HORMA - 302
Breeding of Fruit Crops
Breeding of Fruit Crops
UNIT IV: Breeding of Minor Fruit Crops
📚 Contents
1. LITCHI (Litchi chinensis)
1. Origin, Distribution & Taxonomical Status
- Family: Sapindaceae (Soapberry family).
- Origin: South China.
- Distribution: China is the largest producer, followed by India (Bihar is the main hub).
- Taxonomy: Litchi chinensis is the only commercially important species. Sub-species: philippinensis (Wild litchi of Philippines) and javensis.
- Edible Part: Aril (The fleshy, white, edible covering around the seed).
2. Cytogenetics
- Chromosome Number: 2n = 30.
- Genetics: Highly heterozygous (mixed genetic makeup), which means if you plant a seed, the offspring will be very different from the mother plant.
3. Blossom Biology & Breeding Systems
- Inflorescence: Terminal Panicle (a branched cluster of flowers at the tip of the stem).
- Flower Types: Litchi produces three types of flowers on the same tree:
Male (M1): Appears first, has functional stamens but no ovary.
Female (F): Appears second, sets fruit.
Pseudo-hermaphrodite (M2): Appears last, looks like it has both parts, but acts as a Male. - Pollination: Highly cross-pollinated by insects (Entomophilous). Key pollinators are Honeybees (Apis spp.) and Syrphid flies.
- Fruit Set: Poor fruit set is common due to bad weather during the brief female flowering phase.
4. Breeding Objectives
- Fruit Cracking: The biggest problem in litchi. Need varieties with elastic skin that doesn't split in hot winds.
- Seed Size: Chicken Tongue Seed (Shriveled/small seed) is a highly desirable trait because it increases the edible pulp ratio.
- Maturity: Early ripening varieties to avoid the hot "Loo" winds of May-June.
- Ideotype (Ideal Plant): Dwarf tree, regular bearer, non-cracking fruit, high pulp, small seed.
5. Breeding Approaches
- A. Introduction: Most Indian varieties like China and Purbi were originally introduced from China centuries ago.
- B. Selection: Since litchi is propagated by air-layering (gootee), superior natural mutations were selected and maintained as clones. Examples: Shahi (Standard variety of Bihar), Rose Scented (Distinct aroma).
- C. Hybridization: Very difficult because fruit drop is high, and hybrid seedlings take 8-10 years to flower (Long juvenile phase). Technique: Covering panicles with cloth bags and hand-pollinating female flowers with pollen from desired male flowers.
6. Achievements
| Institute | Variety | Key Features |
|---|---|---|
| IARI (New Delhi) | Pusa Amit | Superior selection. |
| Bihar (RAU) | Shahi | High quality, distinct rose aroma, but susceptible to cracking. |
| China | Late maturing, resistant to cracking. | |
| Bedana | "Seedless" type (Very small seed), high pulp. | |
| IIHR (Bengaluru) | Dehra Rose | Selection for South India. |
7. Future Thrust
- Developing varieties with genetic resistance to fruit cracking.
- Molecular markers to identify "Chicken tongue" seed traits at the seedling stage.
2. JAMUN (Syzygium cumini)
1. Origin & Taxonomy
- Family: Myrtaceae (Guava family).
- Origin: India / Indo-Malaya region.
- Common Names: Black plum, Java plum, Indian Blackberry.
- Species:
S. cumini: The common Jamun.
S. jambos: Rose apple (Gulab Jamun - distinct fruit).
2. Cytogenetics
- Chromosome Number: 2n = 40 (Common).
- Polyploidy: It has varying chromosome numbers (natural aneuploidy/polyploidy) ranging from 2n=33 to 66, making it complex for genetic studies.
3. Blossom Biology
- Inflorescence: Panicles usually on old wood.
- Polyembryony: A single seed produces multiple seedlings. One is sexual (hybrid), others are Nucellar (clones of mother). This is make it easy to propagate true-to-type plants from seed but hard to identify hybrids.
- Pollination: Cross-pollinated by Honeybees, Houseflies, and Wind.
4. Breeding Objectives
- Seed Size: Small seed or seedless traits.
- Pulp: High pulp content with deep purple colour (rich in anthocyanin).
- Taste: Reduced astringency (the "dry" mouthfeel caused by tannins).
- Tree Size: Dwarf canopy (Wild jamun trees are huge and hard to harvest).
5. Breeding Approaches
- Selection: Surveying seedling trees in Uttar Pradesh, Maharashtra, and Gujarat. Selecting for large fruit size ("Paras" type).
- Rootstock Breeding: Utilizing dwarf rootstocks.
6. Achievements
| Institute | Variety | Key Features |
|---|---|---|
| CISH (Lucknow) | Jamwant | (Selection) Large fruits, 90% pulp. |
| KKV (Dapoli) | Konkan Bahadoli | High yield, big fruits. |
| Gujarat | Goma Priyanka | Selection from Thar region, drought tolerant. |
| Hort. Exp. Stn. | Paras | Large fruited local selection. |
3. PHALSA (Grewia subinaequalis)
1. Origin & Taxonomy
- Family: Tiliaceae (Jute family).
- Origin: India.
- Species:
Grewia subinaequalis (Syn: G. asiatica): The cultivated Phalsa. Tall bush.
Grewia tenax: Wild species, drought hardy.
2. Cytogenetics
- Chromosome Number: 2n = 36.
3. Blossom Biology
- Plant Habit: Deciduous shrub (sheds leaves in winter). Flowers appear on new growth (current season shoots).
- Flowering: February-March.
- Pollination: Mostly Self-pollinated, but bees improve fruit set.
- Fruit: Drupe, small, purple-black, ripens in summer (May-June).
4. Breeding Objectives
- Fruit Size: Increasing berry size (currently very small).
- Shelf Life: Phalsa is highly perishable (spoils in 24 hours). Need varieties with tougher skin.
- Ripening: Synchronous maturity (all fruits ripening at once) to reduce harvesting labor. currently, fruits ripen unevenly and need multiple pickings.
5. Breeding Approaches
- Selection: Since it is propagated by seeds, there is immense variation in orchards.
- Pruning: Not a breeding method, but crucial: Phalsa bears fruit only on new wood, so severe pruning is done every winter.
6. Achievements
- Thar Pragati (CIAH, Bikaner): High yielding, suitable for arid (dry) regions.
- Sharbati: Local selection with high juice content.
- UP Swarne: A yellow-fruited selection (rare).
4. MULBERRY (Morus spp.)
1. Origin & Taxonomy
- Family: Moraceae.
- Origin: China (White Mulberry) and India.
- Major Species:
Morus alba: White mulberry (Mainly for silkworm leaves).
Morus nigra: Black mulberry (Best for Fruit quality).
Morus indica: Indian mulberry.
Morus laevigata: Shahtoot (Long fruits).
2. Cytogenetics
- Chromosome Number: Basic x = 14.
- Ploidy Levels:
Diploid (2n=28): Fertile, produces seeds.
Triploid (3n=42): Best for leaves (larger leaves, vigorous).
Tetraploid (4n=56): Used for breeding triploids.
3. Blossom Biology
- Inflorescence: Catkin (a hanging spike of flowers).
- Sex Expression: Can be Monoecious (male and female on same plant) or Dioecious (separate plants).
- Pollination: Anemophilous (Wind pollinated). Pollen is powdery and light.
- Fruit: Sorosis (Multiple fruit formed from an entire inflorescence).
4. Breeding Objectives
- Dual Purpose: Breeding for both quality leaves (for sericulture/silkworms) and fruit.
- Fruit Quality: High anthocyanin (dark color), seedless (parthenocarpic), sweet taste.
- Resistance: Root knot nematode and Leaf spot.
5. Breeding Approaches
- Polyploidy Breeding: Creating Triploids (3n) by crossing Tetraploid (4n) x Diploid (2n). Triploids grow faster and have better leaves/fruit.
- Mutation Breeding: Gamma rays used to create leaf mutants.
6. Achievements
- Thar Lohit: Best fruit variety for arid regions (developed by CIAH).
- Shahtoot (Local): Long fruited, sweet, greenish-yellow.
- S-13, S-36: Sericulture varieties (Leaf focussed), but produce fruit too.
Summary of Important Concepts for Exam
- Chicken Tongue Seed: A shriveled seed in Litchi that is desirable because it means more fruit pulp.
- Polyembryony: Found in Jamun (and Citrus/Mango). One seed gives many plants. Useful for cloning but bad for hybridization.
- Cauliflory: Flowering on the main trunk/bark (Seen in Jackfruit, sometimes Jamun).
- Protandry/Protogyny: Mechanisms to stop self-pollination.
- Protandry: Male matures first (Litchi).
- Protogyny: Female matures first (Avocado, Custard Apple).
📚 References
Bose T.K., Mitra S.K. & Sanyol D. (2002). Fruits of India – Tropical and Sub-tropical. Naya Udyog.
Kumar, N. (2010). Introduction to Spices, Plantation Crops, Medicinal and Aromatic Plants. Oxford & IBH.
Chadha K.L. (2001). Handbook of Horticulture. ICAR.
Pareek O.P. (2001). Fruits for the Future. ICAR.