WELCOME

PRESENTATION ON

GENETIC IMPROVEMENT, ACHIVEMENTS AND HYBRID SEED PRODUCTION IN PETUNIA

ByName-Sunita Kumari ID- 13MSHFC018 M.Sc HorticultureDepartment of HorticultureSHIATS, ALLAHABAD

INTRODUCTIONPetunia is an annual herbaceous plant.

Petunia X hybrida belongs to the family Solanaceae

Petunia is genus of 35 species of flowering plants of South American origin.

It is a result of the hybridization between two different species of petunia flowers i.e. Petunia axillaris (a white large typed and night scented petunia) and Petunia integrifolia a mainly violet colure petunia.

Petunia axillaris X Petunia integrifolia

( Sl or SC?) (SI)

First Petunia hybrids (Sl or SC?) Breeders

select for SC Modern day Petunia hybrida (Sl)

Petunia have a gametophytic system of self incompatibility and Cytoplasmic male sterility.Origin of self-incompatibility:-

Robbins T.P. et al, 1999

Uses of Petunia hybridaPetunia is recommended for the following application :-

Container planting

Border edging

Hanging baskets

Mass planting

General garden use

Types of petunia Petunia varieties can be divided into four main groups or

categories based on flower and growth habits. The four categories are :-

1) Grandifloras -Grandifloras are large-flowered petunias consisting of both single and double flowering forms.

Single grandiflora for window boxes and hanging baskets.

Double grandiflora best suited to containers Single grandifloras

Popular grandiflora petunias include varieties in the Super cascade, Super magic, Ultra, and Falcon Series.

2) Multiflora petunia:- Multiflora petunias have flowers which are smaller and more

flowers than the grandifloras. There are both single and double flowered Multiflora petunias. Single multifloras are excellent in mass plantings in flower beds. Double multifloras are most suitable for containers. petunias include varieties in the Celebrity, Primetime, and

Carpet Series.

Double grandiflora

3) Milliflora petunias:- Milliflora petunias are

compact, miniature plants that produce large numbers of 1- to 1 1/2- inch-diameter flowers.

Their compact size makes them an excellent choice for containers and edging beds and borders.

Varieties in the Fantasy Series are widely grown milliflora petunias.

4) Spreading or “ wave” petunia:- The first introduction in this category was 'Purple Wave.' A 1995 All-America Selection, 'Purple Wave' grows 4 to 6 inches

tall, but can spread 2 to 4 feet. The burgundy-purple flowers measure 2 inches across.

They are excellent choices for hanging baskets and as an annual groundcover Recent additions to this group are 'Pink Wave,' 'Rose Wave,' 'Misty Lilac Wave, and 'Coral Wave.'

BotanyPetunia seed is 0.6-0.7 mm in length, 0.5-0.6 mm in diameter, spheroidal-angular, light to

dark brown in color, reticulate, thin walled with a conspicuous hilum that is the same color as the seed coat.

There are approximately 250,000 petunia seeds per ounce .

The fruit of a petunia is a capsule which varies in size, shape, and seed count depending on the species.

The flowers of petunia are perfect with five epipetalous stamens that terminate at various

heights below the stigma .

The petunia leaves are alternate or opposite, broad-ovate to cordate shaped, 1.5-3.0 inches long, simple, entire margins, with stems and leaves covered

BREEDING OBJECTIVES1) Developed new flower colour2) Creating interesting and unusual flower patterns3) Introduction of spectacular colour range in single

flowered, double flowered, grandifloras and multiflora petunias.

4) Modification of plant growth habit in different groups like mound, prostrate, compact and spreading growth habit.

5) Developing of miniature trailing petunias.

6) Developing dwarf petunia plants and miniature flower for ornamental purpose

7) To induce earliness.8) Creation of attractive petunia which will with stand a

wide variety of conditions.9) Evaluating petunias with excellent performance in the

garden as a bedding plant.

Breeding methods IntroductionModified pedigree selectionHybridizationMutation breeding methodBiotechnology

The grandiflora petunia type was developed in early 1950, with the first F1 hybrid grandiflora, 'Ballerina,' introduced in 1952

The Multiflora petunia type was developed in late 1940, with the first F1 hybrid Multiflora, 'Comanche,' introduced in 1953.

The floribunda type resulted from recent hybridization between grandifloras and multifloras.

Milliflora petunias developed from a chance genetic mutation from Petunia x hybrida, resulting in a true miniature plant.

Spreading type new breed of petunia that has more of a tropical

nature than other petunia types

Cultivars1) New hybrid series Allegro, Apple Tart, Apricot Tart, Blue Danube, Coral Bells, Dream,

Grandiflora- Ballerina , Fairyland, Grape Tart, Multiflora-Silver Medal, Polo, Orange Bells, Summer Sun, Sweet Dream, Mini Purple

2) F1 Hybrid Grandiflora Blue Lace, Blue Magic, Sugar Daddy, Astro, Cascade, Happiness,

Pink Cascade, Pink Magic, Pink Show, Candy Apple, Red Cascade, Red Magic, Snow Lady, White Cascade, White Magic, Snow jewel

3) F1 Hybrid MultifloraPolar Cap, Orange Bells, Red Joy, Mercury, Red Plum, Satellite,

Star Fire, Star Joy, Dream Girl

4) F 1 Hybrid Double Multiflora:- Apple Tart, Cherry Tart, Peach Tart , Pink Delight, Raspberry Tart,

Snowberry

5) Cascade F1 Hybrid :- Pink Cascade, White Cascade

Cytoplasmic Male sterility (CMS)

Emasculation and pollination

Self incompatibility – Pi-SLF (gene

Petunia inflata S-locus F-box) : The

gene responsible for self-

incompatibility was identified

Techniques of hybrid seed production in Petunia hybrida

Cytoplasmic male sterility Maureen Hanson’s group at Cornell University (Ithaca, NY, USA)

has cloned a mitochondrial gene that encodes Cytoplasmic Male Sterility (CMS) in Petunia.

The gene encodes an abnormal protein that disrupts mitochondrial activities.

A nuclear gene (the Restorer fertility or Rf gene) is known to interact with this mutant mitochondrial gene, reducing its expression and thereby restoring normal fertility to male sterile genotypes.

The group has identified the Petunia Rf gene by cloning candidate genes from map position and demonstrating that such a gene is able to confer fertility to CMS Petunia lines.

Subsequently, genes highly similar to the Petunia Rf have been identified as fertility restorers in Brassica and rice.

S

F

S

Male sterile

Male sterile

Male fertile

F1 seeds 100% male sterile

Cytoplasmic male sterility

1) pollen collection

Pollen collection can be a simple procedure for plants that shed large quantities of loose

pollen grains.

Some production facilities have installed centralized vacuum pumps to allow pollen

collection by suction in the entire greenhouse as shown here.

The anthers of some flowers can be collected prior to anthesis.

These anthers are then dried, ground, and pollen grains extracted from the remaining

tissue by sieving.

Extracted pollen can be cold-stored and used for weeks and months.

The pollen should be held in air-tight containers such as glass vials during cold storage in

frostless freezers to maintain proper pollen moisture content. When pollen quantities are

limited, inert materials can be added to allow pollination of a large number of flowers

Emasculation and pollination

2) Emasculation The petals are gently peeled back to expose the immature anthers, which are

removed by hand.

3) Pollination The flowers are ready for pollination one or two days after emasculation.

Flower to flower pollination is practiced when fresh pollen is applied.

The pollen is placed on the stigmatic surfaces by means of a brush as seen here.

Identifying the correct location of the stigma requires training.

The receptive surface is located at the tip of the gynoecium

The timing of pollination is important for seed yield. Optimal seed set is

obtained when the flowers are pollinated at the peak of stigma receptivity.

Inability to set seed from application of pollen produced on same plant or it refers to failure of viable pollen of a given plant to fertilise the ovules of the same plant, but it capable of fertilising effectively the ovules of the most other plant of the same variety.

Brew baker-1957. stated that self incompatibility occurs in more than 3000 sp belonging to 250 genera, spread in about 70 families.

Self incompatibility:

In petunia in the 1930’s, two separate groups (Harland and Atteck, and Wergin) independently confirmed that the genus of Petunia possesses a gametophytic system of self-incompatibility (Ascher, 1984).

Gametophytic. “SI reaction of a pollen is determined

by its own genotype not by the genotype of the plant on which the pollen is produced”

Petunia: Hybrid seed production field view

Sun Ray Purple Ray Candy Pink Ray

Suncatcher Pink Vein Suncatcher Coral Prism

Suncatcher Midnight Blue Suncatcher Dark Lavender Vein

Red Ray Suncacther Plum Vein Sun Spun Silver

Falcon White Celebrity Plum Ice

‘Fantasy Pink Morn', a milliflora type petunia

Petunia ‘Purple Wave'

Thank you