Effects of ratoon stunting disease on growth and endogenous hormone in sugarcane | 宿根矮化病菌对甘蔗生长和内源激素的影响

صينى. 甘蔗宿根矮化病（ratoon stunting disease, RSD）是由Leifsonia xyli subsp.xyli引起的病害。为研究该病对甘蔗的生长和内源激素的影响，选择2个甘蔗品种新台糖22号（ROC22）和果蔗（Badila），采用桶栽种植分别进行3个处理：感染RSD病菌蔗株进行52℃温汤脱菌处理30 min、感染RSD病菌蔗株、健康蔗株（对照），在出苗后90、120、150、180 d测定株高和内源激素的含量，并利用PCR检测确定感病和健康蔗株。结果表明：感染RSD病菌蔗株的株高显著低于对照和温汤脱菌处理；感染RSD病菌处理植株的赤霉素（GA3）、生长素（IAA）含量明显低于对照和温汤脱菌处理，而脱落酸（ABA）含量则相反，感染RSD病菌处理的ABA含量明显高于对照和温汤脱菌处理；对照和温汤脱菌处理的株高和激素含量差异不显著。

إنجليزي. Ratoon stunting disease (RSD) of sugarcane (Sacchrum spp. Hyb.), caused by bacterium Leifsonia xyli subsp, xyli (Lxx), is one of the most important economically damaging diseases worldwide. The objective of the present study was to determine the effects of RSD on plant growth and the endogenous hormone levels in sugar cane stalks. Two mechanical cane varieties (i. e. sugar cane variety of ROC22 and chewing cane variety of Badila) were selected as the plant materials and RSD infection was determined by using PCR reaction. The seed canes were grown in pots, and three treatments were done: pathogen-free seed canes as control; seed canes with thermal treatment: RSD infected seed canes were treated at 52℃ for 30 min; RSD infected seed canes. During the experiment, the plant heights were investigated, and the endogenous hormone levels in cane stalks were analyzed after planting in 90, 120, 150 and 180 d, respectively. The results showed that, the plant heights of the RSD infected seed canes were significantly lower than those of the control and the thermal treatment. The contents of GA3 and IAA were obviously lower in the RSD infected seed canes than those in the control and the thermal treatment in contrast to the content of ABA which was higher in the infected seed cane treatment as compared with the control and the thermal treatment; two cane varieties showed the same patterns and there was no significant difference between the control and the thermal treatment in plant height and endogenous hormone levels. Therefore, the thermal therapy is efficient to control RSD in sugar cane.