Growing up on a farm in the English countryside gave me an enduring appreciation of the plants in and outside farmers' fields. After studies at Cambridge and London Universities, which included botany and plant pathology, I did postdoctoral research in California. I came to Cornell as an assistant professor of plant pathology in 1970. Since then my work has focused on the apple tree, its origins and its diseases. I have also tried to pass on some of my enthusiasm to as many students as I can. I have been particularly interested in improving the apple tree`s ability to stand up for itself against the assaults of myriad diseases, with doing harm to the rest of our wonderful environment. This has led me into close association with apple breeders, with whom I have helped develop varieties with better resistance to diseases. It also led me to explore for wild apples in Central Asia, where we know now the domestic apple originated. As a result we have assembled an excellent collection of apples from the wild, which will be a valuable source of genes to use in future. In recent years we have explored the use of biotechnology to strengthen apple varieties. This promises to be of great value as we gain a much better understanding of the genes in apple trees and how they work, through genomics studies. We have also tried to gain a better understanding of the diseases, so that we can counter them with improved methods. We have paid particular attention to the devastating fire blight disease, which was first found in New York and continues to be the most feared disease of apple trees here and elsewhere.
My research focuses on the diseases of apple and how to manage them. Fire blight, a disease caused by bacteria, has been of particular concern since it is so unpredictable, damaging, and difficult to control. We are studying how the bacteria grow on apple flowers prior to infecting them, and how the bacteria enter the rootstocks of trees and then multiply and kill the whole tree. We are applying a range of techniques to control fire blight, including biologicals and resistance inducers, as well as developing resistant varieties and rootstocks. We have worked with breeders using conventional techniques, and are also using biotechnology to transfer resistance genes more precisely. Both techniques have been successful, but will be considerably enhanced by the development of genomics technologies for apple. We are continuing to collaborate with Colombian scientists on improvement of the coffee plant using similar techniques to those used with apple. We are using a tomato and orange transformation model system to identify genes that may be useful in inhibiting psylla transmission of the bacteria causing HLB (citrus greening disease).
Outreach and Extension Focus
I have no formal extension program but talk to growers as often as possible about our research and its benefits for them. I or one of my staff or graduate students gave 3-4 talks per year to grower groups.
Because of my location at Geneva, I have most contact with graduate students, although we have undergraduate interns in our program during the summer. My main teaching activity is to organize the field course on diseases and insect pests of crops, forests, turf and ornamentals each summer. This course is mainly for graduate students and meets for eight full days during the summer. I also co-organize the graduate student seminar series, which meets most weeks throughout the academic year
- Malnoy, M., Borejsza-Wysocka, E. E., Norelli, J. L., Flaishman, M. A., Gidoni, D., & Aldwinckle, H. S. (2010). Genetic transformation of apple (Malus X domestica) without use of a selectable marker gene. Tree Genetics Genomes. 6:11.
- Baldo, A., Norelli, J. L., Farrell, R. E., Bassett, C. L., Aldwinckle, H. S., & Malnoy, M. (2010). Identification of genes differentially expressed during infection with Erwinia amylovora. BMC Plant Biology. 10:10.
- Ko, K., Brown, S. K., Norelli, J. L., Hrazdina, G., & Aldwinckle, H. S. (2010). In vitro pollen functionality of attacin-transgenic “Royal Gala” apple plants and apples transformed with 1-aminocyclopropane-1-carboxylic acid synthase (ACS)-antisense vector. Plant Biosystems. 144:6.
- Postman, J., Volk, G., & Aldwinckle, H. S. (2010). Standardized plant disease evaluations will enhance resistance gene discovery. HortScience. 45:1317-1320.