Fitness costs of susceptible and resistant radish biotypes to ALS-inhibitor herbicides

Abstract

Radish is an important weed that causes yield reduction in winter crops in southern Brazil. The control chemical of radish is an important and essential step to prevent damage on crops. However the intensive use of ALS-inhibitors herbicides favors the selection resistant biotypes. The selection can influence the adaptive traits of biotypes with physiological changes and growth variables and plant reproduction. The objective of the study was compare the fitness costs of susceptible and resistant radish biotypes to ALS-inhibitors herbicides. The experiment was conducted in greenhouse using completely randomized design with five replications. The treatments were arranged in factorial arrangement corresponding to susceptible and resistant biotypes (B1 and B4) and nine sampling times (14, 28, 42, 56, 70, 84, 98, 112 and 126 days after emergency), respectively. The variables evaluated were plant height, shoot dry matter, root dry matter, total dry matter, leaf area, growth rate, relative growth rate, leaf area ratio, number of siliques and seeds produced per plant. The results showed that the resistant biotype (B4) had no fitness costs when compared to the susceptible biotype (B1).

Growth of canola hybrids resistant and sensitive to herbicides

“…In the present study, LAR values were similar between hybrids for the evaluated period, ranging from 524.95 to 109.88 cm 2 g −1 at 14 and 70 DAE, respectively ( Figure 3B). Similar LAR values were observed when evaluating the fitness cost in radish (Raphanus sativus L.) biotypes resistant and susceptible to ALS inhibiting herbicides, with values ranging from 400 to 100 cm 2 g −1 at 14 and 80 DAE, respectively (Cechin et al, 2017). However, the results for the hybrid Hyola 555TT suggest a need of a greater leaf area to produce STDM, which may be related to its lower photosynthetic efficiency when compared to the other hybrids, as reflected by the NAR values ( Figure 3C).…”

Comparing Fitness Cost Associated with Haloxyfop-R Methyl Ester Resistance in Winter Wild Oat Biotypes

“…Quinclorac (Synthetic auxin), penoxsulam and bispyribacsodium (ALS inhibitors) resistant barnyard grass biotypes (Echinochloa crus-galli L.) had lower chlorophyll content compared to susceptible ones (Yang et al, 2017). Iodosulfuron resistant and susceptible radish (Raphanus sativus L.) biotypes had similar plant height, shoot dry matter, root 3 dry matter, total dry matter, leaf area, growth rate, relative growth rate, leaf area ratio, number of siliques and seeds produced per plant (Cechin et al, 2017). Thus, effects of herbicide resistance on fitness-related traits varies depending on weed species, different resistance mechanisms and environmental condition (Goss and Dyer, 2003;Menalled and Smith, 2007;Sibony and Rubin, 2003;Lehnhoff et al, 2013).…”