Research Article

Resistance Levels of Ludwigia prostrata Roxb. Collected from Jeonnam Province to an ALS Inhibitor Penoxsulam by Soil, Seed, and Whole Plant Bioassays

Se Ji Jang¹ Do Won Lee ¹ Jang Yong Jeong¹ Young Beom Yun ¹ Do Jin Lee ² Jeongran Lee ³ Oh Do Kwon ³ Yong In Kuk ^1,*

¹ Dept. of Development in Oriental Medicine Resources, Sunchon National University, Suncheon 57922, Korea
²Dept. of Agricultural Education, Sunchon National University, Suncheon 57922, Korea
³ National Institute of Agricultural Sciences, RDA, Wanju 55365, Korea

Abstract

This study was carried out to investigate the resistant levels of Ludwigia prostrata to acetolactate synthase (ALS) inhibiting herbicides through soil, seed and whole plant bioassays. A total of 358 soil samples were collected from Gwangju and Chonnam provinces. We also collected seed samples from 26 different Ludwigia prostrata plants from the same areas. We conducted soil tests on collected samples to determine resistance levels to imazosulfuron+pyriminobac-methyl in Ludwigia prostrata. We also conducted seed and whole plant tests from collected species to determine resistance levels to penoxsulam. In the soil tests, Ludwigia prostrata resistance to imazosulfuron+pyriminobac-methyl was confirmed in 12 of the 358 samples (3.3%). Notably, resistance rates of Ludwigia prostrata was the highest in soils from Goheung-gun with 20%. In the seed bioassay, Ludwigia prostrata resistance to penoxsulam was confirmed in 12 of the 26 collecting areas (46.1%). Also worth noting, Ludwigia prostrata from Jangheung (4) was 4 times more resistant to penoxsulam than standard susceptible plants of the same species. However, in whole plant bioassay, Ludwigia prostrata resistance to penoxsulam was confirmed in all 26 collecting areas. In particular, Ludwigia prostrata of Boseong (7) and Jangheung (1) showed appoximately 13 times higher resistance to penoxsulam than standard susceptible plants of the same species. Therefore, it is suggested that we should develop a control system that can inhibit the spread of Ludwigia prostrata which is resistant to penoxsulam and to control it effectively in rice field.

Figures & Tables

Fig. 1.Occurrence rates (%) of an acetolactate synthase (ALS) inhibiting herbicide (imazosulfuron + pyriminobac-methyl) resistant in soil collected in paddy field of Gwangju and Jeonnam provinces.