Eco-Environmental Protection Research Institute, Shanghai Academy of Agricultural Sciences, 201403, Shanghai, China.
School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 201418, Shanghai, China.
BMC Genomics. 2024 Mar 14;25(1):277. doi: 10.1186/s12864-024-10102-x.
Indian jointvetch (Aeschynomene indica) is a common and pernicious weed found in the upland direct-seeding rice fields in the lower reaches of the Yangtze River in China. However, there are few reports on the degree of harm, genetic characteristics, and management methods of this weed. The purpose of this study is to clarify the harm of Indian jointvetch to upland direct-seeding rice, analyze the genetic characteristics of this weed based on chloroplast genomics and identify its related species, and screen herbicides that are effective in managing this weed in upland direct-seeding rice fields.
In a field investigation in upland direct-seeding rice paddies in Shanghai and Jiangsu, we determined that the plant height and maximum lateral distance of Indian jointvetch reached approximately 134.2 cm and 57.9 cm, respectively. With Indian jointvetch present at a density of 4/m and 8/m, the yield of rice decreased by approximately 50% and 70%, respectively. We further obtained the first assembly of the complete chloroplast (cp.) genome sequence of Indian jointvetch (163,613 bp). There were 161 simple sequence repeats, 166 long repeats, and 83 protein-encoding genes. The phylogenetic tree and inverted repeat region expansion and contraction analysis based on cp. genomes demonstrated that species with closer affinity to A. indica included Glycine soja, Glycine max, and Sesbania cannabina. Moreover, a total of 3281, 3840, and 3838 single nucleotide polymorphisms were detected in the coding sequence regions of the cp. genomes of S. cannabina voucher IBSC, G. soja, and G. max compared with the A. indica sequence, respectively. A greenhouse pot experiment indicated that two pre-emergence herbicides, saflufenacil and oxyfluorfen, and two post-emergence herbicides, florpyrauxifen-benzyl and penoxsulam, can more effectively manage Indian jointvetch than other common herbicides in paddy fields. The combination of these two types of herbicides is recommended for managing Indian jointvetch throughout the entire growth period of upland direct-seeding rice.
This study provides molecular resources for future research focusing on the identification of the infrageneric taxa, phylogenetic resolution, and biodiversity of Leguminosae plants, along with recommendations for reliable management methods to control Indian jointvetch.
印度田菁（Aeschynomene indica）是中国长江下游旱地直播稻田中常见且危害性较大的杂草。然而，关于这种杂草的危害程度、遗传特征和管理方法的报道较少。本研究旨在阐明印度田菁对旱地直播稻的危害，基于叶绿体基因组学分析该杂草的遗传特征并鉴定其相关种，筛选旱地直播稻田中有效管理该杂草的除草剂。
在上海和江苏旱地直播稻田的田间调查中，我们确定印度田菁的株高和最大横向距离分别约为 134.2cm 和 57.9cm。当印度田菁的密度分别为 4 株/m 和 8 株/m 时，水稻的产量分别降低约 50%和 70%。我们进一步获得了印度田菁完整叶绿体（cp.）基因组序列的首次组装（163613bp）。其中有 161 个简单序列重复、166 个长重复和 83 个蛋白编码基因。基于 cp.基因组的系统发育树和反向重复区扩张和收缩分析表明，与 A. indica 亲缘关系较近的物种包括大豆（Glycine soja）、大豆（Glycine max）和田菁（Sesbania cannabina）。此外，在 S. cannabina 凭证 IBSC、G. soja 和 G. max 的 cp.基因组编码区中，与 A. indica 序列相比，分别检测到 3281、3840 和 3838 个单核苷酸多态性。温室盆栽试验表明，两种芽前除草剂 saflufenacil 和 oxyfluorfen，以及两种芽后除草剂 florpyrauxifen-benzyl 和 penoxsulam，比稻田中其他常用除草剂更有效地管理印度田菁。建议在旱地直播稻整个生长期间，联合使用这两种类型的除草剂。
本研究为今后 Leguminosae 植物的种下分类群鉴定、系统发育分辨率和生物多样性的研究提供了分子资源，并为可靠的管理方法提供了建议，以控制印度田菁。
