前言从日本赤松和黑松很难发现某些形质差异显著的遗传变异。故笔者希望通过与国外松杂交,寻求这种遗传的变异。从立地条件来说,不可能在国内培育所有外国树种,来探求有益的遗传特性。但国外树种与日本树种杂交所产生的杂种很大程度上可得到有实用价值的个 Preface It is difficult to find significant genetic variations in some qualitative differences from Japanese red pine and black pine. Therefore, I hope to cross with foreign pine, to seek this genetic variation. From the site conditions, it is impossible to cultivate all foreign species in the country to explore the beneficial genetic characteristics. However, hybrids produced by the crossbreeding of foreign species with Japanese species are largely available