Denomination: 'MP21'
Trade name: Tiny Tunia White
Botanical Name: Petunia ×hybrida
Applicant/Holder: NuFlora International Pty. Ltd.
63 Wills Road
Macquarie Fields, New South Wales
Breeder: Graham Noel Brown, Baulkham Hills, Australia
Agent in Canada: Variety Rights Management
475 County Road 18
R.R. #2
Oxford Station, Ontario
K0G 1T0
Tel: 613-258-9015
Application Date: 2000-06-21
Application Number: 00-2326
Date abandoned: 2007-12-10

Variety Description

Variety used for comparison: 'Danpetbri' (Petitunia Bright Dream)

Summary: 'MP21' has shorter shoots and smaller diameter flowers with longer corolla tubes than 'Danpetbri'. Anthocyanin colouration of the stems of 'MP21' is absent while for 'Danpetbri', it is weak. 'MP21' has more conspicuous venation on the inner side of the corolla than 'Danpetbri'. The main colour of the inner side of the corolla tube is yellowish green for 'MP21' while it is light blue violet for 'Danpetbri'. The veins on the inner side of the corolla tube are moderately conspicuous for 'MP21' while those of 'Danpetbri' are very strongly conspicuous.


The plants of 'MP21' are short with a creeping growth habit. The shoots are medium in thickness and short to medium in length with absent to very weak anthocyanin colouration. The leaf blade is elliptic to round in shape with a broad acute apex. The colour of the leaf blade is medium green with no variegation. The leaf blade has no blistering. The sepals range from linear to obovate in shape and have no anthocyanin colouration.

'MP21' has single type, funnel form flowers. The colour of the upper side of the corolla is white. The veins on the inner side of the corolla lobes are yellow green and weak to moderately conspicuous. Undulation of the corolla margin is moderate. The inner side of the corolla tube is mainly yellowish green and conspicuousness of the veins is moderate. The colour of the anthers before pollen dehiscence is light gray.

Origin & Breeding History: 'MP21' originated from a Petunia ×hybrida breeding program started in 1993 by the breeder in Baulkham Hills, New South Wales, Australia. The goal of this breeding program was to develop miniature trailing petunias. A number of smaller flowered petunias including Petunia integrifolia (Hook.) Schinz & Thell. were crossed with a range of annual, single and double varieties. Two cycles of crossing and selection were undertaken each year until 1997 when promising F1 selections were identified. These were crossed in 1997 to give further F1 selections. These selections were crossed in 1998 and the resulting seedlings were grown in field and greenhouse trials during 1999-2000. 'MP21' was selected based on the criteria of the breeding program which were improved flower colour, flower size and plant growth habit.

Tests & Trials: The test and trial for 'MP21' was conducted in a polyhouse during the summer of 2005 at Variety Rights Management in Oxford Station, Ontario. The trial included 15 plants of each variety. The plants were grown in 10 cm pots spaced 15 to 20 cm apart. All colour characteristics were determined using the 2001 Royal Horticultural Society (RHS) colour chart and measured characteristics were based on ten plant measurements.

Comparison tables for 'MP21' with reference variety 'Danpetbri'

Flower diameter (mm)

  'MP21' 'Danpetbri'
mean 32.14 38.50
std. deviation 4.34 4.85

Corolla tube length (mm)

  'MP21' 'Danpetbri'
mean 24.72 20.83
std. deviation 0.83 1.72

Colour of corolla (RHS)

  'MP21' 'Danpetbri'
inner side 155D 155D

Colour of corolla tube (RHS)

  'MP21' 'Danpetbri'
inner side 151B 92D

Click on image for larger view
Petunia: 'MP21' (left) with reference variety 'Danpetbri' (Petitunia Bright Dream) (right)

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