甘薯根腐病菌侵染对甘薯内源激素水平的影响

甘薯根腐病病原菌Fusarium solani(Mart.)Sacc.f.sp.batatas McClure,简称FSB]侵染及其培养液滤液处理高敏感性甘薯品种‘胜利百号’后,引起甘薯叶片、茎尖和根部组织内源ABA含量大幅升高。其中在根部出现最早,但茎尖中积累浓度最高。侵染后甘薯叶片、茎尖和根部组织内源GA1/3含量显著低于对照。甘薯组培苗经FSB培养滤液处理9h后,ABA含量显著上升,处理15h,ABA含量呈下降趋势,而GA1/3含量在101和102稀释液处理15h(103稀释液处理12h)时出现显著上升。这些结果有助于解释甘薯根腐病株矮小不产生藤蔓,并在秋季大量现蕾开花的生理现象。

The Effect of Infection by Fusarium solani f. sp. batatas on Endogenous Hormone Levels in Sweet Potato Seedling

The endogenous hormone ABA concen- trations increased in the leaves, shoots and roots of sweet potato plants infected with Fusarium solani f. sp. batatas (FSB) or treated by its culture filtrate. The accumulation of ABA occurred firstly in the roots (Fig.4A), but the highest concentra- tion was in the shoots (Fig.3A). The endogenous GA1/3 concentration of leaves, shoots and roots of infected sweet potato kept at markedly low levels during the period of experiments (Figs.2B, 3B and 4B).The ABA concentration of sweet potato seed- lings increased observably after 9 h treatment with FSB culture filtrate, but decreased significantly after 15 h, and the GA1/3 concentration increased markedly after 15 h treatment with 101, 102 dilu-tion of FSB culture filtrate (after 12 h treatment with 103 dilution) (Fig.5). The disease symptoms may be induced by the changes in concentration of ABA and GA1/3 in the plants. The root rot-in- fected sweet potatoes grew upright without tailing, having aerial roots in knots near the ground, and were in full bloom in autumn.