Adeyanju Adedayo O, Rich Patrick J, Ejeta Gebisa
Department of Agronomy, Purdue University, West Lafayette, Indiana, USA.
Plant Genome. 2025 Mar;18(1):e20520. doi: 10.1002/tpg2.20520. Epub 2024 Oct 2.
The parasitic weed Striga (Striga hermonthica) limits productivity of sorghum (Sorghum bicolor) and other cereals in sub-Saharan Africa and elsewhere. Improved host plant genetics is an effective control method but verified loci contributing to Striga resistance are limited. LOW GERMINATION STIMULANT 1 remains the only known sorghum locus affecting resistance to Striga. Functional loss (lgs1) alleles at this locus result in low Striga germination stimulant activity. We developed a robust polymerase chain reaction (PCR)-based LGS1 marker that detects all known natural lgs1 alleles. We have successfully used this marker to improve Striga resistance in our sorghum breeding program. To check its utility among diverse sets of germplasm, we genotyped 406 lines of the sorghum association panel (SAP) with the marker and phenotyped them for Striga germination stimulant activity. The SAP contains 23 lines (6%) with lgs1 mutations that involve a complete loss of this gene. Three previously described deletion alleles (lgs1-1, lgs1-2, and lgs1-3) ranging from 28.5 to 34 kbp are present among SAP members with a new one, lgs1-6, missing nearly 50 kbp relative to the reference genome. All 23 members of the SAP carrying lgs1 alleles had low Striga germination stimulant activity. The smaller previously described intragenic deletion mutations lgs1-4 and lgs1-5 are not present in the SAP. The LGS1 marker is useful for both detecting sources of lgs1 and introgressing Striga resistance into new genetic backgrounds.
寄生杂草独脚金（Striga hermonthica）限制了撒哈拉以南非洲及其他地区高粱（Sorghum bicolor）和其他谷物的产量。改良宿主植物的遗传学特性是一种有效的防治方法，但已证实的有助于抗独脚金的基因座有限。低萌发刺激素1仍然是已知的唯一影响高粱对独脚金抗性的基因座。该基因座的功能缺失（lgs1）等位基因导致独脚金萌发刺激活性降低。我们开发了一种基于聚合酶链反应（PCR）的强大LGS1标记，可检测所有已知的天然lgs1等位基因。我们已成功使用该标记在高粱育种计划中提高对独脚金的抗性。为了检验其在不同种质资源中的实用性，我们用该标记对高粱关联群体（SAP）的406个品系进行了基因分型，并对它们的独脚金萌发刺激活性进行了表型分析。SAP包含23个品系（6%）具有lgs1突变，这些突变涉及该基因的完全缺失。在SAP成员中存在三个先前描述的缺失等位基因（lgs1-1、lgs1-2和lgs1-3），范围从28.5到34千碱基对，还有一个新的等位基因lgs1-6，相对于参考基因组缺失近50千碱基对。携带lgs1等位基因的SAP所有23个成员都具有低独脚金萌发刺激活性。SAP中不存在先前描述的较小的基因内缺失突变lgs1-4和lgs1-5。LGS1标记对于检测lgs1的来源以及将对独脚金的抗性导入新的遗传背景都很有用。
