Presentation given by Karen Williams to the Plant Conservation Alliance, 13 January 2016, Washington D.C., USA.

1. Conserving Crop Wild Relatives in the
United States
Karen A. Williams, Stephanie L. Greene, Colin K. Khoury,
Larry Stritch
January 13, 2016
Plant Conservation Alliance
Washington, D. C.

2. Outline
• Background on Crop Wild Relatives (CWR)
• CWR of the United States
• Conservation approaches for CWR:
Ex situ
In situ
• Opportunities for collaboration
Carya illinoiensis Helianthus simulans Diospyros virginiana

3. Crop Wild Relatives (CWR) are wild plant taxa that are
closely related to crop species. They are either the direct
ancestors of crops or other closely related taxa.
Food security depends on genetic diversity. CWR possess
tremendous genetic diversity. Plant breeders utilize traits in
CWR to improve crops.
CWR are generally adapted to extreme environments. Major
efforts are underway to utilize them to develop climate-
resilient crops.
Wild carrot Wild potato Wild peanut
Photo: K.A. WilliamsPhoto: K.A. WilliamsPhoto: K.A. Williams

4. GP - 2
GP -1
GP - 2
GP - 3
GP - 3
GP -1
----------------------
BIOLOGICAL
SPECIES
-----------------------
Plant Breeders’ Concept of CWR
Harlan and de Wet genepool (GP) classification
Primary: the crop
species, including wild
populations.
Secondary: other
species that can cross
with the crop, but
with some difficulty.
Tertiary: species that
can only be crossed
with the crop species
using radical
techniques.
Plus
Enhanced taxon-group concept (Maxted et al. 2006),
which uses taxonomic and other information.

5. Challenges to CWR Utilization
As one breeder has put it, “it’s a bit like
crossing a house cat with a wildcat. You
don’t automatically get a big docile
pussycat. What you get is a lot of wildness
that you probably don’t want lying on your
sofa.” (Guarino & Lobell 2011)
However, utilization & conservation are being facilitated by:
• improved tools
- breeding technologies
- seed storage and germination
• improved information
- distributions, conservation status (GBIF, Genesys, IUCN)
- relationships with crops (e.g. GRIN-Global CWR database)

6. CWR are important to agriculture
6
Maxted and Kell (2009) identified 291 papers documenting use of
189 CWR taxa to improve 29 crops. Key traits:
• 39% disease resistance
• 17% pest resistance
• 17% quality
• 13% abiotic stress tolerance
• 10% yield increase
• 4% other

7. Global collecting priorities
7
Crop Wild Relatives and Climate Change (2013) Online resource.
Accessed on 10-04-2015. www.cwrdiversity.org
High
Medium
Low
NFCR
70%
classified as
high priority
to collect
Ex situ conservation gaps
were examined for 1,100
CWR species of 81 crops

8. Countries with greatest number of reviewed
CWR species ranked as high priority to collect
8
0
20
40
60
80
100
120
140
160
Crop Wild Relatives and Climate Change (2013) Online resource.
Accessed on 10-04-2015. www.cwrdiversity.org

9. What CWR are in our backyard?
Vaccinium corymbosum L.
• Inventory includes CWR and taxa directly used for food,
fiber, forage, medicine, ornamental, and restoration purposes
(native and naturalized)
• 4,600 taxa (http://www.ars-grin.gov/misc/tax/)
• 285 identified as high priority to collect (related to 38 crops)
Khoury et al. (2013). An Inventory of Crop Wild
relatives of the United States. Crop Sci. 53(4): 1496.
F. viginiana subsp. grayanaPhaseolus polystachios
Photo: K.A. Williams

10. Taxon Trait Taxon Trait
Corylus americana
Eastern filbert blight resistance and
other traits
Juglans major Rootstock for high pH soil
Helianthus anomalus Fertility restoration genes Juglans microcarpa Rootstock for high pH soil
Helianthus argophyllus Downy mildew resistance Juglans nigra Anthracnose resistance
Helianthus bolanderi Genetic stock Malus fusca Graftstock
Helianthus debilis Powdery mildew resistance Prunus andersonii Graftstock
Helianthus deserticola Downy mildew resistance Prunus pumila Graftstock
Helianthus divaricatus Broomrape resistance Prunus rivularis Graftstock
Helianthus giganteus Fertility restoration genes Ribes nigrum
Pest and disease resistance. Other
useful agronomic traits.
Helianthus grosseserratus Broomrape resistance Ribes uva-crispa Gall mite resistance
Helianthus hirsutus Fertility restoration genes Solanum stoloniferum Late blight resistance
Helianthus maximilianii Broomrape resistance Tripsacum dactyloides Corn leaf blight resistance
Helianthus neglectus Fertility restoration genes Vitis acerifolia Graftstock
Helianthus paradoxus Salt tolerance Vitis aestivalis Graftstock
Helianthus pauciflorus Cytoplasmic male sterility Vitis cinerea Graftstock
Helianthus petiolaris Verticillium resistance Vitis cinerea var. helleri Graftstock
Helianthus praecox
Downy mildew, rust, verticillium
wilt and broomrape resistance
Vitis labrusca Cold tolerance
Helianthus resinosus Fertility restoration genes Vitis monticola Graftstock
Helianthus strumosus Fertility restoration genes Vitis mustangensis Graftstock
Helianthus tuberosus Broomrape resistance Vitis riparia Phylloxera vitifoliae resistance
Hordeum bulbosum Powdery mildew resistance Vitis rupestris Phylloxera vitifoliae resistance
Juglans californica Graftstock Vitis vulpina Graftstock
Juglans hindsii Vigorous rootstock
Agronomic Uses and Traits in US CWR

11. • High priority CWR genera: Helianthus (sunflower), Fragaria
(strawberry), Lupinus (lupine), Prunus (cherry, plums, etc.), Ribes
(gooseberry, currants), Rubus (raspberry, blackberry), Vaccinium
(blueberry, cranberry) and Vitis (grape).
• CWR genera with limited representation in gene banks:
Gossypium (cotton), Lactuca (lettuce), Prunus, Ribes, Saccharum
(sugarcane), Vaccinium, Tripsacum (maize) and Zizania (wild rice)
• Vulnerability
Inventory Highlights
• 88 - globally vulnerable (G3)
• 22 - globally imperiled (G2), including
Tripsacum floridanum (GP 3 for maize) and
Rubus macraei (GP 2 for red raspberry)
• 8 - critically imperiled (G1), including 2
species of Helianthus and Juglans hindsii
(GP 2 for walnut) Photo: K.A. Williams

12. Cucurbita okeechobeensis subsp. okeechobeensis --
endangered
Zizania texana Hitchc. – endangered
Helianthus paradoxus Heiser – threatened
Prunus geniculata R. M. Harper -- endangered
Examples of FWS listed CWR in the US

13. Taxon US ESA Nature Serve
# of
accessions
Taxon US ESA
Nature
Serve
# of
accessions
Allium munzii LE G1 0Manihot walkerae LE G1 0
Allium obtusum var. conspicuum G4T2-3 0 Phaseolus texensis G2 0
Allium scilloides G2-3 0 Prunus eremophila G1 0
Cucurbita okeechobeensis LE G1 0 Prunus geniculata LE G3 1
Fragaria chiloensis subsp.
sandwicensis
G5T2 2 Prunus murrayana GX 0
Gossypium tomentosum G2-3 0 Ribes binominatum G2-3 3
Helianthus carnosus G1-2 3 Ribes echinellum LT G1 3
Helianthus niveus subsp. tephrodes G4T2 10 Ribes erythrocarpum G2 2
Helianthus nuttallii subsp. parishii G5TH 0 Rubus aliceae GX 0
Helianthus paradoxus
LT
G2 13 Rubus hawaiensis G2-3 13
Helianthus smithii G2 7 Rubus macraei G2 1
Helianthus verticillatus G1 2 Tripsacum floridanum G2 0
Hordeum arizonicum G2 to G4 0 Vanilla mexicana G2-4 0
Ipomoea microdactyla G2 1 Vicia menziesii LE G1 0
Juglans hindsii G1 16 Vicia ocalensis G1 1
Lathyrus grimesii G2 3 Zizania texana LE G1 0
Examples of Threatened US CWR

14. Ex situ – conservation outside of the
natural habitat (genebanks,
botanical gardens, arboreta)
– easily accessible for use
– secure
In situ – conservation in the natural
habitat
– more variation conserved
– less costly
– evolution continues
Complementary Conservation
for CWR
Phaseolus polystachios
Bulow State Park, FL
Photo: K.A. Williams
Photo: K.A. Williams

15. National Plant
Germplasm System

16. National Plant Germplasm
System
• >574,000 accessions
• 2,393 genera
• 15,091 species
• 250,00 distributions annually

17. Plant Explorations in the US
USDA-ARS Plant Exploration Program
• fills gaps in the NPGS
• recent explorations for CWR of
potato, quinoa, sunflower, bean,
sweet potato, and squash
BLM Seeds of Success
• collection of US native plant
materials for restoration
• seeds incorporated into the NPGS
for conservation and distribution
Wild potato, Arizona
Wild sunflower, Louisiana
Photo: J. Bamberg
Photo: K.A. Williams

18. US CWR gap analysis
18
38,000 records
Info on methods: Ramírez-Villegas et al (2010) A Gap Analysis Methodology for Collecting Crop Genepools: A Case Study with Phaseolus Beans. PLoS ONE 5(10): e13497.
doi:10.1371/journal.pone.0013497. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0013497

19. Species distribution models

20. Species richness for US priority CWR

21. Expected Outcomes from Gap Analysis
• Distribution models of CWR
• Ex situ acquisition needs for CWR identified
• Hot spots of CWR diversity
• Understanding the coincidence of CWR
distributions with protected areas
• Data made maximally available and user friendly by
integrating with databases such as NatureServe and
NRCS Plants Database
• Information provided directly to land managers and
interested organizations

22. • Critical need to identify
priority species and areas
for conservation
• Strong links between in situ
and ex situ conservation
are necessary
• In situ conservation is the
only option for some CWR
that are challenging to
store and regenerate
In situ Conservation of CWR
Zizania aquatica, Minnesota
Photo: C. Sperling

23. Forest ServiceARS Cooperation on CWR
• FSARS MOU on
complementary conservation
of native plants – 2011
• Joint Strategic Framework
on the Conservation and Use
of Native Crop Wild Relatives
in the United States – 2014
http://www.fs.fed.us/wildflowers/ethnobotany/docu
ments/cwr/FrameworkNativeCropWildRelativesOct20
14.pdf

24. FSARS Framework on CWR
In situ (two approaches):
Specific crop approach – populations of the CWR of
one crop are designated as In Situ Genetic Resource
Reserves (IGRRs) based on multiple criteria (sustainability,
population size, genetic profile, ease of access,
ecogeography, etc.)
Protected area approach – all CWR within one area
in a NF are identified and the area is designated as an IGRR
USFS manages IGRRs and monitors threats.
Ex situ
- germplasm is conserved ex situ in the NPGS
- germplasm is available to USFS if re-introduction is
ever necessary

25. Specific Crop Approach
Conservation of Cranberry CWR
Vaccinium macrocarpon Ait. Vaccinium oxycoccos L.
Small cranberryLarge cranberry

26. Strategy for Complementary
Conservation of Wild Cranberry
• Documentation and evaluation of
populations by USFS and ARS:
- plant characteristics
- environment (biotic and abiotic)
- herbarium vouchers
- size, health, accessibility, potential threats
• Evaluation of genetic diversity (leaf tissue analyzed using 9
microsatellite markers) at ARSUniv. of Wisconsin (Juan Zalapa)
• Designate In Situ Reserves
Goal: Conserve the range of genetic variation in wild
cranberry species
http://www.fs.fed.us/wildflowers/ethnobotany/cranberry/index.shtml
Photo: K.A. Williams

27. Monongahela NF, WV
George Washington NF, VA
Cherokee NF, TN
Pisgah NF, NC
Chequamegon-Nicolet NF, WI
Superior NF, MN
Cranberry Populations Evaluated
US National Forests
Ottawa NF, MI
Allegheny NF, PA
Hiawatha NF, MI
21 populations V. macrocarpon
17 populations V. oxycoccos

28. Pisgah National
Forest, NC
1,748 m
Chequamegon - Nicolet
National Forest, WI
Photo: L. Rodriguez-Bonilla, UW 490 m
Monongahela National
Forest, WV
1,110 m
George Washington
National Forest, VA
976 m
Cranberry Populations - US National Forests
Photo: K.A. Williams Photo: K.A. Williams
Photo: K.A. Williams

29. CWR Framework
Protected Area Approach
• Checklists of flora for USFS protected areas
• Criteria for designation of protected areas as IGRRs:
- number of CWR taxa
- significance of individual taxa
- uniqueness of CWR taxa
- ease of access for monitoringgermplasm collection
- distance from other IGRRs

30. What does ‘success’ look like for conserving
CWR in the US?
• Comprehensive and easily accessed information on CWR
species, their distributions, occurrences, and conservation
status
• Broad diversity of CWR secured in situ and ex situ
• Germplasm of CWR readily available to global community
of plant breeders and scientists
• National strategy for long-term conservation of US CWR
established and activated, involving broad partnerships
across federal and state agencies, tribal nations, NGOs, and
beyond

31. Key to Success: Collaboration
• Coordination and partnerships needed between
land management and food security agencies to
support in situ and ex situ conservation
• Data provisioning across platforms; data sharing
• Capitalizing on existing program infrastructure
- Can BLM SOS acquisition objectives be broadened to include
CWR?
- Can NPGS exploration funds be used to conduct CWR surveys?
• Cross-agency research with mutual benefits
(e.g., genetic diversity analyses of wild cranberry
populations)

32. Prunus angustifolia
Ocala National Forest
Florida
Contacts:
Karen Williams, USDAARS Karen.Williams@ars.usda.gov
Stephanie Greene, USDAARS Stephanie.Greene@ars.usda.gov
Colin Khoury, USDAARS Colin.Khoury@ars.usda.gov
Larry Stritch, USFS lstritch@fs.fed.us
Photo: K.A. Williams