低気温貯蔵中における短期間ボトムヒート処理によるナス接ぎ木挿し穂の発根促進(繁殖・育苗)  [in Japanese] Short-term Bottom-heat Treatment during Low-air-temperature Storage Improves the Rooting of Eggplant Grafted-cuttings(Propagation & Transplant Production)  [in Japanese]

ナス接ぎ木挿し穂の低温(5-10℃)貯蔵中に挿し穂下端部を温水に浸けるボトムヒート(BH)処理を行うことで,挿し木後の発根促進を試みた.ナス台木(Solanum torvum Sw.)挿し穂の挿し木後における根の成長は,BH処理温度26-31℃で最も促進され,その効果はBH処理期間が長くなるほど大きくなる傾向がみられた.BH処理を5日間継続したところ,処理開始4日目において貯蔵中に発根する挿し穂がみられた.発根した挿し穂は,挿し木する際に根を痛める可能性があることから,最適BH処理期間は3日間程度と考えられた.ナス接ぎ木挿し穂を貯蔵開始直後に処理温度27℃でBH処理を3日間行った結果,挿し木14日後おいて,BH処理した挿し穂の根部生体重はBH処理しなかった挿し穂の1.4倍,貯蔵せず直接挿し木した挿し穂の2.8倍であり,BH処理の効果が認められた.

We investigated the effects of bottom-heat (BH) treatment during low-air-temperature (5-10℃) storage on the rooting of eggplant grafted-cuttings that were planted after storage. BH treatment was applied by holding the cut end of cuttings in warmed water. Root growth of cuttings following storage tended to be much improved by BH treatment temperatures ranging from 26 to 31℃. BH treatment should end just before rooting begins in order to avoid the inhibition of root growth caused by root damage during planting. In this study, optimal BH treatment duration is thought to be 3 days, because rooting during storage was observed 4 days after starting treatment when BH treatment was performed up to 5 days. BH treatment was applied to the grafted-cuttings for 3 days using a BH treatment temperature of 27℃ at the beginning of 14 days' storage. The cuttings stored with BH treatment were planted in the growing medium, and then grown for 14 days. Root fresh weight of the grafted plant obtained from cuttings that received BH treatment was 1.4 and 2.8 times greater than those that were stored without the treatment or not stored at all, respectively.