Meng Lijun, Wang Baoxiang, Zhao Xiangqian, Ponce Kimberly, Qian Qian, Ye Guoyou
CAAS-IRRI Joint Laboratory for Genomics-Assisted Germplasm Enhancement, Agricultural Genomics Institute in Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.
Rice Breeding Platform, International Rice Research Institute, Metro Manila, Philippines.
Front Plant Sci. 2017 Oct 26;8:1822. doi: 10.3389/fpls.2017.01822. eCollection 2017.
Excessive amounts of metal are toxic and severely affect plant growth and development. Understanding the genetic control of metal tolerance is crucial to improve rice resistance to Fe, Zn, and Al toxicity. The multi-parent advanced generation inter-cross (MAGIC) populations were genotyped using a 55 K rice SNP array and screened at the seedling stage for Fe, Zn, and Al toxicity using a hydroponics system. Association analysis was conducted by implementing a mixed linear model (MLM) for each of the five MAGIC populations double cross DC1 (founders were SAGC-08, HHZ5-SAL9-Y3-Y1, BP1976B-2-3-7-TB-1-1, PR33282-B-8-1-1-1-1-1), double cross DC2 (founders of double cross were FFZ1, CT 16658-5-2-2SR-2-3-6MP, IR 68, IR 02A127), eight parents population 8way (founders were SAGC-08, HHZ5-SAL9-Y3-Y1, BP1976B-2-3-7-TB-1-1, PR33282-B-8-1-1-1-1-1, FFZ1, CT 16658-5-2-2SR-2-3-6MP, IR 68, IR 02A127), DC12 (DC1+DC2) and rice multi-parent recombinant inbred line population RMPRIL (DC1+DC2+8way). A total of 21, 30, and 21 QTL were identified for Fe, Zn, and Al toxicity tolerance, respectively. For multi tolerance (MT) as Fe, Zn, and Al tolerance-related traits, three genomic regions, MT1.1 (chr.1: 35.4-36.3 Mb), MT1.2 (chr.1: 35.4-36.3 Mb), and MT3.2 (chr.3: 35.4-36.2 Mb) harbored QTL. The chromosomal regions MT2.1 (chr.2: 2.4-2.8 Mb), MT2.2 (chr.2: 24.5-25.8 Mb), MT4 (chr.4: 1.2 Mb Mb), MT8.1 (chr.8: 0.7-0.9 Mb), and MT8.2 (chr.8: 2.2-2.4 Mb) harbored QTL for Fe and Zn tolerance, while MT2.3 (chr.2: 30.5-31.6 Mb), MT3.1 (chr.3: 12.5-12.8 Mb), and MT6 (chr.6: 2.0-3.0 Mb) possessed QTL for Al and Zn tolerance. The chromosomal region MT9.1 (chr.9: 14.2-14.7 Mb) possessed QTL for Fe and Al tolerance. A total of 11 QTL were detected across different MAGIC populations and 12 clustered regions were detected under different metal conditions, suggesting that these genomic regions might constitute valuable regions for further marker-assisted selection (MAS) in breeding programs.
过量的金属具有毒性，会严重影响植物的生长和发育。了解金属耐受性的遗传控制对于提高水稻对铁、锌和铝毒性的抗性至关重要。利用55K水稻SNP阵列对多亲本高世代杂交（MAGIC）群体进行基因分型，并在幼苗期使用水培系统筛选铁、锌和铝毒性。通过对五个MAGIC群体双交DC1（亲本为SAGC - 08、HHZ5 - SAL9 - Y3 - Y1、BP1976B - 2 - 3 - 7 - TB - 1 - 1、PR33282 - B - 8 - 1 - 1 - 1 - 1 - 1）、双交DC2（双交亲本为FFZ1、CT 16658 - 5 - 2 - 2SR - 2 - 3 - 6MP、IR 68、IR 02A127）、八亲本群体8way（亲本为SAGC - 08、HHZ5 - SAL确N9 - Y3 - Y1、BP1976B - 2 - 3 - 7 - TB - 1 - 1、PR33282 - B - 8 - 1 - 1 - 1 - 1 - 1、FFZ1、CT 16658 - 5 - 2 - 2SR - 2 - 3 - 6MP、IR 68、IR 02A127）、DC12（DC1 + DC2）和水稻多亲本重组自交系群体RMPRIL（DC1 + DC2 + 8way）实施混合线性模型（MLM）进行关联分析。分别鉴定出21个、30个和21个与铁、锌和铝毒性耐受性相关的数量性状基因座（QTL）。对于作为铁、锌和铝耐受性相关性状的多重耐受性（MT），三个基因组区域MT1.1（第1染色体：35.4 - 36.3 Mb）、MT1.2（第1染色体：35.4 - 36.3 Mb）和MT3.2（第3染色体：35.4 - 36.2 Mb）含有QTL。染色体区域MT2.1（第2染色体：2.4 - 2.8 Mb）、MT2.2（第2染色体：24.5 - 25.8 Mb）、MT4（第4染色体：1.2 Mb）、MT8.1（第8染色体：0.7 - 0.9 Mb）和MT8.2（第8染色体：2.2 - 2.4 Mb）含有铁和锌耐受性的QTL，而MT2.3（第2染色体：30.5 - 31.6 Mb）、MT3.1（第3染色体：12.5 - 12.8 Mb）和MT6（第6染色体：2.0 - 3.0 Mb）具有铝和锌耐受性的QTL。染色体区域MT9.1（第9染色体：14.2 - 14.7 Mb）具有铁和铝耐受性的QTL。在不同的MAGIC群体中总共检测到11个QTL，在不同的金属条件下检测到12个聚类区域，这表明这些基因组区域可能构成育种计划中进一步进行标记辅助选择（MAS）的有价值区域。
