白杨派内杂交难易程度及杂交方式的研究

Studies on the Limits Possibilities and Modes of Artificial Hybridization in Section Leuce

本文通过毛白杨(Populus tomentosa carr.)、银白杨(P.alba L.)、毛新杨(P.tomentosa×P.bolleans)、银灰杨(P.×canescens smith)、银腺杨(P.alba×P.glandulosa)等白杨派内树种、杂种间的杂交试验,对白杨派的杂交难易程度、杂交方式进行了研究。研究结果表明:杂种在杂交可配性方面有着突出的优势,其子代表现亦非常好。以杂种作亲本进行再度杂交是一条容易而且有效的杂交手段。杂交方式的优劣顺序为:双交>回交>三交>单交。正交与反交间的比较表明:杨树的正交与反交不能等同于雌雄同株植物的正、反交。正交与反交应被视为两个不同的杂交组合。

The limits and modes of hybridization were discussed through artificial combinations among Populus tomentosa, P. alba, P. x canescens P. bolleana, P, X canescens, P. alba×P. glandulosa etc. The limits and possibilities of hybridization among the species showed that hybrids in Section Leuce had an evident vigor to mate with other species or hybrids. In addition, the performance of their progenies was very good. It is certain that using hybrids as parents to hybridize other species or hybrids is an effective and easy way to obtain hybrid vigor. Comparison among different modes of hybridization showed that differences among the modes are significant. The double cross mode works best, the backcross, triple cross and single cross following it in effectiveness in that order. Comparision between cross and reciprocal cross indicated that hybridization of poplars was not the same as that of the agricultural monoecious plants. The cross and the reciprocal cross should be regarded as two-different things.