Suman K, Neeraja C N, Madhubabu P, Rathod Santosha, Bej Sonali, Jadhav K P, Kumar J Aravind, Chaitanya U, Pawar Smita C, Rani Surekha H, Subbarao Lella V, Voleti Sitapati R
ICAR-Indian Institute of Rice Research, Hyderabad, India.
Department of Genetics & Biotechnology, Osmania University, Hyderabad, India.
Front Plant Sci. 2021 Feb 18;12:587482. doi: 10.3389/fpls.2021.587482. eCollection 2021.
Polished rice is one of the commonly consumed staple foods across the world. However, it contains limited nutrients especially iron (Fe) and zinc (Zn). To identify promising recombinant inbred lines (RILs) for grain Zn and single plant yield, 190 RILs developed from PR116 and Ranbir Basmati were evaluated in two environments (E1 and E2). A subset of 44 contrasting RILs for grain Zn was screened in another two environments (E3 and E4). Phenotypic data was collected for 10 traits, viz., days to 50% flowering, plant height, panicle length, number of tillers, single plant yield (SPY), test weight, Fe and Zn in brown (IBR, ZBR), and polished rice (IPR, ZPR). Stepwise regression analysis of trait data in 190 RILs and a subset of 44 RILs revealed the interdependence of ZPR, ZBR, IPR, and IBR and the negative association of grain Zn with single plant yield. Based on the additive main effect and multiplicative interaction (AMMI) and genotype and genotype × environment interaction (GGE) analyses of the subset of 44 RILs across four environments (E1-E4), six promising RILs were identified for ZPR with >28 ppm. Mapping of 190 RILs with 102 simple sequence repeats (SSRs) resulted in 13 QTLs for best linear unbiased estimates (BLUEs) of traits including advantage over check (AOC). Using genotype-based sequencing (GBS), the subset of 44 RILs was mapped with 1035 single-nucleotide polymorphisms (SNPs) and 21 QTLs were identified. More than 100 epistatic interactions were observed. A major QTL (PV 37.84%) and another QTL (PV 15.47%) were identified for grain Zn in polished rice. A common major QTL ( and ) was also identified on chromosome 2 for grain Zn content across SSR and SNP maps. Two potential candidate genes related to transporters were identified based on network analyses in the genomic regions of QTL < 3 Mb. The RILs identified for grain Zn and SPY were nominated for national evaluation as under rice biofortification, and two QTLs identified based on BLUEs could be used in the rice biofortification breeding programs.
精米是全球普遍食用的主食之一。然而，它含有的营养成分有限，尤其是铁（Fe）和锌（Zn）。为了鉴定出谷粒锌含量和单株产量方面有潜力的重组自交系（RIL），对由PR116和兰比尔巴斯马蒂培育出的190个RIL在两种环境（E1和E2）下进行了评估。在另外两种环境（E3和E4）中筛选了44个谷粒锌含量差异较大的RIL子集。收集了10个性状的表型数据，即50%开花天数、株高、穗长、分蘖数、单株产量（SPY）、容重、糙米中的铁和锌（IBR、ZBR）以及精米中的铁和锌（IPR、ZPR）。对190个RIL和44个RIL子集的性状数据进行逐步回归分析，揭示了ZPR、ZBR、IPR和IBR之间的相互依存关系以及谷粒锌与单株产量之间的负相关。基于对44个RIL子集在四个环境（E1 - E4）中的加性主效应和乘法互作（AMMI）以及基因型与基因型×环境互作（GGE）分析，鉴定出了6个谷粒锌含量>28 ppm的有潜力的RIL。用102个简单序列重复（SSR）对190个RIL进行定位，得到了13个数量性状位点（QTL）用于性状的最佳线性无偏估计（BLUE），包括相对于对照的优势（AOC）。使用基于基因型的测序（GBS）对44个RIL子集进行定位，得到了1035个单核苷酸多态性（SNP），并鉴定出了21个QTL。观察到100多个上位性互作。在精米中鉴定出一个主要QTL（贡献率37.84%）和另一个QTL（贡献率15.47%）用于谷粒锌含量。在第2号染色体上还在SSR和SNP图谱上鉴定出了一个共同的主要QTL（和）。基于QTL < 3 Mb基因组区域的网络分析，鉴定出了两个与转运蛋白相关的潜在候选基因。鉴定出的谷粒锌和SPY方面的RIL被提名为国家评估，用于水稻生物强化，基于BLUE鉴定出的两个QTL可用于水稻生物强化育种计划。
