矽酸鉀對水稻生長及生理之影響

近年來因氣候急遽變遷而降低水稻產量，同時全球人口卻不斷增加，可能導致糧食不足的危機，因此，提升水稻耐逆境能力及增加水稻產量即成為重要議題。許多研究提出，矽在植物遭受逆境時扮演著防禦相關機制的角色，不僅可即時因應環境刺激，減緩逆境傷害外，亦可促進作物生長，提高產量與品質。本研究以葉面噴施矽酸鉀處理，於水稻生長期間調查農藝性狀、產量構成要素與抗氧化酵素之活性。結果顯示水稻經矽酸鉀處理後，可提升株高並增加抗倒伏力約48%，在高溫環境下可穩定分蘗數，不受高溫的影響。在生理指標的部分，施用矽酸鉀之水稻可降低過氧化氫 (Hydrogen peroxide, H2O2) 含量，進而提高葉綠素含量。此外，水稻經矽處理於營養生長初期可提高42%過氧化氫酶 (Catalase, CAT) 活性，至生長後期時分別提高抗壞血酸過氧化物酶 (Ascorbate peroxidase, APX) 活性與穀胱甘肽還原酶 (Glutathione reductase, GR) 活性約35%和42%。分析產量構成要素的結果發現，水稻經矽酸鉀處理在有效分蘗數、單穗粒數、稔實率以及千粒重皆有較佳的趨勢；在單位面積產量上，平均每公頃5220公斤提升至6382公斤，產量顯著增加。綜合上述，水稻於營養生長期處理矽酸鉀後，能夠促進水稻營養及生殖生長，以及提升水稻對環境的耐受性，進而使單位面積產量增加。

關鍵字

矽酸鉀；農藝性狀；抗倒伏力；抗氧化能力；米質

並列摘要

In recent years, extreme climate changes have reduced rice production. Meanwhile, the global population is still increasing, resulted in a crisis of food supply deficit. Therefore, improving rice stress tolerance and increasing rice yield are regarded as important issues. Many studies have shown that silicon plays a crucial role in promoting defense-related mechanisms when plants are subjected to stresses. It not only alleviates the damage of stress, but also promotes crop growth and improves yield and quality. In this study, we investigated the effects of potassium silicate on agronomic traits, yield components, and antioxidant enzyme activities during the rice growth. we found that after using foliar application of potassium silicate, plant height was improved and the lodging resistance was increased by 48%. In addition, the number of tillers was not affected under high-temperature conditions. The content of the Hydrogen peroxide (H2O2) was decreased, while the chlorophyll content was increased. The activity of antioxidants catalase (CAT) was increased by 42% in the beginning of vegetative stage, while the activity of ascorbate peroxidase (APX) and glutathione reductase (GR) was increased by 35% and 42% in the later stage, respectively. The analysis of yield components showed that potassium silicate treatment increased the number of effective tillers and grain number per panicle, the fertility rate, and the 1000-grain weight. In general, the treatment improved the yield significantly from 5220 kg/ha to 6382 kg/ha, and the yield increased significantly. In summary, potassium silicate treatment not only promotes rice growth and development during vegetative and reproductive stages, but also improve the tolerance of rice to biological and abiotic stresses, leading to the increase of rice yield.