羊肚菌菌核形成因予之研究

Studies on the Factors for the Formation of Sclerotla in Morchella esculenta Fr.

菌核的大小受環境及營養的影響很大。28°C以上，菌絲無法生長；12 ～16°C形成菌核數較多；28°C形成菌核直徑最大。光照會阻礙菌核的形成。菌絲生長的適合酸鹼值偏弱酸性，酸鹼值低於5時，不利於菌核產生。碳素源中，五碳糖類、山梨糖及半乳糖醇，不適合菌核生長。萄萄糖、半乳糖、甘露糖、蔗糖、麥芽糖、蕈糖、植物蜜糖、澱粉、菊芋多醣、甘露糖醇、山梨醇適合菌絲利用；阿拉伯糖、木糖、山梨糖、乳糖、半乳糖醇無菌核產生；菊芋多醣菌核量最多；半乳糖、蔗糖，麥芽糖、澱粉及甘露醇形成之菌核易於聚合。氮素源中，蛋白凍的菌絲乾重最大，組織胺酸之菌絲乾重最少；亞硝酸鈉生長速度最快，而組織胺酸生長最慢；甲硫胺酸無菌核產生。硝酸銨形成的菌核數量最多；以尿素為氮素源時菌核會聚合成大片面積。碳氮比為1時，菌絲生長最快；碳氮比1000時所得菌絲乾重值最大；碳氮比大於500時，無菌核產生。水份潛勢在-0.45Mpa時生長最快，水份潛勢低於-2.85Mpa時則無菌核之產生。

Under artificial conditions, the factors for the formation of sclerotia of M. esculenta were observed in the study. The optimum temperature for mycelial growth was occurred at 24°C, The mycelia didn't grow over 32°C. A lot of sclerotia were formed from temperature 12~16°C. The largest sclerotia were formed at 28°C. Light may inhibited the sclerotia formation, Sclerotia were not formed in the media below pH 5.0. In carbon source tested, most of hexoses were better than pentose, sorbose, dulcitol for mycelial growth. Inulin got a maximum amount of the sclerotia. Galactose, sucrose, maltose, starch and mannitol frequently formed a group of sclerotia. In nitrogen source tested, ammonium nitrate, sodium nitrite, sodium nitrate and ammonium sulfate were better than other inorganic nitrogen. While peptone, urea and asparagine were better than other nitrogen sources. Ammonium nitrate get the best one. The selerotia always produced in a compact area if urea was used. The most rapid linear growth of the mycelium was found in C/N ratio equal to 1. In mycelial dry weight measurement, C/N ratio 1000 got the best result. The sclerotium was not formed in C/N ratio over 500. The mycelial growth at water potential in -0.45Mpa got the best result and no sclerotium was found below water potential -2.85Mpa.