Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/36740
標題: 水稻幼苗在過量UV-B照射下UV-B吸收物質之變化及耐感性品種比較
Changes of UV-B absorbing compounds in rice seedlings exposed to excessive UV-B radiation and differential tolerance between tolerant and susceptible cultivars of rice (Oryza sativa L.)
作者: 汪雅敏
Wang, ya-min
關鍵字: UV-B radiation
UV-B輻射
tolerance
耐性
出版社: 農藝學系
摘要: 本試驗以台農67號、四種對UV-B耐感性水稻品種(秈稻感性Dular、秈稻耐性8908、稉稻感性3003、稉稻耐性M202)及台農67號水稻(M9)突變體幼苗作為試驗材料,經過量UV-B照射後,對其植株生育、生理生化反應及UV-B吸收物質反應差異加以比較,以期了解水稻幼苗經過量UV-B照射後傷害變化及UV-B特殊吸收物質之反應,作為日後有關植物和UV-B方面研究之參考。 本試驗項目共分為:一.台農67號水稻幼苗對過量UV-B照射後其生長及UV-B吸收物質之反應。二.耐感UV-B水稻品種幼苗對過量UV-B照射後其生長及UV-B吸收物質反應比較。三.台農67號水稻(M9)突變體幼苗耐感性選拔及其反應。 台農67號及四種耐感性品種水稻幼苗在UV-B照射處理後植株株高生長受抑制、葉片葉綠素之含量相對降低,丙二醛(MDA)含量明顯的增加。在UV-B吸收物質方面,台農67號、四種耐感性水稻幼苗及台農67號水稻(M9)耐感性突變體,其波長330nm吸收值(類黃酮)在處理後第一天即略有增加,且隨著處理時間的增加而大量增加,至處理第五天,略有減少。 類黃酮化合物Catechin含量,台農67號水稻幼苗在UV-B處理後第三天有明顯之增加。在秈稻耐性(8908)及感性(Dular)此兩品種經UV-B處理後第三天Catechin含量亦有明顯之增加,爾後則隨之下降;至於稉稻耐性(M202)感性(3003)品種亦有相同之情形。另外在台農67號及四種耐感性水稻幼苗皆經UV-B處理後,Taxifolin含量有明顯之增加,以第三天為最。一般而言耐性品種UV-B吸收物質之量較感性為多。除外,經過量UV-B照射後,發現有大量花青素合成,特別是耐性品種。 由試驗結果綜合而知顯示台農67號及供試四種水稻品種幼苗經過量UV-B照射後,會發生氧化傷害,間接影響其形態及造成生理的障礙,同時過量UV-B照射可以誘導類黃酮化合物生成,特別是花青素,這些反應在UV-B照射後一天就即產生;又耐 UV-B品種誘導類黃酮化合物累積能力較感性品種大,此部分亦可說明耐性品種對過量UV-B產生耐性機制之一。
The purpose of this study is to explore the UV-absorbing compounds responses of rice seedling exposed to excess UV-B radiation. TNG67、UV-tolerant cultivar、susceptible cultivar and TNG67 were used as matter. Three experiments were performed in this study, the first part was a series of physiological and injury responses were conducted as cultivar TNG67 V3-seedlings exposed to excess UV-B radiation. Second part was compared the physiological and UV-B absorbing compounds responses of tolerant and suspectible rice cultivars to excess UV-B radiation. Last was screening the TNG67 mutants and responses of excess UV-B radiation. Enhanced UV-B radiation depresses physiological responses, resulting in the reduction of rice seedlings growth , including seedlings height and the content of chlorophyll, and clearly increased malondialdehyde(MDA)content. As rice seedlings of TNG67、tolerant cultivars 、suspectible cultivars and TNG67 mutants exposed to excess UV-B radiation, resulted in accumulation of UV-B absorbing compounds, and increasing absorption (O.D.) at 330nm. An example of first day exposed to excess UV-B radiation with increased absorption (O.D.) at 330nm (flavonoids), and then increased during the treament period. At five days, absorpton (O.D.) at 330nm was decreased lightly. The UV-B absorbing compounds are mainly identified as flavonoid, among of flavonoid compounds, the content of catechin was increased at the three days of UV-B radiation. Indica type 8908 (T) and Dular (S) were referred to the content of catechin were also increased at the three days of UV-B radiation, and then decreased during the UV-B treatment period, as well as the japonica type M202 (T) and 3003 (S). On the other side, the content of taxifolin were great increased at the three days of UV-B exposure. The same as UV-B absorbing compounds from tolerant rice cultivars tend to be higher than susceptible rice cultivars. Futhermore the content of anthocyanidins were accumulated to excess UV-B radiation exposure, tolerant cultivars especially. Experimental results indicated that exposed to the excess UV-B radiation occured the peroxidation and affected the morphological and physiological responses indirectly. In the meanwhile, it has been shown that the induced accumulation of these flavonoid compounds, anthocyanidins especially. These responses were produced at the first day of UV-B radiation, and tolerant UV-B cultivars induced higher content of flavonoids than suspectible cultivars. Based on these results, this part is an important factor contributing to UV-B tolerance mechanism in rice cultivars.
URI: http://hdl.handle.net/11455/36740
Appears in Collections:農藝學系

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