Pecan ; cultivating a new commodity

T. Brenneman, M. E. Smith, G. Bonito, and R. Vilgalys

What are truffles? (No, they are not made of chocolate!)

• Below-ground reproductive structures formed by about 200 species of ascomycete fungi to produce and disperse spores (There are at least 1000 species of hypogeous fungi) • Spores not discharged; odor attracts animals (mice, voles, etc.) which eat the truffles and disperse spores in droppings

Truffles (Tuberales)

• Gathered for food since far back into antiquity; an anonymous author in 1600 B.C. refers to them “not as a mushroom but as mysterious products of the earth” • T. melanosporum (Perigord black ) and T. magnatum (Italian white truffle) are among the most sought after culinary delicacies in the world The Most Expensive Foods You Can Buy (MSN - January, 2013)

“Available from September to December, white truffles are a gourmet indulgence that'll cost you — around $200 an ounce, which amounts to about 2 pieces. These special mushrooms, which can only be located by trained pigs or dogs, are found in the Piedmont region of Italy and are becoming increasingly rare every year.” Puffballs are not truffles!

Homogenous gleba

Sterile Base Mycorrhizae (Gr. Mykes = Mushroom + rhiza = root)

• A symbiotic association between the hyphae of certain fungi and the roots of plants. • Truffles are ectomycorrhizae, forming a mantle of growth over the root tips (vs endomycorrhizae within the roots)

Ectomycorrhizae

• hyphae grow intercellularly with a mantle of growth over the root tips. • Root hairs do not develop and the roots are often short and branched • Widespread in nature on many woody plants such as , beech, willow and pines • Most are Basidiomycetes (usually in order Agaricales), but some are Ascomycetes (ex. Truffles)

Mutual Benefits of Ectomycorrhizae

Plant benefits from; 1. improved nutrient uptake 2. roots protected from pathogens 3. plant growth hormones from

Fungus obtains carbohydrates from plant mycorrhizae

• Early researchers (Woodruff, 1933) described 7 different ectomycorrhizae • Nearly all small roots are mycorrhizal • Cultivation and drought can destroy them but they quickly reform

Pecan root with mycorrhizae

Mycorrhizae Pecan Truffle ( lyonii)

• Discovered in Austin, Texas under a pecan tree (Heimsch, 1958) • Found in Georgia in 1987 at Sunnyland farms, and since in many orchards. • Same species reported on other hosts, but taxonomy is “in flux”!

Bonito, Brenneman & Vilgalys, 2011

Rank Abundance of Ectomycorrhizal Taxa on (Bonito, Brenneman & Vilgalys, 2011) Pecan Truffles are Edible, and sell for up to $400/lb (Photo by Rebecca Fyffe)

Several Georgia Restaurants Feature Pecan Truffles When Available

• Red mule grits custard with shaved pecan truffles and lobster • Local squash and sage agnolotti with truffled leek crema, sweet leeks and shaved pecan truffles • Robiolina with Georgia honey and honeycomb, toasted pecans and shaved pecan truffles • Creamy rice with bacon, collards and pecan truffles Demand is Great – Why is the Current Supply so Limited?

1. Cultivating them is not easy 2. Truffles grow underground so they are hard to find Sometimes it is easy! Sometimes it is hard! Truffles are more fun (and safer) to find than bombs ! Want purchase a truffle dog?

Mike Osteen Wynfield Plantation Albany, GA 910-280-0076 Truffle dogs increase the quantity and quality of truffles found Demand is Great – Why is the Current Supply so Limited?

1. Cultivating them is not easy 2. Truffles grow underground so they are hard to find Field Inoculation of Old Trees

Inoculation at Planting Tuber lyonii fruiting fall, 2012 (Trees inoculated January, 2001)

Scale-up for nursery production? More Information

• www.pecantruffles.com serving as a clearinghouse for pecan truffle information • North American Truffle Society at www.natruffling.org has excellent information on truffles in general • Truffle dog in Georgia pecan orchard on Youtube http://youtu.be/h514cjmJD84 Pecan truffles – A fungus with a future!

Photos by Rebecca Fyffe