Hybrid. Features and Method of Maintained Nucleus and Breeder Seed in Self-fertilized Crop.

1. What is Hybrid ?
 The offsprings resulting from the combining the qualities of two organisms of different
breeds, varieties, species or genera through sexual reproduction.
 Progeny of cross between genetically dissimilar parent.

2. Crosses Cross between
1. Single Two inbreeds (A x B). Dis- Shull
2. Double Two single cross (A x B) x (C x D). (4: 2 / Female : Male).
3. Triple Single cross and an inbreed (A x B) x C
4. Top Inbreed line and open pollinated variety. Dis- Davis.
5. Back Cross of F1 with either its parent.
6. Test Cross of F1 with recessive parent.

3. Hybridization
Intra-Specific
Inter-Specific
Inter-generic
Crossing between
two different genotypes
of same spp.
Crossing between
two different spp.
belongs to of same
genus.
Crossing between
two spp. each belonging to
different genus of family.

4. Features of Hybrids
1. Genetic material - (All genetic material involved i.e. Homozygous and Heterozygous).
2. Productivity – (All Hybrid are more productive bez.. Heterosis).
3. Adaptability – (Wider adaptability, to environmental change from inbreed lines and pure lines
variety to high suffering capacity).
4. Application Capacity – a) Developed in Cross and Self pollinated.
b) Depend upon – Heterosis
c) Heterosis hybrids are common in cross and self pollinated crops.
5. Resistance – Hybrids are tolerant biotic and abiotic stress than the inbreed and pure lines.

5. Method of Maintained of Nucleus and Breeder seed in Self fertilized crop
1. Maintenance of nucleus seed of pre- released variety.
2. Maintenance of breeder seed of pre-released variety.

6. Maintenance of nucleus Seed of released variety
• Outline given by - Harrington (1992).
A. Sample of the variety (basis on – Breeding nurseries and yield trials sample for seed purification).
B. Table examination of samples (200 plants/sample and free from diseased, otherwise unaccepted).
C. Locating and seedling of nucleus –
1. Sowing location – grown in clean and fertile land.
2. Selected land not have same kind of crops in the previous years.
D. Inspection of nucleus two rows plots and removal of off types. (Examined critically).
E. Harvesting and threshing of nucleus seed- (About 180 selected out of 200 and harvest individually).

7. Maintenance of Breeder Seed of Pre-released variety
1. Stock seed of nucleus seed (Sown- clean and fertile line).
2. Field is properly isolated.
3. Best farm produce this seeds. (Proper sowing, raising and harvesting).
4. Produced in experimental site.
5. Harvesting breeder seed stock properly. (clean seed and free from any other material).
6. Roughing (process of removing by hand plants of the variety grown for seed that do not appear
healthy or sufficiently characteristic)

8. Maintenance of Breeder Seed of established variety
A)Isolated plots are maintained during the various stages of crop
growth./ Raising the crop isolation
B)By Bulk selection-
1. The genetic purity of variety could be improved by bulk selection.
2. In this method 2000 to 2500 plants typical of variety are selected,
harvested and threshed separately.