Polykaryon formation using a swollen conidium of Trichoderma reesei

The cellulolytic fungus, Trichoderma has oval and mononucleate conidia. When these conidia are incubated in a liquid medium, they begin to swell and their shape becomes spherical followed by an increase in inner space. In such swollen conidia, it is possible to produce a larger autopolyploid nucleus using a mitotic arrester compared with the case of the original conidia. In this study, polykaryon formation was attempted using these swollen conidia. Dried mature green conidia of Trichoderma reesei QM6a (IFO 31326) were incubated in Mandel's medium in order to swell. The swollen conidia were treated with a mitotic arrester, colchicine, for autopolyploidization. After autopolyploidization, polykary on formation was carried out using the swollen conidia. After the treatment, multiple smaller nuclei whose diameter was almost the same as that of the original strain were generated from an autopolyploid nucleus in a swollen conidium. A cellulase hyperproducer without decrease in growth rate could be selected using such swollen conidia.     

秋水仙素诱导铁皮石斛多倍体研究

用不同质量分数秋水仙素处理铁皮石斛种胚原球茎诱导多倍体,结果表明：1.秋水仙素对种胚原球茎的生长有不同程度的抑制作用,对根系生长的抑制尤为明显.2.由于种胚原球茎完整性好,耐受性强,要获得多倍体则需较高质量分数的秋水仙素或较长的处理时间.3.本实验诱导多倍体有相当一部分是非整倍体,通过流式细胞检测到的变异率高于形态学观察的结果.4.经秋水仙素处理后,有些植株的茎变得粗短,出现茎分叉现象,叶片形状呈锯齿状,变小变厚等变异特征.