桑树人工三倍体育种的研究

桑树的人工三倍体,通常由四倍体和二倍体桑杂交获得。无性系品种的四倍体,可以用照射剂量为5000拉特左右的γ-射线辐照刚膨大或休眠的冬芽,或者用浓度为约0.2％的秋水仙碱处理诱导获得。在这些方法中,用2ppmBA(激动素)配制的约0.2％的秋水仙碱溶液注射膨芽最有效。在产生三倍体的两种杂交组合中,由4x×2x组合获得的杂交种子发芽率差,将种子冷藏在2℃7天以上,可以提高发芽率。人工三倍体也可以由二倍体植株的雌花,与用2ppmBA配制的0.05—0.1％的秋水仙碱溶液,每天一次,连续处理7—10天而加倍的雄性配子杂交获得。

BREEDING OF ARTIFICIAL TRIPLOID IN MULBERRY

In general,the artificial tripjoid of mulberry is obtained by hybridization between tetraploid and diploid. the tetraploid of clonal varieties could be induced by gammar ray irradiation of the swelling or dormant buts with the dose of about 5,000 Rad and by the colchicine treatment of the concentration about 0.2%, amony which the most efficient is that 0.2% colchicine solution prepared with 2 ppm BA is injected into swelling buds. In the two hybridized combinations for triploid, the germinating ability of the hybrid seeds from the 4x×2x is quite poor. The seeds could increase the germinating percentage by means of the refrigerating at 2℃ over 7 days. The artificial triploid also might be obtained by a cross between diploid female and diploid male gamete doubled by the treatment of 0.05-0.1% colchicine prtpared with 2 ppm BA solution once a day lasting 7-10 days.