3. INTRODUCTION
• Papaya has 6 genera and 35 species.
• It is naturally a dioecious plant, but gynodioecious cultivars have
been developed in papaya through breeding.
• The leaves are palm like with long talks.
• Fruit : Fleshy Berry.
• Numerous round wrinkled black seeds.
4. CENTRE OF DIVERSITY
• Papaya is native to Tropical America.
• The South America and Costa Rica are the micro centre of origin of
papaya.
• It is a close relative of Carica peltata.
• In India, it was introduced in the early part of the 16th century from
Philippines through Malaysia.
• It was widely spread in different parts of the country particularly
tropical and sub-tropical zones.
• India is the largest producer of papaya in the world.
• It is also cultivated in Brazil, Mexico, Australia, Hawaii, Malaysia,
Taiwan, Peru, Florida, Gold Coast, South Africa and Bangladesh.
• In India it is widely cultivated in Uttar Pradesh, Bihar, Karnataka,
Jharkhand and Madhya Pradesh.
5. GERMPLASM
RESOURCES
• The family Caricaceae consist of 6 genera and 35 species. Carica
and Vasconcellea are the important generas.
• The genus Carica has only one species, Carica papaya the
cultivated species.
• Vasconcellea contain 21 species, which are considered as the wild
relatives of papaya.
• Presently, germplasm is being maintained at TNAU, Coimbatore,
IIHR, Bangalore, IARI Regional Station, Pusa, Bihar, CHES
(Central Horticultural Experiment Station), Ranchi, CHES,
Bhubaneshwar and CISH, Lucknow for further characterization
and evaluation.
8. OBJECTIVES
• To develop dwarf and early bearing varieties.
• To evolve varieties with high yield and good quality fruits.
• To develop varieties with low cavity index and more pulp
thickness.
• To breed varieties having good keeping quality and suitable for
export.
• To develop varieties resistant to biotic and abiotic stresses (virus,
frost, water logging etc).
9. FLORAL BIOLOGY AND
POLLINATION
• Dioecious papaya produces male and female trees separately on
different plants in the ratio of 1:1.
• Female and male flowers develop within 32 and 42 days
respectively after bud initiation.
• The period from bud initiation to anthesis is shorter for male than
female flower bud.
13. SEX FORMS
There are two major sex forms in papaya
1. Dioecious: male and female trees segregate in the ratio of 1:0.
Sibmatingisdoneformaintaining of purity.
2.Gynodioecious:Femaleandandromonoecious(female+bisexualflowersin a
single tree) trees segregated in the ratio of 1:2. Selfing of bisexual
flowers is done for obtained pure seeds.
17. BREEDING METHODS
AND ACHIEVEMENTS
Inbreeding and selection
• In dioecious lines, suitable male plants are selected from the same
progeny which have resemblance to female plants in vegetative
characters, such as stem and leaf colour, stem thickness and height at
flowering etc.
• Progenies raised from S1 inbreds are screened and desired male and
female plants are selected for further sibmating i.e., crossing between the
female plant and male plant of the same cultivar.
• The process is to be continued for 7-8 generations to achieve uniformity
for a group of characters.
• In this method, the progeny will have male and female in equal
proportion.
• Many dioecious cultivars have been bred by this method.
18. ACHIEVEMENTS
• Development of cultivar with high papain content was started at
TNAU, Agricultural College and Research Institute, Coimbatore.
• As a result of intensive breeding programme, four cultivars i.e.,
CO1, CO2, CO5 and CO6 were developed through inbred selection
which are dioeicous at Coimbatore.
19. • Recently during 2011, CO 8 papaya was developed in the dioecious
group through sib-mating of CO 2 variety, which is a red fleshed
variety and this variety is unique for the red pulp colour which is not
exist in any of the dioecious papaya varieties developed.
• As a result of inbreeding and selection for 8 generations during 1966-
1982, uniform lines of Pusa Delicious, Pusa Majesty, Pusa Giant and
Pusa Dwarf with desirable attributes were developed.
22. HYBRIDIZATION
• A few hybrid varieties have been developed by the intervarietal
or intergeneric hybridization. But still there is great scope for
development of superior cultivars with better quality and yield.
• At TNAU, Coimbatore three varieties have been developed viz.
CO3 (CO2 x Sunrise Solo), CO4 (CO1 x Washington) and CO7
(CP.75 x Coorg Honey Dew).
• At IIHR Bangalore, two hybrids IIHR-39 named as Surya (Sun
Rise Solo x Pink Flesh Sweet), and IIHR-54 (Waimanalo x Pink
Flesh Sweet) were developed (Dinesh and Yadav 1998), Hybrid
HPSC-3 (Tripura local x Honey dew) was developed by the
ICAR Research Complex Tripura (Singh and Sharma, 1996).
23. MUTATION BREEDING
• Ram and Majumder (1981) developed a dwarf mutant line by
treating papaya seed with 15K gamma rays. Initially, 3 dwarf
plants were isolated from M2 population. Repeated sibmating
among the dwarf plants helped in establishing a homozygous
dwarf line Pusa Nanha.
26. QUESTIONS
1. Papaya known as.
Ans: Wholesome fruit
2. Name a transgenic papaya
Ans: U.H Rainbow
3. Name two papaya varieties suitable for papain extraction as well as table purpose are
Ans: CO2 and CO5
4. Vasconcellea cauliflora is resistant to
Ans: Papaya Ring Spot Virus (PRSV).
5. . Pusa Nanha is developed through.
Ans: Mutation breeding
6. Two major sex forms in papaya are
Ans: Dioecious and Gynodioceious
