DIVERSIFYING TREE HOST RANGE FOR SUSTAINABLE PRODUCTION OF BIANCHETTO TRUFFLES- TUBER BORCHII

Truffle farming is an emerging agricultural system in the US. Efforts to develop sustainable systems for its cultivation are critical and needed from the onset. Truffles develop in association with roots of live trees in a symbiotic relationship. As of today, truffles are the most expensive agricultural produce depending on the species ($200-$1000/lb) and will be a big boost to US farmers if developed sustainably. Approximately 95% of truffle consumed in the US are imported from Europe. Their increased global demand and decline in collection from the wild, has resulted in proliferation of cultivated truffle orchards. The Mushroom Biology & Fungal Biotechnology Laboratory at North Carolina A&T State University Greensboro is at the forefront of domesticating both local and European truffles in the US. Significant progress has been made in the domestication of Tuber borchii (common name = bianchetto truffle) on just one host plant- loblolly pine. Expanding the host range of Tuber borchii to other economically important and ecologically diverse pine species will potentially increase its production and sustainability in the South East USA. The first objective is to study and diversify the host range and ecological niche for T. borchii truffles. Accumulated from several years of studies on truffle synthesis on loblolly pine seedlings, we have observed substantial reduction in seedling growth due to nutrient limitations. The dynamic balance of nutrient supply to support optimal seedling growth, mycelia growth, mycorrhizal synthesis, and root colonization is not known for T. borchii. The second objective will focus on determining the optimum level of inorganic nutrients (nitrogen, phosphorus and potassium (NPK)), which will most enhance pine seedling growth and colonization by T. borchii in the greenhouse.To achieve these objectives, three pine species- Long leaf pine (Pinus palustris), short leaf pine (Pinus echinata) both agroforestry trees, and dwarf pine (Pinus strobus) an ornamental tree will be mycorrhized with Tuber borchii and their performance will be compared to the already-established truffle host tree- the loblolly pine. In the second part of the project, seedlings of loblolly pine will be mycorrhized and exposed to different levels of NPK fertilizer. Plant growth parameters and truffle colonization will be monitored and compared to non-fertilized controls. Mycorrhized trees from selected fertilizer treatments will be out-planted to the field and monitored throughout the project.It is expected that the three pine species will be suitable hosts for truffle colonization, establishment and eventual fructification at maturity. However, the extent to which each species support mycorrhization will be determined by experimentation. NPK fertilizer will definitely enhance plant growth but we will be able to determine levels that will concurrently enhance plant growth and truffle symbiosis. The project will have huge impact on increasing truffle production in the US by 1) diversifying the host range of T. borchii truffles from one to four trees, 2) increasing the regions where truffles could be cultivated since these species grow in different regions and ecological niches in the US, and 3) publishing data that will be useful for truffle growers and stakeholders.