The Power of Host Plant Resistance for Fall Armyworm Control

Host Plant Resistance, integrated with other IPM approaches, is an important part of the proposed ASEAN Resistance Management Plan work. But what does this mean and why is it important to the ASEAN Action Plan on Fall Armyworm?

In this Blog we ask international expert, Dr Prasanna Boddupalli, from CIMMYT’s Global Maize Program and CGIAR Research Program MAIZE to explain.

What do we mean when we talk about fall armyworm (FAW) and "host plant resistance"?

PB: “Host plant resistance” can be defined as “the collective heritable characteristics by which a plant reduces the possibility of damage by an insect-pest or a pathogen and/or the ability of the plant to recover or repair after the injury occurs, resulting in minimum reduction in yield as compared to other cultivars of the same plant species under similar conditions”.

What is the difference between native genetic resistance and Bt-based transgenic resistance to FAW?

PB: Host plant resistance (HPR) could be either native genetic resistance (with sources of resistance available within the plant’s own gene pool) or transgenic resistance (where a gene or combination of genes from an external source(s) is transferred to make the host plant resistant to an insect-pest like FAW). Genetically speaking, native genetic resistance to FAW is polygenic i.e., controlled by several genes, and does not confer high levels of resistance compared to Bt-based transgenic resistance, which is either monogenic (conferred by a single gene from an external source) or oligogenic (conferred by 2-3 genes from an external source).

We must also recognize that native genetic resistance, once identified, can be used in crop breeding programs similar to other traits and improved varieties developed and deployed to farming communities, while development of transgenic/Bt crops with resistance to an insect-pest like FAW requires access to specific intellectual property and significant institutional expertise to develop such varieties, before they are tested for their biosafety and efficacy, and released by regulatory authorities.