Basics Flashcards
(17 cards)
Cultivar
plant variety that has been selectively bred and maintained for specific desirable traits
Marker assisted selection (MAS)
The use of molecular markers (specific DNA sequences) to identify desirable genetic traits in plants
Qualitative traits
Traits that are controlled by a single gene or a small number of genes and exhibit clear, distinct categories or classes.
These traits are often inherited in a Mendelian fashion.
law of Dominace
When two different alleles for a trait are present in an organism, one allele (dominant) will mask the expression of the other allele
Incomplete dominance (co-dominance)
when neither allele is completely dominant over the other, resulting in a blended or intermediate trait in the offspring
law of segregation
Each organism has two alleles for a trait, which separate during gamete formation so that each gamete carries only one allele. This ensures that offspring inherit one allele from each parent.
Law of independent assortment
genes for different traits assort independently of one another during gamete formation, given that the genes are on different chromosomes or far apart on the same chromosome.
Apomixis
asexual reproduction of seed with fertilization
QTL (quantitative trait)
traits that are controlled by multiple loci (QTLs) and exhibit a continuous range of variations, rather than distinct categories.
Some QTLs are more important than others (Major QTLs and minor).
They have additive effects
They are also influenced by the environment
Epistasis
The effect of one gene is dependent on the presence of one or multiple other genes
Heterosis (hybrid vigor)
The phenomenon where the offspring of genetically diverse parents show superior traits compared to either parent
Heritability
is a measure of how much of the variation in a trait within a population is due to genetic differences among individuals, rather than environmental factors.
Broad sense heritability
The proportion of total phenotypic variance due to all genetic factors
Genetic variance includes all components: Dominant/recessive, additive and epistatic interaction
Narrow sense heritability
Genetic variance only includes additive effects
genic actions (within a QTL)
Additive effect and dominace effect
intergenic actions (among diffrent QTLs)
Epistasis
Pleiotropy (a single gene affects multiple traits)
genotype and environmental interaction
Variables that measure heritability
phenotypic variance
-genetic variance
- environmental variance
- genotype and environmental interaction
Genetic Variance
additive variance
dominance variance
epistatic variance
