Trends of Molecular breeding in floriculture.ppt

Ornamental horticulture is a very important economic aspect of horticulture, and floriculture is in turn a dominant sector of ornamental horticulture. One feature of floriculture, which covers both cut flowers and pot plants, is that certain crops dominate sales. This is obviously an important consideration in any program aimed towards the development of genetically modified ornamental products. A second feature is that the cut flower industry is a global industry.Ornamental horticulture, and particularly floriculture, is well suited to the application of genetic engineering technology. One reason is that the end product is not a food and thus reduces the need to undergo food safety studies, thereby reducing the cost of commercialization. Genetic engineering allows the introduction of genes from outside the gene pool, and is precise, because a gene or genes targeted for a specific trait can be introduced. Biotechnology also shortens the time frame for new variety development.

1. P. Lalitha Kameswari

2. Introduction
•Ornamental floriculture is becoming an important
industry
•Ornamentals include a large variety of crop plants
Cut flowers,
Bulbs and corms
Flowering pot plants
Foliage plants
All the present day ornamental varieties and
novelties are as a result of extensive hybridization,
induced mutation and selection

3. •Color modification
•Vase life and perfume: S-linalool
isolated from clarkia used to modify
scent in carnations and lisianthus
Cut
flowers
•Novelty
•Colour modification
•Enhancement of flower life
•Manipulation of plant & flower form
•Reduction in leaf senescence
•Hormone metabolism to dwarf the plants
Pot &
bedding
plants Introduction

4. Plantbreedingisathreestepprocess,
whereinpopulationsorgermplasm
collectionswithusefulgeneticvariationare
createdorassembled,individualswith
superiorphenotypesareidentified,and
improvedcultivarsaredevelopedfrom
selectedindividuals.
Molecular Plant Breeding
-Expands Useful Genetic Diversity for Crop
improvement
-Increases Favorable Gene Action
-Increases the Efficiency of Selection

5. Prospects of Molecular breeding in
floricultural crops
Genetic engineering has the capability of increasing the
gene pool available for crop improvement.
The genes conferring desirable traits such as blue
pigmentation potentially can be transferred to species
where these genes previously did not exist.
Molecular breeding approach lies in the ability to alter
a single trait without altering other genetic traits of plant.
Thus molecular breeding provide the opportunity to
produce novel and elite flower varieties that will
command a high premium in the market.

6. Limitations of traditional breeding in flower
crops
The improvement is hampered by a limited gene pool.
Extreme heterozygosity in many valuable floricultural
crops like rose, chrysanthemum, carnations etc
Lack of inbred lines, directed breeding efforts for
individual traits are very difficult.
Modification of one character through hybridization can
often be at the expense of another equally valuable feature.
Lack of precision.
sexual compatibility of the plants involved.

7. The production of novel flower colour
Other traits that have received attention include
floral scent,
floral and plant morphology,
delayed senescence of flowers both on the plant
and post-harvest and
disease and insect resistance.
success stories in floriculture molecular
breeding….

8. Traitsthatbreedershavetriedto
incorporateintocultivatedfloricultural
cropsinclude:
Increased quality and yield of the crop
Increased tolerance of environmental
pressures (salinity, extreme
temperature, drought)
Resistance to viruses, fungi and bacteria
Increased tolerance to insect pests
Increased tolerance of herbicides

9. 10
Desired gene
Traditional plant breeding
DNA is a strand of genes,
much like a strand of
pearls. Traditional plant
breeding combines many
genes at once.
Traditional donorCommercial varietyNew variety
Desired Gene
X =
(crosses)
(many genes are transferred)
Plant biotechnology
Using plant biotechnology,
a single gene may be
added to the strand.
Desired geneCommercial varietyNew variety
(transfers)
=
Desired gene
(only desired gene is transferred)
What is plant biotechnology?

10. Deoxyribonucleic Acid (DNA)

11. Molecular approaches in floral crops
Molecular markers and mapping
Gene cloning
Plant transformation

12. What is a molecular marker?

13. GENETIC LINKAGE

14. TYPES OF MOLECULAR MARKERS
•Due to rapid developments in the field of molecular genetics, a
variety of molecular markers has emerged during the last few
decades
Biochemical
marker
Allozyme
Non-PCR based
marker
RFLP, Minisatellite (VNTR)
PCR based
marker
Microsatellite, RAPD, AFLP, CAPS
(PCR-RFLP), ISSR, SSCP, SCAR,
SNP, etc.
Traditional
marker systems
PCR generation:
in vitro DNA
amplification

15. Application of molecular markers
•Assessing the genetic variation within a crop
•Selection of favourable genotypes for crossing
•Mapping genes and/or QTLs in breedingmaterial
•Introgression of genes of genomic regions into
breeding material
•Assessing distinctness, uniformity and stability
of crop varieties

16. MASreferstotheuseofDNAmarkers
thataretightly-linkedtotargetlocias
asubstituteforortoassistphenotypic
screening.Bydeterminingtheallele
ofaDNAmarker,plantsthatpossess
particulargenesorquantitativetrait
loci(QTLs)maybeidentifiedbasedon
theirgenotyperatherthantheir
phenotype.
MARKER ASSISTED SELECTION

17. Marker Assisted Selection
A
Gene of interest
AMarker linked to gene
X
A
Cycles of breeding
A A A
A
A
X
Eliminate
individuals
without marker
New variety

19. Advantages of MAS
•Simpler method compared to
phenotypic screening
–Especially for traits with laborious screening
–May save time and resources
•Selection at seedling stage
–Important for traits such as flower quality
•Increased reliability
–No environmental effects
–Can discriminate between homozygotesand
heterozygotesand select single plants

20. Potentials oftransgenic crops
Plant transformation is the introduction of small
fragments of DNA into the chromosomes of a host plant.
➢Gene(s) for desirable traits from anyorganism
can be functionally introduced into the crop of interest
➢Gene dosage can be precisely controlled
➢Tissue-specific expression of the
transgene can be regulated
➢Genes in the wild species can be cloned
and introduced into desired cultivars

21. •Using r DNA technology -multiple copies of a desired gene-
all identical in a bacterial cell or any other host cell as inserted
DNA replicate along with host DNA-Gene cloning.
•Of late gene cloning in a computerized machine Thermocycler
by Polymerase Chain Reaction (PCR)
Genetic engineering

22. CODING SEQUENCEINTRON poly A signalPROMOTER
Building the Transgenes
Plant Transgene
bacterial genes
•antibiotic marker
•replication origin
Plant Selectable
Marker Gene
Plasmid DNA
Construct
ON/OFF Switch Makes Protein stop sign

23. Gene cloning

24. GM Plants-Milestones
23 biotech crop countries.
biotech crop area grew 114.3 million hectares,2007
Therecentintegrationof
advancesinbiotechnology,
genomicresearch,andmolecular
marker applicationswith
conventionalplantbreeding
practiceshascreatedthe
foundationformolecularplant
breeding

25. 14
More than 50 biotech food products
have been approved for commercial
use in the United States
•Canola
•Corn
•Cotton
•Papaya
•Potato
•Soybeans
•Squash
•Sugarbeets
•Sweet corn
•Tomato
Products on the market

26. 15
Four crops accounted for nearly all of
the global biotech crop area in 2002
Sourc e: International Serv ice for the Acquisition of Agri-biotec h Applications5%
12%
21%
62%
Canola
Cotton
Corn
Soybeans
Products on the market

27. 16
Four countries accounted for 99 percent*
of the global biotech crop area in 2002
*Australia, Bulgaria, Colombia, Germany, Honduras, India, Indonesia, Mexico, Romania, South
Africa, Spain and Uruguay accounted for the remaining 1 percent of biotech crop acres.
Sourc e: Internati onal Serv ice for the Acquisi tion of Agri-biotec h Appli cations4%
6%
23%
66%
China
Canada
Argentina
United States
Products on the market

28. How are GMOs generated?
insert into plant
…via biolistics-or -Agrobacterium tumefaceins
...uses tools of molecular
genetics,
-i.e. applied bacteria and
virus genetics.

29. Transgenic Plants
•based on DNA technology,
•singlegenes/traits can be transferred,
•species boundaries are not limiting.

30. •Genetic engineering of plants is much easier than animals.
there is natural transformation system for plants
(Agrobacterium)
Gene gun method (biolistictransformation)
Electroporationmethod
Agrobacteriumtumefacienscan infect wounded plant
tissue, transferring a large plasmid, the Ti plasmid, to the
plant cell.
Genetic engineering contd..

31. Agrobacteriumtumefaciens
Kalanchoe Stem
w/ infection.
Natural soil bacterium
that infects plants,
hosts: 160 Genera,
families: > 60,
effect; poor growth, low
yield.

34. Agrobacterium
Plant Cells
Nature
Ti-Plasmid Transfer-DNA
Hormone
genes
Opines
genes
Lab
Selectable Markers, etc
Any Gene
Out: Ti genes, opine genes,
In: DNA of choice.
T-DNA
Ti:tumor inducing
Plasmid:
extrachromosomal DNA
evolved for genetic
transfer.

35. Genegun
www.tritechresearch.com

36. Biolistics

37. Biolistics
•DNA is bound to metal (often gold) particles and
literaly shot into the cell (gunpowder or
compressed gas).
•The rare events in which foreign DNA has been
incorporated into the host genome are identified
using screening for selectable marker phenotypes
(e.g. herbicide resistance)

38. •Microinjection:
•DNA solution is injected
directly inside the cell
using capillary glass
micropipetts
Genetic engineering contd..

40. IMPORTANT TRAITS USED IN TRANSGENIC FLOWERS
TRAIT GENE(S) AND PATHWAYS
Flowercolour Flavonoid biosyntheticand regulatory genes
Anthocyaninbiosynthesis genes
Betalainbiosynthesis genes
Co-pigmentation production genes
Genes governing vacuolar pH in petals
Flower shelf lifeEthylene biosynthesis genes(ACC synthase, ACC oxidase, ACC
deaminase
Ethylene receptors and signal transduction(ETR,FBP 1 genes)
Floralscent Genes of fatty acid derivatives
Genes responsible for volatile production like S-linalool synthase
FlowerarchitectureGenes that regulate switching ofvegetative meristemsto floral
meristems
Genes that regulate inflorescence development and arrangement
Genes that regulate flower architecture especially petals and sepals
PlantarchitectureGenes that regulate height, phyllotaxy, shoot branching and plant type

41. Flower colour modification
•Flower colour is predominantly due to three
types of pigment:
flavonoids, carotenoids and betalains.
•Anthocyanins are colored class of flavonoids, water
soluble pigments responsible of orange,red,purple
and blue
•Carotenoids are lipid soluble responsible for yellow
and orange flowers
•Betalains are water soluble nitrogenous compounds
produced from tyrosine amino acid precursor.
•The red to violet colour is due to betacyanins and
yellow to orange colour is due to betaxanthins.

42. Thecolourofaflowerisgenerallyacombinationofanumber
offactorsincludingthetypeofanthocyaninaccumulation,
modificationstoanthocyanidinmolecule,co-pigmentation
andvacuolarpH.
Co-pigments:Flavonolsandflavonesarethecommon
copigmentsthatstabilizeandlendbluingtoanthocyaninsby
formingcomplexeswiththem.
VacuolarpH:oftenmaintainedasweaklyacidiciscriticalto
anthocyaninstabilityandcolour.HigherpHyieldsblueflower
colours.Theonlystructuralgenethat
regulatevacuolarpHisfoundin
morningglory.Thisgeneishighly
expressesjustbeforefloweropening,
whichelevatespHfrom6.5to7.5and
changesthecolourfrompurpletoblue.

43. FLAVONOID BIOSYNTHETIC PATHWAY

44. Color modification of Torenia hybrida cv. Summerwave Blue.
By genetic engineering blue cultivar is generated to white lines.
Left; the host, middle; a transgenic line with a co-suppressed
DFR gene, right; a transgenic line with co-suppressed CHS gene
(Suzuki et al., 2000).
GENERATING WHITE FLOWERS BY GENE SUPPRESSION
White flowers from anthocyanin producing flowers can be obtained
by down regulating the expression of structural or regulatory genes in
the pathway.
CHS(Chalcone synthase) is the common target for down regulation of
anthocyanin biosynthesis.

45. •Reducing expression of endogenous pigment
biosynthesis:
•This has been accomplished in Petunia using
antisense RNA technique.
Genetic engineering for white flower contd..

46. •It invloves insertion of a reverse orientation copy of the
endogenous gene ( encoding chalcone synthase)
•The expression of this inserted gene gives rise to
complementory mRNA or antisenese mRNA strand that
forms a duplex with the sense strand.
•This duplex likely is unstable and is not available for
translation
Genetic engineering for white flower contd..

47. Normal gene
3’ TAC ACC TCG TTC CTC 5’
Antisense gene
3’GAG GAA CGA GGT GTA 5’
5’ATG TGG AGC AAG GAG 3’ 5’ CTC CTT GCT CCA CAT 3’
mRNA Antisense mRNA
5’AUG UGG AGC AAG GAG 3’ 5’ CUC CUU GCU CCA CAU 3’
Double stranded mRNA
5’ AUG UGG AGC AAG GAG 3’
3’ UAC ACC UGC UUC CUC 5’
No translation
No enzyme

48. Genetic engineering for white flower

49. •CHS-silencing would lead to the abolishment of the entire
array of flavonoidcompounds in plants.
•sometimes, this would cause the plants to be more sensitive
to environmental stresses and might lead to sterility in
some species.
•DFR and F3’H –alternative silensingtargets for producing
white flowers.
•When F3’H is silenced in carnations transgenic plants were
obtained with reduced anthocyaninsand increased
fragrance (Zukeret al., 2002)
Genetic engineering for white flower contd..

50. -Colour modification of Lobelia erinus, Left: the host,
right; a transgenic lobelia expressing lisianthus F3’5’H.
(Kanno et al., 2003).
-Carnation cultivar Exquisite (left) accumulates
predominantly cyanidin-based pigments,
transgenic Exquisite flower expressing petunia
F3’5’H
-cytochrome b5 genes (right) accumulates
predominantly delphinidin-based pigments.
(Brugliera et al., 2000b).
GENERATING BLUE FLOWERS
-Most blue flowers contain delphinidin derivatives
-Key enzyme in the biosythesis of delphinidin is F3’5’H
-F3’5’H genes are isolated and cloned from petunia,
lisianthus and canterbury bells.

51. Florigene Ltd. And Suntory Ltd developed a range of violet carnations by
introduction of F3’5’ H gene with a petunia DFR gene into a white carnation.
Four standard (upper) and two spray (lower) varieties are sold in USA, Australia
and Japan in the name of Moondust, Moonshadow, Moonvista, Moonacqua,
Moon lite and Moonshade.
Besides gene F3’5’H gene expression, the presence of flavone a copigment
and high vacuolar pH of 5.5 accounted for accumulation of delphinidin type of
anthocyanins.
VIOLET CARNATIONS

52. •In petunia cyanidinand delphinidinderivatives but no
pelargonidinderivatives.
•Enzyme dihydroflavonol4 reductaseshows substrate
specificity -can’t reduce dihydrokaempferol–no
pelargonidin
•A1 gene from maize encodes dihydroquercetin4 reductase-
doesn’t show substrate specificity as
does petunia enzyme.
Genetic engineering for red/ orange flowers

53. Petunia DFR is unable to reduce dihydrokaempferol and
so flowers rarely contain brick red colours.
Red petunia producing pelargonidin was made by
downregulation of the F3’H gene and expression of rose
DFR gene
(Mizutani et al., 2003).
Initially the F3’5’H gene was down
regulated so that light pink flowers were
obtained.
Over-expression of a torenia F3’H gene in
the line generated darker pink flowers in
torenia cv. Summerwave
(Ueyama et al., 2002).
GENERATING RED TO ORANGE FLOWERS

54. Chalcones and aurones contribute to yellow
flowers. A pale yellow petunia expressing a
PKR (polyketide reductase )gene from
Medicago sativa
PKR gene stabilizes chalcone and results in
yellow colour
Insertion of transposon into a flavonoid
biosynthetic gene has resulted in white
sectors in a coloured background.
Morning glory flowers with transposons.
GENERATING YELLOW FLOWERS
(Davis etal, 1998)
(Iida etal., 1999)

55. Crop Flower trait Target
Petunia hybridaWhite to red
Purple to white
White to red
Sepal colour genes to dark
purple
White to pale yellow
Mutant maize gene
Chalconesynthase
Maize LC regulatory gene
Maize LC regulatory gene
Flavonoid biosynthesis
Rose Red to deep purple
Redto pink
Red to light/magenta red
Red to blue
F3’5’H gene
Anthocyaninbiosynthesis
Anthocyaninbiosynthesis
Delphinidin accumulation
Dianthus White to mauve, violet
Orange to cream
Flavonoid biosynthesis
F3’H
Gerbera
Dendrathema
Red to pink, cream
Pinkto white
Chalconesynthase gene
Flavonoid biosynthesis
Torentia Blue to white
Blue to red
Anthocyaninbiosynthesis
CytochromeP450 gene
MOLECULAR TARGETS FOR MODIFYING FLOWER COLOUR

56. Genetic engineering for longer vase life
The post harvest life of flowers is influenced by nutrition,
microbial colonization and ethylene, a plant hormone
associated with senescence
The effect of ethylene on post harvest
life of cut flowers is tremendous.
Even though chemicals such as STS
are used to improve the vase life, they
are toxic and pose risk at several stages
Genetically manipulating the ethylene
production can bring about the
improvement of shelf life.
ACC oxidase and ACC synthase are
the two important genes involved.

57. TRAIT GENE(S) AND PATHWAYS
ACC synthaseInhibition causes reduced ethylene production
ACC oxidaseInhibition causes reduced ethylene production
ACC
deaminase
Over expression causesreduced ethylene
production
Etr1 Expression of a defective gene causes reduced
ethyleneproduction
ERS Expression of a mutated gene causes reduced
ethylene production
GENES FOR ENHANCING FLOWER SHELF LIFE

58. Genetic engineering for longer vase life
Left : the original carnations senescenced after 2 weeks of harvest
Right: Transgenic carnations
Centre : STS treated carnations

59. Genetic engineering for floral scent
Floral scent plays an important role in
attracting the pollinators and also consumers.
Fragrance is a result of numerous volatile
aromatic organic substances present in the
flower that include hydrocarbons, alcohols,
aldehydes, ketones, esters, ethers.
The first structural gene isolated encoding a
floral scent biosynthetic enzyme was S-linalool
synthase (LIS) from Clarkia breweri that emits a
strong sweet scent of which S-Linalool is a
major component.

60. Isopentenyl
diphosphate
Geranyl
pyrphosphate
Farnesyl
pyrophophate
Geranygeranyl
pyrophosphate
carotenoids
linalool
limonene
casbene
kaurene
Gibberellic acid
BIOSYNTHETIC PATHWAY OF TERPENOIDS

61. Genetic engineering for floral scent
LIS,theenzymeactivityisdistributedinpetals,
pistilandstamensandishighestduringthefirst
twotothreedaysafteranthesis.
PetuniahybridaW115wastransformedwiththe
ClarkiaLISgene.
Snapdragonflowersemitamajorphenylpropanoid
floralscentcomponenet,methylbenzoate.

63. Modification of floral organs and
inflorescence by recombinant technology

64. A C
B
1 2 3 4
sepal petal stamen carpel
A C
B
ectopic B
1 2 3 4
petal petal stamen stamen
Wild type
Ectopic
expression of B
Changing the expression of gene

65. A
B
1 2 3 4
sepal petal petal sepal
A
B
ectopic B
1 2 3 4
petal petal petal petal
Ectopic
suppression of C
Ectopic
expression of B
& Ectopic
suppression of C
Changing the expression of gene

66. ABC model
Class A genes : AP 1 and AP 2 (APETALA 2)
Specifies sepals to form in first whorl
Class B genes : AP 3 (APETALA 3) and PISTILLATA (PI)
A+B specifies to form petals in second whorl
Class C genes : AG (AGAMOUS)
B+C specifies to form stamens in third whorl
C alone specifies to form carpelsin fourth whorl
Class D genes : FBP 7 and FBP 11
specifies to form ovules and placenta in petunia
Class E genes : SEP1,SEP2, SEP3

67. Revised ABC model for Floral organ identity

68. TRAIT GENE(S) AND PATHWAYS
Agamous Regulator of determinate floral development
Apetala Key regulator of ABC model of flower
development
Terminal
flower
Development of continuousinflorescence
development
Leafy Floral meristemidentity
Clavata1,2 &3Regulatorof meristemmaintenance
Wuschel Regulator of meristeminitiation
Shoot
meristemless
Establishment andmaintenance of functional
meristem
IMPORTANT GENES REGULATING FLOWER &
INFLORESCENCE DEVELOPMENT

69. •Control of plant height is of great importance in
floriculture.
•Chrysanthemum cv. ‘Iridon’ engineered to express tobacco
phytochrome B1 gene under control of caMV35s
•Transgenic plants were shorter in structure, larger branch
angles than wild type. (Zheng et al., 2001)
•rolC-Transgenic carnation -exhibite increased axillary
bud break, more stem cuttings, increased flowering.
Genetic engineering to modify plant architecture

70. Transformed petunia
Suntory Ltd successfully
inducing dwarfing in
petunia by introducing
genomic gai-1 sequences
into petunia.
This gene greatly reduced
gibberellic acid
responsiveness during
vegetative growth.

71. Dwarf Bougainvilleas

72. -Australian and Japanese researchers have demonstrated the application of
RNAi technology for gene replacement in plants, developing the world's only
blue rose.
The CSIRO-under license by Florigene Ltd, a Melbourne-based biotechnology
company and part of the Japanese Suntory group of companies developed the
blue rose.
Development of blue Rose
-Roses lacks violet to blue flower varieties due to
absence of delphinidin based anthocyanins
because roses do not possess flavonoid 3’5’
hydroxylase(F3’5’H).
-Anthocyanins also change their colour with pH of
the petals. Bluer in weakly acidic or neutral pH and
redder in acidic pH.
-The substrate specificity of the DFR often determines which anthocyanidins a plant
accumulates. The DFR of Iris did not utilize dihydrakaemferol as a substrate. It
efficiently reduces dihydramyricetin leading to delphinidin biosynthesis.

73. FLAVONOID BIOSYNTHETIC PATHWAY

74. Florigene’s scientists cloned delphinidin gene from
petunia in 1991.
At CSIRO plant Industry, Dr.Waterhouse developed RNAi
technology to switchoff DFR gene in a red rose to block
the cyanidin pathway.
The three-gene package(pansy delphinidin, iris DFR,
anti-rose DFR)worked:
Blue shades should be achievable if Florigene and
Suntory researchers can make the rose's petals less
acidic.
Rose petals are moderately acidic, with a pH around
4.5, while carnation petals are less so, with a pH of 5.5.
Finally used RNAi gene knockout technology to
identify genes influencing petal acidity.
Development of blue Rose

75. Gene Silencing -RNAi
•A technology that uses a basic plant process to
silence selected genes

77. The rose cultivars(A) WKS77,(B)WKS82,(C)WKS100,(D)WKS116,(E)WKS124
and (F)WKS140 were transformed roses.
Left: host
Right: a transformant
BLUE ROSES

80. TRANSGENIC FLORICULTURE CROPS WITH MODIFIED TRAITS
Species Trait
Anthurium andraeanum Delay in bacterial blight symptom development
Antirrhinum majus Altered phenotype (dwarfness, decreased apical
dominance,increased flower number)
Begonia X cheimantha Increased keeping quality
B. tuberhybrida Modified phenotype (dwarfness, delayed flowering, wrinkled
leaves and petals)
B. Semperflorens Altered flower color Glyphosate tolerant
Calendula officinalis Glyphosate resistant
Dendrathema grandiflora Modified flower color (pink to pale pink, white
Enhanced resistance to grey mold
Improved resistance to tomato spotted wilt virus
Modified plant architecture (shorter plant, larger branch angle)
Reduced plant height
Modified phenotype (no branch)
Modified phenotype (compact growth, increased number of
axillary shoots)
Dendrobium Altered flower color, disease resistant
Dianthus caryophyllus Altered flower color (white to light mauve, mauve, violet)
Increased vase life
Altered flower color (pink to pale pink)
Increased vase life
Improved fusarium wilt tolerance
Flower color altered (orange to cream), increased fragrance
in some transgenic plants
Improved tolerance to fusarium contd….

81. Species Trait
Eustoma grandiflorum Altered flower color (purple to white or pattern)
Altered flower color (purple to magenta)
Gentian triflora Altered flower color (blue to pale blue, white)
Gerbera hybrida Altered flower color (red to pale pink or cream
Gladiolus Enhanced resistance to bean yellow mosaic virus
Osteospermum Modified ornamental traits
Pelargonium Improved ornamental characters and fragrance production
Botrytis cinerea resistant, extended flower life
Botrytis cinerea resistant
Glyphosate tolerant
Altered flower color
Dwarf phenotype
Petunia hybrida Altered flower color (white to red and pattern)
Altered flower color (purple to white and pattern)
Altered flower color (white to red)
Disease resistant
Extended flower life
Altered leaf, stem and sepal color (green to dark purple)
Altered flower color (white to pale yellow)
Early flowering
Extended flower life
Extended flower life
Extended flower life
Altered flower color (white to pink)
Glyphosate tolerant

82. Conclusion
Recentdevelopmentsinplantmolecularbiology
provideopportunitiestousetechniquesof
geneticengineeringforimprovementofflower
crops.
Ashorticulturescientists,weshouldwait
fordevelopmentstoreachthestageof
application