Useful insights from evolutionary biology for developing perennial grain crops

Area of Science:

• Agricultural Science
• Plant Breeding
• Evolutionary Genetics

Background:

• Annual grain crops are globally dominant but cause land degradation.
• Perennial grain crops offer a sustainable alternative to mitigate environmental impacts.
• Naturally occurring perennial grains with high seed yield are rare, suggesting evolutionary constraints.

Purpose of the Study:

• To explore the potential of perennial grain crops for sustainable agriculture.
• To review literature on genetics, domestication, and molecular biology for perennial grain development.
• To propose effective breeding strategies for rapid perennial grain domestication.

Main Methods:

• Literature review encompassing population genetics, evolutionary genetics, domestication, and molecular biology.
• Analysis of trade-off theories (rugged fitness landscapes vs. sink competition models).
• Consideration of artificial selection versus natural selection for domestication.

Main Results:

• Artificial selection can accelerate progress in perennial grain domestication despite trade-offs.
• Perennial grain types will likely differ significantly from current domesticated crops.
• Novel breeding strategies, including exploiting large-effect genes, pleiotropy, epistasis, and cryptic genetic variation, are necessary.

Conclusions:

• Perennial grain domestication requires distinct approaches from traditional crop breeding.
• Strategies like population subdivision, large population evaluation, high selection intensity, rapid cycling, and heterosis are predicted to be beneficial.
• Heterosis is particularly important for developing stable yields and tolerance to crowding in perennial grains.