2018 ASHS Annual Conference

Background

North Carolina State University has a long history in blueberry cultivar development. Cooperative breeding efforts between NC State and the USDA began in the 1930s following the loss of plants of the early blueberry cultivars developed by the USDA in New Jersey that were resistant to blueberry stem canker. Stem canker is a fungal disease caused by Botryosphaeria corticis. The first stem canker resistant cultivars were released in the 1950s, with 'Wolcott' being the most widely planted initially, but in a few years it lost its resistance and was replaced by 'Croatan'. Two significant events played an important role in the NC State blueberry breeding program in the 1970s. The first was the increasing incidence of stem blight, caused by Botyosphaeria dothidea, which devastated two large-fruited NC State cultivars, 'Harrison' and 'Bluechip'. The impact of this disease prevented either cultivar from becoming economically important. The second significant event was the introduction of “southern highbush blueberry” (SHB) cultivars into breeding programs throughout the southeastern US. SHB has been developed by interspecific crossing between Northern highbush blueberries and wild FL diploid Vaccinium darrowii; this combination allowed wider adaptation of blueberry to the southern US. The first SHB cultivars released from NC State were 'O’Neal', 'Blue Ridge' and 'Cape Fear', of which 'O’Neal' has been most important to the NC industry, the southeastern US and helped to establish some of the first international plantings in most of the low chill production areas around the world. The second most significant SHB cultivar from NC State University has been 'Reveille', which had the distinction of being the first cultivar adapted to mechanical harvest for the fresh market. The improved adaptation and superior fruit quality of SHB continues to dominate our breeding efforts today. Altogether 11 standard highbush, 16 southern highbush, 11 rabbiteye, 2 pentaploids and 4 ornamental blueberry cultivars have been introduced by the NCSU breeding program over the years.

Drs. E. B. Marrow, G. Galletta and J. R. Ballington have played an important role in releasing of all NC State blueberry cultivars. I joined the Department of Horticultural Science in April 2015 with two important missions: the continued success of the traditional breeding program and incorporation of new technologies in our conventional breeding program. Breeding blueberries via traditional methods is a long-term process that usually takes 15-20 years to release one cultivar. However, this period can be shortened by using marker-assisted breeding. I will address three components of my program, which mirror my formal responsibilities at NC State University in which I am assigned 70% research, 20% education and 10% extension and service.

Research

First, there is a wealth of germplasm that has been collected from around the world during the past 75 years by my predecessors. Second, blueberry does not have adequate genomic resources available, despite advances in molecular biology during the past 50 years. The genomic resources include bi-parental or association mapping populations, genetic maps, DNA based markers, transcriptome and genome sequences, databases, and genome browsers. As of April 2015, there were only two low-density genetic maps and one fragmented reference genome sequence available. Tasks involved: first, preserving the germplasm and to use them to develop new mapping populations, and second, building genomic resources for our current breeding program, that will also be available to other blueberry researchers. In addition I am involved in developing genomic resources for other fruit crops including such as blackberry, red raspberry and muscadine grape.

With the advent of next generation sequencing (NGS), we have reached to new stage of molecular breeding that requires training a new generation breeders. Breeders who not only understand the art and science of traditional breeding, but also understand the implications of working with large datasets and making sense out of a tremendous amount of data that is generated by NGS technologies every day. In addition, to a lesser extent now and continuing to grow in the near future, another challenge is to work with phenomics data and processing image files. These emerging technologies will require the training another group of students who are interested in image processing, engineering and data science. I have built a collaborative project with the University of Georgia to explore these technologies in phenotyping blueberry breeding populations.

Training and Education

Breeding will continue to be an important component of agriculture progress as we are continually challenged by changing environmental, pest and cultural demands. My goal in my current position is to train and educate the next generation of breeders who are ready to fill the very competitive positions of the current job market. Also, to Keep myself and my students informed about the fast changing DNA sequencing technologies. Students who are applying for graduate studies in Horticultural Science at NC State often do not have a background in bioinformatics or next generation sequencing. By introducing these new concepts to the students in our department, I have implemented an interdisciplinary course of study in which students will learn the important aspects of NGS. In the lab they learn how to construct sequencing libraries, how to interpret the sequencing data and how to run bioinformatics pipelines to analyze the large datasets on servers and computer clusters. In addition, in the field and greenhouses, we will see the results of our screening as we evaluate seedlings and selections.

Outreach and Extension

I have been fortunate that North Carolina blueberry growers are proactive in supporting my program. The NC Blueberry Council are excited about the new opportunities and prospects that we have provided at NC State for the current and future blueberry growers. Translating the genomics research outcomes to a simple and understandable language to the public is an art. I teach my students to communicate their research results with blueberry growers during blueberry farm days or growers meetings in a grower friendly, yet scientifically appropriate level. My lab is actively involved in communicating their findings with public through websites, social media and weblogs which can be accessed via https://blueberry.cals.ncsu.edu/.