Forchlorfenuron促進設施栽培網紋甜瓜著果及果實發育

Application of Forchlorfenuron Enhances Fruit Setting and Growth of Muskmelon (Cucumis meloL.) Cultivated in Greenhouse

設施甜瓜（Cucumis meloL.）生產高度依賴授粉，極端的氣溫或光線不足不僅會降低授粉昆蟲訪花的頻率，亦會降低花粉的活力，導致授粉效率不佳。本研究評估苯基脲細胞分裂素[Forchlorfenuron, N-（2-chloro-4-pyridinyl-N‘-phenylurea, CPPU]對網紋甜瓜（var. reticulatusNaud.）著果和果實發育的影響，為生產者提供新的管理策略。與僅使用人工授粉的甜瓜相比，無論是人工授粉（AP）還是未授粉（NP），5 mg·L-1 CPPU在開花前一天（T1）、開花當天（T2）和開花後一天（T3）施用可提高6.4%-11.7%的著果率，同時也誘導了NP果實不稔實種子產生，呈現單偽結果的趨勢。著果率最高的情況發生在AP+T1，NP條件下CPPU三處理時間則無差異，著果率皆超過98%，畸形果率則分別從73.7%降低至48.6%和46.9%。隨著外源CPPU施用濃度增加果重顯著提升，NP+10 mg·L-1CPPU處理果重達1,013.2 g，甚至超過AP處理果實組，果腔比例由49.1%降至18.6%-24.2%，果肉厚度在不同濃度處理下從3.0 cm增加到4.2 cm。在食味品質方面，總可溶性固形物（total soluble solid, TSS）累積量於施用時間或濃度處理並未表現一致性的結果，然綜觀CPPU處理之AP和NP果實在成熟採收期葫蘆素B降低至2.1-3.6 mg·L-1。

Melon (Cucumis meloL.) production under greenhouse relies highly on pollination. Extreme temperature or insufficient light not only reduces flower visiting bypollinators but also lower pollen viability resulting in poor pollination. Forchlorfenuron [N-(2-Chloro-4-pyridyl)-N’-phenylurea, CPPU], a phenyl urea-cytokinin, was evaluated for its effect on fruit set and fruit development of muskmelon (C. meloL. Cantaloupensis group) in the present study. It is expected to provide a new management strategy for growers. Compared to fruit set by hand pollination (CK), 5 mg·L-1CPPU applied on one day before (T1), the day (T2), and one day after flowering (T3) whether accompanied with artificial pollination (AP) either or no pollination (NP) increased fruit set rate by 6.4%-11.7%. CPPU treatment tended to induce parthenocarpic fruit with the presence of unfertilized seed. The best fruiting rate was obtained in AP+T1 whilethree CPPU-sprayed timing in NP group are close all up to 98% approximately, then decreasing abnormal rates from 73.7% to 48.6% and 46.9%, respectively. Elevated exogenous CPPU concentration obviously increased fruit weight, NP+10 mg·L-1CPPU treated fruit had the heaviest fruit weight 1013.2 g which was even greater than AP. It resulted in a smaller cavity ratio from 49.1% to 18.6%-24.2% and thickened pulp from 3.0 cm to 4.2 cm. Regarding to taste quality, no consistent results were observed on total soluble solid (TSS) accumulation in CPPU treatment of varying application time and concentrations. However, cucurbitacin B contents dropped to 2.1-3.6 mg·L-1among both CPPU-treated AP and NP fruits at harvest maturity.