供病毒病防治策略擬定之參考。 本研究主要在探討瓜類病毒病害之時空動態，因此首先使用在彰化縣北斗鎮種植冬瓜來探討其感染病毒發生經過之時間效應，以時間模式來配適病勢進展曲線，找尋其最適模式，說明病勢進展速率。並使用所收集之田間資料利用二維距離型態分析（two-dimensional distance class analysis, 2DCLASS）、二維相關分析（two-dimensional correlation analysis, 2DCORR）和空間分析距離指標（Spatial Analysis by Distance IndicEs, SADIE）等統計方法，來探討北斗冬瓜和南投縣竹山鎮之胡瓜感染病毒的空間變異性（spatial variability）情形。並使用Spearman’s rank correlation coefficient（ρ）和空間分析距離指標中的關係指標，分別來分析種植在竹山胡瓜與屏東縣里港鄉所種植之冬瓜，目的在瞭解病毒間的空間關係（spatial association），並闡述探討病害發生率與感染多種病毒空間關係的關聯性。

Cucurbits are often damaged by several viruses during growing seasons in Taiwan. The affected plants were severely stunted and had mottling leaves, up-grown shoots, blight tips, or malformed fruits and that resulted in significant reduction of yield and quality. As the viruses have already spread widely, no practical control measures are available currently. Hence, the development of the techniques on the surveillance and establishment of the model in epidemiology is important for the pest management of Cucurbits. In this thesis, we used the models of the spatio-temporal dynamics of virus epidemics for cucurbits infected several viruses to assess the association among viruses. The objective of this thesis will be to provide the protected methods of cucurbits for virus diseases. First, this study was conducted at Beidou township of Changhua county for two seasons to investigate the time effect of the wax gourd infected by viruses. The temporal model can be fitted to the disease progress curves in order to search the best fitted model and calculate the infected rate of the disease progress. Secondly, the spatial variability of the wax gourd cultivated in Beidou township and the cucumber cultivated in Chushang township is assessed by using the statistical methods of 2DCLASS, 2DCORR and SADIE to analyze the above dataset. Moreover, the spatial association of the virus disease of the wax gourd cultivated in Ligang township and the cucumber cultivated in Chushang township are evaluated by using Spearman's rank correlation coefficient (ρ) and SADIE's index of association. Furthermore, relationship between the disease incidence and spatial association of the viruses are also discussed.