The phase transition of Silwet L-77(a kind of siloxane surfactant) dilute aqueous solution with temperature was investigated by dielectric relaxation spectroscopy.In the initial heating process,a dielectric relaxation...The phase transition of Silwet L-77(a kind of siloxane surfactant) dilute aqueous solution with temperature was investigated by dielectric relaxation spectroscopy.In the initial heating process,a dielectric relaxation was found at about 10~6 Hz,which was considered as the interface polarization ascribed to the interface between water and liquid phases(W and L_1).With the temperature increasing further,a new dielectric relaxation was observed at about 10~4 Hz,which was assigned to the appearance of liquid crystal phase(L_α).According to the dielectric parameters fitted by Cole-Cole equation,the coexistence temperature of W,L_1 and L_αwas determined at about 37.0℃.展开更多
Three main parameters were selected to study their importance in transformation by budmicroinjection in non-head Chinese cabbage [Brassica campestris ssp. chinensis (L.) Makinovar. communis Tsen et Lee]. The results s...Three main parameters were selected to study their importance in transformation by budmicroinjection in non-head Chinese cabbage [Brassica campestris ssp. chinensis (L.) Makinovar. communis Tsen et Lee]. The results showed that the developmental stage of floral bud, theconcentrations of sucrose and surfactant Silwet L-77 were critical for the successfultransformation by this new method. The suitable bud size is 2-3 mm in length, the favorableconcentration of sucrose and surfactant Silwet L-77 are 8 and 0.02% respectively. When thesucrose concentration was greater than 10% or that of Silwet L-77 was above 0.1%, the treatedbuds became yellow and finally blighted. 4/6 T1 seedlings resistant to kanamycin were positiveby PCR analysis, and T2 progeny of all these positive T1 plants have one or more hybridizingbands by Southern blot. Under 5% sucrose, 0.02% Silwet L-77 and grade 2 bud (2-3 mm in itslength) parameters, the most favorable transformation efficiency is about 0.56%, and meanefficiency reaches 0.16% in all experiments indicating that bud microinjection is potentialtransformation way in non-head Chinese cabbage.展开更多
基金supported by Beijing Municipal Commission of Education
文摘The phase transition of Silwet L-77(a kind of siloxane surfactant) dilute aqueous solution with temperature was investigated by dielectric relaxation spectroscopy.In the initial heating process,a dielectric relaxation was found at about 10~6 Hz,which was considered as the interface polarization ascribed to the interface between water and liquid phases(W and L_1).With the temperature increasing further,a new dielectric relaxation was observed at about 10~4 Hz,which was assigned to the appearance of liquid crystal phase(L_α).According to the dielectric parameters fitted by Cole-Cole equation,the coexistence temperature of W,L_1 and L_αwas determined at about 37.0℃.
文摘Three main parameters were selected to study their importance in transformation by budmicroinjection in non-head Chinese cabbage [Brassica campestris ssp. chinensis (L.) Makinovar. communis Tsen et Lee]. The results showed that the developmental stage of floral bud, theconcentrations of sucrose and surfactant Silwet L-77 were critical for the successfultransformation by this new method. The suitable bud size is 2-3 mm in length, the favorableconcentration of sucrose and surfactant Silwet L-77 are 8 and 0.02% respectively. When thesucrose concentration was greater than 10% or that of Silwet L-77 was above 0.1%, the treatedbuds became yellow and finally blighted. 4/6 T1 seedlings resistant to kanamycin were positiveby PCR analysis, and T2 progeny of all these positive T1 plants have one or more hybridizingbands by Southern blot. Under 5% sucrose, 0.02% Silwet L-77 and grade 2 bud (2-3 mm in itslength) parameters, the most favorable transformation efficiency is about 0.56%, and meanefficiency reaches 0.16% in all experiments indicating that bud microinjection is potentialtransformation way in non-head Chinese cabbage.
