台灣菊花田間植物寄生性線蟲調查及鑑定兩個新紀錄種

The survey of plant parasitic nematodes on the chrysanthemum fields in Taiwan and identification of 2 new recorded species

"多年生植物菊花（Chrysanthemum morifollium Ram.），為台灣最大宗的切花作物之一，本研究針對台灣切花菊類菊花栽培地彰化、嘉義以及食用類杭菊栽培地苗栗、台東進行菊花作物上之植物寄生性線蟲相的調查，依照出現頻率高低排列，分別為Rotylenchulus、Paratylenchus、Pratylenchus、Hel icotylenchus、T r ichodorus、Tylenchorhynchus、Hirschmanniella及Meloidogyne。在苗栗、嘉義地區，腎形線蟲（reniform nematode）為主要發生線蟲族群，彰化永靖及田尾則是以根腐線蟲（root lesion nematode）及釘線蟲（pin nematode）為主要線蟲族群。田尾地區進行水稻輪作或休耕的田區，各種類寄生性線蟲族群量皆大幅降低到無法偵測，判斷休耕以及輪作水稻皆能有效抑制菊花田間植物寄生性線蟲族群。本研究純化培養4個菊花田區常見線蟲族群，分別為苗栗腎形線蟲ML-2、彰化田尾根腐線蟲TW-2、彰化田尾釘線蟲TW-4、嘉義腎形線蟲CY-2。利用型態資料再加上ITS序列片段與資料庫比對後，鑑定出兩個台灣新紀錄種,分別是TW-2的根腐線蟲Pratylenchus kumamotoensis及TW-4的釘線蟲Paratylenchus dianthus。另外兩個族群ML-2與CY-2則鑑定為Rotylenchulus reniformis。本試驗根腐線蟲TW-2對杭菊之危害測試結果顯示，僅根系於600隻接種量（2隻/ml土）的處理40天後有明顯的根部壞疽，地上部鮮重最低且與其他組別有顯著差異。推測此線蟲若在田中未進行防治，可能會嚴重危害連作菊花的田區。"

"Chrysanthemum (Chrysanthemum morifollium Ramat.) is a perennial crop belonging to the Asteraceae family, and one of the primary cut-flower crops in Taiwan. This study surveyed the plant parasitic nematodes (PPNs) in the major chrysanthemum planting regions in Taiwan. Chunghua and Chiayi counties are primary cutflower chrysanthemum cultivated region, but Miaoli and Taitung counties grow 'Hang' chrysanthemum for health supplements. Eight genus of plant parasitic nematodes identified in this study were Rotylenchulus, Pratylenchus, Paratylenchus, Trichodorus, Helicotylenchus, Tylenchorhynchus, Hirschmanniella, and Meloidogyne. In Miaoli and Chiayi counties, the reniform nematode was the dominant PPN population. In Chunghua and Chiayi counties, the root lesion nematode and pin nematode were the predominate populations. Soil samples at fields TW-1, TW-2, TW-3 after they rotated with rice, and TW-4, TW-8 after they practiced fallow showed that the PPNs populations in all fields decreased to an undetectable level. Four field populations were selected for mass cultivation, and processed for identification. Morphology and morphometric data as well as rDNA ITS sequences of the populations were obtained. Two populations in Miaoli and Chiayi (ML-2, CY-2) were identified as Rotylenchulus reniformis. The populations in Chunghua were identified as Pratylenchus kumamotoensis (TW-2), Paratylenchus dianthus (TW-4), respectively, and were two new recorded species in Taiwan. When challenged six hundred P. kumamotoensis on different chrysanthemum (2 all stage / ml soil treatment) cv. 'Hang' showed obvious lesion on roots, the treatment also had lowest shoot weight. This study indicates this plant parasitic nematode has high potential to cause severe damage on monocropping chrysanthemum cultivation regions."