氮肥與激勃素對草莓植株及走莖生長之影響

Effects of Nitrogen Fertilization and Gibberellic Acid on Plant Growth and Runner Development in Strawberry

本研究測試氮肥濃度與激勃素（GA3）之添加對‘豐香’草莓植株與走莖生長之影響。盆栽草莓苗使用0（CK）、2000、3000、4000 mg•L^(-1)硝酸銨液做為氮肥，一組添加50 mg•L^(-1)GA3而另一組不添加，共成八種處理。結果增施氮肥處理可增加草莓植株葉數、葉面積、冠莖直徑、地上部鮮、乾重與走莖苗（ramet）數量，但過高的硝酸銨濃度（4000 mg•L^(-1)）會抑制根部生長發育，而且走莖長度隨著氮肥濃度的增加而降低。無論氮肥濃度高低，添加GA3均可提高草莓植株之生長與走莖長度。在較低硝酸銨濃度（2000 mg•L^(-1)）處理下GA3增大植株的葉片、增加地上部鮮重與乾重、增加走莖數與走莖苗之生長。添加GA3可提高草莓植株與走莖苗之蛋白質含量，也增加低氮肥處理組之可溶性碳水化合物累積。顯示GA3的添加，可促進草莓植株對氮素的利用，進而促進草莓種苗生長。 The effect of nitrogen and gibberellic acid (GA3) application on plant growth and runner development in 'Toyonoka' strawberry was studied. Potted young strawberry plants were given 0 (CK), 2000, 3000 or 4000 mg•L^(-1) ammonium nitrate with or without an addition of 50 mg•L^(-1) GA3. The leaf number, leaf area, crown diameter, shoot fresh and dry weights of the plants as well as the number of ramets increased as nitrogen concentration increased. However, excessive nitrogen (4000 mg•L^(-1) ammonium nitrate) inhibited the plant's root growth and reduced the length of runners. Application of GA3 promoted plant growth and runner elongation. Under the low nitrogen (2000 mg•L^(-1)) condition, GA3 increased the leaf area, biomass, number of runners, and the growth of ramets. GA3 also increased soluble carbohydrate and protein contents of the plants. GA3 seemed to have enhanced the plant's nitrogen-use efficiency, thus promoted plant growth and runner development of the strawberry.