Has Selection for Improved Agronomic Traits Made Reed Canarygrass Invasive?

Abstract

Plant breeders have played an essential role in improving agricultural crops, and their efforts will be critical to meet the increasing demand for cellulosic bioenergy feedstocks. However, a major concern is the potential development of novel invasive species that result from breeders' efforts to improve agronomic traits in a crop. We use reed canarygrass as a case study to evaluate the potential of plant breeding to give rise to invasive species. Reed canarygrass has been improved by breeders for use as a forage crop, but it is unclear whether breeding efforts have given rise to more vigorous populations of the species. We evaluated cultivars, European wild, and North American invader populations in upland and wetland environments to identify differences in vigor between the groups of populations. While cultivars were among the most vigorous populations in an agricultural environment (upland soils with nitrogen addition), there were no differences in above- or below-ground production between any populations in wetland environments. These results suggest that breeding has only marginally increased vigor in upland environments and that these gains are not maintained in wetland environments. Breeding focuses on selection for improvements of a specific target population of environments, and stability across a wide range of environments has proved elusive for even the most intensively bred crops. We conclude that breeding efforts are not responsible for wetland invasion by reed canarygrass and offer guidelines that will help reduce the possibility of breeding programs releasing cultivars that will become invasive.

Screening of molecular markers linked to dwarf trait in crape myrtle by bulked segregant analysis

“…PCR products of AFLP and SSR were verified using GeneMarker Version 1.71 (SoftGenetics, State College, PA, USA) according to the method described by Jakubowski et al (2011). AFLP data were scored as '1' or '0' in the form of Excel, while SSR data were exported as fragment sizes.…”

Genetic Variability of US and Czech Phalaris Arundinacea L. Wild and Cultivated Populations

“…Nelson et al [30] determined that the population genetic structure of wild, forage, and ornamental exotic and N. American Phalaris harbored a high amount of genetic diversity within, as opposed to among, populations. Thus, range expansion of P. arundinacea in N. America is not a result of hybridization among exotic, forage, and native genotypes [38] despite previous theories [28].…”

“…Casler et al [42] and Jakubowski et al [38,39] used 15 SSR molecular markers to distinguish among N. American native and exotic (European) P. arundinacea herbaria specimens. They found that the forage cultivars AUB ('Auburn') and SUP ('Superior'), used in the present study, were native American in origin.…”

“…Thus, it may be possible that additional native N. American strains included herein exist. Future work will be devoted to identifying this possibility using the 15 SSR markers speciic to N. American Phalaris already identiied [38,39,42].…”

“…rotgesii [36]. Recent molecular genetic analyses of herbarium specimens have conirmed the existence of native N. American populations across the continent [38][39][40]. Nelson et al [30] determined that the population genetic structure of wild, forage, and ornamental exotic and N. American Phalaris harbored a high amount of genetic diversity within, as opposed to among, populations.…”