Lxx侵染甘蔗后在蔗茎中的积累及对蔗茎组织结构的影响

以接种病原菌 Leifsonia xyli subsp. Xyli（Lxx）的‘拔地拉’（‘Badila’）甘蔗为研究材料,利用实时定量PCR技术研究病原菌Lxx在蔗茎中的积累情况,采用半薄切片技术研究茎维管束的病变规律。结果表明,在接种Lxx的Badila中,Lxx菌量积累随蔗茎由基层到尾层呈现递减趋势。半薄切片结果表明,接种Lxx蔗茎基部维管组织中的韧皮部和木质部损坏严重,甘蔗茎节处相对茎间的基本细胞小得多,且具有木质部异形、细胞大小不一、细胞整体较为密集。接种Lxx蔗茎维管组织中的韧皮部和木质部损坏程度与Lxx菌量分布呈正相关。甘蔗茎节与茎间的组织结构差异是Lxx菌量由基层到尾层呈现递减的原因之一。本研究为进一步研究Lxx与甘蔗寄主的互作提供了理论依据。

Accumulation of Lxx in Infected Sugarcane Stem and Its Effect on Structure of Sugarcane Stem

Sugarcane variety ‘Badila’ which infected with Leifsonia xyli subsp. xyli (Lxx) was used as the materials in this research. The accumulation of Lxx in sugarcane stems was studied by real-time qPCR. And the pathological changes of vascular bundle of stems were studied by the semi-thin section technique. The results showed that the accumulation of Lxx decreased from the base layer to the tail layer in ‘Badila’. Severe damage to phloem and xylem in the vascular tissue of the base of sugarcane stems. The basal cells between the stem nodes were much smaller than those between the stems. The xylem was heteromorphism, the cell of xylem was different in size and arranged tightly. The damage of phloem and xylem in the vascular tissue of sugarcane stem infected with Lxx was positively correlated with the distribution of Lxx. It was speculated that the structure difference between the stem node and stem was one of the reasons why the quantity of Lxx decreased from the base layer to the tail layer. It would provide a theoretical basis for the further study of the interaction between bacterial of Lxx and sugarcane hosts.