Pan African University, Institute for Basic Sciences, Technology and Innovation, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya.
Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya.
Pest Manag Sci. 2021 Jun;77(6):2894-2902. doi: 10.1002/ps.6325. Epub 2021 Mar 1.
Pre-attachment resistance to the parasitic plants Striga hermonthica and S. asiatica occurs in sorghum mutants designated low germination stimulant 1 (lgs1). However, only a few of these mutants have been identified and their resistance validated. Additionally, pre-attachment resistance in sorghum beyond lgs1 mutants has not been explored. We used lgs1-specific markers to identify new lgs1-like mutants in a diverse global sorghum collection. The sorghum collection was also evaluated for pre-attachment resistance against Striga using an in vitro assay that measured Striga germination activity and radicle growth.
From a total of 177 sorghum accessions, 60 recorded mean germination levels of below 42%, which is comparable with the previously identified lgs1-like sorghum (SRN39 and IS9830) used as controls in this study. Furthermore, 32 of these accessions recorded Striga radicle lengths comparable or lower than the controls (0.42 mm). Thirty-eight accessions contained the lgs1 mutation and although overall, lgs1 mutants had considerably reduced Striga germination, some low inducers of Striga germination were wild-type for lgs1. Germination was positively but weakly correlated with radicle length pointing to additional radicle growth inhibitory activity.
lgs1 mutations, alongside other mechanisms for low Striga germination stimulation, are prevalent in sorghum, and poor Striga radicle growth is suggestive of host-derived inhibition. As an outcome, our study makes available multiple Striga-resistant sorghum with adaptability to diverse agro-ecological regions in sub-Saharan Africa making immediate deployment possible. © 2021 Society of Chemical Industry.
寄生植物独脚金和亚洲独脚金对高粱的预附着抗性存在于被称为低发芽刺激素 1（lgs1）的高粱突变体中。然而，只有少数突变体被鉴定出来并验证了它们的抗性。此外，尚未探索高粱中除 lgs1 突变体之外的预附着抗性。我们使用 lgs1 特异性标记物在多样化的全球高粱收集物中鉴定新的 lgs1 样突变体。还使用体外测定法评估了高粱对独脚金的预附着抗性，该测定法测量了独脚金的发芽活性和胚根生长。
在总共 177 个高粱品系中，有 60 个品系的平均发芽率低于 42%，这与本研究中用作对照的先前鉴定的 lgs1 样高粱（SRN39 和 IS9830）相当。此外，其中 32 个品系记录的独脚金胚根长度与对照品系相当或更低（0.42mm）。38 个品系含有 lgs1 突变体，尽管总体而言，lgs1 突变体使独脚金的发芽率大大降低，但一些低独脚金发芽诱导剂的 lgs1 为野生型。发芽与胚根长度呈正相关，但相关性较弱，表明存在其他抑制胚根生长的活性。
lgs1 突变体与低独脚金发芽刺激的其他机制一样，在高粱中普遍存在，而独脚金胚根生长不良表明宿主来源的抑制作用。因此，我们的研究提供了多种对撒哈拉以南非洲不同农业生态区具有适应性的抗独脚金高粱，可立即部署。© 2021 化学工业协会。
