利用常规研究方法,对甜菜单体附加系M 14品系(B eta vu lg aris L.,VV+1C、2n=18+1)的生殖方式进行细胞学与胚胎学研究.结果表明:(1)甜菜单体附加系M 14的4代细胞学检查表明:染色体组分别为VV+1C、2n=18+1;VV+0、2n=18+0;VV+2C、2n=18+2...利用常规研究方法,对甜菜单体附加系M 14品系(B eta vu lg aris L.,VV+1C、2n=18+1)的生殖方式进行细胞学与胚胎学研究.结果表明:(1)甜菜单体附加系M 14的4代细胞学检查表明:染色体组分别为VV+1C、2n=18+1;VV+0、2n=18+0;VV+2C、2n=18+2;VVV+0、2n=27+0;VVV+1C、2n=27+1;VVV+2C、2n=27+2等,其中VV+1C、2n=18+1的植株传递率平均为96.7%,表现为稳定传递,具有二倍体孢子无融合生殖特性;其余各种分离植株的传递率总计为3.25%,有性生殖发生率较低.(2)胚胎学研究表明,二倍体孢子无融合生殖的胚珠中,珠孔处看不到花粉管,胚囊没有发生受精作用.2个助细胞提前退化,半数卵细胞的极性与正常卵细胞相反;卵与次生核不经受精而自发分裂,卵细胞自发分裂产生无性胚,次生核自发分裂产生核型胚乳,而且次生核自发分裂早于卵细胞分裂;有性生殖胚珠中,珠孔处可见多条花粉管,胚囊里见到精卵融合的图像.表明甜菜单体附加系M 14是以二倍体孢子无融合生殖为主要繁殖方式,有性生殖为次要敏殖方式的兼性无融合生殖体.展开更多
The geometries, bondings, and vibrational frequencies of C 2n H ( n =3-9) and C 2n -1 N( n =3-9) were investigated by means of density functional theory(DFT). The vertical excitation energies for th...The geometries, bondings, and vibrational frequencies of C 2n H ( n =3-9) and C 2n -1 N( n =3-9) were investigated by means of density functional theory(DFT). The vertical excitation energies for the X 2Π→ 2Π transitions of C 2n H( n =3-9) and for the X 2Σ→ 2Π and the X 2Π→ 2Π transitions of C 2n -1 N( n =3-9) have been calculated by the time-dependent density functional theory(TD-DFT) approach. On the basis of present calculations, the explicit expression for the wavelengths of the excitation energies in linear carbon chains is suggested, namely, λ 0=[1240 6A/(2+[KF(]3n+6-3n+3)](1-B e -Cn ), where A=3 24463, B=0 90742 , and C = 0 07862 for C 2n H, and A=2 94714, B=0 83929 , and C =0 08539 for C 2n -1 N. In consideration of a comparison of the theory with the experiment, both the expressions are modified as λ 1=0 92( λ 0+100) and λ 1= 0 95( λ 0+90) for C 2n H and C 2n -1 N, respectively. (1-B e -Cn ), where A=3 24463, B=0 90742 , and C = 0 07862 for C 2n H, and A=2 94714, B=0 83929 , and C =0 08539 for C 2n -1 N. In consideration of a comparison of the theory with the experiment, both the expressions are modified as λ 1=0 92( λ 0+100) and λ 1= 0 95( λ 0+90) for C 2n H and C 2n -1 N, respectively.展开更多
文摘利用常规研究方法,对甜菜单体附加系M 14品系(B eta vu lg aris L.,VV+1C、2n=18+1)的生殖方式进行细胞学与胚胎学研究.结果表明:(1)甜菜单体附加系M 14的4代细胞学检查表明:染色体组分别为VV+1C、2n=18+1;VV+0、2n=18+0;VV+2C、2n=18+2;VVV+0、2n=27+0;VVV+1C、2n=27+1;VVV+2C、2n=27+2等,其中VV+1C、2n=18+1的植株传递率平均为96.7%,表现为稳定传递,具有二倍体孢子无融合生殖特性;其余各种分离植株的传递率总计为3.25%,有性生殖发生率较低.(2)胚胎学研究表明,二倍体孢子无融合生殖的胚珠中,珠孔处看不到花粉管,胚囊没有发生受精作用.2个助细胞提前退化,半数卵细胞的极性与正常卵细胞相反;卵与次生核不经受精而自发分裂,卵细胞自发分裂产生无性胚,次生核自发分裂产生核型胚乳,而且次生核自发分裂早于卵细胞分裂;有性生殖胚珠中,珠孔处可见多条花粉管,胚囊里见到精卵融合的图像.表明甜菜单体附加系M 14是以二倍体孢子无融合生殖为主要繁殖方式,有性生殖为次要敏殖方式的兼性无融合生殖体.
基金Supported by the National Natural Science Foundation of China( Nos.2 0 1730 4 2 ,2 0 2 330 2 0 and2 0 0 2 10 0 2 ) and Trans-Century Training Programm e Foundation of the Educational Ministry of China
文摘The geometries, bondings, and vibrational frequencies of C 2n H ( n =3-9) and C 2n -1 N( n =3-9) were investigated by means of density functional theory(DFT). The vertical excitation energies for the X 2Π→ 2Π transitions of C 2n H( n =3-9) and for the X 2Σ→ 2Π and the X 2Π→ 2Π transitions of C 2n -1 N( n =3-9) have been calculated by the time-dependent density functional theory(TD-DFT) approach. On the basis of present calculations, the explicit expression for the wavelengths of the excitation energies in linear carbon chains is suggested, namely, λ 0=[1240 6A/(2+[KF(]3n+6-3n+3)](1-B e -Cn ), where A=3 24463, B=0 90742 , and C = 0 07862 for C 2n H, and A=2 94714, B=0 83929 , and C =0 08539 for C 2n -1 N. In consideration of a comparison of the theory with the experiment, both the expressions are modified as λ 1=0 92( λ 0+100) and λ 1= 0 95( λ 0+90) for C 2n H and C 2n -1 N, respectively. (1-B e -Cn ), where A=3 24463, B=0 90742 , and C = 0 07862 for C 2n H, and A=2 94714, B=0 83929 , and C =0 08539 for C 2n -1 N. In consideration of a comparison of the theory with the experiment, both the expressions are modified as λ 1=0 92( λ 0+100) and λ 1= 0 95( λ 0+90) for C 2n H and C 2n -1 N, respectively.
