What is heterosis in plant breeding?
Heterosis is a common biological phenomenon in nature. It refers to the heterozygote produced by hybridization between two or more parents with different genetic bases. Hybrids are superior to parents in terms of yield, growth rate, viability, and disease resistance (Hochholdinger and Hoecker, 2007).
What is heterosis in breeding depression?
Definition. Heterosis, also known as hybrid vigor, is the enhancement of characteristics in the offspring. Inbreeding depression is a reduction in fitness in the offspring as a result of inbreeding. Parents. It occurs as a result of cross between two genetically different parents.
What is the formula for heterosis?
When the heterosis is estimated over the better parent is known as better parent heterosis. It is also known as heterobeltiosis and calculated by using formula: Heterobeltiosis = (F1- BP) / 100 x BP Where BP is mean of better parents.
What is heterosis and its types?
Heterosis may be defined as the superiority of an F1, hybrid over both its parents in terms of yield or some other character. Heterosis, or hybrid vigour, describes the superior performance of heterozygous hybrid individuals compared with their homozygous parental inbred lines.
What are the three main types of heterosis?
Heterosis comes in three different forms: individual, maternal, and paternal. Bourdon (2000) explains that retained heterosis is the increase in performance of crossbred progeny relative to that of its purebred parents.
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 heterosis example?
For example, hybrids between radish (Raphanus sativus) and cabbage (Brassica oleracea) exhibit extensive biomass heterosis (Karpechenko, 1927), as do hybrids between a wild tomato species, Solanum pennelli, and cultivated tomato, Solanum lycopersicum (Eshed and Zamir, 1995).
What is the function of heterosis?
Heterosis, hybrid vigor, or outbreeding enhancement is the improved or increased function of any biological quality in a hybrid offspring. An offspring is heterotic if its traits are enhanced as a result of mixing the genetic contributions of its parents.
What is the role of heterosis?
In plants, heterosis helps in increasing the yield of the crops by producing better quality and higher resistance to pests and diseases. It is accomplished by crossing different heterotic groups to produce a vigorous F1 hybrid progeny.
How heterosis is useful in plant breeding?
Heterosis results in more vigorous growth which ultimately leads to healthier and faster growing plants with increase in size than the parents.
What is heterosis breeding?
Crop breeding to manifest heterosis is called heterosis breeding. The term heterosis was 1st used by Shull in 1914. It brings out the superiority in F1 individuals but the vigor tends to decrease from F2 generation onwards.
What is the difference between heterosis and hybrid vigour?
Hybrid vigour has been used as a synonym of heterosis. Crop breeding to manifest heterosis is called heterosis breeding. The term heterosis was 1st used by Shull in 1914.
Do hybrid plants grow faster than their parents?
In some cases, hybrids show a faster growth rate than their parents, but that does not always produce larger plant size than the parents. 8. More disease resistant Some hybrids are known to exhibit a greater resistant to insects or diseases than their parents.