Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/36943
標題: 淹水對高粱生長與發育的影響
Effects of waterolgging on the growth and development of sorghum
作者: 蔡吉豐
Tsai, Chi-Feng
關鍵字: sorghum
高粱
waterlogging
growth
yield
淹水
生長
產量
出版社: 農藝學研究所
摘要: 本試驗主要目的在於要瞭解淹水對高粱生長及產量之 影響。以雜交高粱台中五號為材料,試驗內容包括淹水對 種子發芽的影響,敏感時期的決定,淹水如何減少產量- 從供源與積儲方面說明,以及淹水如何影響光合產物之運 轉。 高粱種子播種 3小時後遭受淹水即能明顯抑制發芽, 播種24小時後遭受淹水處理之抑制最為嚴重,其幼苗出土 率、成苗率、出土係數、株高和幼苗乾重皆明顯受到抑制。 推其原因,可能在播種24小時後種子內代謝旺盛,各種酵 素正在活化,若遭受淹水導致種子快速吸水,細胞膜發生 破裂,電解質滲漏嚴重,細胞內物質快速向外滲出。缺氧 下種子內的 ATP能量生成不足,使得種子內許多需能的化 學反應與代謝作用無法正常進行,種子生理活性降低,造 成出土率嚴重下降。 高粱植株生長過程若遭受淹水處理五天,大都會影響 植株正常生長與子粒產量,顯見高粱植株對淹水逆境非常 敏感,其中以孕穗期對濕害最為敏感,植株地上部乾重抑 制最大,產量減少50%以上;產量之減少主要是由於果穗 每一環節子粒數嚴重減少,特別是下位子粒數之減少最多, 而百粒重之減少為其次。淹水處理導致植株 CGR、NAR 和 PFR降低,LAD和PEFD之影響不大,造成植株供源潛勢和積 儲潛勢的降低。 孕穗期淹水五天後植株葉片生長受到抑制,葉片二氧 化碳交換速率降低,Rubisco 活性下降,葉綠素含量降低, 使葉片固定二氧化碳的能力下降,葉片蔗糖和葡萄糖含量 累積減少;次外,淹水後有降低葉片水分潛勢以及發生滲 透調節的現象。另外,淹水處理後對劍葉蔗糖代謝和澱粉 合成酵素活性表現,並未有明顯的抑制現象。 果穗著生不同位置子粒的單一重量明顯呈上>中>下 位之現象,主要是因上、中位子粒充實速率明顯較下位子 粒為高。孕穗期淹水處理後由於子粒數減少太多,以致果 穗每一環節單粒重與對照組並未呈顯著差異,因此孕穗期 淹水處理後對結實子粒蔗糖代謝和澱粉合成酵素活性表現 並未有直接的影響,單一子粒蔗糖、葡萄糖和澱粉含量與 對照組無顯著的差異。 孕穗期淹水五天後植株劍葉 ATP含量明顯較低,約為 對照組的45%,能量價亦較低,顯示淹水植株劍葉維持生 理活性所需的能量不足;而淹水後植株上位莖稈的能量價 則於排水後有較低的趨勢,推測對光合產物的運轉能力會 受到影響。此外,經[U-14C]sucrose標定試驗知,淹水處 理後劍葉和上位莖稈的光合產物運轉能力減弱,光合產物 從劍葉運轉至穗的路徑中可能受到阻礙。
The experiments were conducted to explore the responses of sorghum plants (Sorghum bicolor L.) to waterlogging. Hybrid sorghum cultivar Taichung 5 was used as plant materials. The four items have been conducted including seedling emergence res- ponses, sensitive stage determination, leaf growth and grain filling responses. And the results will be discussed in aspects of source-sink relationship and translocation of assimilates. Seedling emergence was significantly inhibited by waterlogging performed at 3-hour after sowing, and it was inhibited severely at 24-hour after sowing. Emergence percentage, seedling percentage, emergence coefficent, seedling height and seedling dry weight were all decreased significantly. It was probably due to the vigorously enzymatic activity in seed within 24-hour after sowing and the increa- sed water uptake, cell membrane breakage, electro- lyte leakage and internal solute lose of seeds as seeds subjected to waterlogging. The ATP generation in seeds was declined under anoxia, resulted in a decrease of physiological activities, and the seed- ling emergence was severely reduced ultimately. Dry matter accumulation and grain yield were significantly decreased when the sorghum plant were subjected to waterlogging for 5-day. The most sen- sitive stage to waterlogging was booting stage, grain yield was significantly decreased about 50%, mainly due to the decrease of grain number of pani- cle per whorl, and such decrease occurred at the lower grain position was more obvious, the reduction of 100-grain weight was lesser. The reduction of yield was closely related to lower source potential and sink potential, which was mainly derivated from the reduction of crop growth rate (CGR), net assi- milation rate (NAR), and panicle filling rate (PFR), but the leaf area duration (LAD) and panicle effec- tive filling duration (PEFD) were not affected by waterlogging. The leaf growth was also inhibited as sorghum plants subjected to 5-day waterlogging, leaf CO2 exchange rate, Rubisco activity, and chlorophyll content were all declined, resulting in the decrease of the CO2 fixation ability. The reduction of accu- mulation of sucrose and glucose in leaf were also observed. In addition, the leaf water potential was reduced and the osmotic adjustment was observed significantly by waterlogging. However, the enzy- matic activies of sucrose metabolism and starch synthesis in leaf were not significantly inhibited by waterlogging. Although the reduction of grain yield occurred uneer the waterlogging, the severe decrease of grain number resulted in no changes in single grain weight of panicle per whorl. Consequently, the enzymatic activies of sucrose metabolism and starch synthesis in single grain were not directly affected by water- logging, and sucrose, glucose, and starch contents in grain were also unaffected by waterlogging. After a 5-day waterlogging at booting stage, the ATP content and energy charge of the flag leaf were lowered significantly. The results indicated that energy deficiency could not be enough to maintain physiological activity of the flag leaf. Also the decreasing tendency of energy charge of the upper culm after drainage might suggested that ability of photosynthate translocation were inhibited. In addi- tion, the pathway of photosynthate translocation from flag leaf to panicle might be blocked.
URI: http://hdl.handle.net/11455/36943
Appears in Collections:農藝學系

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