LE3 .A278 2013

2013

Reekie, Edward

Acadia University

Bachelor of Science

Honours

Biology

Biology

Endophytes are organisms that live symbiotically within plants. The two have been intermingling for millions of years with relationships varying from mutualistic to antagonistic. Fungal endophytes can produce secondary metabolites (e.g. rugulosin) with anti-herbivory characteristics providing protection for their host and suggesting an eco-friendly solution to insect pests for the forest industry. Previous research also shows that endophytes can affect their hosts’ physiology and morphology. This study examined the effects of three fungal endophyte strains on photosynthetic rate, stomatal conductance and leaf/shoot morphology of 24 white spruce genotypes. In vivo gas exchange measurements were conducted using an ‘open flow gas exchange system’ to survey physiological responses. Tree height and stem volume measurements were recorded along with needle length and width to survey morphological responses. Effects of treatment were strongly influenced by endophyte strain and white spruce genotype. Responses varied between positive and negative, with one endophyte strain increasing needle width and stem volume. The same strain also improved stomatal conductance when measured under decreasing light levels. The different genotypes responded in a variety of ways to treatment and showed marked differences in their characteristics. These results, combined with entomological data, can be useful in determining which spruce genotypes and endophyte strains are most suitable for use in the forest industry.

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https://scholar.acadiau.ca/islandora/object/theses:951