Genetics of resistance to stored grain weevil (Sitophilus oryzae L.) in maize

Abstract

Stored grain weevil (Sitophilus oryzae) has emerged as important storage grain pest of maize, causing substantial economic losses. Owing to high costs and environmental hazards of pesticides, host plant resistance holds promise for effective control of weevils. In the present study, a set of experimental maize hybrids generated using line × tester mating design were evaluated against S. oryzae. Significant variation for grain weight loss (GWL) (6.0–49.1%), number of insect progeny emerged (NIP) (17.8–203.3), grain hardness (GH) (263.1–495.4 N), and pericarp thickness (PT) (60.3–161.0 μm) was observed. Strong positive association was observed between GWL and NIP. GH and PT did not show any correlation with GWL and NIP. Additive and non-additive gene actions were important for both GWL and NIP. Promising inbreds and experimental crosses identified can be effectively utilized in the resistance breeding programme. In majority of promising crosses having desirable SCA effects, one of the parents had desirable GCA effects, indicating that selection of inbred parents based on per se performance for generating resistant crosses may be possible. The commercial hybrid checks were highly susceptible compared to experimental hybrids. The inbreds and experimental hybrids identified hold promise in developing weevil resistant maize cultivars offering sustainable solution to management of weevils in maize.

Keywords:

• storage pests
• rice weevil
• grain loss
• gene action
• Zea mays

Public Interest Statement

The work presented in the manuscript describes the phenotypic characters and their association towards weevil (S. oryzae) resistance in maize. The genetic basis deciphered in the present study will help in designing suitable breeding strategy for imparting weevil resistance in maize. The resistant cultivars, thus developed will serve as sustainable and cost-effective solution to post-harvest loss of grains during storage.

Competing interests

The authors declare no competing interest.

Acknowledgments

The first author sincerely acknowledges the Indian Council of Agricultural Research for the Junior Research Fellowship for his M.Sc. programme.

Additional information

Funding

Funding. The study was carried out as a part of the ICAR-IARI funded project on “Genetics and breeding for improved productivity, stress tolerance and quality traits in maize (Gen 09:3)”.

Notes on contributors

Firoz Hossain

ICAR-Indian Agricultural Research Institute, New Delhi is a flagship organization for providing food and nutritional security in the country. The research group is involved in genetic improvement of maize for diverse biotic stresses. The present report was aimed to decipher the genetic basis of resistance to Sitophilus oryzae, a major post-harvest pest in maize causing substantial loss in Asian countries. The study identified promising inbreds and crosses possessing weevil resistance. These genotypes will serve as rich genetic resource in the resistance breeding programme.