What do you mean by transgressive segregation?
In genetics, transgressive segregation is the formation of extreme phenotypes, or transgressive phenotypes, observed in segregated hybrid populations compared to phenotypes observed in the parental lines. The appearance of these transgressive (extreme) phenotypes can be either positive or negative in terms of fitness.
Which method is used in transgressive breeding?
The cause for transgressive segregation is the accumulation of favourable genes from both the parents as a result of recombination. Pedigree method and its modification and population approach are suited for high recovery of transgressive segregants and hence transgressive breeding.
What is the opposite of hybrid vigor?
Heterosis, otherwise known as outbreeding enhancement, is the opposite of inbreeding depression and is sometimes referred to as hybrid vigor.
Which type of gene action is the main reason of transgressive segregation?
Quantitative genetic studies of plant hybrids consistently point to the action of complementary genes as the primary cause of transgression, although overdominance and epistasis also contribute.
What is the correct definition of segregation?
1 : the act or process of segregating : the state of being segregated. 2a : the separation or isolation of a race, class, or ethnic group by enforced or voluntary residence in a restricted area, by barriers to social intercourse, by separate educational facilities, or by other discriminatory means.
What does the word transgressive mean?
Definition of transgression : an act, process, or instance of transgressing: such as. a : infringement or violation of a law, command, or duty. b : the spread of the sea over land areas and the consequent unconformable deposit of sediments on older rocks.
What are progeny rows?
The progeny rows are grown from each selected plant and are evaluated for desirable character. The superior progenies are identified. Several similar plants are selected from the progenies and allowed to open pollinate thus selection process is repeated.
What is heterosis PDF?
Heterosis refers to the phenomenon that progeny of diverse varieties of a species or crosses between species exhibit greater biomass, speed of development, and fertility than both parents. Various models have been posited to explain heterosis, including dominance, overdominance, and pseudo-overdominance.
What is cow heterosis?
Davis Cattle, Westminster, South Carolina. Heterosis is that hybrid vigor resulting from crossbreeding. It can result in enhanced performance in traits such as growth, fertility, longevity, and disease resistance.
What is the difference between broad sense and narrow sense heritability?
The broad-sense heritability of a trait is the proportion of phenotypic variance attributable to genetic causes, while the narrow-sense heritability is the proportion attributable to additive gene effects.