Identification and characterization of quantitative trait loci affecting spikelet number per panicle in rice (Oryza sativa L.)
Identification and characterization of quantitative trait loci affecting spikelet number per panicle in rice (Oryza sativa L.)
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DOI：
10.1016/j.fcr.2004.02.004
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发表时间：
2004-10-08
影响因子：
5.8
通讯作者：
Khush, GS
中科院分区：
文献类型：
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作者：
Kobayashi, S;Fukuta, Y;Khush, GS
水稻(Oryza sativa L.)通过育种获得的产量需要很好地了解控制构成性状的遗传因素，如每穗小穗数(SN/PNN)。本研究的目的是利用重组自交系(RI)和异源自交系(HIF)鉴定和鉴定SN/PNN的数量性状基因座(QTL)，重点研究它们与生长环境的互作。以两个遗传差异较大的高产品种米阳23(M23)和秋光(AK)为供试材料，在日本柔津(温带气候)和菲律宾洛斯巴诺斯(热带气候)连续3个作物季节，利用简单的区间作图法检测SN/PNN的QTL。在染色体(Chr.)1(2)、2(2)、4(2)和6(2)的8个基因组区域重复检测到QTL。位于CHR短臂上的两个紧密连锁的QTL。1(最接近的RFLP标记XNpb359)增加的SN/PNN与M23等位基因相比，珠江(LOD=14.0-18.2)显著高于Los Banos(LOD=5.7-9.6)。检测到对CHR的QTL效应。4(C513)在Joetsu和CHR也有同样的增强。洛斯巴诺斯旱季为2(XNpb298)和6(XNpb12)。因此，在SN/PNN的测定中，QTL与环境的互作起着重要的作用。以获得在CHR上检测到的大效应QTL的详细特征。1(XNpb359)，20个在基因组区域分离且M23和AK纯合子在其他区域等基因的HIF品系在Los Banos对SN/PNN和其他农艺性状进行了评估。在抽穗期，M23纯合子导致分蘖数比AK纯合子减少29%；在收获期，M23纯合子导致SN/PNN和穗数分别增加和减少25%。这些结果表明，CHR上的QTL。1主要影响分蘖，之后SN/PNN和PNN在与环境相互作用的同时，根据存在的等位基因以相反的方向出现。进一步讨论了SN/PNN QTL与先前报道的PNN QTL的位置关系，从而显示了在不抑制另一性状的情况下改善两个性状的关键QTL。QTL的定位、效应及其与环境互作的信息将有助于SN/PNN的遗传改良，最终有助于提高不同地点的水稻产量。(C)2004爱思唯尔B.V.保留所有权利。
Improvement of rice (Oryza sativa L.) yields through breeding requires a good understanding of genetic factors that control component traits, such as spikelet number per panicle (SN/PnN). The objective of this study was to identify and characterize quantitative trait loci (QTLs) for SN/PnN with emphasis on their interactions with growth environments using recombinant inbred (RI) and heterogeneous inbred family (HIF) lines. One-hundred-and-ninety-one RI lines (F-7) derived from a cross between two genetically divergent high-yielding varieties, Milyang 23 (M23, Indica type with a large SN/PnN) and Akihikari (AK, Japonica type), were grown for three crop seasons in both Joetsu, Japan (temperate climate) and Los Banos, Philippines (tropical climate) to detect QTLs for SN/PnN at the LOD threshold of 2.0 using simple interval mapping. QTLs were detected repeatedly in eight genomic regions on chromosomes (chr.) 1 (two regions), 2 (two), 4 (two) and 6 (two). Two closely linked QTLs located on the short arm of chr. 1 (the nearest RFLP marker, XNpb359) increased SN/PnN with the M23 allele more significantly in Joetsu (LOD = 14.0-18.2) than in Los Banos (LOD = 5.7-9.6). The QTL effect detected on chr. 4 (C513) was likewise enhanced in Joetsu, and those on chr. 2 (XNpb298) and 6 (XNpb12) for the Los Banos dry season. Thus, the interaction between QTL and environment was greatly involved in the determination of SN/PnN. For detailed characterization of the large-effect QTLs detected on chr. 1 (XNpb359), 20 HIF lines that segregated for the genomic region with the M23 and AK homozygotes as being isogenic for other regions were evaluated in Los Banos for SN/PnN and other agronomic traits. For the heading stage, the M23 homozygote resulted in a 29% decrease in tiller number relative to the AK homozygote, and for the harvesting stage, the M23 homozygote resulted in >25% increase and decrease in SN/PnN and panicle number (PnN), respectively. These results demonstrate that the QTLs on chr. 1 primarily affect tillering, thereafter SN/PnN and PnN in opposite directions depending on the alleles present, while interacting with the environment. SN/PnN QTLs are further discussed with respect to their positional relations to PnN QTLs previously reported, thereby showing key QTLs for improving either trait without suppressing the other trait. The information on the QTL locations, effects and interactions with the environments would be helpful for genetic improvement of SN/PnN and ultimately for increasing rice yields over different locations. (C) 2004 Elsevier B.V. All rights reserved.