{"title":"Phylogenetic analyses and pathogenic diversity of Meloidogyne graminicola of rice (cv. BRRI Dhan28) from different agro-ecological zones of Bangladesh","authors":"","doi":"10.1016/j.jksus.2024.103472","DOIUrl":null,"url":null,"abstract":"<div><div>Rice root-knot caused by <em>Meloidogyne graminicola</em> is a major yield-limiting factor in all rice growing countries around the world, which is often ignored in Bangladesh due to its subtle and obscure above ground symptoms. The current study proposes a comprehensive diagnosis of rice root-knot nematode at the molecular level and analyzes the pathogenic diversity of <em>M. graminicola</em> population of different AEZs. Rice seedlings of a popular variety (BRRI Dhan28) showing galls in the roots were collected from thirty Agro-Ecological-Zones (AEZs) of Bangladesh. For molecular identification, nuclear DNA was collected from single second-stage juvenile and internal transcribed spacer (ITS) was used as a universal primer. Molecular identification and phylogenetic analyses revealed that all nematode populations of galled rice seedlings from different locations belong to <em>M. graminicola</em>. The nematode populations constitute six phylogenetic clades. Nematode population of phylogenetic clade II showed the highest no. of galls (178 ± 1.67), although galling index was higher and similar in clade I, clade-II, clade-III and clade-VI. The highest percent reduction in both vegetative and yield-contributing traits were recorded in clade-II. A negative correlation was found in galling incidence and all growth and yield parameters. Comparative hatching of <em>M. graminicola</em> from different locations reveals that the pathogenicity of <em>M. graminicola</em> depends on the genetic variability of the nematode population, but not on the hatched juveniles. It might be concluded that the rice root-knot nematodes (<em>M. graminicola</em>) are prevalent in all agro-ecological zones of Bangladesh, despite the most pathogenic groups being frequent in AEZ- 1, 6, 7, 10, 18, 19, 21 and appropriate management initiatives are therefore crucial for maximizing rice yield.</div></div>","PeriodicalId":16205,"journal":{"name":"Journal of King Saud University - Science","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of King Saud University - Science","FirstCategoryId":"103","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1018364724003847","RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MULTIDISCIPLINARY SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Rice root-knot caused by Meloidogyne graminicola is a major yield-limiting factor in all rice growing countries around the world, which is often ignored in Bangladesh due to its subtle and obscure above ground symptoms. The current study proposes a comprehensive diagnosis of rice root-knot nematode at the molecular level and analyzes the pathogenic diversity of M. graminicola population of different AEZs. Rice seedlings of a popular variety (BRRI Dhan28) showing galls in the roots were collected from thirty Agro-Ecological-Zones (AEZs) of Bangladesh. For molecular identification, nuclear DNA was collected from single second-stage juvenile and internal transcribed spacer (ITS) was used as a universal primer. Molecular identification and phylogenetic analyses revealed that all nematode populations of galled rice seedlings from different locations belong to M. graminicola. The nematode populations constitute six phylogenetic clades. Nematode population of phylogenetic clade II showed the highest no. of galls (178 ± 1.67), although galling index was higher and similar in clade I, clade-II, clade-III and clade-VI. The highest percent reduction in both vegetative and yield-contributing traits were recorded in clade-II. A negative correlation was found in galling incidence and all growth and yield parameters. Comparative hatching of M. graminicola from different locations reveals that the pathogenicity of M. graminicola depends on the genetic variability of the nematode population, but not on the hatched juveniles. It might be concluded that the rice root-knot nematodes (M. graminicola) are prevalent in all agro-ecological zones of Bangladesh, despite the most pathogenic groups being frequent in AEZ- 1, 6, 7, 10, 18, 19, 21 and appropriate management initiatives are therefore crucial for maximizing rice yield.
由禾谷圆线虫(Meloidogyne graminicola)引起的水稻根结线虫是世界上所有水稻种植国的一个主要产量限制因素,在孟加拉国,由于其细微和不明显的地上部症状,往往被忽视。本研究提出了分子水平的水稻根结线虫综合诊断方法,并分析了不同农业经济区禾谷盘线虫种群的致病多样性。从孟加拉国 30 个农业生态区(AEZ)采集了根部出现虫瘿的流行品种(BRRI Dhan28)的稻苗。为进行分子鉴定,从单株第二期幼苗中采集了核 DNA,并使用内部转录间隔(ITS)作为通用引物。分子鉴定和系统进化分析表明,来自不同地点的五倍子水稻幼苗中的所有线虫种群都属于禾本科线虫(M. graminicola)。线虫种群构成了六个系统发育支系。系统发育支系 II 的线虫种群虫瘿数量最多(178 ± 1.67),但支系 I、支系 II、支系 III 和支系 VI 的虫瘿指数较高且相似。支系 II 的无性系和产量贡献性状的减少百分比最高。虫瘿发生率与所有生长和产量参数呈负相关。对不同地点的啮齿目线虫孵化情况进行比较后发现,啮齿目线虫的致病性取决于线虫种群的遗传变异,而不取决于孵化的幼虫。因此,适当的管理措施对最大限度提高水稻产量至关重要。
期刊介绍:
Journal of King Saud University – Science is an official refereed publication of King Saud University and the publishing services is provided by Elsevier. It publishes peer-reviewed research articles in the fields of physics, astronomy, mathematics, statistics, chemistry, biochemistry, earth sciences, life and environmental sciences on the basis of scientific originality and interdisciplinary interest. It is devoted primarily to research papers but short communications, reviews and book reviews are also included. The editorial board and associated editors, composed of prominent scientists from around the world, are representative of the disciplines covered by the journal.