|Previously Proposed Denomination:||'AAC Exacta'|
|Botanical Name:||Lactuca sativa|
Agriculture & Agri-Food Canada
Office of Intellectual Property and Commercialization
6000 C&E Trail
Sylvie Jenni, Agriculture & Agri-Food Canada, Saint-Jean-sur-Richelieu, Quebec
|Agent in Canada:||
Foundation for Breeding Lettuce and Leafy Vegetables
316, Rang Saint-André
Varieties used for comparison: 'AAC Canicula', 'Prestige' and 'Estival'
Summary: The shape of the outer leaf of 'AAC Global' is circular whereas that of 'AAC Canicula' has a transverse narrow elliptic shape and that of 'Prestige' has transverse broad elliptic shape. At harvest maturity, 'AAC Global' has a shorter stem than that of 'Prestige'. In cross-section, the head of 'AAC Global' has a narrower diameter than that of 'Prestige' and 'Estival'. 'AAC Global' has weak to medium blistering on the upper side of the leaves whereas it is very weak on the leaves of 'Prestige'. At flowering, the plant of 'AAC Global' is shorter than 'AAC Canicula' and 'Estival'. Under long day conditions, bolting begins mid to late in the season for 'AAC Global' whereas 'Prestige' begins bolting early to mid-season.
PLANT: closed head type, bolting under long day conditions begins mid to late season, harvest maturity at mid-season
SEEDLING: no anthocyanin colouration, no division of leaf blade at 10 to 12 leaf stage
HEAD: closed head formation with a medium degree of overlapping of upper part of leaves, dense, circular shape in longitudinal section
LEAF: medium to thick, semi-erect to horizontal attitude at harvest maturity, circular shape, no hue of other colour on green outer leaf, moderate to strong intensity of green colouration on outer side of outer leaf, no anthocyanin colouration, weak to moderate glossiness on inner side, weak to medium degree of blistering, medium sized blisters, weak degree of undulation of margin, flabellate (fan shaped) venation
INCISIONS OF MARGIN ON APICAL PART OF LEAF: sparse to medium density, shallow
SEED: black seed coat
Origin & Breeding History: 'AAC Global' (experimental designations 'X300' and 'QSJ-05') originated from a cross made in October 1998 between 'Valleyfield', as the female parent, and 'Ithaca', as the male parent, in the greenhouses of the Agriculture and Agri-Food Canada Horticultural Research and Development Centre in Saint-Jean-sur-Richelieu, Quebec followed by single plant selection using the pedigree method. F1 seeds were planted in the greenhouses in December of 1998 and F2 seeds were collected and bulk massed in June of 1999. From 2000 to 2001, successive generations were grown and harvested at the Sainte-Clotilde experimental station and at a muck soil farm in Napierville, Quebec. The selections from each were based on good 'Vanguard' character combined with size, colour, weight, low ribbiness, leaf configuration, short stem, pointed base and lack of symptoms of rib discolouration and tipburn. In 2003, F5 seedlings were transplanted and evaluated. One of these selections (Number 251) was regenerated using in vitro culture and produced 1755 F6 seeds. From 2004 to 2006, consecutive single plant selections continued on the F6 to F8 plants. In 2007, F9 seedlings started in the greenhouse were transplanted to be evaluated at four planting sites in Sainte-Clotilde and Napierville. In addition, F9 seeds were planted in single plant progeny rows in the San Joaquin Valley in California for seed evaluation and multiplication. Ten single plants were selected and F10 seeds were collected from individual plants, the remainder of which were bulk massed after harvest in September of that year. Trials were assessed in replicated plots from 2008 to 2014. In December of 2014, the new variety became known as 'QSJ-05'.
Tests & Trials: The comparative trials for 'AAC Global' were conducted at the Ferme JPL Guérin, in Sherrington, Quebec during the 2016 and 2017 growing seasons. Both the candidate and reference varieties were sown in the greenhouse and later transplanted into fields of organic soil. Plots were arranged in a RCB design with 4 replications in 2016 and 3 replications in 2017. Each plot contained 80 plants resulting in a total of 320 and 240 plants per variety in 2016 and 2017, respectively . The plots were composed of two rows spaced 35.5 cm and planted in mounds that were 14.6 metres long and 0.91 metres wide. The plants were grown under normal conditions for cultivation with long days (photoperiod between 15 and 16 hours per day). The lettuce was harvested and evaluated at the time of optimal maturity during the last 2 weeks of July. For each trial year, measured characteristics were based on measurements of at least 12 plants per replicate for a total of 48 plants in 2016 and 36 plants in 2017 per variety except for the plant height at flowering which was based on a total of 20 plant measurements per variety. Mean differences were significant at the 5% probability level based on LSD values.
Comparison tables for 'AAC Global' with reference varieties 'AAC Canicula', 'Prestige' and 'Estival'
Length of stem (from base of first external leaf forming head to apical bud) (mm)
|'AAC Global'||'AAC Canicula'||'Prestige'||'Estival'|
|mean (2016) (LSD=5.0)||55.9||51.9||67.4||57.1|
|std. deviation (2016)||5.0||7.5||7.1||5.7|
|mean (2017) (LSD=5.1)||52.8||48.3||65.8||53.3|
|std. deviation (2017)||3.3||3.1||6.9||5.0|
Plant height at flowering (cm)
|'AAC Global'||'AAC Canicula'||'Prestige'||'Estival'|
|mean (2016) (LSD=4.5)||97.4||102.5||95.5||106.2|
|std. deviation (2016)||8.5||6.2||6.5||6.9|
|mean (2017) (LSD=4.1)||99.7||104.3||98.4||108.1|
|std. deviation (2017)||6.2||5.6||7.2||6.5|
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