Polyploidy and Invasion of English Ivy in North American Forests. Presented by: Justin Ramsey & Tara Ramsey

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1 Polyploidy and Invasion of English Ivy in North American Forests Presented by: Justin Ramsey & Tara Ramsey

traditional pathway! Peace Corps, liberal arts teaching, & now at private company Tara S.

of Rochester, Researcher (until 2013) Black Hills State, Researcher (current) Justin Ramsey

3 Adam F. Green PhD University of Rochester (NY), 2011 MS in molecular biology, U of R, 2003 Not traditional pathway! Peace Corps, liberal arts teaching, & now at private company Tara S. Ramsey PhD University of Washington Ecologist: community & population ecology Univ. of Rochester, Researcher (until 2013) Black Hills State, Researcher (current) Justin Ramsey PhD University of Washington Evolutionary Biologist: polyploidy & speciation Univ. of Rochester, Asst. Prof. (until 2013) Black Hills State, Asst. Prof. (current) Main research focuses on yarrow (Achillea)

4 Biological Invasions Impact factor = (5-year) 1 st or 2 nd quartile Journal founded in 2009 Published by Springer (European publisher)

7 Background information Plant invasion Polyploidy Genus Hedera (Ivy)

8 Problems of invasive plants Outcompete native species Change habitats Cost a lot of money to control Given the negative impacts of biological invasion can we predict what species will become invasive before they are established?

9 What makes a plant invasive? Invasive behavior in other geographic regions Life-history characteristics Reproductive traits Genetic attributes

10 Polyploidy = genetic attribute Diploid: 2n = 2x = 8 Polyploid: 2n = 4x = 16

11 Polyploids: more DNAàlarger nucleiàlarger cellsàlarger plants

12 Polyploids: more alleles à more genetic diversity super-duper heterozygote advantage!

13 Ivy (Hedera spp., Araliaceae)

14 Ivy (Hedera spp., Araliaceae) Long-lived perennial (juvenile + adult stages) Fleshy, bird-dispersed fruits Native to Europe, Asia, and northern Africa Staple of the U.S. horticultural industry

15 Ivy Life Cycle

16 The genus Hedera (2x, 4x, 6x, 8x ) colchica nepalensis maroccana ibirica pastuchovii cypria algeriensis hibernica 4x azorica canariensis helix 2x maderensis rhombea

Native range Green, A., T. Ramsey, & J. Ramsey. 2011.

17 Native range Green, A., T. Ramsey, & J. Ramsey Systematic Botany 36: Widespread Continental climate Less widespread Coastal climate

18 Introduced range Everywhere sort of (not too cold or dry) South America? (probably) South Africa Australia New Zealand North America - Pacific Coast - Atlantic Seaboard - Other regions

19 So what!? Consequences of ivy invasion Provides rat habitat Damages walls and fences Engulfs tree trunks and canopies Outcompetes understory plants Costs $$$$$$$ to control (> 300 hours per acre, or lots of herbicide)

20 Invasive (forests) Cultivated (suburbs)

21 Ivy Desert

22 Research questions: 1. Which ivies are invading North America? 2. In what geographic regions are they invading? 3. What are the demographic attributes of diploid vs. tetraploid ivies in the wild? 4. Do diploid and tetraploid ivies maintain phenotype differences in a common garden?

23 Research questions: 1. Which ivies are invading North America? 2. In what geographic regions are they invading? 3. What are the demographic attributes of diploid vs. tetraploid ivies in the wild? 4. Do diploid and tetraploid ivies maintain phenotype differences in a common garden?

24 Methods: 1. Which ivies are invading North America? Field collections and reference samples DNA extractions Non-coding cpdna sequencing

25 Field collections West Coast sampling East Coast sampling Field sampling (131 populations, 585 plants)

27 Cuttings grown DNA extracted

28 American Ivy Society (AIS) reference collection colchica nepalensis maroccana ibirica pastuchovii cypria algeriensis hibernica azorica canariensis helix maderensis rhombea

29 w. Mediterranean e. Mediterranean Macaronesia e. Mediterranean Europe Green et al Non-coding cpdna (12 regions, ~10.5 kb) Asia

30 Results: (Q1 Which ivies are invading?) cpdna sequencing (5 non-coding regions, N=108 plants) Table 3

31 Table 3

32 6.4% 7.3% 86.3% Composition of U.S. Naturalized Populations

33 Results: 1. Which ivies are invading North America? Some eastern Mediterranean ivies Mostly European ivies: H. helix & H. hibernica But cpdna can t distinguish!!!!

34 Research questions: 1. Which ivies are invading North America? 2. In what geographic regions are they invading? 3. What are the demographic attributes of diploid vs. tetraploid ivies in the wild? 4. Do diploid and tetraploid ivies maintain phenotype differences in a common garden?

35 Methods: 2. In what geographic regions are they invading? Flow cytometry (ploidy determination)

36 Flow Cytometry Facs-Calibur Frequency Fluorescence (DNA content)

37 Fig. 2 One flow cytometry run (2x + 3x + 4x ivy leaves)

38 Fig. 1 Flow cytometry data (all Hedera species)

39 Flow cytometry data (invasive populations, N=585 plants) Fig. 2

40 helix (2x) hibernica (4x) Fig. 2

41 Diploid: 2n = 2x Triploid: 2n = 3x Tetraploid: 2n = 4x

42 Results: (Q2 In what region?) Diploid (H. helix) Tetraploid (H. hibernica) Mixed 21% 79% Fig. 4 N=186 plants

43 Results: (Q2 In what region?) Diploid (H. helix) Tetraploid (H. hibernica) Mixed Fig. 3 28% 72% N=397 plants

44 Tetraploid (H. hibernica) Diploid (H. helix) 72% 28% N=397 plants 79% 21% N=186 plants

45 Results: 2. In what geographic regions are they invading? Diploid H. helix primary invader of east coast Tetraploid H. hibernica primary invader of west coast Ecological filter? May be invading regions with similar climates as their native European ranges ( Triploids present)

46 Research questions: 1. Which ivies are invading North America? 2. In what geographic regions are they invading? 3. What are the demographic attributes of diploid vs. tetraploid ivies in the wild? 4. Do diploid and tetraploid ivies maintain phenotype differences in a common garden?

47 Methods: 3. What are the demographic attributes of diploid vs. tetraploid ivies in the wild? Field surveys (observational) Ivy patch mapping (location, size, species ID) Fruit production

48 Puget Sound (Seattle) Mixed population Natural forest habitat and surrounding suburbs Early invasion stage (comprehensive surveys) Characterization of plant size and reproductive state Flow cytometry analyses

50 Results: (Q3 Demographic attributes in wild?) Fig. 5

51 Tetraploid larger and more reproductive Fig. 5

52 Year 1 Year 2 Most seeds being produced in the suburbs

53 Suburbs Forest 8 63 Tetraploid more likely to invade Fig. 5

54 Results: 3. What are the demographic attributes of diploid vs. tetraploid ivies in the wild? Tetraploid patches are larger Tetraploids have more reproductives Fruit production is greater in the suburbs Park 2x/4x ratio doesn t match suburb ratio

55 Research questions: 1. Which ivies are invading North America? 2. In what geographic regions are they invading? 3. What are the demographic attributes of diploid vs. tetraploid ivies in the wild? 4. Do diploid and tetraploid ivies maintain phenotype differences in a common garden?

56 Methods: 4. Do diploid and tetraploid ivies maintain phenotype differences in a common garden? Common garden experiment (New York) Cuttings from invasive plants Two years Plants collected and measured

57 No. cuttings = 720 No. genotypes = 59 (H. helix + H. hibernica) Triploid genotypes = 8

59 Grown men, playing in the mud

61 Truxton Meridian Georgetwn Battery Potomoc DC Univ Roosevelt Trinidad St. Edward Camano Young Sharp Chuckanut No. leaves ( / ) H. helix (2x) H. hibernica (4x) Fig. 6

62 Leaf surface area ( / ) Truxton Meridian Georgetwn Battery Potomoc DC Univ Roosevelt Trinidad St. Edward Camano Young Sharp Chuckanut H. helix (2x) H. hibernica (4x) Fig. 6

63 No. branches ( / ) Truxton Meridian Georgetwn Battery Potomoc DC Univ Roosevelt Trinidad St. Edward Camano Young Sharp Chuckanut H. helix (2x) H. hibernica (4x) Fig. 6

64 Stem density ( / ) Truxton Meridian Georgetwn Battery Potomoc DC Univ Roosevelt Trinidad St. Edward Camano Young Sharp Chuckanut H. helix (2x) H. hibernica (4x) Fig. 6

65 Results: 4. Do diploid and tetraploid ivies maintain phenotype differences in a common garden? Tetraploids have larger, but fewer leaves Tetraploids have denser stems, but fewer branches

66 Overall summary: European species main invaders Ecological filter may determine where they invade Tetraploids are bigger and more reproductive in field (on Pacific Coast) Tetraploids are bigger in common garden

67 Significance: Can this research help stop ivy invasion? Applied: - Can limit import of some species of ivy - Triploids may be an option Basic: - Some species may be preadapted - Polyploids are bigger, and may be better invaders in some places

68 Caveats: Current distribution may reflect human history of introduction rather than ecological filter Molecular data doesn t clearly say where in Europe they originated No direct measures of plant fitness in their natural habitat (e.g., east + west coast forests) No distinction between polyploidy and overall genetic divergence between species

69 Questions?

Polyploidy and invasion of English ivy (Hedera spp., Araliaceae) in North American forests. Adam F. Green, Tara S. Ramsey & Justin Ramsey

Polyploidy and invasion of English ivy (Hedera spp., Araliaceae) in North American forests Adam F. Green, Tara S. Ramsey & Justin Ramsey Biological Invasions ISSN 1387-3547 Volume 15 Number 10 Biol Invasions