- 學位論文
接種叢枝菌根菌(AMF)對台灣產山藥（Dioscorea alata L.）植株生長發育、塊莖產量、尿囊素含量及抗氧化能力之研究
Study on Arbuscular Mycorrhizal Fungi (AMF) Inoculation on the Growth and Development, Tuber Weight, Allantoin Content and Antioxidant Ability in Yam (Dioscorea alata L.) Cultivated in Taiwan
摘要
叢枝菌根菌(AMF)與植物根部的共生作用廣泛分布於自然環境中，AMF提供給植物宿主的益處包括增進大量與微量元素的吸收，增加植物對土壤病原菌的抵抗力，對鹽分、重金屬和乾旱等環境逆境的耐受力，維持土壤結構的穩定性和影響植物二次代謝產物的含量。山藥(Dioscorea spp.)塊莖可供食用、藥用或保健利用，是目前相當被重視的藥用植物。山藥塊莖含有豐富的總酚、類黃酮和花青素等抗氧化成分，山藥塊莖也含有高量可防止人體皮膚發炎與潰瘍的尿囊素成分，因此山藥內部之二次代謝物成分在醫藥保健實務上具有開發利用的價值。 本研究以台灣常見之五個商業化品種（系）山藥(Dioscorea alata L.) 台農1號、台農2號、二刺品系、紫玉血薯和台農5號在田間栽培條件下，分別接種Glomus clarum（Gc）、G. etunicatum（Ge）、G. fasciculatum（Gf）、G. mosseae（Gm）、Gigaspora sp.（Gg）和Acaulospora sp（Asp）等六種叢枝菌根菌，探討對山藥菌根形成率、葉片生理成分、養分分析、塊莖產量與其內部二次代謝物含量與抗氧化能力的影響。研究結果顯示六種AMF菌種均能與五個品種（系）山藥宿主根部形成菌根構造，菌根形成 率分別從63.3％至90.0％不等，顯示AMF與各山藥宿主間展現了高度親和性。 山藥接種AMF後多數的山藥植株葉片葉綠素、可溶醣類與可溶蛋白含量高於未接菌之對照組。與對照組相較，山藥接種AMF台農1號、台農2號、二刺品系、紫玉血薯和台農5號分別獲得最高葉綠素 (處理組/對照組)1.93/1.73、2.30 /2.10、2.12/1.86、1.93/1.62、與1.93 /1.66 mg/g含量；也分別獲得最高可溶蛋白質(處理組/對照組)76.55/60.83、98.99/73.70、147.33/120.80、74.06/51.37與92.91/ 59.41 mg/g之含量與最高可溶醣類 (處理組/對照組)140.75/105.75、104.62/81.73、129.88/103.54、158.13/11.28與157.90/ 134.27 mg/g之含量。根部被AMF纏化的山藥宿主植株葉片含有較高的氮和鉀元素；然而接種六種AMF六週後並沒有使山藥葉片的可溶性磷含量增加。研究顯示五種山藥接種AMF在塊莖產量方面有促進的效果，接種Ge菌種之五種山藥品種台農1號、台農2號、二刺品系、紫玉血薯和台農5號塊莖產量較對照組分別增加39%、35%、20%、56%和40%。 山藥接種AMF顯著的增加塊莖肉質部和表皮的二次代謝物總酚、類黃酮與花青素等抗氧化成分的含量，各品種間塊莖肉質部最高可分別增加40%總酚、42%類黃酮和106%花青素的含量。山藥塊莖表皮可以萃取豐富的總酚類、類黃酮與花青素等機能性成分，有開發利用提高山藥塊莖利用率之價值。山藥接種AMF增加抗氧化成分含量，可能有提升抗氧化能力之正面效應。本試驗結果顯示山藥表皮尿囊素含量高於肉質部，五種山藥接種AMF之每克表皮尿囊素含量高於肉質部分別達到159%、209%、64%、99%和97%。五種山藥台農1號、台農2號、二刺品系、紫玉血薯和台農5號接種AMF之HPLC尿囊素含量分析結果與對照組相較，顯示肉質部最高分別增加10.7%、8.3%、7.6%、3.2%和12.3%；而表皮最高分別增加15.4%、18.0%、15.2%、4.0%和22.5%。 台農1號、台農2號與二刺品系等白肉山藥接種Ge與Gm兩種AMF菌種能夠增加山藥塊莖產量與總酚類和黃酮等抗氧化物質之含量。紫玉血薯和台農5號兩種紅肉山藥接種Ge和Gg菌種則會增加山藥塊莖產量與增加總酚、類黃酮與花青素含量。AMF接種於台灣栽培之山藥品種可促進植株之生育，提高塊莖產量與抗氧化物質、尿囊素二次代謝產物的含量，AMF在山藥栽培與生產上具有發展的潛力，可做為微生物性肥料之利用。
並列摘要
The symbiotic association between arbuscular mycorrhizal fungi (AMF) and the roots of plants is widespread in the natural environment. AMF benefit their host plant principally by increasing the uptake of macronutrients and some micronutrients, resistance to soil pathogens, tolerance to salinity, heavy metals, and drought stress; maintenance of soil aggregate stability and influence the secondary metabolism levels of plants. The yam (Dioscorea spp.) tubers are edible, medicinal, and used as health foods, they have received considerable attention among the medicinal plants. Yam tubers can produce considerable amounts of antioxidant namely, polyphenols, flavonoids and anthocyanins. They also contained high levels of allantoin that is playing an important role in present skin inflammation and ulcers of the human body; thus, the secondary metabolites that exist in yam tubers have value for development and utilization in medicine practice and health care. In this study, five commercial species and line of yams (Dioscorea alata L.) were inoculated with six species of AMF, Glomus clarum, G. etunicatum, G. fasciculatum, Gigaspora sp., G. mosseae, and Acaulospora sp., in field cultivation conditions to investigate the influence of AMF inoculation on mycorrhizae formation rates, physiological components of leaves, nutrition analysis, tuber weights, secondary metabolite content and antioxidant ability in yam tubers. The results showed that all six AMF species were able to form mycorrhizae relationship with the host yams, and mycorrhizae formation rates ranged from 63.33% to 90%, indicating that these AMF present high compatibility with the host yams. In this research, the majority of the yam plants with AMF inoculation had substantially higher chlorophyll content as well as soluble carbohydrate and protein compared with those non-inoculation control group. The amount of chlorophyll content in yam leaves inoculated with AMF the control group were 1.93/1.73, 2.30 /2.10, 2.12/1.86, 1.93/1.62 and 1.93 /1.66 mg/g for Tainung No. 1, Tainung No. 2, Zihyuxieshu , Ercih and Tainung No. 5 respectively; and the maximum increased amount of both the soluble protein and carbohydrate were 76.55/60.83, 98.99/73.70, 147.33/120.80, 74.06/51.37 and 92.91/ 59.41 mg/g; 140.75/105.75, 104.62/81.73, 129.88/103.54, 158.13/110.28 and 157.90/134.27 mg/g respectively. The root colonization by AMF enabled the leaves of host yam presented high concentrations of nitrogen and potassium than those of the controls. However, yams inoculated with six of AMF for six weeks did not increase the content of soluble phosphorus. Our study showed that AMF inoculation can improve the tuber weights of five yams. G. etunicatum inoculation treatment increased the yam tuber weights by 39%, 35%, 20%, 56%, and 40% for Tainung No. 1, Tainung No. 2, Ercih, Zihyuxieshu, and Tainung No. 5 compared with the control group, respectively. The content of secondary metabolites, such as polyphenols, flavonoids, and anthocyanin, was significantly increased by the AMF treatment in tuber flesh and peel of the tested yam. Specifically, the maximums exchange of secondary metabolite contents increased to 40%, 42%, and 106% for polyphenols, flavonoids and anthocyanin respectively in the tuber fresh. Moreover, those ample functional ingredients, involving polyphenols, flavonoids and anthocyanins can be extracted from the peel of tuber, thereby increasing the potency and utilization of yam tubers. The AMF inoculation boost the secondary metabolites antioxidant compounds, thus enhancing the antioxidant ability of yams. The allantoin analysis experiments showed that the yam tuber peels was with higher allantoin content than the yam tuber flesh. The peels of per gram of tuber are 159%, 209%, 64%, 99% and 97% higher than those of the fresh of Tainung No. 1, Tainung No. 2, Ercih, Zihyuxieshu, and Tainung No. 5, respectively. Compared with the non-inoculated yams, the allantoin levels in tubers presented that in both the fresh and peels were 10.7%, 8.3%, 7.6%, 3.2% and 12.3%; 15.4%, 18.0%, 15.2%, 4.0% and 22.5% for Tainung No. 1, Tainung No. 2, Ercih, Zihyuxieshu, and Tainung No. 5 respectively. In this study, the data showed that Tainung No. 1, Tainung No. 2 and Ercih three white flesh yams species treated with G. etunicatum and G. mosseae enhanced the yam tuber yield and polyphenols and flavonoids content. The two species of purple yams, Zihyuxieshu and Tainung No. 5, treated with G. etunicatum and Gigaspora sp. enhance the yam tuber yield and polyphenols, flavonoids and anthocyanins content. The inoculation of yams with AMF can expedite plant growth and increase the tuber weight, antioxidants, allantoin content of secondary metabolites in tubers. Therefore, AMF can be used as a microbial fertilizer and developed for yam cultivation and production.