SONG News January 2005 no. 70
In this Issue ...

Canadian Chestnut Council Tree Restoration Plan

The objective of the Canadian Chestnut Council intends to return the American chestnut tree (Castanea dentata) to the forests of southern Canada.

Few Canadians are aware today of the former glorious giant of the woodlands of southwestern Ontario, and the much more extensive forests of the eastern USA. The chestnut once constituted about 25% of the landscape covered by hardwood trees. Then, in the early years of the last century the blight struck. Trade with the Orient introduced the deadly chestnut canker fungus. The disease was first observed in the New York Botanic Gardens in 1904. The spores of the deadly fungus were carried by birds, insects, wind and other means, advancing the frontal wave of the infection up to 50 km a year. By 1924 the blight had entered southern Ontario. In the Carolinian Zone, where the chestnut was native, no living trees escaped infection. By the mid 1940s, dead and dying chestnut trees were everywhere except Nova Scotia, where the blight did not reach.

In pre-blight times, a typical mature American chestnut tree rose over 35 meters in height and had a trunk diameter of a meter or more. Only in rare isolation or other freakish occurrence does one find a native chestnut tree approaching this size today. Death continues to stalk these exceptions in southern Ontario. In Nova Scotia, the Ashdale chestnut tree had a trunk diameter of a meter in 1998; it has the greatest girth of any chestnut now living in Canada. The tree had supplied timbers and lumber for buildings of all kinds, wood for furniture, fence posts, railway ties, etc. Bountiful annual harvests of sweet nuts nourished humans and wildlife alike. The tree was a treasure store for early settlers.

Although most infected trees attempted to survive by sending up root sprouts, recurrent infections have continued through the years. Despite nature's attempts at recovery, the persistent fungus has prevented the chestnut from gaining ground. In 1987 the tree was declared "threatened" by the Committee on the Status of Endangered Wildlife in Canada.

During the first 50 years of the disaster, forest scientists - particularly in the USA - used all known means available to bring the blight under control, without success. Breeding for blight resistance was begun in the 1920s by crossing the native chestnut with the blight-resistant Chinese chestnut. Unfortunately, a mistake was made in applying the genetic approach. While a good measure of blight resistance was obtained, the resultant hybrids were undesirable trees of small stature. The US breeding program was discontinued in the 1950s.

In the 1980s, Dr. Charles Burnham, a renowned com breeder working at the University of Minnesota, discovered the error. The upshot of Dr. Burnham's studies was that the Minnesota scientists were able to start a revised breeding program. The centre for the program is Meadowview, Virginia.

Although the Chinese chestnut (and similarly for the Japanese chestnut) is highly resistant to the blight, both are trees of small stature - like standard apple trees. In crossbreeding, blight resistance must be retained while the tall stature of the native chestnut must be selected into dominance. Through a process of back-crossing and intercrossing, Dr. Burnham set out the model for the American Chestnut Foundation (TACF). That model is in use and approaching the desired goal.

In 2000, the CCC decided to embark on a breeding program quite similar to that of TACF. Starting from the beginning could not be justified when advanced breeding lines were available in the USA. The CCC therefore accepted an offer from Dr. Sandra Anagnostakis, Connecticut Agricultural Experimental Station, of advanced breeding material. The germplasm was brought into Canada in the form of pollen. Ten native "mother" chestnut trees in five Ontario counties were pollinated on site. Nuts resulting from these hybridizations have been stratified and germinated, and seedlings grown in the Simcoe Research Station greenhouses under the direction of Dr. Adam Dale, University of Guelph.

Seedlings from the pollinations made in 2001, 2002 and 2003 have been planted in two nurseries located near St. George and Calton, Ontario. When these hybrids attain a designated size, they will be inoculated with the virulent fungus. Those trees with the greatest blight resistance and other desirable features (including tall structure) will be selected as advanced breeding lines. Backcrossings and intercrossings will be carried out as required.

The CCC has established time schedules to complete the various phases of its overall program. It is estimated that 12 to 15 years will be required before blight-resistant germlines will be available to reforest the woodlands of southern Canada.

Since forming the CCC in 1987, primarily through the efforts of Drs. Colin McKeen and John Ambrose, several chestnut tree surveys have been conducted. As well, several research studies have been undertaken by Dr. Greg Boland and his students at the University of Guelph to learn more about the blight fungus. A large part of this effort has been devoted to finding how hypovirulent strains (a lower order of virulence) found in Canada, USA and Europe can be used to control or alleviate the damage caused by virulent strains. Although hypovirulence falls short of the promise it was thought to show some 20 years ago, it has a role to play in defeating the virus: that is to increase the longevity of infected trees that contain valuable germ-plasm. In trying to overcome the damage caused by a deadly fungus like the chestnut blight pathogen, all options must be explored. The blight-resistance breeding program seems to offer the most promise of success at present.

The CCC program represents the tireless efforts of a group of dedicated, largely volunteer, enthusiasts of various vocations and avocations. More details of the program can be obtained by contacting the Secretary, Charles Hooker, at R.R.# 2 Orangeville ON L9W2Y9.

Heartnuts: a Brief History

Recorded history in Japan indicates that the Japanese walnut has been used as a source of food since 7500 BC, but was never developed as a cultivated species. Once the Persian walnut was introduced into Japan interest in the native species declined. A small cottage industry exists where heartnuts, known as Hime Gerumi, little walnut", are still gathered and sold. Without mechanization the industry has remained small.

Early taxonomists considered the Japanese walnut and the heartnut to be two distinct species, Juglans ailantifolia, and Juglans cordiformis. Later it was decided that the heartnut was a variation, and not a distinct species. This leads us to conjecture how the heartnut shape evolved. It may be assumed that the heartnut is a mutation of the more normal egg shaped walnut form.

Early food gatherers noticed they could get nut meats out of the unusual nuts easier, so they planted them. As the generations went by, the form became more common and through selection, the heart-nut shape improved. This kind of genetic variation is not unknown in the walnut family, the black walnut, there are also a few genetic variations. A single lobed black walnut cultivar called Peanut produces an easier cracking black walnut form. Had the indigenous peoples and the pioneers of this country worked with this characteristic, we might have an improved black walnut variation today.

It is believed that the Japanese walnut and the heartnut were first imported into North America about 1870 by a nursery in the Santa Clara Valley in California. It spread through the United States and Southern Canada by subsequent introductions and nurseries. The lush green foliage and large compound leaves of the wide spreading, round topped, 25 metre tall tree has a tropical appearance.

It was through organizations like the Northern Nut Growers Association and the state groups that cultivars of heartnuts were developed for nut qualities. Many named heartnut cultivars were named in the 1920's and 1930's. Most had hard shells with pinched lobes that released the kernel with some prying. Few had commercial potential, but members of the organizations continued their research for the perfect heartnut.

In 1972 the Society of Ontario Nut Growers (SONG) formed, giving impetus to the enthusiasm that people with a common interest have. More nut trees were planted, and searches were made for the ideal nut. Fayette Etter of Pennsylvania was reputed to have some interesting selections, so Douglas Campbell of Niagara-on-the-Lake decided to try and improve on them. John Gordon near Buffalo, New York planted several thousand heartnut seedlings in the search for more improved heartnut selections.

Grimo Nut Nursery of Niagara-on-the-Lake grafted and planted a small test orchard of the selections made by these growers. Encouraged by the potential, he began selling grafted trees for backyard growers and orchards alike. Small orchards have since sprung up from the Niagara area, along the shores of Lake Erie, westward to the eastern shore of Lake Michigan.

It is their combined efforts that have created the heartnut cultivars we have today, forming the basis of a heartnut industry for us.

Where can you buy Heartnuts? A number of growers have planted heartnuts in recent years. The best place to find current supplies of heartnuts as well as to purchase trees is through the SONG website. If you don't have web access, you can contact Ernie Grimo and he can direct you to supplies that are available.

Vegetarian Meatloaf

Sauté in 2 Tbsp cooking oil over medium heat:
1 cup chopped onion
1/2 cup chopped mushrooms
1 clove garlic, chopped
1/4 tsp salt
1/8 tsp black pepper
until onions are translucent and the mushrooms are soft. Remove from the heat and add:
1/2 cup rolled oats
1 cup cooked brown rice
1-1/2 cups chopped heartnuts
Stir until mixed, and allow the pan and mixture to cool before adding,
1 lb. Grated cheddar cheese
4 eggs
Stir to combine and pour into a buttered bread tin. Bake at 350°F. for 45-50 minutes. The loaf will be firm to the touch when done. Let stand for 10 minutes before serving. This meatloaf also serves up cold for sandwiches.

Apple Heartnut Salad

2 large apples peeled and sliced (Courtland or Spy)
1/3 cup mayonnaise
1 Tbsp Lemon juice
1 cup seedless grapes halved or 1/2 cup sultanas
1/2 cup heartnuts
1 stalk of celery sliced thinly on the bias
Stir together and serve.
Optional: stir in 1/4 cup 35% cream.

Lemon Heartnut Muffins

2 cups all purpose flour
1/2 cup white sugar
1/2 tsp baking powder
1/2 tsp baking soda
1/2 tsp salt
mix well, add
zest of one lemon
3/4 cup heartnut pieces
1 cup buttermilk
1 egg
1/2 cup oil
1 Tbsp lemon juice
Stir until just mixed. There should be no flour lumps or streaks of egg. Spoon into greased or paper lined muffin tins, and bake at 350°F for 25 minutes. When done they should be golden and cooked through.

These recipes are from our own Heartnut cookbook, and if you like them please buy a cookbook and try some of the other excellent recipes.

DNA Cracks Tree Riddle

Scientists have successfully used DNA testing to match the stump of a stolen black walnut tree with two logs sold to a lumber mill 95 km away. "This DNA technology puts the log back on the stump," says Keith Woeste, a molecular geneticist at Perdue University in Indianapolis. The case began in November when an incensed Indiana landowner contacted the state department of natural resources after finding the stumps and chain sawed branches of a black walnut and a black cherry tree on his property. The wood from the 17 metre tall black walnut was worth $2500.00 US.

Visual Match
Conservation officer Don Dyson said a timber cutting crew had been working in the area when the trees were cut. A timber mill the harvester routinely sold to had two large black walnut logs that appeared to match the missing tree. The scientists' analysis matched the various pieces of wood to such a high degree of accuracy that, like DNA evidence, it would have been admissible in court. The timber cutter paid the landowner $9000 US to avoid that scenario.

Provided by SONG. Feel free to copy with a credit.