柑桔原生质体辐射诱变筛选抗寒再生植株

STUDIES ON SCREENING FREEZING RESISTANT REGEN ERATED PLANTS FROM X RAY IRRADIATED CITRUS PROTOPLASTS 

用１１６１Ｃ／ｋｇ软Ｘ射线辐射“Ｐａｇｅ”桔柚（ＣｉｔｒｕｓｒｅｔｉｃｕｌａｔａＢｌａｎｃｏ×Ｃ．ｇｒａｎｄｉｓＯｓｂ．ｃｖ．Ｐａｇｅ）胚性愈伤组织分离的原生质体，经－１１℃低温选择后，将存活的原生质体培养再生植株。研究表明，“Ｐａｇｅ”桔柚胚性愈伤组织原生质体在４１２８Ｃ／ｋｇ辐射剂量处理后几乎不能恢复分裂；２０６４Ｃ／ｋｇ辐射时分裂频率低，即使分裂也难以发育为胚状体；而１１６１Ｃ／ｋｇ辐射后，经－１１℃低温处理仍有１０２％～１６９％的分裂频率，且部分细胞团能发育为胚状体。辐射的原生质体培养成胚状体后，经低温筛选，在改良的生芽培养基和生根培养基中萌发成为植株。再生植株中检测出２株的叶片原生质体的低温半致死温度（ＬＴ５０）分别比对照低１．９６℃和１６８℃。

The response of cell division in the “Page”(Citrus reticulata Blanco×C.grandis Osb.cv.Page) protoplasts from embryonic callus to radiation challenge varied with the intensity of the X ray dose charged. When the protoplasts were irradiated with a dose of 4128 C/kg failure of cell division was completely irreversible, those after 2064 C/kg treatment revealed low frequence of cell division. Those after treatment with 1161 C/kg of X ray and kept at -11 ℃ gave off a 10.2%～16.9% frequence of division. Some of those viable protoplasts developed into embryoids from which plantlets were regenerated. The LT 50 of the leaf protoplasts in 2 of the regenerated plants was markedly lower than that in the controls.