Origins of Susceptibility to Insect Herbivores in High-Yielding Hybrid and Inbred Rice Genotypes

• Published in: Insects (Basel, Switzerland) Vol. 15; no. 8; p. 608
• Main Authors: Horgan, Finbarr G, Almazan, Maria Liberty P, Bernal, Carmencita C, Dilla-Ermita, Christine Jade, Ardestani, Goli, Mundaca, Enrique A, Crisol-Martínez, Eduardo
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 12.08.2024; MDPI
• Subjects: Bioassays; Borers; Borers (Insects); brown planthopper; Comparative analysis; Damage; Dry season; Eggs; Environmental aspects; Experiments; Farm buildings; Females; fertilizer; Fitness; Food and nutrition; Genetic diversity; Genotypes; Greenhouses; Herbivores; host plant resistance; Hybrid rice; Hybrids; Inbreeding; Insects; Nucleotides; Nutritional aspects; Origins; Pest control; Pest resistance; Phylogenetics; Phylogeny; Physiological aspects; Physiology; Plant biomass; Plant breeding; Planthoppers; Reproductive fitness; Rice; rice breeding; rice herbivores; rice phylogeny; Seeds; Single-nucleotide polymorphism; Susceptibility; Ireland; Asia; China; rice herbivores; host plant resistance; rice phylogeny; whitebacked planthopper; brown planthopper; rice breeding; fertilizer; yellow stemborer
• ISSN: 2075-4450; 2075-4450
• DOI: 10.3390/insects15080608

Several studies have reported higher damage from insect herbivores to hybrid compared to inbred (pure line) rice. We used a collection of 20 hybrid and 12 inbred genotypes from diverse origins to test the hypotheses that hybrid rice susceptibility is due to (a) the hybrid plant type and/or (b) rice phylogeny. We challenged the genotypes with (BPH), (WBPH) and (YSB) in greenhouse and screenhouse bioassays and monitored herbivores in field plots. We used single nucleotide polymorphic (SNP) markers to assess genetic similarities between the genotypes and found that the hybrids and inbreds formed two distinct clusters regardless of origin. In the screenhouse, hybrids were more susceptible than inbreds to YSB; however, resistant hybrids and susceptible inbreds were also apparent from both the screenhouse and field plots. Plant biomass was the best predictor of susceptibility to YSB. Plant origin had a greater effect than plant type on susceptibility to BPH and WBPH. WBPH was the most abundant planthopper in the field plots where numbers were highly correlated with planthopper fitness in the greenhouse bioassays. Our results provide evidence that high-yielding hybrids that are relatively resistant to herbivores can be achieved through careful breeding. The avoidance of susceptible genotypes during breeding should remain a key element of integrated rice pest management.