Four big surviving American Chestnut Trees live on the high ridges of Jackson County, Tennessee
Rex Barber, biology instructor at Volunteer State Community College, found the latest big mama chestnut in the Cub Creek area of Jackson Co. on Nov. 6, 2005. While stalking deer on a high ridge, he came upon a more elusive quarry--a large fruiting American chestnut! This relatively large tree (14.5 inches diameter at breast height) was cankered but appeared to be vigorous. In a vain attempt at reproduction, this isolated tree had dropped a plethora of burs on the ground, all filled with sterile seeds. Next summer we will have an arborist apply TACF backcross pollen to this tree. Then it will produce some fertile nuts which will grow into robust seedlings in one or more Tennessee backcross orchards. Some of this tree's progeny will be moderately resistant to blight and will be crossed with other moderately resistant backcross 3 hybrids; then the most resistant BC3F2 offspring of that cross will be selected and will be crossed with other strongly resistant BC3F2 trees to produce BC3F3 offspring that will be strongly resistant to blight and will breed true for that all important trait. In this way, we will produce American chestnut trees adapted to the eastern Highland Rim soils and climate; these hybrid trees will look like and hopefully will grow like American chestnut trees but will have the Chinese chestnut's genes for blight resistance.
Below, Whitney (the property owner) stands next to a recently discovered large American chestnut survivor in the Columbus Hills community of Jackson County. This accessible tree was producing numerous infertile fruits this year, but TACF pollinators will apply hybrid pollen to it next summer so as to include its germplasm in The American Chestnut Foundation's blight-resistance breeding program. This tree had numerous healed cankers on the trunk and limbs indicating it has successfully fought the blight for many years. Of the 1000 + American chestnut specimens we have found throughout Tennessee, it is interesting that the three largest surviving American chestnut trees in overall size all occur in Jackson County in north central Tennessee, not far north of Cookeville. They are growing at an elevation of about 1000 feet on deep, well-drained, cherty, acidic soils characteristic of the ridges and upper slopes of the eastern Highland Rim region.
Photos by Mark Vance
Roger (left) and Mark (right) stand by another large Jackson County chestnut survivor. It was discovered in the summer of 2004 and was pollinated in June, 2005; nuts were harvested in late September, 2005. This tree has been cloned.
Photos by Joe Schibig
From the left, Roger, Kelly, Mark, and Clint stand next to the largest of the Jackson County chestnut trees which was discovered in the winter of 2003. It has not been pollinated yet due to its inaccessibility, but it has been cloned. It is the largest surviving American chestnut in Tennessee we have found thus far.
Photo by Joe Schibig
