- 作者: 林奕耀
- 作者服務機構: 國立中興大學
- 中文摘要: 食菌性線蟲Paraphelenchus myceliophthorus 可以在試管內生長之七種植物病原真菌或食用菌菌絲上飼養並繁殖。其中,以Fusarium sp.最適合本線蟲之繁殖,依次為Alternaria citri,Rhizoctonia sp., Agricus bisporus, Phytophthora colocasiae,而以Aspergillus oryzae及Phythiumsp.為最差。依據洋菜平板上觀察本線蟲取食A. citri之菌絲結果,獲悉其尋找食物之移動,每分鐘可達18-42次,定位置取食時間則為3~21秒,平均每秒口針穿刺約為2次。 本線蟲繁殖最適溫度為28及30°C。以濕熱47.5°C處理20分鐘以上,或以50°C處理5分鐘以上,均可使本線蟲全部致死。 在室溫( 29~33°C)之蒸餾水中,本線蟲之甫自母體產下之卵,自單細胞期發育至幼蟲孵化需40~43小時,而在28°C恆溫下,則僅需38-40小時。在A. citri菌絲上,于28°C恆溫下,本線蟲完成一個世代所需時間約為4~5天。其生殖方式則依孤雌生殖( Parthenogenesis)進行。
- 英文摘要: The mycophagous nematode Paraphelenchus myceliophthorus fed and reproduced onseven species of plant pathogenic and edible. mushroom fungi grown in vitro.The best host for nematode reproduction was Fusarium sp., followed by Alternariacitri, Rhizoctonia sp., Agaricus bisporus Phytophthora colocasiae, Aspergillus oryzae, andPythium sp.. By the observation in agar preparations, behavior leading to feeding ofP, myceliophthorus on mycelia of A. citri was active. The movement times for searchingthe suitable point on mycelium was 18-42times'min. When the feeding point on thehost mycelium was selected, it stoped moving and its lips rubbed, then pressedagainst hypha and penetrated by slow stylet thrusts (2 times'sec) for 3-21 sec atthe same point. The optimum temperatures for nematode reproduction were 28and 30°C. The lethal effects of high temperature with hot water treatment showedthat the nematode were killed when treated with 47.5°C for 20 min. or treatedwith 50°C for 5 min. In distilled water, development of P. myceliophthorus from the single-cell stageto the larva took 40-43 hrs at room temperatures (29-33°C), whereas it took 38-40hrs at 28°C. Only 1 nucleus was found in each egg of P. myceliophthorus inspectedimmediately after oviposition. About 45 min after oviposition, the egg underwentits first eleavage transversely to the egg axis, producing two cells of equal size.During the second cleavage the anterior cell divided tranrversely into an anteriorand a posterior cell of unequal size. The posterior then divided transversely to givethe four-celled stage embryo. Several rapid divisions then underwent followed byfive-celled stage, six-celled stage, seven-celled stage, and multiple-celled stage forma-tion. These cells showed some variations in arrangement. The embryo developed"tadpole stage" about 31 hrs after oviposition. And then, the first molting of larvacompleted, stylet formed, and the second stage of larva were hatechd by 43 hrs afteroviposition. A life cycle of P. myceliophthorus fed on A. cirri at 28°C was completed about4-5 deys. The reproduction of the nematode was found by parthenogenesis fromegg and gravid female to new generation of larva.
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