Janet A. Morrison research interests: plant-pathogen interactions

I am primarily interested in the relative influence of environmental variation and host genetic variation in the infection of host individuals in natural plant populations. While pathogen response to host genetic variation has started to receive substantial research attention, its interaction with environmental variation has been largely ignored. Until this question is addressed fully, we can not adequately understand the evolutionary role of disease in nature. To date, I have done research on four different study systems:

1.  The rush Juncus dichotomus and the smut fungus Cintractia junci.

This rush is a major component of open meadow communitites in the Long Island pine barrens.  Stands can be heavily infected with the smut fungus, which invades the reproductive tissue, rendering the plant sterile. 

Ph.D. thesis: Ecological and genetic factors influencing a natural plant-pathogen interaction. 1994. State University of New York at Stony Brook

Morrison, J.A. 1996. Infection of Juncus dichotomus by the smut fungus Cintractia junci : an experimental field test of the effects of neighboring plants, environment, and host plant genotype. Journal of Ecology 84: 691-702.

Morrison, J.A. 1995. Multiple ecological and genetic factors in an experimental plant-pathogen system: soil water, plant clone, and environmental heterogeneity. Abstract. Supplement to the Bulletin of the Ecological Society of America 76(2):190.

Morrison, J.A. 1994. An indirect effect of interspecific plant competition on a plant-pathogen interaction. Abstract. Supplement to the Bulletin of the Ecological Society of America 75(2):160.

Morrison, J.A. 1993. Infection of Juncus dichotomus by the smut fungus Cintractia junci: a field test of the effects of pathogen density, host density, and host genotype. Abstract. Supplement to the Bulletin of the Ecological Society of America 74(2):367.

Morrison, J.A. 1992. Microsite dependence of environmental and genetic effects in a natural plant-pathogen interaction. Abstract. Supplement to the Bulletin of the Ecological Society of America 73(2):278.

Morrison, J.A. 1991. Causal factors of spatial pattern in a plant-pathogen relationship. Abstract. Supplement to the Bulletin of the Ecological Society of America 72(2):200.

(Manuscripts in prep)

2. Flowering dogwood, Cornus florida, and dogwood anthracnose, Discula destructiva.

Dogwood anthracnose is a fungal disease that appeared about 20 years ago near New York City. It initially caused high mortality rates, but not all trees succumbed, so that both trees and the fungus are still present in the woodlands near New York City where I have studied it. I used this system to look at the effect of the urban environment on decline and disease in forest trees, while I was a researcher at The New York Botanical Garden in Bronx, NY. I am using  GPS and GIS to map and analyze the spatial pattern of disease in the NYBG forest.

Morrison J.A. 2000. Dogwood decline in the urban New York Botanical Garden Forest. Submitted abstract, Botanical Society of America Annual Meeting 2000.

 Morrison, J.A. 1997. Dogwood decline and disease along an urban-rural gradient. Abstract. Supplement to the Bulletin of the Ecological Society of America 78.

(Manuscripts in prep).

3. Andropogon virginicus (broomsedge) and smut fungus infection.

This grass is widespread in the eastern United States, and is a dominant perennial in abandoned agricultural fields in New Jersey. As are many grass species, A. virginicus is subject to infection with smut fungi that infect its reproductive structures, rendering it sterile. I am now initiating a new research program with this system. It will include both manipulative field experiments to examine the role of host genotype and environmental variation in disease, and also analysis of spatial and temporal patterns of disease in the central New Jersey region (using GPS and GIS technology).  

4. Rapid-cycling Brassica rapa and the white-rust fungus Albugo candida.

I have used this system in the lab for Independent Study students. 

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