TY - JOUR
T1 - Virulence adaptation in a rice leafhopper
T2 - Exposure to ineffective genes compromises pyramided resistance
AU - Horgan, Finbarr G.
AU - Bernal, Carmencita C.
AU - Vu, Quynh
AU - Almazan, Maria Liberty P.
AU - Ramal, Angelee Fame
AU - Yasui, Hideshi
AU - Fujita, Daisuke
N1 - Funding Information:
The authors thank Arizza Arida, Reyuel Quintana, Alberto Naredo, Vincent Virtudes, Jenerose Geronda, Marol Recide and Ellen Genil for advice and assistance in conducting experiments. We thank two anonymous reviewers for helpful comments to improve the manuscript. This research was funded by the Bill and Melinda Gates Foundation ( CSISA: Cereal Systems Initiative for South Asia ), the Global Rice Science Partnership (GRiSP) under the directorship of Achim Dobermann, and the School of Life Sciences of the University of Technology Sydney . QV was funded through a scholarship from the Asian Development Bank .
Publisher Copyright:
© 2018 The Authors
PY - 2018/11
Y1 - 2018/11
N2 - Pyramiding resistance genes is predicted to increase the durability of resistant rice varieties against phloem-feeding herbivores. We examined responses by the green leafhopper, Nephotettix virescens (Hemiptera: Cicadellidae), to near-isogenic rice lines with zero, one and two resistance genes. The recurrent parent (T65) and monogenic lines (GRH2-NIL and GRH4-NIL) with genes for resistance to the green rice leafhopper, Nephotettix cincticeps (Hemiptera: Cicadellidae), were susceptible to the green leafhopper, but the pyramided line (GRH2/GRH4-PYL) was highly resistant to the green leafhopper. We selected green leafhoppers, N. virescens, from five sites in the Philippines for over 20 generations on each of the four lines. Populations selected on GRH2/GRH4-PYL gained partial virulence (feeding and development equal to that on T65) to the pyramided line within 10 generations and complete virulence (egg-laying equal to that on T65) within 20 generations. After 20 generations of rearing on the susceptible monogenic lines, green leafhoppers were also capable of developing and laying eggs on GRH2/GRH4-PYL. Furthermore, green leafhoppers reared on the susceptible GRH4-NIL for 20 generations showed equal preferences for T65 and GRH2/GRH4-PYL in choice bioassays. Our results indicate that previous long-term exposure to ineffective genes (including unperceived resistance genes) could dramatically reduce the durability of pyramided resistance. We suggest that informed crop management and deployment strategies should be developed to accompany rice lines with pyramided resistance and avoid the build-up of virulent herbivore populations.
AB - Pyramiding resistance genes is predicted to increase the durability of resistant rice varieties against phloem-feeding herbivores. We examined responses by the green leafhopper, Nephotettix virescens (Hemiptera: Cicadellidae), to near-isogenic rice lines with zero, one and two resistance genes. The recurrent parent (T65) and monogenic lines (GRH2-NIL and GRH4-NIL) with genes for resistance to the green rice leafhopper, Nephotettix cincticeps (Hemiptera: Cicadellidae), were susceptible to the green leafhopper, but the pyramided line (GRH2/GRH4-PYL) was highly resistant to the green leafhopper. We selected green leafhoppers, N. virescens, from five sites in the Philippines for over 20 generations on each of the four lines. Populations selected on GRH2/GRH4-PYL gained partial virulence (feeding and development equal to that on T65) to the pyramided line within 10 generations and complete virulence (egg-laying equal to that on T65) within 20 generations. After 20 generations of rearing on the susceptible monogenic lines, green leafhoppers were also capable of developing and laying eggs on GRH2/GRH4-PYL. Furthermore, green leafhoppers reared on the susceptible GRH4-NIL for 20 generations showed equal preferences for T65 and GRH2/GRH4-PYL in choice bioassays. Our results indicate that previous long-term exposure to ineffective genes (including unperceived resistance genes) could dramatically reduce the durability of pyramided resistance. We suggest that informed crop management and deployment strategies should be developed to accompany rice lines with pyramided resistance and avoid the build-up of virulent herbivore populations.
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U2 - 10.1016/j.cropro.2018.07.010
DO - 10.1016/j.cropro.2018.07.010
M3 - Article
AN - SCOPUS:85050345240
SN - 0261-2194
VL - 113
SP - 40
EP - 47
JO - Crop Protection
JF - Crop Protection
ER -