Morphological differences, molecular characterization, and herbicide sensitivity of catchweed bedstraw (Galium aparine) populations

Abstract

Plants of catchweed bedstraw from different Norwegian locations and from three other countries were compared with respect to morphological factors, herbicide sensitivity, and genetic variation. For the morphological comparison of cotyledons, whorls, leaves, and fruits five populations, grown outdoors but sheltered from rain, were used. Plants from Belgium and Sweden showed a high similarity, whereas one Norwegian population differed significantly in nearly all parameters. The same populations were used for a comparison of the sensitivity to the herbicide mecoprop-P. In this study, only slight differences appeared between the five populations. Finally, a deoxyribonucleic acid (DNA) sequence analysis of the internal transcribed spacer (ITS) regions was performed. The entire sequence of the ITS1 and ITS2 and the 5.8S subunit of ribosomal DNA were obtained from 15 populations (12 from Norway and one each from Sweden, Belgium, and Germany). The sequences had a length between 590 and 662 base pairs; intraspecific length variation was observed. Based on six insertions–deletions and 26 nucleotide substitutions, two DNA types could be distinguished. The first type consisted of eight Norwegian populations, whereas the second one contained the other seven populations including all non-Norwegian populations. The sequence alignments were used to build a phylogenetic tree. The results of the morphological comparison mostly corresponded with the results of the ITS sequence analysis. The variation was only to some extent correlated with the geographic distribution of the populations.

Evaluation of Galium species and populations using morphological characters and molecular markers

“…has already been used to detect variation in the Stylosanthes species complex, where it was useful in identifying S. guianensis genotypes (Vander Stappen et al ., ). Similarly, the ITS region of G. aparine has been sequenced from European populations, with significant variation (both molecular and morphological) reported between populations (Hübner et al ., ). This is the only molecular study to date in Galium species; however, only G. aparine was characterised in this study (Hübner et al ., ).…”

Response of two catchweed bedstraw (Galium aparine) populations to post-emergence herbicides in winter wheat

“…Various studies indicating differential sensitivity to auxin-type herbicides such as fluroxypyr and mecoprop, have been reported in catchweed bedstraw (Lutman and Lovegrove 1985;Froud-Williams and Ferris-Kaan 1991;Hill and Courtney 1991;Hill et al 1996;Hubner et al 2003).However, the reported range in herbicide sensitivity was rather narrow, with only two-or three-fold difference between the most and the least sensitive populations.…”

“…The herbicide tolerance is not dramatic and might have developed in concert with changes in the environment, flexibility in the timing of seed germination, growth form, lifecycle, freezing tolerance, seed dispersal ability and, last but not least, genetic diversity (Taylor 1999;Hubner et al 2003;Mennan 2003;Mennan and Ngouajio 2006). Catchweed bedstraw has a diverse genetic background that gives it the ability to adapt to many different environments (Hubner et al 2003). Also, the incidences of herbicide resistance have been rather infrequent in the Galium genus with only two cases reported for cleavers (Galium spurium L.) with ALS resistance and cross-resistance to some auxin herbicides in Canada (Hall et al 1998).…”

“…Catchweed bedstraw (Galium aparine L.) is a highly adaptable species owing to its flexibility in the timing of seed germination, variable growth forms, multiple annual lifecycles, freezing tolerance, high dispersal ability, and high genetic diversity (Taylor 1999;Hubner et al 2003;Mennan and Ngouajio 2006). Possibly originating from southwest Asia, this annual, troublesome broad-leaved weed is dispersed throughout Eurasia and North America (Roebuck 1987;Wilson and Wright 1987;Defelice 2002;Mennan and Zandstra 2005).…”

Caracterización morfológica de biotipos de Phalaris minor resistentes y susceptible a herbicidas inhibidores de la ACCasa

“…En algunos otros estudios morfológicos, las diferencias morfológicas y fi siológicas se deben al origen geográfi co o ecológico de las poblaciones (Hübner et al, 2003), y a esto también se atribuye el grado de sensibilidad a los herbicidas. En el presente estudio no es posible afi rmar que pase lo mismo, ya que los biotipos provienen de áreas ubicadas en la misma región y un ambiente similar.…”