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Abstract：
Grain weight (GW) is the most important stable trait that directly contributes to crop yield in case of cereals. A total of 105 backcross introgression lines (BC2F10 BILs) derived from Swarna/O. nivara IRGC81848 (NPS) and 90 BILs from Swarna/O. nivara IRGC81832 (NPK) were evaluated for thousand-grain weight (TGW) across four years (wet seasons 2014, 2015, 2016 and 2018) and chromosome segment substitution lines (CSSLs) were selected. From significant pair- wise mean comparison with Swarna, a total of 77 positively and 29 negatively significant NPS lines and 62 positively and 29 negatively significant NPK lines were identified. In all 4 years, 14 NPS lines and 9 NPK lines were positively significant and one-line NPS69 (IET22161) was negatively significant for TGW over Swarna consistently. NPS lines and NPK lines were genotyped using 111 and 140 polymorphic SSRs respectively. Quantitative trait locus (QTL) mapping using ICIM v4.2 software showed 13 QTLs for TGW in NPS. Three major effect QTLs qTGW2.1, qTGW8.1 and qTGW11.1 were identified in NPS for two or more years with PVE ranging from 8 to 14%. Likewise, 10 QTLs were identified in NPK and including two major effect QTL qTGW3.1 and qTGW12.1 with 6 to 32% PVE. In all QTLs, O. nivara alleles increased TGW. These consistent QTLs are very suitable for fine mapping and functional analysis of grain weight. Further in this study, CSSLs NPS1 (10-2S) and NPK61 (158 K) with significantly higher grain weight than the recurrent parent, Swarna cv. Oryza sativa were selected from each population and secondary F2 mapping populations were developed. Using Bulked Segregant QTL sequencing, a grain weight QTL, designated as qTGW3.1 was fine mapped from the cross between NPK61 and Swarna. This QTL explained 48% (logarithm of odds = 32.2) of the phenotypic variations and was fine mapped to a 31 kb interval using recombinant analysis. GRAS transcription factor gene (OS03go103400) involved in plant growth and development located at this genomic locus might be the candidate gene for qTGW3.1. The results of this study will help in further functional studies and improving the knowledge related to the molecular mechanism of grain weight in Oryza and lays a solid foundation for the breeding for high yield.
UNASSIGNED: The online version contains supplementary material available at 10.1007/s12298-024-01483-0.
UNASSIGNED: The online version contains supplementary material available at 10.1007/s12298-024-01483-0.
摘要：
谷粒重量（GW）是最重要的稳定性状，在谷物的情况下直接影响作物产量。来自Swarna/O的总共105个回交基因渗入系（BC2F10BIL）。来自Swarna/O的nivaraIRGC81848（NPS）和90BIL。对nivaraIRGC81832（NPK）进行了四年（2014年，2015年，2016年和2018年）的千粒重（TGW）评估，并选择了染色体片段替代系（CSSL）。从与Swarna的显著成对平均值比较来看，共鉴定出77个阳性和29个阴性显著NPS系以及62个阳性和29个阴性显著NPK系。在所有的四年里，在Swarna上，TGW的14个NPS系和9个NPK系始终为正显著，单系NPS69（IET22161）为负显著。NPS系和NPK系分别使用111和140个多态性SSR进行基因分型。使用ICIMv4.2软件的数量性状基因座（QTL）作图显示NPS中TGW的13个QTL。在NPS中发现了三个主要效应QTLqTGW2.1，qTGW8.1和qTGW11.1，持续两年或更长时间，PVE范围为8％至14％。同样，在NPK中鉴定了10个QTL，包括两个主要效应QTLqTGW3.1和qTGW12.1，分别为6％至32％PVE。在所有QTL中，O.nivara等位基因增加TGW。这些一致的QTL非常适合用于粒重的精细作图和功能分析。在这项研究中，CSSLsNPS1（10-2S）和NPK61（158K）的粒重明显高于轮回亲本，Swarna简历.从每个种群中选择水稻，并开发了次级F2作图种群。使用批量分离QTL测序，一个粒重QTL，命名为qTGW3.1是从NPK61和Swarna之间的杂交中绘制的。该QTL解释了48％（赔率对数=32.2）的表型变异，并使用重组分析精细映射到31kb的间隔。位于该基因组位点的参与植物生长发育的GRAS转录因子基因（OS03go103400）可能是qTGW3.1的候选基因。本研究的结果将有助于进一步的功能研究和提高水稻粒重分子机制的相关知识，为高产育种奠定坚实的基础。
■在线版本包含补充材料，可在10.1007/s12298-024-01483-0获得。
■在线版本包含补充材料，可在10.1007/s12298-024-01483-0获得。
