Identification of sources of resistance to Diceraeus melacanthus Dallas, 1851 in maize varieties, molecular, chemical and morphological characterization of the interaction and identification of resistance elicitors

• Grant number: 24/13368-0
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2025
• End date: July 31, 2028
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Eduardo Neves Costa
• Grantee: Eduardo Neves Costa
• Host Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated researchers: Bruno Henrique Sardinha de Souza ; MARCOS GINO FERNANDES ; Paulo Roberto Da Silva

Abstract

The green-belly stink bug, Diceraeus melacanthus it is a major pest in the initial phase of maize crop development. The pest, due to sap sucking, affects plant development, with yield reductions ranging between 13 and 46%. Concern about this pest has been increasing since these herbivores have evolved resistance to several insecticide molecules. Thus, it is necessary to develop alternative strategies for controlling D. melacanthus, such as the use of plants with innate resistance and the identification of molecules that can induce this resistance. These strategies can contribute to reduce the population of insect pests, exert repellent or deterrence, or even the plant can be more tolerant to herbivore attack, without showing yield reduction. In this context, the selection of resistant varieties, the identification of synthetic molecules effective in inducing maize resistance and the characterization of morphological, chemical and molecular responses related to plant resistance can contribute to the development of effective strategies for integrated management of D. melacanthus in a more economical, effective and sustainable way. Therefore, the objectives of this project are: (i) identify maize varieties resistant to D. melacanthus; (ii) determine which doses of methyl jasmonate (MeJA) and salicylic acid (SA) are most appropriate to induce resistance to the stink bug, by foliar application and seed treatment; (iii) define the most appropriate seed immersion time for treatment with synthetic elicitors; and (iv) identify morphological, chemical and molecular mechanisms that are involved in resistance. To identify resistant sources, screening of 30 hybrids/varieties will be carried out in a controlled environment and in a field with stink bug infestation. To determine the ideal dose of synthetic elicitors, different doses will be applied to the leaves or seeds and then resistance will be assessed. The morphological and chemical components of resistance will be quantified by comparative analysis between resistant and susceptible varieties. To identify genes and molecular routes of resistance to the stink bug, a comparative analysis will be carried out using the transcriptome, obtained by RNAseq, of a resistant and a susceptible maize variety infested or uninfested by the stink bug. The results of this project may contribute to providing alternatives for controlling D. melacanthus in the short or medium term, through the combined use of data on resistant varieties, molecular, morphological and chemical response mechanisms and doses and forms of application of synthetic elicitors. (AU)