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Vaccinium L., a kind of perennial evergreen or deciduous shrub, belongs to Vaccinium spp., Ericaceae, is native to North America. It has alternate simple leaves and axillary racemes of white or pink flowers. The leaves are often ovoid. And the flowers sometimes have a rad lace. In different species or genus, the size and colour of the fruits are generally different. Fruits of some cultivated species are covered with white powder. On the basis of the discrepancy of growing development and morphological character, Vaccinium L. in different species or genus could fill the various kinds of landscaping requirements.In the world, there has been found more than 400 species and most of them distributed in North America.Three cultivars (Darrow, Bluecrop and Garden Blue) of Vaccinium L. had been planted mixed. After free pollination, seedings was produced. We found 6 seedings blossomed and beared fruits in the next year after planting. we look on the matter as unusual.In this paper the wall degradation hypotonic method of preparing mitotic chromosome sample in plant was used for the karyotype analysis of 6 seedlings and their parent plants (Darrow, Bluecrop and Garden Blue). Through the comparative study of correlative parameters, we found a high-efficient technique system on metaphase chromosme preparation for Vaccinium L..The result of karyotype shows that all the karyotype of the experimental material belong to "2B" type. The karyotype formula of seedling 1 is K(2n)=4x=34m+12sm(2SAT)+2T, karyotype formula of seedling 2 is K(2n)=4x=48=32m(2SAT)+10sm(2SAT)+4st+2T, karyotype formula of seedling 3 is K(2n)=4x=48=38m(2SAT)+8sm+2T, karyotype formula of seedling 4 is K(2n)=4x=48 =30m(4SAT)+12sm+6st, karyotype formula of seedling 5 is K(2n)=2x=24=20m+4sm(2SAT), karyotype formula of seedling 6 is K(2n)=2x=24=16m+6sm(2SAT)+2st. karyotype formula of Darrow is 2n=2x=24=18m+6sm(2SAT), karyotype formula of Bluecrop is 2n=4x=48=42m(4SAT) +4sm+2st, karyotype formula of Garden Blue is 2n=6x=72=40m(2SAT)+22sm+8st+2t.We believe seedling5, seedling6 are posterities of Darrow while seedling, seedling2, seedling3 and seedling4 are posterities of Bluecrop.In addition, we measured and analyzed 9 leaf anatomical structure indexes related to drought resistance of the 6 seedings, including leaf thickness, diameter of main leaf vein, thickness of palisade tissue, leaf tissue structure tense ratio and so on. The result of multiple comparison show that there ars 4 indexes with a high sense.According to the 4 indexes, an order of drought resistance of the 6 seedings was given by using memberhip function values analysis:seedling5>Garden Blue>Darrow>Bluecrop>seedling3> seedling 1>seedling2>seedling6>seedling4.
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