嘉磷塞（glyphosate）引起植物藥害與shikimate累積之相關性

Analysis of Shikimate Accumulation for Diagnosis of Glyphosate Injury to Crops

蔣永正(Yeong-Jene Chiang) ； 蔣慕琰(Mou-Yen Chiang)

《中華民國雜草學會會刊》 24卷1期 (2003/06) Pp. 25-35

摘要

探討利用嘉磷塞處理後導致植物細胞內shikimate 累積之反應，做為嘉磷塞藥害診斷之依據與適用範圍。不同劑量之嘉磷塞、百速隆及伏寄普，噴施於胡瓜及玉米3-4葉齡植株上，定期調查植株藥害發生率，及分析植體內shikimate含量。嘉磷塞引起玉米及胡瓜葉片黃化及植株乾枯之藥害徵狀，藥害發生率最高可達100%，shikimate含量隨藥害程度的提高而明顯增加。玉米藥害達100%等級時，shikimate含量為574±13μmol g fwt-1，為正常株5倍左右；胡瓜在藥害達100%時，含量為710±6μmol g fwt-1，亦高達未發生藥害株之5倍。Shikimate含量隨嘉磷塞施用劑量的提高呈線性上升；同時亦隨施藥後日數的延長而增加。百速隆三種測試劑量造成胡瓜之最大藥害程度可達100%，但shikimate最高含量175±3μmol g fwt-1，僅為正常株的127%。伏寄普對玉米亦有類似之影響趨勢；最高含量195±22μmol g fwt-1，為未發生藥害樣品之188%。另以三種測試藥劑處理西瓜、番茄、青梗白菜等作物及雜草－牛筋草，調查藥害發生程度與shikimate含量變化之相關性。測試藥劑均會引起植株發生不同程度之藥害，僅有嘉磷塞處理會導致shikimate累積，且隨劑量提高而增加，但不同種類植物間的累稱量有明顯差異；西瓜、番茄、青梗白菜均達90%藥害發生時，shikimate 含量分別增加為正常株之660%、1390%及1820%。嘉磷塞及伏寄普對牛筋草，亦可引起90%以上之傷，前者造成shikimate累積達630%倍，後者則與對照株無明顯差異(110%)。嘉磷塞處理之植物細胞內shikimate會明顯累積，且隨藥劑施用量及施藥後日數的增加而提高。百速隆及伏寄普在引植物顯著藥害時，未觀察到shikimate含量上升之現象。

關鍵字

嘉磷塞 ； 百速隆 ； 伏寄普 ； silicate含量 ； 藥害診斷

並列摘要

Glyphosate is a broad-spectrum non-selective systemic herbicide. It is registered to apply postemergence at 1.6-2.8 kg ha-1 to control most established weeds on the fields in Taiwan. It shows a strong herbicidal activity at a low application rate against a wide rang of upland weeds, and inadequate use could result in phytotoxicity of crops in farmland bordering the plantation. Simple and sensitive methods for detecting of responsible agent are very useful in the diagnosis of phytotoxicity. Glyphosate inhibits the biosynthesis of aromatic amino acid, and caused accumulation of shikimate in plants. This research was conducted to investigate the relationship between phytotoxicity and the change of shikimate content caused by glyphosate for diagnosis of herbicide injury. Corn and cucumber plants at 3 - 4 leaf stage were treated with glyphosate over a range of dosages. Damaged plants would appear leaf yellowing, crinkle and reduction of leaf size. Foliar application of glyphosate at 205-2050 G ha-1 resulted in the rapid accumulation of shikimate in corn and cucumber plants within 14 days. Results showed increasing dosage of glyphosate caused marked accumulation of shikimate and close relationship exited between phytotoxicity and shikimate accumulation of glyphosate-treated plants. This suggested that high levels of shikimate content in a damaged plant indicate glyphosate injury. Furthermore, the accumulation of shikimate in herbicides-treated plants was only due to glyphosate and not due to pyrazosulfuron-ethy1 or fluazifop-P-buty1. However, this type of response was obtained in other tested species when golyphosate was applied.

並列關鍵字

glyphosate ； pyrazosulfuron-ethy1 ； fluazifop-P-buty1 ； shikimate accumulation ； diagnosis of glyphosate injury