北美红杉起源的时间和地点的探讨

根据笔者认为的北美红杉的亲本可能是分别以水杉、巨杉为直接后裔或留下近缘的水杉属和巨杉属的二个古代种及Florin的古植物学资料,本文推测北美红杉这个AAAABB同源异源多倍体(autoallopolyploid)杂交起源的时间和地点有三种可能:(1)中新世的美国西部(以俄勒冈州及其附近为中心);(2)古新世的格陵兰岛西海岸;(3)晚白垩纪的美国中西部(包括怀俄明州、科罗拉多州)。其中第一个推测的可能性更大。

CRITICAL NOTES ON THE ORIGINAL YEARS AND LOCALITY OF SEQUOIA SEMPERVIRENS

The author5,8] infered that some two ancient species of Meta-sequoia and Sequoiadendron, whose direct descendants were probably M. glyptostroboides and S. giganteum, might be the parents of Sequoia semper-virens. According to the previous result and Florin's 10] paleobotany data, the present paper conjectured that the years and locality of hybridizational origin of autoallopolyploid (AAAABB) S. sempervirens might be in (1) Miocene, West America (take Oregon and its neighbourhood as the center) (Fig. l-3); (2) Paleocene, the west coast of Greenland (Fig. 1-5); (3) late Cretaceous, Central-West America (including Wyoming, Colorado) (Fig. 1-4). The present author here considered that the possibility of the first conjecture was greater possible than the other two.