Fertility regulation and molecular design hybrid breeding in crops

Fertility regulation affects crop yield as well as heterosis utilization. Here we summarize the genetic basis and molecular regulatory mechanism of male sterility and hybrid sterility in crops. The advances include cytoplasmic male sterility and its application in three-line hybrid breeding, photoperiod- and temperature-sensitive genic male sterility and its application in two-line hybrid breeding, biotechnology-based male sterility system and its application by molecular design breeding technology, and hybrid fertility and its application in distant hybrid breeding. On this basis, we discuss the bottleneck and strategies for exploring mechanisms of crop fertility regulation and molecular design hybrid breeding in China, with future trend predicted.