Mondal Sandip, Purohit Arnab, Hazra Anjan, Das Sampa, Chakrabarti Manohar, Khan Matiyar Rahaman, Lopez-Nicora Horacio, Chakraborti Dipankar, Mukherjee Abhishek
Indian Statistical Institute, Giridih, Jharkhand, 815301, India.
Department of Plant Pathology, The Ohio State University, Columbus, OH, 43210, USA.
Sci Rep. 2024 Dec 3;14(1):30032. doi: 10.1038/s41598-024-73980-x.
In the rice agroecosystems of Southeast Asia, rice root knot nematode (Meloidogyne graminicola) significantly impairs yield, representing a major species within the 'graminis-group' known for its morphological similarities with other root knot nematodes (RKNs). This study delves into the variations in reproductive potential, morphology, morphometrics, and genetic diversity among thirty RKN populations in rice across three distinct agroecological zones in Jharkhand, India. Despite notable differences in reproductive potential among the populations, morphological and morphometric correlations to reproductive potential were inconclusive. However, male and juvenile morphometrics were crucial for identifying intraspecific variability. Genetic analysis utilizing five molecular markers (ITS, 18 S rRNA, D2-D3 of 28 S, COX-I, and COX-II) affirmed the populations as M. graminicola, with ITS marker revealing significant intraspecific variability. Phylogenetic analysis underscored the close relationship between M. oryzae and M. graminicola, distinct from other mitotic RKN species. Low genetic distance and nucleotide diversity, coupled with high haplotype diversity, negative Tajima's D, and Fu's Fs of haplotype network analysis, suggested that all M. graminicola populations are expanding. These findings highlight the urgent need for comprehensive management strategies against M. graminicola, providing valuable insights for growers, extension officials, and plant breeders to develop targeted management approaches and resistance breeding programs.
在东南亚的水稻农业生态系统中，水稻根结线虫（禾本科根结线虫）严重影响产量，是“禾本科组”中的一个主要物种，因其与其他根结线虫在形态上相似而闻名。本研究深入探讨了印度贾坎德邦三个不同农业生态区的30个水稻根结线虫种群在繁殖潜力、形态、形态测量和遗传多样性方面的差异。尽管种群间繁殖潜力存在显著差异，但形态和形态测量与繁殖潜力之间的相关性尚无定论。然而，雄性和幼虫的形态测量对于识别种内变异性至关重要。利用五个分子标记（ITS、18 S rRNA、28 S的D2-D3、COX-I和COX-II）进行的遗传分析证实这些种群为禾本科根结线虫，ITS标记显示出显著的种内变异性。系统发育分析强调了稻根结线虫和禾本科根结线虫之间的密切关系，这与其他有丝分裂根结线虫物种不同。低遗传距离和核苷酸多样性，再加上单倍型网络分析中的高单倍型多样性、负Tajima's D和Fu's Fs，表明所有禾本科根结线虫种群都在扩张。这些发现凸显了针对禾本科根结线虫制定综合管理策略的迫切需求，为种植者、推广官员和植物育种者制定有针对性的管理方法和抗性育种计划提供了有价值的见解。
