| We used"zhongyi","X1","GBN-08" as the materials in this study, aiming to research2n gametes induction, formation and ploidy identification of hybrid offspring on ramie, exploring the induced technological system and the formation of2n gametes, to lay the foundation for2n gametes genetic breeding on ramie. The main research results are as follows:1,induction study of2n gametes on ramieUsing of different concentration0.02%,0.05%,0.1%,0.2%and0.25%, to induce male and female bud of three varieties ramie, we observed the morphology and cytology of ramie, the results show that:the pollen grain average diameter of "zhongyi","X1""GBN-08"are the biggest with0.1%colchicine, and2n gametes are the highest proportion. The highest proportion to induce2n gamete on ramie "zhongyi","X1","GBN-08" is respectively17.6%,15.8%,18.68%.2,the formation study of2n gametes on ramieWe observed the pollen mother cells meiosis of ramie "zhongyi","X1","GBN-08", the results show that there are triads and dyads in the tetrad period, and triads is the main way to form2n gametes on the three varieties ramie, existing a few dyads, the proportion of triads on "zhongyi","GBN-08","X1"7.9%,10.67%and11.89%, the proportion of dyads respectively is1.61%,0.74%, and0.82%. In addition, we observed five fission, six fission, seven fission and eight fission on the ramie "GBN-08". To sum up, the triads is the main formation of2n male gamete on ramie.3,The identification of hybrid offspring on ramieWe trained the hybrid offspring seeds getting from2n×n and nx2n of "zhongyi" on culture medium, to get offspring plant. Then to determine the ploidy of hybrid offspring by the external morphological observation, chromosome identification and flow cytometry testing, the results show that:in the external morphological, there is a plant among30plants with leaves big and thick,depth colour,much wrinkles getting from2nxn in2010. In the chromosome, the plant has many cells with different chromosome number, there are haploid, diploid and aneuploid. Further we measured the content of DNA with flow cytometry, the plant turn to triploid level, and we also found there are two plants turn to haploid level among30plants. The rate of normal diploid and aneuploid in hybrid offspring is respectively50%, the plant turn to triploid level is3.33%, the plant turn to haploid level is6.67%. The plant is normal diploid getting from n×2n in2010; there are55%normal diploid and45%aneuploid getting from n×2n in2011, we did not detect the plant turn to triploid level and haploid level. |
