Breeding and developing new nursery crops with enhanced pest resistance, adaptability, and commercial potential.

There is great interest in further developing hemp as a valuable specialty crop. Hemp is morphologically identical to marijuana; the only difference is that marijuana is grown for its primary psychoactive chemical �����������9-tetrahydrocannabinol (i.e., THC), while hemp is grown for seed/fiber or cannabidiols (CBDs) that are not psychoactive but attenuate the psychoactive effect of THC. Hemp farmers face high risks of destroying their hemp plants from their farms if they accidently grow hemp with THC content higher than the 0.3% legal limit. It is one of the highest priorities for the hemp industry to significantly reduce the hemp THC content. The proposed research aims to genetically enhance industrial Hemp by using a combination of breeding and biotechnological approaches to improve CBD production and reduce THC content. Firstly we will use conventional breeding strategies to develop and assess new tetraploid and triploid cultivars with the intent of developing seedless forms with enhanced CBD production. Secondly we will use biotechnological approaches to develop regeneration and agrobacterium transformation protocols for gene editing approaches to reduce THC content.

The overall goal of this project is to develop bioengineering pipelines for specific landscape crops with high economic value in order to provide the most immediate impacts for crop improvement. These systems will have broad utility and provide a foundation for developing improved crops with enhanced disease and insect resistance, non-invasiveness, unique phenotypes and greater commercial potential. Transgene-free end products will be realized by segregating out transgenes with selective breeding or with the use of DNA-free delivery systems.

Soilless cultivation of horticultural crops is prospected to grow rapidly due to the growing market. To meet the increasing demand from the market together with the limited availability of peat and other traditional soilless substrate components, the growing media industry is searching for new alternative raw materials. Any suitable growing medium or substrate should fulfill three requirements including reliable plant growth performance, economically feasible and and have minimal environmental impacts. Miscanthus, a perennial rhizomatous grass, could be a promising renewable feedstock for growing media because of its high biomass production with low environmental im-pacts. Besides its main role as biomass crop for solid fuel, miscanthus has had limited investigation as soilless growing media in Europe and North America since 2000s.

Eastern Redbud, a famous ornamental tree, is mainly propagated by grafting, leading to high production costs and shortages in supply. Stem cutting will be a solution. However, many current cultivars lost the rooting ability in stem cutting. The proposal is targeting finding usable germplasm to initiate Eastern Redbud (Cercis Canadensis L.) cultivar breeding for Enhanced Propagation ability. Rooting abilities of stem cuttings of Eastern Redbud cultivars and relative species will be tested and used in initiating breeding populations.

The sugarcane complex (Poaceae subtribe Saccharrinae) comprises several genera that have shown significant potential as bioenergy crops, including Saccharum, Tripidium and Miscanthus. High-yielding Saccharum hybrids, known as energy canes may produce biomass yields exceeding 26 t/ac annually. However, most energy canes have limited cold hardiness and have been restricted to warm temperate or sub-tropical environments. In comparison Tripidium and Miscanthus have greater cold hardiness and can be grown in cool temperate regions. Our previous work has been highly successful in developing improved interspecific hybrids of Tripidium and Miscanthus with increased biomass. Traditionally these species have been commercially propagated through division or rhizomes. However, new technologies are being developed for improved propagation and planting efficiencies. New Energy Farms have developed a technology that allows for enhanced field establishment of directly from tissue culture derived plants. This technology referred to as ���������������CEEDS������������������ may have particular value for our newly developed Tripidium and Miscanthus hybrids with reduced rhizomatous mass. In this project we will work with New Energy Farms to a) to modify and enhance in vitro regeneration protocols to adapt to the CEEDS system and b) to assess field establishment of elite cultivars propagated through CEEDS.

The sugarcane complex (Poaceae subtribe Saccharrinae) comprises several genera that have shown significant potential as bioenergy crops, including Saccharum, Tripidium and Miscanthus. High-yielding Saccharum hybrids, known as energy canes may produce biomass yields exceeding 26 t/ac annually. However, most energy canes have limited cold hardiness and have been restricted to warm temperate or sub-tropical environments. In comparison Tripidium and Miscanthus have greater cold hardiness and can be grown in cool temperate regions. Our previous work has been highly successful in developing improved interspecific hybrids of Tripidium and Miscanthus and more recently we have been successful in developing intergeneric hybrids between these two genera. In this project we will use a multi-directional approach with the overall aim of expanding the range of high-yielding, bioenergy grasses in North Carolina. Firstly, we will comprehensively evaluate new energy canes that have been developed by USDA at the Williamsdale Biofuels Field Laboratory, Wallace, NC. Secondly, we will establish and evaluate field trials of newly developed intergeneric hybrids between Miscanthus and Tripidium at the MHCREC, Mills River, NC. Thirdly, we will expand breeding efforts with the aim of introgressing cold hardiness from Miscanthus and Tripidium into advanced energy cane lines.

The Southeast U.S. needs affordable, sustainable, high-yielding, readily-convertible biomass to promote biofuel and bioproducts production. Our project team has made advances toward establishing a biomass supply chain for miscanthus, a perennial grass with superior dry matter yields, beneficial nitrogen cycling mechanisms, and physical properties conducive to multiple crop production strategies. We have developed 15 advanced, high-yielding triploid hybrids and have over 6 years' experience establishing and managing significant acreage of standard miscanthus lines to support project evaluation goals. This project will build on this experience and address these objectives: 1) Evaluate performance (above and below ground) of newly developed hybrids in different geophysical regions of NC with varying nutrient management strategies; 2) Assess production impacts on nutrient and water use efficiency, greenhouse gas fluxes, soil health and microflora; 3) Develop cost-efficient supply chains to deliver on-spec miscanthus to emerging biofuels and bioproducts producers; 4) Support Bioenergy Feedstock Library and related databases within DOE National Labs and USDA. University of Iowa Biomass Fuel Project will serve as our primary conversion technology developer for biopower and monitor end-use economics, product quality, and supply chain sustainability. Data from this miscanthus cropping system will support grower acceptance, industry needs, and environmental and economic sustainability.

In the United States roses one of the most important landscape and floricultural crops with a combined economic value of nearly $7 billion. However, roses are being devastated by the spread lethal Rose Rosette Virus (RRV), posing a significant threat to the industry. Conventional efforts focused on identifying and breeding resistance have been met with minimal success. However, advances in gene editing technologies may provide novel approaches in developing RRV resistant roses. The CRISPR/Cas13a construct has been identified to specifically target viral RNA. By embedding the CRISPR/Cas13a construct in roses, it may be possible to establish a synthetic immune system to protect roses from RRV. In this project, we propose to develop a platform to implement technology for the development RRV resistant roses. We will y=use a multidisciplinary approach to: a) develop effective in vitro regeneration protocols for elite rose cultivars, b) develop efficient agrobacterium mediated transformation for rose cultivars and c) develop a CRISPR/Cas13a construct specific for rose rosette virus.

The sugarcane complex (Poaceae subtribe Saccharrinae) includes some of the most efficient, fastest-growing, greatest biomass-producing plants on the planet. Biomass yields of some of these wild species can exceed 20 dry tons per acer per year (T/A/Y). The potential to further improve biomass yields, regional adaptability, and production characteristics is substantial. The broad genetic compatibility within this complex allows for wide hybridization between species and genera. Our prior work has been successful in developing improved interspecific, fertile, tetraploid hybrids of both Miscanthus and Tripidium species that combine enhanced cold-hardiness and biomass yields and serve as valuable breeding lines. Moving forward, this project will focus on developing intergeneric hybrids between Miscanthus and Tripidium. Combining unique traits from these two genera will allow for new hybrids with broad genetic diversity and novel combinations of desirable traits ideally suited for production in North Carolina.