Germination and growth of Fimbristylis miliacea biotypes resistant and susceptible to acetolactate synthase-inhibiting herbicides

Abstract

-Weed biotypes resistant and susceptible to herbicides may have differences in their adaptive values. The aims of this study were to compare, under controlled and noncompetitive condition, the growth analysis, germination features and seed weight of Fimbristylis miliacea (FIMMI) biotypes resistant and susceptible to acetolactate synthase (ALS) inhibiting herbicides. Experiments were conducted in a greenhouse and in a laboratory from October 2008 to February 2010. Two resistant biotypes (FIMMI 10 and FIMMI 12) and one susceptible biotype (FIMMI 13) were used for the studies. For the study on growth analysis, the treatments were arranged in a completely randomized experimental design with four replications and sampled at 21, 28, 35, 42, 49, 56, 69 days after emergence (DAE) and at flowering stage. For the studies on germination speed, germination and seed weight, the indexes for germination speed, percentage of germination at different temperatures and seed weight of the biotypes were determined. The results showed that the resistant biotype FIMMI 12 shows differences in all variables compared to the resistant biotype FIMMI 10 and compared to the susceptible biotype FIMMI 13, only for the evaluation at flowering. The susceptible biotype FIMMI 13 showed a higher germination speed index and higher germination rate when compared with the resistant biotypes. On the other hand, the resistant biotypes FIMMI 10 and FIMMI 12 showed higher seed weight.

Valor adaptativo e habilidade competitiva de azevém resistente e suscetível ao iodosulfuron em competição com o trigo

“…Em biótipos de azevém suscetível e com resistência de nível baixo ao fluazifop, também foi verificado valor adaptativo similar entre biótipos (Fraga et al, 2013). Para biótipos de Fimbristylis miliacea (L.) Vahl resistente e suscetível a inibidores da enzima ALS, houve diferenças quanto aos seus valores adaptativos no início do florescimento; contudo, não foram relatadas diferenças em estádios iniciais de desenvolvimento (Schaedler et al, 2013). A ausência de efeitos negativos no crescimento de plantas com diferentes mutações na enzima ALS contribui para explicar a alta frequência de alelos de resistência na população Li et al, 2013).…”

Growth, phenology, and seed viability between glyphosate-resistant and glyphosate-susceptible hary fleabane

“…These findings may have ecological significance to the population dynamics and may help to understand the behavior of GR biotypes. The physiological characteristics of resistant and susceptible biotypes become crucial to understand and define the competitive ability of a species and may therefore help in the development and use of management methods and prevention of herbicide resistance (Schaedler et al 2013).…”

Prevalence of herbicide‐resistant weed species in Malaysian rice fields: A review

“…Commonly known as “globe fingerush,” F. miliacea is a true indigene of tropical America, principally on the coast of the south region of Brazil and several regions in The Amazon (Schaedler et al . ). A semi‐aquatic plant and prolific seed producer with a phalanx growth habit, F. miliacea is very aggressive in rice fields.…”