棉 花 学 报 Cotton Science 2007，19(6)：461-466
Effect of Plant Preservation on the Fertility and Chromosome Configuration of a Quadri-specific Hybrid Derived from 4 Cultivated Cotton Species Abstract：A quadri-specific hybrid F1(G.arboreum，G.herbaccum，G.hirsutum，and G.barbadense)were produced by crossing the chromosome doubled (G.arboreum×G.herbaccum)F1 with(G.hirsutum×G.barbadense)F1．The hybrid plants were preserved for 15 year via the method of grafting．The hybrid flowers were self-crossed and back-crossed every year，and the pollen vigor was tested as well．The results showed that the percentage of fertile pollens and poor vigor pollens was increasing with the time of plant preservation，especially for those with of poor vigor that occupied about 10% of the total pollens after 15 years growth．Meanwhile，the percentage of the sterile pollens was decreasing with the plant preservation，and the fertility of the quadri-specific hybrid was recovered partially．After plant preservation for more than 10 years，some backcrossed seeds were obtained via backcrossing with the upland cotton parent，and a few self-crossed seeds were produced finally ． The characteristics of chromosome behavior and the chromosome configuration during the meiosis were studied and the results showed that the chromosome configuration of the quadri-specific hybrid grown plant for 15 years was 2n=52=4.92Ⅰ+14.62Ⅱ+2.29Ⅲ+1.56Ⅳ+0.71Ⅴ+0.19Ⅵ，while the chromosome configuration from that plants 15 years ago was 2n=52=8.4Ⅰ+8.1Ⅱ+5.7Ⅲ+1.9Ⅳ +0.6Ⅴ．It was showed that the univalents were decreased about 3.5 per cell，bivalents were increased by 6.5 per cell，and the number of multivalents was decreased obviously as well．It was found from this experiment that extended the growth period by the method of grafting with cultivated plants would be helpful to harmonize the relationship among the different chromosome groups which came from different parents，and balance the chromosome configuration ，which led to the partially recovering in plant fertility of the interspecific hybrids．
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