DANVILLE, Va. (AP) -- -

Researchers have dropped an effort to clone the Virginia International Raceway's iconic white oak tree.

The tree marked the track's apex until it fell last summer. Raceway officials asked the Institute for Advanced Learning and Research in Danville to conduct tests on the tree to determine whether it could be cloned.

Media outlets say the institute announced Tuesday that the more than 150-year-old tree was too old to clone.

Raceway owner Connie Nyholm says track officials hope to plant a memorial tree in the fall. They also have discussed creating mementos from the fallen tree, such as salad bowls and furniture.

Here is the news release from the Institute for Advanced Learning and Research:

(Danville, VA) – On July 5, 2013, three days after the iconic oak tree at Virginia International Raceway (VIR) collapsed members of the Institute for Advanced Learning and Research’s (IALR) research team went out to the track and collected several branches and other materials from the tree, with hopes of cloning it to its true genotype.

After a year’s worth of researching literature and attempting to clone the plant through two different methods, both unsuccessful, the project has come to a halt.

The iconic landmark was a White Oak tree (Quercus alba) and was more than 150 years old. Although its many years of existence at the corner station on the south end of the track led it to become a symbol of VIR, in this case, its age may have been one of the leading factors that made the research so difficult.

“The tree age plays a critical role in tissue culture. The younger the source tree is, the easier it is to get shoot regeneration,” Song Zhang, PhD, IALR scientist who led the research on the oak tree project, said. “Of the several publications I found on white oak tissue culture, all of them used trees less than seven years old.”

The physiological statue of the tree is also very important. According to Zhang, young and healthy trees are best for treatments. Unfortunately, the oak tree materials collected were from a tree that had neither of these characteristics but a dead tree that had fallen either because of aging or disease and infection.

It is also important to note that among the many different variations of oak trees, the White Oak is the most recalcitrant specie for tissue culture and vegetative propagation, meaning it is extremely uncooperative.

Despite all of these known challenges, Zhang attempted two different processes to clone the tree. One was by inducing roots from the tree cuttings and the second was to induce shoot regeneration through tissue culture.

After months of trying many different combinations of treatments in multiple types of environments with no real positive results, IALR’s Director of Applied Research, Michael Duncan along with the concurrence of Connie Nyholm, owner and CEO of VIR made the decision to end the project.

According to Zhang, the research may have been more successful if the team could have gotten younger materials like seedlings or new branches from the trunk. “They would have been a much better young material for tissue culture,” Zhang said.

“We wish the results had been different but sometimes things just don’t work out the way we want them to,” Duncan said. “However, I along with VIR appreciate the hard work and dedication the research staff put towards this project.”