Modern plant breeding aims to increase crop productivity at a rate more phenomenal than previous achievements. According to several research groups addressing this problem, the solution is to produce more biomass through improved photosystem biochemistry, greater assimilation of assimilates to the economically valuable portion of the plant, and increased light use efficiency, but a form of unanimity appears to exist. This chapter draws attention to the concept of heterosis and how it manifests itself in maize, sorghum, and other crops, through various models, in which higher biomass and yield have been obtained, depending on its association with plant breeding concepts such as combining ability and mitochondrial inheritance. Heterosis is employed extensively nowadays without fully grasping the underlying genetic and molecular principles to classify the species into different heterotic groups. Thus, a significant finding that would completely transform plant breeding today would be the comprehension and prediction of the genetic and epigenetic underpinnings governing heterosis.
Classification of heterosis, DNA methylation and heterosis, Prediction of heterosis
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