关键词: 梨, 矮生性状, β–微管蛋白, 基因结构, 转录水平

Abstract: Using the β-tubulins of Arabidopsis as references，9 β-tubulin genes were identified from the Pyrus communis genome. These genes were mapped in the corresponding chromosomes based on the principle of conservation and collinearity between the genomes of apple and pear. Sequence analysis showed that each of these genes contain 3 exons and 2 introns. For the genes located in the pair of chromosomes which originated from the genome wide duplication in evolution，the lengths of exons and introns are more conserved，and their coding sequences of amino-acid residues are with higher similarity. The result of qRT-PCR showed that，7 out of the 9 β-tubulin genes expressed normally in the tissue of stem tips. Among them，the transcriptional level of the gene with the transcript number of PCP044487.1，mapped in chromosome 16，is significantly different at P ≤ 0.01 between the dwarf type and the standard type pears stem tips，which suggested that this gene probably related to molecular regulation of the dwarf trait formation.

Key words: pear, dwarf trait, β-tubulin, gene structure, transcriptional level