Badu-Apraku B, Adewale S, Paterne A, Offornedo Q, Gedil M
International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria.
Front Genet. 2023 Jan 12;14:1012460. doi: 10.3389/fgene.2023.1012460. eCollection 2023.
The parasitic weed, is a major biological constraint to cereal production in sub-Saharan Africa (SSA) and threatens food and nutrition security. Two hundred and twenty-three (223) F mapping population involving individuals derived from TZdEI 352 x TZEI 916 were phenotyped for four -adaptive traits and genotyped using the Diversity Arrays Technology (DArT) to determine the genomic regions responsible for resistance in maize. After removing distorted SNP markers, a genetic linkage map was constructed using 1,918 DArTseq markers which covered 2092.1 cM. Using the inclusive composite interval mapping method in IciMapping, twenty-three QTLs influencing resistance traits were identified across four -infested environments with five stable QTLs (4, 2.1, 2.2, 5, and 6) detected in more than one environment. The variations explained by the QTLs ranged from 4.1% (2.3) to 14.4% (7.1). Six QTLs each with significant additive × environment interactions were also identified for grain yield and damage. Gene annotation revealed candidate genes underlying the QTLs, including the gene models GRMZM2G077002 and GRMZM2G404973 which encode the GATA transcription factors, GRMZM2G178998 and GRMZM2G134073 encoding the NAC transcription factors, GRMZM2G053868 and GRMZM2G157068 which encode the nitrate transporter protein and GRMZM2G371033 encoding the SBP-transcription factor. These candidate genes play crucial roles in plant growth and developmental processes and defense functions. This study provides further insights into the genetic mechanisms of resistance to parasitism in maize. The QTL detected in more than one environment would be useful for further fine-mapping and marker-assisted selection for the development of resistant and high-yielding maize cultivars.
这种寄生性杂草是撒哈拉以南非洲地区（SSA）谷物生产的主要生物限制因素，威胁着粮食和营养安全。以TZdEI 352与TZEI 916杂交后代为材料构建了223个F群体，对其四个适应性性状进行了表型分析，并利用多样性阵列技术（DArT）进行基因分型，以确定玉米中负责抗该寄生性杂草的基因组区域。去除偏态SNP标记后，利用1918个DArTseq标记构建了遗传连锁图谱，覆盖长度为2092.1厘摩。采用IciMapping中的包容性复合区间作图法，在四个受该寄生性杂草侵染的环境中鉴定出23个影响抗该寄生性杂草性状的QTL，其中5个稳定QTL（4、2.1、2.2、5和6）在多个环境中被检测到。QTL解释的变异范围为4.1%（2.3）至14.4%（7.1）。还鉴定出6个对籽粒产量和该寄生性杂草危害具有显著加性×环境互作的QTL。基因注释揭示了QTL潜在的候选基因，包括编码GATA转录因子的基因模型GRMZM2G077002和GRMZM2G404973、编码NAC转录因子的GRMZM2G178998和GRMZM2G134073、编码硝酸盐转运蛋白的GRMZM2G053868和GRMZM2G157068以及编码SBP转录因子的GRMZM2G371033。这些候选基因在植物生长发育过程和防御功能中发挥着关键作用。本研究为玉米抗该寄生性杂草的遗传机制提供了进一步的见解。在多个环境中检测到的QTL将有助于进一步精细定位和标记辅助选择，以培育抗该寄生性杂草的高产玉米品种。
