Division of Crop Protection, Indian Institute of Pulse Research, IIPR, Kanpur, Uttar Pradesh, India.
Division of Nematology, ICAR-Indian Agricultural Research Institute, Pusa, New Delhi, India.
J Basic Microbiol. 2023 Nov;63(11):1233-1241. doi: 10.1002/jobm.202300146. Epub 2023 Aug 1.
The effects of four nematicidal rhizobacterial isolates; Bacillus subtilis, Bacillus pumilus, Bacillus megaterium, and Bacillus cereus on infection and multiplication of root-knot nematode, Meloidogyne incognita on tomato were compared with the application of a chemical nematicide, fluopyram 34.48% SC (Velum Prime). The bio-efficacy trial conducted in pots preinoculated with the above isolates followed by M. incognita inoculation resulted in a significant reduction in percent root galling viz. 91.95 in B. subtilis, 84.21 in B. pumilus, 83.70 in B. megaterium, and 81.8 in B. cereus, at 75 days after inoculation (DAI). The reproduction factor of the nematode was the lowest (15.83) in B. subtilis, followed by B. pumilus (21.00), compared with 48.16 in control, with enhanced photosynthetic and transpiration rates. The mechanism of induced resistance was assessed using quantitative reverse-transcription polymerase chain reaction (qRT-PCR) for quantification of three key defense genes (PR-1b, JERF3, and CAT) at 0,2,4,8 and16 days DAI. The defence genes, PR-1b, JERF3, and CAT were expressed at 2.5-7.5-folds in rhizobacterialtreated plants, but not in nematicide treatment. The defense enzymes viz., super oxide dismutase (SOD), polyphenol oxidase (PPO), peroxidase (PO), and phenylalanine ammonia lyase (PAL) when quantified (μmol/mg protein) showed an increase from 1.5 to 17.5 for SOD, 2.1 to 7.8 in PPO, 1.8 to 10.2 in PO, and 1.8 to 8.7 in PAL during 0 to 16 DAI, in rhizobacteria-treated plants.
比较了 4 种杀线虫根际细菌分离物（枯草芽孢杆菌、短小芽孢杆菌、巨大芽孢杆菌和蜡样芽孢杆菌）和化学杀线虫剂氟吡菌酰胺 34.48% SC（Velum Prime）对番茄根结线虫（Meloidogyne incognita）侵染和繁殖的影响。在预先接种上述分离物的盆中进行生物功效试验，然后接种 M. incognita，结果导致根结百分比显著降低，接种后 75 天分别为 91.95%（B. subtilis）、84.21%（B. pumilus）、83.70%（B. megaterium）和 81.80%（B. cereus）。线虫的繁殖系数最低（15.83）为 B. subtilis，其次是 B. pumilus（21.00），而对照为 48.16，同时提高了光合和蒸腾速率。通过定量逆转录聚合酶链反应（qRT-PCR）评估了诱导抗性的机制，以量化接种后 0、2、4、8 和 16 天的 3 种关键防御基因（PR-1b、JERF3 和 CAT）的含量。在根际细菌处理的植物中，防御基因 PR-1b、JERF3 和 CAT 的表达水平为 2.5-7.5 倍，但在杀线虫剂处理中没有表达。防御酶超氧化物歧化酶（SOD）、多酚氧化酶（PPO）、过氧化物酶（PO）和苯丙氨酸解氨酶（PAL）的含量（μmol/mg 蛋白）在 0 至 16 天内从 1.5 增加到 17.5，在 SOD 中增加 2.1 至 7.8，在 PPO 中增加 1.8 至 10.2，在 PO 中增加 1.8 至 8.7，在 PAL 中增加 1.8 至 8.7。
