The analyses of these three types of data in the hybrid and its parents could provide new information on genomic composition and evolutionary mechanisms of the hybrid . the main results are the followings : 1 . rdna fish chromosomal localization of 18s and 5s rdna was carried out for two soft pines ( subgenus strobus ) and five hard pines ( subgenus pinus ) using fish Rdna荧光原位杂交( fish )通过对华山松和白皮松两种单维管束亚属植物及油松、云南松、高山松、马尾松和南亚松等五种双维管束亚属植物的18srdna与5srdna的荧光原位杂交,结果表明: ( 1 )裸子植物的18srdna位点数目明显多于二倍体被子植物。