Mango Breeding

Introduction:

1. Mango: Mangifera indica L.

2. Chromosome No. 2n = 40

3. Family: Anacardiaceae

4. Mango is king of fruit

5. The name Mangifera given by ‘Botinus’ in 1658.

6. Primary centre of origin: Indo-Burma region

7. Indian region gives rise to mono-embryonic varieties and domestication in Indo-China.

8. Poly-embryonic varieties: Thailand and Myanmar

9. Wild mangoes occur in: India (Sikkim), Sri Lanka, Bangladesh, Myanmar, Thailand, Vietnam, Malaysia, Indonesia, Philipines

Important Species of Mango:

1. Mangifera cochinchinensis

2. Mangifera indica

3. Mangifera sylvatica

4. Mangifera minor

5. Mangifera khasiana

6. Mangifera similis

7. Mangifera altissima

8. Mangifera andamanica

9. Mangifera odorata??

Floral Biology:

1. Inflorescence is terminal panicle with perfect and hermaphrodite flowers- on same panicle (Fraser, 1927).

2. Flowering bud differentiation to be October – December, depend upon climatic conditions.

3. Flowering in South India: December

4. Flowering in North India: February – March

5. Panicle branched (1000-6000) flowers, may be male and hermaphrodite flowers (andromonoecious)

6. Flowering period: 2 – 3 weeks

7. Low temperature may extend and high temperature shortens the mango flowering period.

8. Pollen grains are oval / triangular / oblong.

9. Self sterility in mango (Dijkman and Soule, 1951)

10. Adventive embryony: one or more recessive genes

Breeding Objectives:

A) Fruit quality:

1. Attractive good quality

2. Golden apricot colour on ripening

3. Medium size: 5 in a kg

4. High pulp: stone ratio

5. Firm and fibreless flesh

6. Incorporation of good colour

7. Good transport and processing qualities

8. Varieties for export market

B) Resistance to insects, pests and diseases:

1. Diseases: Sooty Mould, Mango Malformation

2. Insects / Pests: Stem Borer, Nut Weevil

C) Fruit Bearing:

1. Precocity and regularity in bearing

2. Strong biennial bearing tendency

D) Fruit Free From Disorder:

1. Fruits free from soft tissues

2. Fruits free from malformation

3. Fruits are free from black tip

E) For Rootstock:

1. Wide geographical adaptability

2. Easily propagated, asexual reproduction

3. Resistance to biotic and abiotic stresses

4. Induction of dwarfing without affecting productivity of scion cultivars

5. Dwarf tree growth habit an ideal mango variety possess tree dwarfness

F) For Scion Cultivars:

1. Dwarf stature

2. Regular, prolific bearing per unit canopy area

3. High productivity with good quality fruits

4. Resistance to biotic and abiotic stresses

5. Attractive fruit colour, with pleasant aroma

6. Suitable for processing and export

7. Good keeping and transport quality

Breeding Methods:

1. Introduction

2. Selection

3. Clonal Selection

4. Chance Seedlings

5. Hybridization

6. Caging Technique

7. Marker Gene

8. Mutation Breeding

9. Polyploidy Breeding

10. Suspension Culture

11. Somatic Embryogenesis

Problems in Mango Breeding:

1. Long juvenile period

2. Presence of single seed in a fruit

3. Heterozygosity and cross pollination makes difficult to predict fruit quality

4. Complex nature of panicle and flowers

5. Excessive fruit drop

6. Large area required for raising hybrid seedlings

7. Lack of knowledge on inheritance pattern

8. Problem of polyembryony

9. Lack of pre selection procedures

a) Soil type: deep fertile, well drained, alluvial as well as laterite with pH 5.5 to 6.5

b) Mango crop is highly heterozygous

c) Ideal method of mango propagation is grafting

d) Commercial propagation method: Inarching, Vineer, Softwood, Stone / Epicotyl grafting

e) Ideal growing season: June to Sept

Procedure:

1. Raising of rootstocks

2. Scion collection

3. Scion forms canopy of tree, rootstock forms lower trunk and roots

Steps:

1. Terminal portion of rootstock is removed

2. Make shallow downward cut on cut portion of rootstock

3. Make sloping cut 1 inch long at the base of scion, exposing cambium

4. Insert cut surface of scion against cut surface of rootstock

5. Seal entire graft area with warm grafting wax or polythene stripe

6. Newly grafted tree placed in a shade. Graft begin to grow in 10 – 21 days

7. Following grafting, any shoots from rootstock removed, as these shoots may overcome developing scion

Flowering and Fruiting:

1. Flowering depends on variety and climatic conditions

2. Inflorescence: Panicle (Male + Hermaphrodite)

3. Flowers come terminally on previous season shoot

4. Warmer environment during flower: More perfect flower

5. Highly cross pollinated crop

6. Perfect flowers are protogynous

7. Fruit setting improved exogenous application of NAA @ 200 ppm or 2-4 D @ 10 – 15 ppm at time of flower bud initiation.