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A mutation in the herbicide target site acetohydroxyacid synthase produces morphological and structural alterations and reduces fitness in Amaranthus powellii
Author(s) -
Tardif François J.,
Rajcan Irena,
Costea Mihai
Publication year - 2006
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2005.01596.x
Subject(s) - biology , population , mutation , population structure , biomass (ecology) , botany , genetics , agronomy , gene , demography , sociology
Summary• We investigated the effect of a herbicide resistance‐conferring mutation on fitness in Amaranthus powellii . • Morphological and histological observations were made. Growth and leaf appearance were recorded for six resistant and six susceptible populations. The competitiveness of a susceptible population was compared with that of a resistant population using a replacement series experiment. • Leaves of the resistant plants were distorted and much smaller than those of susceptible plants. Additionally, they exhibited an abnormal morphological and structural pattern consisting of a mosaic of heterogeneous areas in the same leaf blade. The roots and stems had similar structures in susceptible and resistant plants, but the former were up to four times more developed. The resistant plants were slower to develop and produced 67% less biomass and 58% lower leaf area than susceptible plants. Under competitive conditions, one susceptible population outperformed one resistant population by 7–15 times. • The Trp 574 Leu acetohydroxyacid synthase ( AHAS ) mutation appears to have considerable pleiotropic effects on the early growth and development of the plants which, in competitive conditions, greatly reduce fitness.