Weed Science (2013) 61, 48-54

Rocío Alarcón-Reverte, Alejandro García, Jaime Urzúa and Albert J. Fischer (2013)
Resistance to glyphosate in junglerice (Echinochloa colona) from California
Weed Science 61 (1), 48-54
Abstract: A suspected glyphosate-resistant (R) junglerice population was collected from a glyphosate-R corn field near Durham in northern California where glyphosate had been applied at least twice a year for over 6 yr. Based on the amount of glyphosate required to reduce growth by 50% (ED₅₀), the R population was 6.6 times more R than the susceptible (S) standard population. Based on the glyphosate concentration that inhibits EPSPS by 50% based on shikimate accumulation (I₅₀) in leaf discs, R plants were four times more R than S plants. By 3 d after treatment with 0.42 kg ae ha⁻¹ glyphosate, the S population had accumulated approximately five times more shikimate than the R population. No differences in [¹⁴C]-glyphosate uptake and translocation were detected between R and S plants. However, partial sequencing of the EPSPS gene revealed a mutation in R plants causing a proline to serine change at EPSPS position 106 (P106S). Our results reveal the first case of a P106S target site mutation associated with glyphosate resistance in junglerice.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Albert J. Fischer

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Echinochloa colona (weed)	Maize/corn (Zea mays)	U.S.A. (SW)