Page 221 - PC2019 Program & Proceedings

PLANT CANADA 2019

P15. Molecular and biochemical assessment of mechanisms driving abiotic stress tolerance in
Medicago sativa subsp. falcata
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Singer, S. ; R. Orlando ; G. Dhariwal ; K. Burton Hughes ; A. Hannoufa ; E. Schultz ; S. Acharya
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1 Agriculture and Agri-Food Canada
2 Agriculture and Agri-Food Canada
3 University of Lethbridge
Alfalfa (Medicago sativa L.) is the most extensively grown perennial forage legume in Canada, with a
cropping area of approximately 4M Ha. Unfortunately, alfalfa production is hindered by adverse
environmental conditions such as drought and salinity, which are expected to worsen in coming years in
terms of their severity and frequency. Since the demand for ruminant products such as meat and milk is
anticipated to expand considerably in the foreseeable future as a result of our growing population and
increasing affluence, the need for highly productive alfalfa cultivars with enhanced climate resiliency will
be vital. The objective of this project is thus to identify novel sources of genetic variation for the
downstream generation of alfalfa germplasm with improvements in abiotic stress tolerance through
comparative analyses with Medicago sativa subsp. falcata, which is a close relative of cultivated alfalfa
(M. sativa subsp. sativa) that is known for its high levels of resilience to environmental pressures.
Responses to drought and salinity in terms of both performance and biochemical alterations are currently
being assessed. The results of this study will contribute to our understanding of the mechanisms behind
the superior ability of M. sativa subsp. falcata to withstand unfavourable conditions, which will facilitate
the development of novel alfalfa cultivars in the future.

Stacy Singer (stacy.singer@canada.ca)

P16. RNAi-mediated down-regulation of stress-response regulators in alfalfa for the improvement
of abiotic stress tolerance
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Singer, S. ; U. Subedi ; G. Dhariwal ; K. Burton Hughes ; G. Chen ; S. Acharya
1 Agriculture and Agri-Food Canada
2 University of Alberta
The livestock industry is vitally dependent upon our capacity to grow forage crops in a highly productive
manner. While alfalfa (Medicago sativa L.) is the most widely grown of the perennial leguminous
forages, unfavourable environmental conditions frequently have a considerable negative impact on its
production. It is anticipated that such climatic events will increase both in their severity and frequency in
the future as a result of climate change, and as such, there is an imminent need to improve alfalfa
productivity through the development of cultivars that are resilient to various types of abiotic stress.
Although several studies have shown promise in this regard, the vast majority have involved the stable
over-expression of transgenes. Despite their potential for economic benefit, public concern and regulatory
constraints surrounding the use of such technology for trait improvement have proven challenging.
Therefore, the aim of this project is to assess the effect of down-regulating a selection of gene homologs
in alfalfa shown previously in other species to act as negative regulators of stress response. Six such
homologs have been identified in alfalfa, and RNAi genotypes targeting each homolog have been
generated and are currently under assessment. Such targets have the potential to be utilized downstream
for the development of novel alfalfa cultivars with superior climate adaptability using either conventional
breeding or genome editing platforms.

Stacy Singer (stacy.singer@canada.ca)

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