Page 270 - PC2019 Program & Proceedings

PLANT CANADA 2019

P113. Minimizing unwanted callus during in vitro multiplication of daylilies
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Callaghan, J. ; M. Jones
University of Guelph

Daylilies (Hemerocallis spp.) are ornamental flowers renowned for their diversity, with over 80,000
registered cultivars varying in colour, shape and pattern. Traditionally propagated through division,
multiplication ranges from 1-20 divisions per season depending on the cultivar. Unfortunately, this leads
to a delay of up to 20 years for newly registered cultivars to reach marketable levels of plant material.
Micropropagation offers an alternative approach that can dramatically increase multiplication rates and is
used extensively for the species. However, protocols have only been developed for selected genotypes
and many protocols go through a callus phase introducing concern related to genetic mutations due to
somaclonal variation. Though direct regeneration has been documented, further research is needed to
refine the protocol and apply it to multiple genotypes. Our objective was to identify and optimize the
factors that encourage direct regeneration and evaluate their effect over multiple cultivars. From
comparative studies analyzing liquid vs. semi-solid systems, to cytokinin compositions, we have
significantly increased the leaf to callus ratio while maintaining a high rate of multiplication

Joshua Callaghan (callaghj@uoguelph.ca)

TOPIC 10: Crop Physiology (Poster P114)

P114. Investigation of the critical growth period for yield component determination in quinoa
McCabe, J.; H. Earl
University of Guelph

It has been shown that there is a critical growth period for different yield components in crops such as
corn, soybean and sunflower. This experiment will investigate the critical growth stage of quinoa for seed
number, 1000 seed weight and total seed yield. The experiment consists of 8 plots per rep with 4 reps.
There were 3 treatments with 2 levels per treatment: Nitrogen (100 kg/ha and 21 kg/ha), seeding rate (9
kg/ha and 3 kg/ha) and irrigation (irrigated and rainfed). Treatments were designed to create variation in
crop growth rates. Although nitrogen and irrigation treatments failed to cause statistical differences for
the majority of harvests, plots still differed significantly from themselves. Eight biomass harvests were
taken throughout the growing season and a final harvest was taken to measure yield components. These
biomass measurements were fitted to a growth equation and crop growth rates were taken from the fitted
curves. The correlation coefficient for crop growth rates at different times throughout the season and final
yield components was calculated. Early results indicate that early growth is more critical to seed number
and seed yield while later growth is more important for 1000 seed weight.

James McCabe (mccabej@uoguelph.ca)

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