An Overview on the Concept and Utilization of Heterosis in Livestock
Aayush Yadav Asit Jain Jyotimala Sahu Ashutosh Dubey Rajkumar Gadpayle Deepti Kiran Barwa Sandhya Kasyap Anuj Singh
Vol 9(11), 26-37
Heterosis or hybrid vigour is the excellence of F1 cross beyond the average performance of the two parents and noticeable across species. Heterosis, coined by Professor G.H. Shull in 1914 is well known to exploit the benefits of crossbreeding. Heterosis is usually positive but negative heterosis does occur and is uncommon. Heterosis is widely accepted to occur due to non-additive gene action i.e. dominance, over-dominance and epistasis. The heterotic effects are usually expressed in percentage and always highest in F1 generation followed by a decline in later generations. This decline is mainly due to the recombination and segregation losses. Rotational crossbreeding systems are therefore followed to maintain levels of heterosis in later generations. Estimates of heterosis are high in low heritable traits followed by moderate in moderately heritable traits and negligible in high heritable traits. Besides improvement, there are some limitations to heterosis that shall overcome shortly.
Keywords : Crossbreeding Heritability Heterosis Hybrid Vigour Non-additive Gene Action
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