Page 271 - PC2019 Program & Proceedings

PLANT CANADA 2019

TOPIC 11: Development and Reproduction (Posters P115-P119)

P115. The effect of hermaphroditism versus cross-pollination on sex ratios and genetic variation in
Cannabis sativa L.
*
Holmes, J. ; Z. Punja
Simon Fraser University

Cannabis sativa L. is a dioecious plant in which genetically female plants are cultivated for their
inflorescences (buds) which contain high levels of cannabinoids (THC, CBD). Male plants are undesired
except during breeding, as seed formation in flower buds reduces cannabinoid levels and quality. Under
certain environmental conditions, female flowers produce male anthers that form within the bud
(hermaphrodites, HF) and release pollen, causing undesired seed formation (feminized seeds, FS). HF
developing spontaneously during commercial production of three cannabis strains were studied. Anthers
were collected and morphological features were found to be similar to those of anthers in genetically male
flowers. The FS were viable and gave rise to 100% genetically female seedlings (compared to 50:50
female:male from cross-pollination) using a PCR-based gender identification test. In this test, a 540 bp
size band was present in female plants and 540 bp + 390 bp bands (or only a 390 bp band) were seen in
male plants. Features of LTR retrotransposons were found within these sequences. Anther tissues from
HF displayed the female banding pattern. The extent of genetic variation within seedlings derived from
FS was compared to that derived from cross-pollinated seeds using six ISSR primers. Percentage of
polymorphic loci was 44% to 72 % and Nei’s index of gene diversity and Shannon’s Information index
were comparable for both populations.

Janesse Holmes (janesseh@sfu.ca)

P116. Characterizing and understanding the underlying molecular mechanism of the sugarcane
anti-florigen ScFT2
1
*1
1
2
Lesy, V. ; M. Minow ; C. Coelho ; Z. Xu ; Z. Leblanc ; S. Rothstein ; A. Chalfun Junior ; J. Colasanti 1
1
1
1
1 University of Guelph
2 Universidade Federal de Lavras
Flowering time is a tightly regulated process that is essential for seed production and proliferation in
higher plants. The vegetative to reproductive transition is controlled by diverse cues acting through
distinct genetic pathways that converge at mobile floral integrators called florigens. These conserved
phosphatidylethanolamine-binding proteins (PEBPs) are synthesized in leaves and migrate to the shoot
apex to form a floral activation complex (FAC), which initiates reproductive growth by activating floral
organ specificity. In sugarcane (Saccharum spp.), several florigen gene candidates have been identified,
such as ScFT2. Interestingly, overexpression of this gene in Arabidopsis disrupts the floral transition and
causes a dramatic change in shoot architecture. This research aims to characterize the mechanism behind
this protein to determine how ScFT2 overexpression causes an extreme vegetative phenotype.
Localization experiments and interaction assays will be conducted to determine if ScFT2 interferes with
FAC formation by outcompeting endogenous PEBPs, and to identify new entities involved in floral
regulation. Mutants of well characterized floral genes will be complemented with ScFT2 overexpression
to prove clues as to the potential players involved in the anti-flowering phenotype. ScFT2 will also be
transformed into other species to fine-tune flowering for agricultural applications.

Victoria Lesy (vlesy@uoguelph.ca)

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