Division of Plant Breeding, Genetics and Biotechnology, International Rice Research Institute, Manila, Philippines.
Rice (N Y). 2013 May 6;6(1):11. doi: 10.1186/1939-8433-6-11.
This article describes the development of Multi-parent Advanced Generation Inter-Cross populations (MAGIC) in rice and discusses potential applications for mapping quantitative trait loci (QTLs) and for rice varietal development. We have developed 4 multi-parent populations: indica MAGIC (8 indica parents); MAGIC plus (8 indica parents with two additional rounds of 8-way F1 inter-crossing); japonica MAGIC (8 japonica parents); and Global MAGIC (16 parents - 8 indica and 8 japonica). The parents used in creating these populations are improved varieties with desirable traits for biotic and abiotic stress tolerance, yield, and grain quality. The purpose is to fine map QTLs for multiple traits and to directly and indirectly use the highly recombined lines in breeding programs. These MAGIC populations provide a useful germplasm resource with diverse allelic combinations to be exploited by the rice community.
The indica MAGIC population is the most advanced of the MAGIC populations developed thus far and comprises 1328 lines produced by single seed descent (SSD). At the S4 stage of SSD a subset (200 lines) of this population was genotyped using a genotyping-by-sequencing (GBS) approach and was phenotyped for multiple traits, including: blast and bacterial blight resistance, salinity and submergence tolerance, and grain quality. Genome-wide association mapping identified several known major genes and QTLs including Sub1 associated with submergence tolerance and Xa4 and xa5 associated with resistance to bacterial blight. Moreover, the genome-wide association study (GWAS) results also identified potentially novel loci associated with essential traits for rice improvement.
The MAGIC populations serve a dual purpose: permanent mapping populations for precise QTL mapping and for direct and indirect use in variety development. Unlike a set of naturally diverse germplasm, this population is tailor-made for breeders with a combination of useful traits derived from multiple elite breeding lines. The MAGIC populations also present opportunities for studying the interactions of genome introgressions and chromosomal recombination.
本文描述了水稻多亲本高级世代互交群体（MAGIC）的发展，并讨论了其在定位数量性状基因座（QTL）和水稻品种开发方面的潜在应用。我们已经开发了 4 个多亲本群体：籼稻 MAGIC（8 个籼稻亲本）；MAGIC plus（8 个籼稻亲本，外加两轮 8 向 F1 杂交）；粳稻 MAGIC（8 个粳稻亲本）；和全球 MAGIC（16 个亲本-8 个籼稻和 8 个粳稻）。创建这些群体所使用的亲本是具有生物和非生物胁迫耐受性、产量和谷物品质等理想性状的改良品种。其目的是对多个性状进行精细定位，并直接和间接利用高度重组的系在育成计划中。这些 MAGIC 群体为水稻社区提供了一个有用的遗传资源，其中包含了各种等位基因组合。
籼稻 MAGIC 群体是迄今为止开发的 MAGIC 群体中最先进的群体，由通过单粒传代（SSD）产生的 1328 个系组成。在 SSD 的 S4 阶段，该群体的一个子集（200 个系）使用基于测序的基因型分析（GBS）方法进行了基因型分析，并对多个性状进行了表型分析，包括：稻瘟病和细菌性条斑病抗性、耐盐性和耐淹性以及谷物品质。全基因组关联作图鉴定了一些已知的主要基因和 QTL，包括与耐淹性相关的 Sub1 以及与细菌性条斑病抗性相关的 Xa4 和 xa5。此外，全基因组关联研究（GWAS）的结果还鉴定了与水稻改良相关的潜在新的与关键性状相关的基因座。
MAGIC 群体具有双重用途：用于精确 QTL 作图的永久作图群体，以及直接和间接用于品种开发。与一组自然多样化的种质资源不同，该群体是为具有多种来自多个优秀育成系的有用性状的育种者量身定制的。MAGIC 群体也为研究基因组渗入和染色体重组的相互作用提供了机会。
