柑橘多胚性砧木枳橙同源四倍体的发掘与SSR鉴定

Excavation and SSR Identification of Autotetraploids in Citrus Polyembryonic Rootstock‘Citrange’

为发掘枳橙同源四倍体资源,从而为柑橘砧木遗传改良提供新种质,本研究通过初步的形态学观察,从具多胚性的柑橘重要砧木资源枳橙实生苗群体750个单株中初步筛选出具典型多倍体特征的植株24株,其中流式细胞仪鉴定为枳橙四倍体22株,群体四倍体自然发生率达2.93%。下表皮气孔分析表明枳橙四倍体气孔密度显著低于二倍体对照。对获得的四倍体植株进行了SSR分子鉴定,19对引物扩增结果均显示枳橙四倍体与其二倍体对照的带型完全一致,表明获得的四倍体枳橙均为同源四倍体。本研究表明将形态学初选与流式细胞仪快速鉴定及SSR分析相结合是从多胚性柑橘资源实生群体获得同源四倍体的简便有效途径,本研究发掘的同源四倍体枳橙是柑橘砧木遗传改良相关研究的良好资源。

To find autotetraploid plants from seedling progenies of citrange,and to provide materials for genetic improvemnet in citrus rootstocks,24 suspected plants were screened from the seedling population of citrange,an important citrus polyembryony rootstock,according to tetraploid-like morphological phenotype.Flow cytometry method was used to detect the chromosome ploidy of the preliminarily selected plants and 22 tetraploids of citrange were ultimately identified.The stomata density of the tetraploids was significantly lower than that of the diploids at 0.01 level.19 pairs of SSR primers were further applied to identify the origin of these tetraploid plants.The result indicated that the band profiles of the tetroploids were identical to the diploid maternal line,which validated that these tetroploids should be all autotetraploids.This study indicated that it is a simple and effective method to find autotetroploids from the seeding population of citrus polyembryony germplasm based on phenotype preselection combined with flow cytometry identification and SSR analysis.The autotetroploids of citrange obtained hold great significance to citrus rootstock germplasm improvement.