Identification and characterization ofGypsophila paniculatacolor morphs in Sleeping Bear Dunes National Lakeshore, MI, USA

Abstract

14 Background. 15Gypsophila paniculata (baby's breath) is an invasive species found throughout much of the 16 northwest United States and western Canada. Recently, plants exhibiting a different color 17 morphology were identified within the coastal dunes along eastern Lake Michigan. The common 18 baby's breath (G. paniculata) typically produces stems that are purple in color (purple morph), 19 while the atypical morph has stems that are green-yellow (green-yellow morph). The purpose of 20 this study was to characterize these newly identified morphs and determine if they are genetically 21 distinct species from the common baby's breath in order to assess whether alternative 22 management strategies should be employed to control these populations. 23 2 24 Methods. We sequenced two chloroplast regions, rbcL and matK, and one nuclear region, ITS2, 25 from the purple morphs and green-yellow morphs collected from Sleeping Bear Dunes National 26 Lakeshore, MI, USA (SBDNL). Sequences were aligned to the reference sequences from other 27Gypsophila species obtained from the Barcode of Life (BOLD) and GenBank databases. We also 28 collected seeds from wild purple morph and wild green-yellow morph plants in SBDNL. We 29 grew the seeds in a common garden setting and characterized the proportion of green-yellow 30 individuals produced from the two color morphs after five-months of growth. 31 32Results. Phylogenetic analyses based upon rbcL, matK, and ITS2 regions suggest that the two 33 color morphs are not distinct species and they both belong to G. paniculata. Seeds collected from 34 wild green-yellow morphs produced a significantly higher proportion of green-yellow 35 individuals compared to the number produced by seeds collected from wild purple morphs. 36However, seeds collected from both color morphs produced more purple morphs than green-37 yellow morphs. 38 39 Discussion. Based upon these results, we propose that the two color morphs are variants of G. 40 paniculata. Given the significant difference in the number of green-yellow morphs produced 41 from the seeds of each morph type, we also suggest that this color difference has some genetic 42 basis. We propose that current management continue to treat the two color morphs in a similar 43 manner in terms of removal to prevent the further spread of this species. 44 45 46