LE3 .A278 2020

2020

Evans, Rodger
Walker, Allison

Acadia University

Bachelor of Science

Honours

Biology

Biology

Crocanthemum canadense(L.) Britt. (Cistaceae), Rockrose, is a small perennial herb found in Eastern North America sand barrens. It is classified as critically imperiled in Nova Scotia under the Nova Scotia Endangered Species Act. Nova Scotia Rockrose populations continue to decline; recent counts estimate only 5000-5500 plants remain. To better understand Rockrose biology, we analysed symbiotic mycorrhizal associations among native Nova Scotia populations. Recent research from our group has documented the presence of arbuscular mycorrhizal fungi (AMF) within Rockrose roots of plants in their native habitat; the present study is the first to focus primarily on the benefits of this symbiotic relationship between Rockrose and AMF, and to identify the fungal partner. AMF improve water and nutrient uptake (phosphorus and nitrogen) by the plant. In return, they rely on the plant as a host and carbon source. In a greenhouse trial with varying percentages of AMF inocula, we determined how AMF would affect the growth of Rockrose plants propagated from tissue culture. The 1:25 inoculum had the most significant effect on the height of the shoots (cm) while the 1:50 inoculated plants had the largest root mass (g). Previous studies indicate that the lack of phosphorus in the experimental trial could have had a negative effect on the growth and symbiosis of C. canadense and AMF. The identity of AMF in the roots and the inoculum was determined using rDNA barcoding. A potentially novel species of AMF sister to Funneliformis mosseae was identified. This research will aid in the conservation and restoration of this critically imperiled species by further understanding beneficial soil fungi, an understudied component of the declining sand barrens habitat.

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https://scholar.acadiau.ca/islandora/object/theses:3411