Population behavior and settling process of introduced and hybrid dandelions

引种及杂交蒲公英的种群行为及定居过程

基本信息

批准号：
16510177
负责人：
OGAWA Kiyoshi
金额：
$ 2.43万
依托单位：
Tokyo Gakugei University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

项目摘要

1. The following facts turned out about the artificial pure introduced dandelion population in the Tokyo Bay shore.(1) The seedlings of the early summer birth were annihilated, and there were some surviving ones of the autumn birth.(2) Being compared with the estimated value by the photograph of 2002, the decrease of the density of the dandelions was admitted in the order of 1/100 on the east side slope though an increase was done on the north side slope.(3) The pure introduced species had wide range of germinating temperature, and did not have seed dormancy. In the tetraploid crossbreed, similar characteristics were seen, though some inhibition of seed germination by the high temperature was seen like in the native species.(4) The viability loss of buried seeds in soil was remarkable in the introduced species and the tetraploid crossbreed, though the survival value of the seeds was excellent in the native dandelion in experiment until autumn.(5) From the size comparison of the pollen in the population, the plants with a comparatively uniform diameter and the ones with various sizes were identified.(6) As for the ploidy ratio of the introduction population, the pure introduced triploid was detected 85% and the diploid was done 15%. It was the remarkable difference of the ploidy composition in comparison with the populations in Tokyo, having higher ratio of triploid crossbreed than that of the pure introduced plants.2. The frequency of the pure introduced species was higher than that of the crossbreed in Tohoku and the Hokkaido region. On the other hand, the advancement of the crossbreed was confirmed at the mountain aria in Central mainland of Japan, which was similarly the cold district as the regions mentioned above.

1. 东京湾沿岸人工纯引种蒲公英种群的事实如下：（1）初夏生的幼苗被消灭，秋季生的幼苗有一些幸存。（2）与根据2002年照片的估计值，虽然北坡的蒲公英密度有所增加，但东坡的蒲公英密度减少了约1/100 (3)纯引进品种发芽温度范围广,种子不存在休眠现象。在四倍体杂交品种中，也表现出相似的特征，尽管与本地物种一样，高温对种子发芽有一定的抑制作用。（4）在引进物种和四倍体杂交品种中，土壤中埋藏种子的活力丧失是显着的， (5)从种群中花粉大小比较来看,直径比较均匀的植株和大小不等的植株都比较好。 (6)引种群体倍性比,纯引种三倍体检出率为85%,二倍体检出率为15%。其倍性组成与东京种群相比差异显着，三倍体杂交比例高于纯引种植物。 2．东北和北海道地区纯种引进的频率高于杂交品种。另一方面，杂交品种的进步在日本中部大陆的山区得到了证实，该地区与上述地区同样是寒冷地区。