以機械模擬熊蜂振動行為評估番茄受粉成效

Abstract

大部分的作物都需要昆蟲授粉，其中以蜜蜂為最常見的授粉昆蟲。然而，部分作物像是番茄或藍莓等，就必須依賴熊蜂或木蜂等昆蟲藉由產生特殊的振動頻率，使作物釋出花粉而授粉。人工繁殖的歐洲熊蜂經常被用來為溫室內的作物授粉，但對本土生態有潛在的威脅，而本土熊蜂的價格較高且活動受環境溫度影響，因此尋找替代且穩定的授粉方式是必要的。本研究目的為（1）利用機器模擬熊蜂的振動，測試番茄花釋出花粉的最佳振動頻率；（2）使用此最佳頻率在有機溫室進行番茄授粉，搭配不同的振動操作次數與模擬熊蜂授粉傷口，與熊蜂授粉後的著果率與果實品質做比較。研究結果顯示，500, 700, 800 與 900 Hz可以從番茄花中振出最多花粉粒，且振動時間並不會影響花粉粒數量。在田間試驗中，利用機械授粉振動單次的種子數量與著果率都顯著低於熊蜂授粉組，但一些機械授粉組別和熊蜂授粉有類似的番茄果實型質、甜度與酸度。提高機械授粉次數（振動一次增加為三次）後，不論是著果率、果實型質或風味都與熊蜂授粉組類似。人為模仿熊蜂在花藥錐所造成的授粉傷口並不會影響果實的型質特徵、甜度與酸度。本研究顯示機械授粉和熊蜂授粉的番茄果實品質相近；而增加振動次數後，可有效提升機械授粉的著果率，在未來氣候變遷或是授粉昆蟲減少的情況下，機械授粉應可提供有效且穩定的授粉方式。

Most crops need insects for pollination, with honey bees being the most common pollinators. However, crops like blueberry and tomato rely on bumble bees and carpenter bees, which use their flight muscles to produce specific vibrations to extract pollen from poricidal anthers. Commercial European bumble bees are commonly introduced to pollinate greenhouse crops, but they pose an invasive risk, and native bumble bee (Bombus eximius) is expensive and their activities could be influenced by ambient temperature. Therefore, developing artificial pollination methods for stable crop pollination is necessary. The study aims to: (1) use machine-mimicked bumble bee vibrations to determine the optimal vibration frequency for pollen release in tomato flowers; and (2) apply this optimal pollination frequency and duration, combined with different numbers of pollination and simulated bumble bee-induced scars, in an organic farming greenhouse to compare fruit set ratio and fruit quality between machine and bumble bee buzz pollination. The study showed that 500, 700, 800, and 900 Hz can release the most pollen grains from tomato flowers, and vibration duration does not affect the number of pollen grains released. In the field experiment, the seed number and fruit set ratio from single machine pollination were significantly lower than those from bumble bee pollination. However, some machine pollination groups showed similar tomato fruit morphology, sweetness, and acidity to bumble bee pollination. Increasing the number of machine pollinations from one to three times resulted in a fruit set ratio, fruit morphology and flavor similar to that of bumble bee pollination. Artificially mimicking scars on the anther cone did not affect fruit morphometrics, sweetness, or acidity. This study shows that machine pollination and bumble bee pollination produce fruits of similar quality, and increasing the number of vibrations effectively improves the fruit set ratio of machine pollination. In the future, machine pollination may provide an efficient and stable pollination method in the face of climate change and the decline of natural pollinators.