台灣地區過氧硝酸乙醯酯污染物對萵苣之影響

Effects of Perosyacetyl Nitrate on Lettuce Plants in Taiwan

孫岩章(E. J. Sun)

《植物病理學會刊》 2卷1期 (1993/03) Pp. 33-42

https://doi.org/10.6649/PPB.199303_2(1).0006

摘要

台灣地區自1989年起發現本地種劍葉萵苣(Lactuca sativa L. cv. Sword-leaf)及圓葉萵苣(L. sativa L. cv. Round-leaf)不斷出現類似過氧硝酸乙醯酯(Peroxyacetyl nitrate, 簡稱PAN)造成的下表面亮銅斑（Bronzing）及銀白斑（Silvering）病徵。經調查受害品種尚有盤萵苣(L. sativa L. cv. Pan-leaf)等。植物受害典型病徵一般在數小時或一天內開始呈現，且其分佈依不同葉齡及組織成熟度而呈特殊橫帶狀分佈，調查發現幼葉之葉尖，剛成熟的上半葉，及已成熟的下半葉出現較多病徵。此些特殊病徵及其以人工產製之PAN氣體在光線充足的連續攪拌熏氣箱(Continuously stirred tank reactor)內對各種萵苣熏氣亦能產生完全一致之病徵，證實萵苣病變係因PAN所引起，而利用臭氧進行相同的處理則不產生相同的病徵與病情。熏氣試驗測定得知五種萵苣的敏感度大小分別是劍葉萵苣＞圓葉萵苣＞盤萵苣與嫩莖萵苣＞皺葉萵苣，此與天然受害所見之敏感度一致。進一步以氣相層析儀配合電子捕捉檢知器測定大氣中之PAN濃度，並以氮氧化物分析儀加以校正，得知台北市台灣大學農場附近之PAN濃度最高達27 ppb，其發生皆在晴天風小、空氣污濁之時，而在降雨日、陰天、風大之日皆不發生，污染日中PAN之高峰出現在每日中午時分。劍葉萵苣及圓葉萵苣經證實可供做PAN污染之田間指標植物，利用此些指標植物不惟可研判PAN發生為害之頻率，亦可供了解PAN真正的為害面積範圍。此一研究證明目前在台北盆地約500平方公里，台中、彰化、南投約400平方公里及高雄、屏東約1,200平方公里的地區，皆屬目前PAN的危害區。

關鍵字

過氧硝酸乙醯酯 ； 萵苣 ； 光化學煙霧 ； 指標植物

並列摘要

Bronzing and silvering on lower leaf surfaces of Sword-leaf lettuce (Lactuea sativa L. cv. Sword-leaf) and Round-leaf lettuce (L. sativa L. cv. Round-leaf) were first found in Taipei area in 1989. Later these peroxyacetyl nitrate (PAM)-type symptoms were also found in Taichung and Kaohsiung areas on more lettuce cultivars including Pan-leaf lettuce. Usually the typical symptoms developed within one day after a calm sunny day with heavy smog. They occurred on the tip portion of young leaf, midsection portion of newly developed leaf, and the base portion of mature leaf. The symptoms and distribution patterns on lettuce leaves can be simulated after exposure of these lettuce plants to man-made peroxyacetyl nitrate at phytotoxic concentrations in continuously stirred tank reactors (CSTRs) in the greenhouse. These symptoms were completely different from those exhibited in the ozone exposure test in the same CSTRs. Results also showed that the degree of sensitivity of five cultivars or varieties of lettuce tested to PAN is as follows: Sword-leaf lettuce ＞ Round-leaf lettuce ＞ Pan-leaf lettuce, Celtuce lettuce ＞ Crisp-leaf lettuce. Similar result can be demonstrated after a heavily polluted day in the greenhouse of Taiwan University where these cultivars or varieties were planted. Measurement of the PAN in the atmosphere near National Taiwan University at Taipei showed that it could reach as high as 27 ppb at noon time in smogy days, but was undetectable in rainy, cloudy or windy days. In the month of June, 1992, there were six days showing high concentrations of PAN near the noon time. Of them only three days showed PAN concentrations phytotoxic to the Sword-leaf lettuce. It was suggested that the Sword-leaf and Round-leaf lettuce plants be used as PAN bioindieators to investigate the occurrence and severity of PAN injury in the field. Investigation in the past 3 years showed that. PAN is at present affecting about 500 square km in Taipei areas, 400 square km in Taichung areas, and 1,200 squre km in Kaohsiung areas.

並列關鍵字

Peroxyacetyl nitrate ； Lettuce ； Photochemical smog ； Indicator plant