Li Qiankun, Xu Xingyang, Yao Hanyang, Li Yunxia, Ning Dekai, Tian Jijuan, Hu Xianqi, Yang Yanmei
College of Plant Protection, Yunnan Agricultural University/State Key Laboratory for Conservation and Utilization of Bio-resources in Yunnan, Kunming, China.
Technology Center of Kunming Company, Yunnan Tobacco Company, Kunming, China.
Front Plant Sci. 2025 Aug 28;16:1636579. doi: 10.3389/fpls.2025.1636579. eCollection 2025.
To explore the changes in agronomic traits, differences in disease resistance, and related enzymatic mechanisms of tobacco grafted progeny after inoculation with root-knot nematodes (RKNs), and to elucidate their defense responses.
We used the F1 progeny of tobacco grafts 'Banqiao B (moderately resistant rootstock) + Honghua Dajinyuan (susceptible scion)' (BHF1) and 'G278 (resistant rootstock)+ Honghua Dajinyuan' (GHF1) as experimental materials, with the scion variety Honghua Dajinyuan (HD) as the control. We conducted a systematic comparison of agronomic traits, disease resistance, and enzymatic characteristics among the materials 90 days post-inoculation with RKNs.
Agronomic traits did not differ significantly between the grafted progeny and HD. The disease index (DI) of HD and BHF1 was 74.07, indicating susceptibility (S), while GHF1 exhibited a DI of 22.22, indicating moderate resistance (MR). The Soil and Plant Analyzer Development (SPAD) value of GHF1 was significantly higher than that in HD and BHF1. Although superoxide dismutase (SOD) and catalase (CAT) activities in the leaves and roots of GHF1 were comparable to those in HD, the activities of peroxidase (POD), phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), chitinase (CHT), and β-1,3-glucanase (GLU) in the roots were significantly elevated compared to those in the other treatments. Correlation analysis revealed significant negative correlations between the DI and both the SPAD value and the activities of POD, PAL, PPO, CHT, and GLU, suggesting that increased chlorophyll content and enhanced defense-related enzyme activities contributed to the improved resistance of GHF1. GHF1 thus constitutes a valuable germplasm for nematode resistance. These findings provide a foundation for the selection, propagation, and characterization of grafted tobacco progeny and offer new strategies for breeding tobacco cultivars resistant to RKNs.
探究接种根结线虫后烟草嫁接后代的农艺性状变化、抗病性差异及相关酶促机制，阐明其防御反应。
以烟草嫁接组合‘板桥B（中抗砧木）+ 红花大金元（感病接穗）’（BHF1）和‘G278（抗病砧木）+ 红花大金元’（GHF1）的F1代作为试验材料，以接穗品种红花大金元（HD）为对照。在接种根结线虫90天后，对各材料的农艺性状、抗病性和酶学特性进行系统比较。
嫁接后代与HD的农艺性状差异不显著。HD和BHF1的病情指数（DI）为74.07，表现为感病（S），而GHF1的DI为22.22，表现为中抗（MR）。GHF1的土壤-植物分析发展（SPAD）值显著高于HD和BHF1。虽然GHF1叶片和根系中的超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性与HD相当，但与其他处理相比，GHF1根系中的过氧化物酶（POD）、苯丙氨酸解氨酶（PAL）、多酚氧化酶（PPO）、几丁质酶（CHT）和β-1,3-葡聚糖酶（GLU）活性显著升高。相关性分析表明，DI与SPAD值以及POD、PAL、PPO、CHT和GLU的活性均呈显著负相关，表明叶绿素含量增加和防御相关酶活性增强有助于提高GHF1的抗性。因此，GHF1是一种有价值的抗线虫种质。这些研究结果为烟草嫁接后代的选择、繁殖和特性鉴定提供了基础，并为培育抗根结线虫烟草品种提供了新策略。
