A Cryptic, Invasive, Haplotype of the Common Reed Phragmites australis

1. A Cryptic, Invasive, Haplotype of the Common Reed Phragmites australis Ed Vasquez Dr. Ed Glenn Dr. Stephen Nelson

2. Phragmites australis (common reed) • A tall (to over 4m), emergent wetland grass • Invasive haplotype introduced to North America from Eurasia • Invasive to NE coastal salt-marshes within the past 30 years • Alters their ecological functions

3. Comparison of M-Haplotype (invasive) and F-Haplotype (native)

7. Research Objective • Compare the salinity tolerance and growth characteristics of the introduced haplotype of P. australis with those of two native haplotypes

8. Hypothesis: The physiological characteristics of the introduced haplotype differs from those of the native haplotypes

9. Materials and Methods

10. Source of Germplasm and Initial Growout of Plants • Rhizome sections of P. australis were collected from reed populations in Delaware and Maryland • Samples included two native haplotypes (F and AC) and of the introduced invasive haplotype (M) • Rhizomes were immediately shipped to the U. of A. Environmental Research Lab (ERL)

11. Salinity Experiment • Forty rhizome sections (˜5g) of haplotypes F, AC, and M were planted • Irrigated for 12 days under fresh water

12. Salinity Study • Propagated rhizomes were placed into 5 randomized blocks • Plants were randomly assigned to irrigation treatment : 0M, 0.9M, 0.18M, 0.27M, or 0.36M NaCl

13. RESULTS

14. Figure 1. Typical shoot growth produced from rhizomes of M, F, and AC haplotypes of Phragmites australis

15. Table 1. Survival (%) of Phragmites australis haplotypes on different salinity treatments, calculated based on survival after 56 days (initial n = 5)

16. Figure 2. Salinity (M) in the treatment pots compared to salinity of the irrigation water. Data were calculated for drainage water collected from pots following an irrigation near the end of the experiment when plant water use was highest.

17. Figure 3. Growth of shoots of P. australis haplotype at different salinities, showing plant height (a), number of shoots per pot (b), relative growth rate (RGR) (c), and dry weight of rhizomes (d) over the experiment. F, M, and AC haplotypes are shown by solid circles, open circles, and triangles, respectively. Error bars are SEM

18. Figure 4. (a) Molar concentration of Na + K in the shoot tissues vs NaCl in the soil solution for haplotypes of Phragmites australis, and (b) water content grown at different salinities. F, M, and AC haplotypes are shown by solid circles, open circles, and triangles, respectively. Error bar are SEM

19. CONCLUSION • M haplotype exhibited the characteristics of a halophyte • M haplotype exhibits a greater rate of shoot initiation and, subsequently, biomass accumulation • M haplotype appears to be adapted to a weedy growth strategy • The M haplotype of P. australis differs in ecophysiology from the native haplotypes • The genetic and enzymatic mechanisms underlying these differences remain to be explored

20. Acknowledgements • Advisors Ed Glenn Stephen Nelson Sponsors Jed Brown Glenn Guntenspergen