借助细胞流式仪进行枇杷基因组学测序材料的倍性鉴定

Ploidy identification of loquats for genome sequencing project by flow cytometry

利用流式细胞仪进行测试枇杷品种的染色体倍数鉴定,并用低深度测序结果进行验证,据此为选择枇杷全基因组测序材料提供依据。结果表明,来自华南农业大学种质资源圃和四川石棉的‘大五星’均与‘解放钟’一样为二倍体,而来自四川农业大学的两份‘大五星’枇杷1号和188号材料均为三倍体。测序结果显示,来自华南农业大学资源圃的‘解放钟’枇杷为二倍体,773 Mb;而来自四川农大的‘大五星’枇杷1号和188号可能都为三倍体,基因组大小分别为749 Mb和765 Mb。以已确定基因组大小的植物萝卜、番茄和大豆为参照测定了‘解放钟’枇杷的基因组大小,结果为654.399 Mb。

In order to screen a suitable material for the loquat genome sequencing project, some loquat varieties （＇Dawuxing＇ and ＇Jiefangzhong＇ from SCAU Germplasm Resources Repository, ＇ Dawuxing＇ from Shimian, Sichuan, ＇Dawuxing No. 1 ＇and ＇Dawuxing No. 188＇ from Sichuan Agricultural Universi- ty） were tested. The flow cytometry was used to obtain some loquat genome information, including ploidy identification and genome size. Then the results were examined by the high-throughput and low-depth sequencing. The flow cytometry results showed that both ＇Dawuxing＇ from SCAU and Shimian, Sichuan are diploid as ＇Jiefangzhong＇ ,while ＇Dawuxing No.1 ＇and ＇Dawuxing No.188＇ are triploid. The highthroughput and low-depth sequencing results showed that ＇Jiefangzhong＇ is diploid with a 773 Mb genome size, both ＇Dawuxing No.1 ＇and ＇Dawuxing No.188＇ are probably triploid,their genome sizes are 749 Mb and 765 Mb respectively. These two different methods got the similar results, which indicated that the flow eytometry is a reliable method for ploidy identification in loquat varieties. Finally, according to the results, ＇Jiefangzhong＇ was selected as the material for the loquat genome sequencing project. Besides, the nuclear DNA content of ＇ Jiefangzhong＇ is tested by the use of flow cytometry with the standard reference genome , including Raphanus sativus L. ＇ Saxa＇ （2C= 1.1 lpg）, Solanum lycopersicum L. ＇ Stupicke polni tyckove rane＇ （2C=1.96 pg） and Glycine max L. Merr （2C=2.50 pg）. Its estimated genome size was 654.399 Mb （1C）.