Genetic recombination results in novel allele combinations and is the most important genetic phenomenon for generating variation in breeding populations. However, in most organisms, the number of genetic recombinations is tightly constrained, which hampers the introgression of new genetic traits and limits genetic variation during agricultural breeding. Therefore, the possibility of increasing genetic recombination frequency has attracted much interest from crop breeders because of the obvious practical applications in traditional breeding. However, to date, the goal of increasing the recombination frequency has not been achieved in crops.

Recently, researchers from China National Rice Research Institute (CNRRI) of CAAS found that partial loss-of-function of the rice synaptonemal complex (SC) component ZEP1 reduced the strength of genetic interference and increased the genetic recombination frequency. Further cytological and double-mutant analyses implied that those additional COs were derived from the class I pathway. Taken together, the results support the enduring controversial hypothesis that the SC has universal roles in mediating interference and limiting COs. In addition, the zep1-3 mutant retained substantial fertility, so it is very likely that the mutant could be used directly to elevate genetic variation during rice breeding. As the SC is universal among crop plants, the results could also be of great interest for the breeding of other crop plants.

This research was supported by the National Natural Science Foundation of China (31271681), the Zhejiang Provincial Natural Science Foundation of China (LZ14C130003), and the CAAS’ Agricultural Science and Technology Innovation Program (ASTIP).