台灣南部地區番石榴園炭疽病菌（Colletotrichum spp.）多樣性及對殺菌劑之敏感性

Genetic Diversity and Fungicide Sensitivity of Colletotrichum spp. Isolated from Guava Fields in Southern Taiwan

蔡蕣隍(Shuen-Huang Tsai) ； 陳冠妏(Kuan-Wen Chen) ； 黃健瑞(Chien-Jui Huang)

《台灣農業研究》 70卷2期 (2021/06) Pp. 140-156

https://doi.org/10.6156/JTAR.202106_70(2).0006

摘要

番石榴炭疽病是番石榴果實採收期至採收後其中一種重要病害，本研究主要目的在於瞭解目前發生在番石榴園之炭疽病菌族群的主要種類，以及探討這些炭疽病菌族群對核准用來防治炭疽病殺菌劑之敏感性。本試驗於2019－2020年間至南部番石榴主要產區採集番石榴炭疽病，採集部位包括無病徵葉片及已產生病斑之病果，將15分離株分別接種至「珍珠拔」果實。結果顯示，在有傷口的情況下，大部分菌株皆可造成不等程度的果腐病徵，其中分離自果實菌株的致病力普遍比分離自無病徵葉片強。為了確認所分離之炭疽病菌株種類，將internal transcribed spacer（ITS）、glyceraldehyde-3-phosphate dehydrogenase（GAPDH）、β-tubulin 2（TUB2）、chitin synthase 1（CHS-1）及calmodulin（CAL）5個基因序列作定序並建構親緣樹。由建構之番石榴炭疽病族群親緣樹顯示，台灣番石榴炭疽病至少包含Colletotrichum siamense、Colletotrichum fructicola與Colletotrichum tropicale等3種。由藥劑試驗結果顯示，C. siamense、C. fructicola對benzimidazoles類及strobilurins類藥劑普遍呈現不敏感；而C. tropicale對benzimidazoles類藥劑具敏感性，但對strobilurins類藥劑呈不敏感，因此C. tropicale相對於其他兩種炭疽病菌對benzimidazoles藥劑具敏感度的差異性。另外，當藥劑濃度100 mg a.i. L^(-1)時，克熱淨及鋅錳乃浦可完全抑制3種炭疽病菌菌絲生長，當藥劑濃度1 mg a.i. L^(-1)時，僅腐絕快得寧及腈硫醌可顯著抑制3種炭疽病菌孢子發芽。由以上藥劑試驗結果，可提供農民在田間綜合防治管理炭疽病的參考。

關鍵字

番石榴 ； 炭疽病菌 ； 族群親緣分析 ； 藥劑敏感性

並列摘要

Guava anthracnose is one of the important diseases of guava fruit from harvest to post-harvest. The aim of this study is to understand the main species of Colletotrichum that currently occur in guava orchards, and to investigate the sensitivity of these Colletotrichum spp. to the approved fungicides registered for anthracnose management. From 2019 to 2020, symptomless leaves and diseased fruits of guava anthracnose were collected from the main production areas in southern Taiwan. Fifteen isolates were obtained and inoculated on 'Zhen-chu Ba', respectively. The results showed that wounds are needed for most isolates to cause fruit rot symptoms, and the isolates obtained from diseased fruit is generally more virulent than the isolates obtained from symptomless leaves. To identify the species of collected Colletotrichum isolates, five genes including internal transcribed spacer (ITS), glyceraldehyde- 3-phosphate dehydrogenase (GAPDH), β-tubulin 2 (TUB2), chitin synthase 1 (CHS-1) and calmodulin (CAL) were sequenced and a phylogenetic tree was constructed. The constructed phylogenetic tree indicated that guava anthracnose in Taiwan includes at least three species, namely, Colletotrichum siamense, Colletotrichum fructicola and Colletotrichum tropicale. The fungicide tests show that C. siamense and C. fructicola are generally insensitive to benzimidazoles and strobilurins, while C. tropicale is sensitive to benzimidazoles but it is not sensitive to strobilurins. Comparing with the other two Colletotrichum spp., C. tropicale has a different sensitivity to benzimidazoles. In addition, at concentration of 100 mg active ingredient per liter, iminoctadine and mancozeb can completely inhibit the mycelial growth of the three Colletotrichum spp. thiabendazole + oxine copper and dithianon can significantly inhibit the germination of the spores among three Colletotrichum spp. The above results can provide farmers a reference for integrated pest management of anthracnose in the field.

並列關鍵字

Guava (Psidium guajava L.) ； Colletotrichum spp. ； Phylogenetic analyses ； Fungicides sensitivity test