Development of a sex-specific molecular marker for Japanese hop Humulus Japonicus Siebold & Zucc

Japanese hop (Humulus japonicus Siebold & Zucc.) is a dioecious plant and a suitable model for studying the XX/XY1Y2 system of sex chromosomes. To develop a sex-specific marker, 12 RAPD and 36 ISSR markers were analyzed on the basis of pools of male and female plants identified after flowering. We were the first to identify ISSR marker K-16, which manifested stable amplification of an approximately 300-bp fragment in male plants and the absence of amplification in female plants in the populations examined. Marker effectiveness was confirmed in several Japanese hop populations of different origin.