全國中小學科展

植物學

Plantastic Pods: The Grow Stick Rooting Revolution for Seeds & Cuttings

Cultivating plants from seeds or cuttings is a fundamental aspect of gardening and agriculture. While traditional methods have been practiced for centuries, there is a persistent need for innovative and efficient approaches to enhance plant growth and development. This section explores the challenges associated with traditional propagation methods and examines potential solutions offered by emerging technologies and materials. Plant propagation is necessary to allow efficient multiplication and distribution of desirable plant varieties (Sorensen & Garland, 2024). Plant propagation is the process of creating new plants. There are two primary methods of propagation: sexual and asexual. .Sexual propagation involves the union of pollen and egg, drawing genetic material from two parent plants to create a new, genetically diverse offspring. This process utilizes the floral parts of a plant. .Asexual propagation, on the other hand, involves taking a part of a single parent plant and inducing it to regenerate into a new plant. The resulting offspring is genetically identical to its parent. This method utilises the vegetative parts of a plant, such as stems, roots, or leaves. One emerging technology that has garnered attention in this field is the use of cocopeat, a sustainable growing medium derived from coconut husks (Pane et al. 2021). Cocopeat has been extensively studied as a potential alternative to peat moss in plant propagation (Gericke, 1940). It offers a favourable balance between air porosity and water holding capacity, promoting root development and nutrient uptake (Kalaivani and Jawaharlal, 2019). Furthermore, cocopeat is a renewable and environmentally-friendly resource, making it an attractive option for sustainable seedling cultivation. Research has shown that the use of cocopeat as a growing medium can enhance the growth of both vegetables and various ornamental plants, such as Impatiens. The biostimulant effect of the Trichoderma atroviride fungus, which can readily colonize coir, has been observed to increase aboveground biomass, flower production, pigments, and nutrient concentration in these plants (Traversari et al., 2024).

大「逆」不道—局部逆境下植物體內傳訊與物質分配機制

When a leaf of a plant encounters stress, how does the plant convey the stress signal to other tissues and manage nutrient distribution? This field of study has been largely unexplored. However, the unique interconnected frond structure of Lemna trisulca, along with the use of a divided Petri dish, is very suitable for handling localized stress and investigating the mechanisms of intracellular signaling and nutrient distribution. Research has shown that when the mother leaf experiences localized stress, it releases healthy daughter leaves to minimize collateral damage to the daughter leaves. Conversely, when the daughter leaves face localized stress, the mother leaf chooses to retain them and continues supplying them with nutrients to support their survival. In-depth studies revealed that stressed daughter leaves accumulate Reactive Oxygen Species (ROS), triggering nutrient distribution by sending a distress signal to the mother leaf. This prompts the mother leaf to use Ca2+ as a signaling molecule to deliver nutrients to the daughter leaves. Selective detachment is regulated and triggered by the interaction between Ca2+ and ROS within the mother leaf. When the mother leaf undergoes stress, Ca2+ acts upstream to induce ROS accumulation at the nodes, sending a unidirectional detachment signal to the daughter leaves. This causes ROS accumulation at the daughter leaf nodes, inducing detachment and thereby reducing the collateral damage the daughter leaf could experience due to the mother leaves.

探討候選基因對角質層與氣孔發育的調控之影響

植物進化成陸生植物的過程中,氣孔和角質層是關鍵特徵。氣孔由保衛細胞調控,負責二氧化碳進入和水分蒸發;角質層則保護植物免受水分流失及環境壓力。調控這些特徵的基因尚不明確。本研究利用全基因組關聯分析(GWAS)探討阿拉伯芥的角質層和氣孔發育。GWAS結果顯示,與角質層厚度相關的基因位於第二條染色體,而與二氧化碳吸收效率相關的基因位於第五條染色體。氣孔導度和水分吸收效率的調控基因可能在第一、三、四條染色體上。角質層變薄時,氣孔密度下降,導致氣孔導度和水分蒸散率上升;而當角質層通透性增加到一定程度時,二氧化碳固定效率達飽和。此外,透過反向遺傳學篩選候選基因,研究特定基因對角質層合成及光合作用效率的影響。突變株分析顯示,抑制控制角質層或氣孔的基因會促進另一性狀的表現,未來可進一步探討自然族群中相關基因的功能。

花容失色-鳳凰花的旗瓣為何會先凋零?

鳳凰木的花朵擁有五片花瓣,上方花瓣與其他紅色花瓣不同,是白色底紅色斑點,根據文獻,這片花瓣稱為旗瓣,功能是作為蜜標來吸引傳粉者。研究觀察發現鳳凰花的旗瓣會先捲曲凋零,和蜜標存在的功能互相矛盾,本組推論與環境、授粉有關連。經研究發現,旗瓣凋零與生長環境、花粉及花蜜是否被採集無關,與授粉方式有關。異株授粉導致旗瓣凋零的時間提前;同株異花授粉旗瓣凋零的時間與自然狀態相近;自花授粉、無授粉則導致旗瓣凋零的時間延後。異株授粉對鳳凰花而言是有效且成功的授粉,會導致旗瓣提早凋零,蜜標隱藏,提高其他尚未有效授粉花朵成功授粉的機會,並且產生成熟的種莢。無效的授粉會導致旗瓣凋零時間延後,藉此等待有效的授粉機會。

高山生態群聚植物集中開花與昆蟲交互作用網絡之研究

本研究首度以植物學、花粉學、昆蟲學及生態統計學探討臺灣高山傳粉生態網絡。花季中期以蜂類為主,後期為蠅類。昆蟲及植物交互網絡緊密連結無子群體,仰賴優勢物種支撐。蜂期為高山薔薇、玉山櫻草、貓兒菊、信義雄蜂;蠅期為一枝黃花、貓兒菊、家蠅。此兩期昆蟲與植物的穩健性不足,蠅期更易崩解。蜂類訪花具多樣性,蠅類訪花較專一。因蜂類、蠅類習性與身體特徵不相同,蠅類對花展幅 (Visit Unit)大、花冠筒淺、花冠筒筒徑小、還原糖含量高、花粉及花蜜之間的距離大、柱頭面積小的植物較能專一攜帶其花粉。共用傳粉者帶來異種花粉,以GLMM分析同異種花粉數量變化關係,發現一起開花略助於授粉。貓兒菊已入侵成為優勢物種,花粉汙染90%的物種,必須移除。

羽轉綠肥-自製肥料對蔬果生長的影響

羽毛廢棄物是畜產類廢棄物排名第二大宗,為了提高廢棄羽毛的實用價值與效益,我們利用啤酒酵母菌進行雞羽毛分解。經啤酒酵母分解一個月後的雞毛液肥,含有胺基酸濃度約為0.17 M,是市售肥組的5.67倍。以雞毛液肥灌溉高經濟價值的彩椒及福山萵苣,彩椒果實總質量比市售肥組高出84.6%,果實中含有葡萄糖濃度為23.8%,比市售肥組多出49.7%。碘量法的抗氧化能力試驗中,發現雞毛液肥灌溉的彩椒抗氧化能力比市售肥組高出91.3 %。清除DPPH自由基的能力實驗中,雞毛液肥組的彩椒果實汁液清除自由基能力約是市售肥組的2.82倍。雞毛液肥灌溉的福山萵苣的葉片總質量比市售肥組多出116.2%。可以發現啤酒酵母分解的雞毛液肥,確實可取代市售肥料,當作彩椒及福山萵苣的養分。希望藉此研究能將廢棄雞毛再利用,減少環境負擔,讓農業永續發展。

水蕨孢子的發芽及打破休眠機制

水蕨(Ceratopteris thalictroides)為台灣本土常見的水生蕨類,亦為觀察植物生活史的絕佳教材。然而發現秋季採集的水蕨孢子具有明顯的休眠現象,因此本研究旨在探討水蕨孢子的休眠現象與機制,以及成熟度、低溫儲存、吉貝素及光照等因素對於水蕨孢子發芽的影響。研究發現,孢子的休眠現象與成熟度具有顯著相關性,並且可以藉由低溫儲存有效打破休眠狀態。適當濃度的吉貝素則可以有效逆轉離層酸對於水蕨孢子發芽的抑制作用,並促進孢子發芽。針對光照處理,結果發現藍強光及紅光能顯著提升孢子發芽率,藍弱光則無,而遠紅光則具有拮抗紅光的效果,此驗證了光敏素對於水蕨孢子發芽的調節機制,此外也發現於不同光照處理間需存在一定時間的黑暗間期,使光敏素進行轉換。本研究對於水蕨孢子採集與培養之條件,可提供培養水蕨時的參考,未來期望能應用於其他蕨類植物的培養與復育。

探討候選基因對角質層與氣孔發育的調控之影響

植物進化成陸生植物的過程中,氣孔和角質層是關鍵特徵。氣孔由保衛細胞調控,負責二氧化碳進入和水分蒸發;角質層則保護植物免受水分流失及環境壓力。調控這些特徵的基因尚不明確。本研究利用全基因組關聯分析(GWAS)探討阿拉伯芥的角質層和氣孔發育。GWAS結果顯示,與角質層厚度相關的基因位於第二條染色體,而與二氧化碳吸收效率相關的基因位於第五條染色體。氣孔導度和水分吸收效率的調控基因可能在第一、三、四條染色體上。角質層變薄時,氣孔密度下降,導致氣孔導度和水分蒸散率上升;而當角質層通透性增加到一定程度時,二氧化碳固定效率達飽和。此外,透過反向遺傳學篩選候選基因,研究特定基因對角質層合成及光合作用效率的影響。突變株分析顯示,抑制控制角質層或氣孔的基因會促進另一性狀的表現,未來可進一步探討自然族群中相關基因的功能。

蔗糖、葡萄糖及果糖對阿拉伯芥幼苗 防禦基因PR1表現的影響

本研究藉由觀察不同濃度及種類的糖對 pPR1:GUS 轉殖株的影響,探討糖是否可以作為植物的危險信號,進而觸發植物的防禦系統。我們推測蔗糖環境濃度 0.5%、1%、2%及果糖濃度 6%時可以促進植物的防禦機制。我們認為可能是植物偏好蔗糖,所以發展出使用蔗糖作為危險信號。然而,在感病實驗中,我們卻發現使用 2%蔗糖條件處理植物根部及葉片,並不會增加植物的抗病性。

空氣鳳梨毛狀體降低空汙之探討與應用

本研究主要是探討空氣鳳梨葉子作為清淨環境空氣和降低 PM2.5 濃度以及物理性微粒的功能。為了解空氣鳳梨的吸附能力,我們先測量空氣鳳梨的滯塵能力,發現高居室內植物滯塵能力第二名:其次是測量植株能否降低線香微粒濃度,發現其葉片具有減少懸浮微粒的能力,顯示其具有空氣淨化效果;猜測上述能力應與毛狀體結構有關,於是著手測量去毛後的吸附能力,得知毛狀體是影響吸附能力的關鍵。接著我們學習 Image J 操作,進一步了解空氣鳳梨在各部位的吸收能力及運送途徑。透過數位化影像分析,推測微粒的路徑為葉基→葉中→葉尖。最後比較了吸附微粒後的植株與對照組的抗氧化能力,發現實驗組明顯降低,說明微粒會對空氣鳳梨造成氧化壓力並影響生理代謝。