中文摘要：

狗蔷薇不定根可被噻苯隆（TDZ）高效诱导形成类原球茎,深入探讨其诱导阶段的分子生物学机制,有利于指导切花月季建立类似高效再生和遗传转化体系。快速、准确克隆和筛选狗蔷薇类原球茎发生的关键基因是进行分子生物学水平研究的一个重要前提。利用苹果（Malus×domestica）、桃（Prunus persica）和草莓（Fragaria vesca）高同源性基因5＇UTR（非翻译区）的相对保守性,在其内保守区域设计上游简并引物,以M-MLV逆转录酶反转录合成cDNA为模板,直接扩增蔷薇科植物狗蔷薇（Rosa canina）RcPIN1（pin-formed）和RcPLT（plethora）基因5＇末端,大大减少了获取众多目的基因全长的时间及成本。结果显示,在狗蔷薇RcPIN1和RcPLT基因与其对应苹果、桃和草莓高同源性基因的5＇UTR内,很多区域表现出较高保守性,表明在5＇UTR相对保守区域设计上游简并引物扩增目的基因5＇末端的合理性。与常规5＇CDNA末端快速扩增技术（5＇RACE）相比,本方法无需对cDNA模板5＇末端加尾同聚物和引入锚定引物,即不必使用昂贵的5＇RACE试剂盒,具有快捷、节约等优点,是一种获取蔷薇科植物基因5＇末端的可行途径。

英文摘要：

Protocorm-like bodies （PLBs） can be efficiently induced by TDZ from Rosa canina rhizoids. More understandings on the molecular biological mechanism of PLBs induction contributes to the establishment of protocorm-like bodies protocols of cut roses. One important premise of the mechanism study in the molecular biological level is to quickly and accurately clone and screen the key genes during PLBs induction. On the basis of ＇conserved sequences＇ in 5′ untranslated regions（5′UTR） of homologous genes with high scores of Malus×domestica, Prunus persica and Fragaria vesca, we designed the forward degenerate primers to directly isolate the cDNA 5′ends of PIN1（pin-formed） and PLT（plethora） of R. canina by PCR amplification using the cDNA template catalyzed by M-MLV reverse transcriptase. The results showed that there were some conserved fragments in the 5′ rapid amplification of cDNA ends（5′UTR） of RcPIN1, RcPLT and their homologous genes with high scores of Malus×domestica, Fragaria vesca and Prunus persica, which indicated the above method was practicable. With this method, costly 5′RACE kits were entirely unnecessary because no homopolymer sequence and abridged anchor primers were to be introduced to the 5′ ends of cDNA template, for genes from plants of Rosacease family. As a result, this method took advantages of speediness and economy. It is believed that this method will be a practical pathway and worthy reference to identify cDNA 5′ends for some Rosaceae plants.