国内外香稻资源遗传多样性研究

Genetic Diversity of Global Aromatic Rice Varieties

收集来源于16个国家和地区的345份香稻和89份非香材料开展了遗传多样性研究。利用分布于12条染色体上77对SSR标记，共检测出573个等位基因位点，多态信息含量（PIC）变幅为0．090～0．845，平均为0．516：基因多样性（GD）变幅为0．091～0．859，平均为0．573；主效等位基因频率（MAF）平均为0．540，变幅从0．251～0．953。聚类分析和群体结构分析将434份材料分成3个亚群，亚群与亚群间FST平均为-0．116，变幅从-0．623～0．494；据Nei’s方法计算的亚群间遗传距离从0．207～0．355；各亚群内的主效等位基因频率为0．408～0．746，基因多样性变幅为0．354～0．699，多态信息含量则从0．320～0．658。通过对18个水稻品种中的6个线粒体基因测序结果发现5个基因内不存在核苷酸的差异，仅Mit4中包含了3个SNP的两种基因型，可以作为反应籼粳分化与香味基因进化的重要功能标记。本研究较为系统地反映了不同香稻材料间以及与非香稻资源间的亲缘关系，为进一步了解国内外香稻种质资源和优质香稻育种提供了重要的参考依据。

Genetic diversity of 434 rice accessions collected from 16 countries, including 345 fragrance rice varieties and 89 non-fragrance rice varieties, have been analyzed. A total of 573 alleles were detected by using 77 simple se- quence repeats （SSR） primer pairs covering all rice 12 chromosomes. The value of allelic polymorphism information content （PIC） ranged from 0. 090 to 0. 845, with an average of 0. 516 per locus; Gene diversity （GD） varied from 0. 091 to 0. 859, with an average of 0. 573; The mean value of major allele frequencies （MAF） was 0. 540, covering from 0. 251 to 0. 953. In addition, 434 rice accessions are divided into three sub-populations by clnster and popula- tion structure analysis, and FST between sub-populations showed a mean of -0. 116, ranging from -0. 623 to 0. 494; The score of genetic distance calculated by Nei＇s method appeared from 0. 207 to 0. 355. Major allele frequencies within each sub-population distributed from 0. 408 to 0. 746, and gene diversity level from 0. 354 to 0. 699, while PIC from 0. 320 to 0. 658. Sequencing 6 mitochondrion genes in 18 rice varieties exhibited no different in 5 genes, whereas Mit4 contains a 3 SNPs in the gene body, which acts as an important marker to understanding the relation-ship between Irtdica/Japonica differentiation and the evolution of fragrant gene. Finally, genetic diversity and mito- chondrion gene sequencing would help to know about the origin of fragrant resource and benefit rice breeding.