Joseph Louis Antoniel, Lima Nívea Maria Pereira, Rocha Pedro Augusto Laurindo, Júnior Aloísio Freitas Chagas, Rocha João Pedro Laurindo, Pereira Jéssica Soares, Martins Auxiliadora Oliveira, de Moraes Cristiano Bueno, de Oliveira Márcio Leles Romarco, Araújo Wagner Luiz, Sarmento Maíra Ignacio, Sarmento Renato Almeida
Graduate Program in Plant Production, Federal University of Tocantins (UFT), Campus Gurupi, Gurupi, Tocantins, 77402-970, Brazil.
Graduate Program in Forestry and Environmental Sciences, Federal University of Tocantins (UFT), Campus Gurupi, Gurupi, Tocantins, 77402-970, Brazil.
Braz J Microbiol. 2025 Jun 4. doi: 10.1007/s42770-025-01704-y.
The gall wasp Leptocybe invasa Fisher & La Salle (Hymenoptera: Eulophidae) is a major limiting factor in the cultivation of eucalyptus both in Brazil and across the world. This insect induces a gall formation on the principal veins of leaves, apices and petioles. This study investigated the impact of inoculating the fungus T. harzianum on plant growth and defense responses of Eucalyptus to Leptocybe invasa. Two hybrid eucalypt clones (Eucalyptus tereticornis Sm. × Eucalyptus camaldulensis Dehnh.) were used to produce seedlings. Plants were inoculated by spraying the T. harzianum conidial suspension onto the fourth, fifth and sixth fully expanded leaves. Evaluations of ovipositions and galls were carried out 7 and 44 days after infestation (d.a.i), and growth parameters were assessed at six points during the experiment: 15, 30, 45, 60, 75 and 90 d.a.i. Our findings show that susceptible and resistant non-inoculated Eucalyptus plants infested by L. invasa developed galls. However, only oviposition marks were observed in inoculated plants without gall formation, indicating that T. harzianum inoculation enhances Eucalyptus resistance to L. invasa. Additionally, inoculated plants showed increased height, leaf count and branch growth. The findings of this study suggest that T. harzianum has significant potential for controlling L. invasa infestations in susceptible Eucalyptus plantations and the added advantage of enhanced plant growth.
桉树枝瘿姬小蜂（Leptocybe invasa Fisher & La Salle，膜翅目：姬小蜂科）是巴西乃至全球桉树种植中的主要限制因素。这种昆虫会在叶片主脉、叶尖和叶柄上诱导形成虫瘿。本研究调查了接种哈茨木霉（T. harzianum）对桉树生长及对桉树枝瘿姬小蜂防御反应的影响。使用两个杂交桉克隆（细叶桉（Eucalyptus tereticornis Sm.）× 赤桉（Eucalyptus camaldulensis Dehnh.））培育幼苗。通过将哈茨木霉分生孢子悬浮液喷洒到第四、第五和第六片完全展开的叶子上对植株进行接种。在侵染后7天和44天（d.a.i）进行产卵和虫瘿评估，并在实验期间的六个时间点（侵染后15、30、45、60、75和90天）评估生长参数。我们的研究结果表明，受桉树枝瘿姬小蜂侵染的未接种的易感和抗性桉树植株都形成了虫瘿。然而，在接种的植株中仅观察到产卵痕迹，未形成虫瘿，这表明接种哈茨木霉增强了桉树对桉树枝瘿姬小蜂的抗性。此外，接种的植株高度、叶片数量和枝条生长均增加。本研究结果表明，哈茨木霉在控制易感桉树林中桉树枝瘿姬小蜂侵染方面具有巨大潜力，并且具有促进植株生长的额外优势。
