Factors influencing the occurrence and development of rhizoid and protocorm-like body in rosa spp. | 蔷薇属植物类根体和类原球茎发生发育的影响因子

Chinese. 目的以多种蔷薇属植物的叶片为外植体，研究影响类根体和类原球茎发生发育的影响因子，为进一步揭示类根体和类原球茎发生发育的机理及蔷薇属植物分子育种奠定基础。方法在MS基本培养基上，通过改变植物生长调节剂种类、浓度、培养条件和类根体与愈伤组织的完整性来观察并统计类根体和类原球茎发生发育情况。结果类根体的发生受生长素类调控，3种不同结构类型的生长素类物质诱导的类根体在数量和质量存在差异，其中2,4-D对类根体的诱导效应最明显，IBA次之，NAA最差，细胞分裂素不能诱导类根体的形成；形成高质量的类根体暗培养和是必需条件，与光暗培养差异极显著，类根体的发生率和每个外植体类根体数存在差异；相反，类根体发育成类原球茎必需有光照的参与，暗培养的类根体不能变绿、膨大并最终发育成类原球茎,TDZ和光照在类根体发育成类原球茎的过程中具有协同作用；被从顶部截去1/3长度的类根体仍然可以变绿并发育为类原球茎；相反，将类根体从愈伤组织直接剪下，无论直插还是平放，类根体都不能变绿发育成类原球茎，而是逐渐变褐死亡。结论生长素类物质控制类根体的发生具有普遍性，但形成的类根体在数量和质量上存在差异；光照抑制类根体的发生但可以促进类原球茎的产生，光照和TDZ在类根体发育成类原球茎过程中具有协同作用；类根体先端不是形成类原球茎的必需条件而下部组织的完整性是必不可少的。

English. Objective Leaf explants of multiple species of Rosa spp. were used for investigation of the factors influencing the occurrence and development of rhizoid and protocorm-like body in this paper，which can lay a foundation for revealing the occurrence mechanism of PLB and molecular breeding. Method The growth of rhizoid and protocorm-like body were observed and statistics were made by changing the medium components, different growth regulators and their concentrations, culture conditions and the integrity of the rhizoid on the Murashige and Skoog (MS) medium.ResultThe results showed that the occurrence and size of the rhizoid was different depending on the type of auxin, but not cytokinin. Rhizoid could be induced from leaf explants of Rosa spp. on the Murashige and Skoog (MS) medium containing any type of the three auxins. On the other hand, rhizoid could be induced from the leaf explants only in dark, however, this process was significantly suppressed under light condition. On the contrary, lighting promoted the matured rhizoid turning green and developed into protocorm-like body(PLB), but this process did not happen under dark condition and light-dark condition without TDZ. Cutting part of the matured rhizoid from the top, the rhizoid could also develop into PLBs, whereas, the rhizoid cut from the callus surface, couldn’t grow into PLBs, but rather turn brown and died, whether they were placed horizontally or vertically. This indicated that the tip of the rhizoid was not essential for the PLBs formation, but the bottom of rhizoid was vitally important for TDZ absorption, loss of the callus on the rhizoid bottom affected the absorption and transportation of TDZ, and further, the development of the protocorm-like body was suppressed. Conclusion This method is of universality for the rhizoid induced by auxin. Lighting is a inhibitor for the occurrence of the rhizoid but a promoting factor for the information of the PLB, lighting and TDZ has a synergistic action on the process of rhizoid developing into protocorm-like body. The tip of rhizoid is not the essential for the PLBs formation, but the bottom of rhizoid is very important for TDZ absorption.