中文摘要：

利用NCBI数据库和蔷薇科基因组数据库中的数据对48个果实PG基因进行系统进化分析,结果表明3个进化支中都包含与果实软化相关的PG基因,属于A支和属于B支的PG基因有明显的功能差异。氨基酸序列分析显示,3个进化支中的PG基因存在多个差异位点,A支和C支PG基因的N端比B支短60~70个氨基酸。PG基因结构（包括启动子、内含子和编码区）的变异对其功能差异有重要影响。对苹果和桃的PG基因进行了基因组精确定位,其附近存在果实软化相关性状标记。

英文摘要：

Forty-eight PG genes were classified into three major clades by phylogenetic analysis and each clade contained PG genes that involved in fruit softening.PG genes belonged to clade A and clade B had functional divergence obviously.There were some different amino acid sites in amino acid sequence of PG genes from different clades.PG genes in clade A and clade C had a deletion of 60-70 amino acids in N terminal end compared with PG genes in clade B.Variation in the structure of PG genes（mainly including promoter regions,introns and encoding regions）had a significant impact on their functions.PG genes in apple and peach were accurately localized in genome respectively and around the genes there were some fruit softening markers.