Terminologies
- Apomixis: Vegetative reproduction in which seeds are formed but embryo develop without fertilization.
- Apospory: Some vegetative cell of the ovule develops into unreduced embryonic sac after meiosis.
- Diplospory: Embryo sac is produced from megaspore; may be haploid or diploids.
- Transgene: Gene taken from one organism and inserted to another by recombinant DNA technology
- Penetrance: Ability of gene to express itself.
- Expressivity: Ability of gene to express itself uniformly in all individuals.
- Threshold Characters: Development depends upon specific environment
i.e. Heritability ( H) = Vg/Vp [ Broad sense]
- Biometrical genetics : Study of quantitative inheritance
- Xenia: Effect of genotype of pollen grains on the phenotype of seed tissues.
- Inbreeding depression; Loss of vigor and fertility as a result of inbreeding.
- Genetic load: Sum total of harmful alleles in mandelian population
- Heterosis: F1 hybrid superior to Parents
- Luxuriance: Increased vigor and size of interspecific hybrids.
- Mass selection: Based on phenotype
- Pedigree: Record of all parents offspring relationship; record of ancestory.
- Back cross: Hybrid plant + one of its parents
- Test cross: Hybrid plant + recessive parent.
- Synthetic varieties: Cross-pollinated species
- Asexual reproduction: Clone
- Deviation in chromosomal number/structure is called chromosomal aberrations.
- Horizontal resistance: Governed by polygenes
- Vertical resistance: governed by oligogenes