PS 6545691


Denomination: 'PS 6545691'
Botanical Name: Lactuca sativa
Applicant/Holder: Seminis Vegetable Seeds, Inc.
800 North Lindbergh Blvd.
St. Louis, Missouri
United States of America
Breeder: Bill Waycott, Seminis Vegetable Seeds, Inc., Oxnard, United States of America
Agent in Canada: Seminis Vegetable Seeds, Inc.
613 Tomahawk Cresent
Ancaster, Ontario
L9G 3T4
Tel: 905-304-1795
Application Date: 2004-08-11
Application Number: 04-4315
Grant of Rights Date: 2009-02-27
Certificate Number: 3455
Date rights revoked: 2011-07-19

Variety Description

Variety used for comparison: 'Clemente'

Summary: 'PS 6545691' has a smaller, denser head than 'Clemente'. The leaves of 'PS 6545691' are slightly darker green, thicker and less erect than 'Clemente. 'PS 6545691' has an obovate shaped leaf while it is elliptic in 'Clemente'. The leaf margin of 'PS 6545691' has stronger undulation with deeper incisions than 'Clemente'.


SEEDLING: absent or very weak anthocyanin, small narrow elliptic cotyledon

LEAF: semi-erect attitude at maturity, thick, obovate, dark grey green, no anthocyanin, medium glossiness on upper side, flat surface profile of outer leaves, absent or very weak small blisters, entire margin, strong undulation of margin, medium depth incisions of apical part, medium density of incisions of apical part, not flabellate venation, absent or very weak axillary sprouting

HEAD: romaine type, open to closed (overlapping) formation, medium density, elliptical shape in longitudinal section

SEED: black

DISEASE RESISTANCE: resistant to lettuce mosaic virus (strain Ls1)

Origin & Breeding History: 'PS 6545691' originated from a cross made in 1993 of 'PI206964' by 'Salinas 88' at the Petoseed Company's Research Station in Arroyo Grande, California, USA. Pedigree selection using both single plant and mass selection practices were used with the selection criteria of plant form, leaf colour, leaf texture, taste, head density and disease resistance.

Tests & Trials: Tests and trials were conducted during the summer of 2007 in Lynden, Ontario. There were 10 replications with 15 plants per replicate. Plants were spaced 15 centimeters apart within the row, with a row spacing of 75 centimeters. Results were supported by the official Plant Breeders' Right technical examination report, 2003/2147, purchased from the Community Plant Variety Office.

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PS 6545691
Lettuce: 'PS 6545691' (left) with reference variety 'Clemente' (right)

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