Isozyme application for variety identification and progeny hybridity in Japanese sugarcane

In order to apply Isozymes as genetic markers in sugarcane breeding, the po lymorphism of 24 Japanese varieties, including breeding materials, was anal yzed using 12 enzyme systems. Of the enzymes examined, the activity of Alco hol dehydrogenase (ADH), Esterase (EST), Glutamate oxaloacetate transaminas e (GOT), Isocitric dehydrogenase (IDH) and Peroxidase (POX) was clearly rev ealed and polymorphism was detected among the varieties. The 24 varieties c ould be identified by these five enzyme systems. In the selfed progenies of NIF8, Ni9 and RK86-129, large numbers of bands in EST and POX were segrega ted. Segregation patterns in some of the isozymes in EST and POX showed a m onogenic segregation ratio of 3 : 1. However, others deviated from the mono genic segregation ratio. In a parentage test using isozymes, the hybridity of almost all the seedlings could be identified in 10 cross combinations. T hese results indicate that the isozyme technique is a useful tool for varie ty identification and progeny hybridity in sugarcane breeding.