Abstract:

Abstract： In this study, tetraploid of oil camellia (Camellia oleifera) was identified from the superior clones which were treated with colchicine, and the tetraploid variation was investigated with the experimental material. Analysis of the number of chromosome showed the chromosome number of the tetraploid oil camellia was 2n=4x=60, compared with the diploid (2n=2x=30). The morphological observation showed that the leaf area, leaf length, leaf width, leaf thickness and the space of leaf in the tetraploid were respectively increased by 98%, 385%, 25%, 4825%, 67%, compared with the diploid. The chlorophyll content and the length and width of guard cells were respectively increased by 4787%, 4815% and 3726%, while the leaf\|shape index reduced 381% than that in the control group. In addition, the leaf of tetraploid plant became more round, the total DNA content was twice as the control group was, and the net photosynthetic rate was also greater than that of the control group. The genetic polymorphism analysis with the mt DNA and cpDNA primers showed that no polymorphic locus was found in the tetraploid, which meant that the tetraploid was autotetraploid, however the genetic polymorphism analysis in the nDNA exhibited that the polymorphic ratio was 51%.

Key words: Key words： Camellia oleifera, tetraploid, chromosome identification, mutation breeding