Premium
Influence of multiple herbicide resistance on growth in Amaranthus tuberculatus
Author(s) -
Jones E A L,
Owen M D K,
Leon R G
Publication year - 2019
Publication title -
weed research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 74
eISSN - 1365-3180
pISSN - 0043-1737
DOI - 10.1111/wre.12361
Subject(s) - biology , herbicide resistance , population , resistance (ecology) , shoot , agronomy , botany , weed , demography , sociology
Summary Plant defence traits, such as herbicide resistance mutations, may incur a fitness cost to plants that become evident when the trait is not needed. However, individuals with multiple herbicide resistance traits may decrease fitness beyond that of plants with a single herbicide resistance mutation. Multiple herbicide‐resistant ( MHR ) Amaranthus tuberculatus populations are becoming more prevalent in Midwest United States agroecosystems. The objective was to determine whether selected MHR A. tuberculatus populations express differential development when grown in a herbicide‐free environment. The hypothesis was that MHR A. tuberculatus populations become increasingly less fit when additional herbicide resistances evolve. Multiple herbicide‐resistant and herbicide‐susceptible A. tuberculatus populations were grown in a herbicide‐free field for 20 weeks for two seasons. Differences ( P < 0.001) in apical growth were detected 5 and 7 weeks after transplanting for all populations in 2016 and 2017 respectively. Gender and population influenced ( P < 0.001) flowering date, with males flowering up to 1.5 weeks earlier than females, but did not cause pollination asynchrony. Shoot biomass was not different ( P = 0.84) across A. tuberculatus populations, but there were differences ( P < 0.001) for gender and year. Seed production was different amongst A. tuberculatus populations ( P = 0.001), but was not influenced by the number of MHR traits. Conversely, a negative quadratic relationship between seed mass and the number of MHR traits was observed ( r 2 = 0.32; P < 0.001). The experiment results demonstrate that MHR in A. tuberculatus populations is not incurring a fitness penalty that will remove the populations in the immediate future.