Pandian Balaji Aravindhan, Varanasi Aruna, Vennapusa Amaranatha R, Sathishraj Rajendran, Lin Guifang, Zhao Mingxia, Tunnell Madison, Tesso Tesfaye, Liu Sanzhen, Prasad P V Vara, Jugulam Mithila
Department of Agronomy, Kansas State University, Manhattan, KS, United States.
Bayer Crop Science, St. Louis, MO, United States.
Front Plant Sci. 2020 Dec 9;11:596581. doi: 10.3389/fpls.2020.596581. eCollection 2020.
Postemergence grass weed control continues to be a major challenge in grain sorghum [ (L.) Moench], primarily due to lack of herbicide options registered for use in this crop. The development of herbicide-resistant sorghum technology to facilitate broad-spectrum postemergence weed control can be an economical and viable solution. The 4-hydroxyphenylpyruvate dioxygenase-inhibitor herbicides (e.g., mesotrione or tembotrione) can control a broad spectrum of weeds including grasses, which, however, are not registered for postemergence application in sorghum due to crop injury. In this study, we identified two tembotrione-resistant sorghum genotypes (G-200, G-350) and one susceptible genotype (S-1) by screening 317 sorghum lines from a sorghum association panel (SAP). These tembotrione-resistant and tembotrione-susceptible genotypes were evaluated in a tembotrione dose-response [0, 5.75, 11.5, 23, 46, 92 (label recommended dose), 184, 368, and 736 g ai ha] assay. Compared with S-1, the genotypes G-200 and G-350 exhibited 10- and seven fold more resistance to tembotrione, respectively. To understand the inheritance of tembotrione-resistant trait, crosses were performed using S-1 and G-200 or G-350 to generate F and F progeny. The F and F progeny were assessed for their response to tembotrione treatment. Genetic analyses of the F and F progeny demonstrated that the tembotrione resistance in G-200 and G-350 is a partially dominant polygenic trait. Furthermore, cytochrome P450 (CYP)-inhibitor assay using malathion and piperonyl butoxide suggested possible CYP-mediated metabolism of tembotrione in G-200 and G-350. Genotype-by-sequencing based quantitative trait loci (QTL) mapping revealed QTLs associated with tembotrione resistance in G-200 and G-350 genotypes. Overall, the genotypes G-200 and G-350 confer a high level of metabolic resistance to tembotrione and controlled by a polygenic trait. There is an enormous potential to introgress the tembotrione resistance into breeding lines to develop agronomically desirable sorghum hybrids.
苗后禾本科杂草防除仍是高粱[（L.）Moench]生产中的一项重大挑战，主要原因是缺乏登记用于该作物的除草剂品种。开发抗除草剂高粱技术以促进苗后广谱杂草防除可能是一种经济可行的解决方案。4-羟基苯丙酮酸双加氧酶抑制剂类除草剂（如甲基磺草酮或苯唑草酮）能防除包括禾本科杂草在内的多种杂草，然而，由于会对作物造成伤害，这类除草剂未登记用于高粱苗后施用。在本研究中，我们通过对高粱关联群体（SAP）中的317份高粱品系进行筛选，鉴定出了两个抗苯唑草酮的高粱基因型（G-200、G-350）和一个敏感基因型（S-1）。在苯唑草酮剂量反应试验[0、5.75、11.5、23、46、92（标签推荐剂量）、184、368和736 g ai/ha]中对这些抗苯唑草酮和对苯唑草酮敏感的基因型进行了评估。与S-1相比，基因型G-200和G-350对苯唑草酮的抗性分别高10倍和7倍。为了解苯唑草酮抗性性状的遗传规律，利用S-1与G-200或G-350进行杂交以获得F1和F2后代。对F1和F2后代进行了苯唑草酮处理反应评估。对F1和F2后代的遗传分析表明，G-200和G-350中的苯唑草酮抗性是一个部分显性的多基因性状。此外，使用马拉硫磷和胡椒基丁醚进行的细胞色素P450（CYP）抑制剂试验表明，G-200和G-350中可能存在CYP介导的苯唑草酮代谢。基于基因型测序的数量性状位点（QTL）定位揭示了与G-200和G-350基因型中苯唑草酮抗性相关的QTL。总体而言，基因型G-200和G-350对苯唑草酮具有高水平的代谢抗性，且受多基因性状控制。将苯唑草酮抗性导入育种系以培育农艺性状优良的高粱杂交种具有巨大潜力。
