采用常规压片法和去壁低渗法,以生长于广西凭祥和广东深圳的广东万年青(Aglaonema modestumSchott ex Engl.)为材料,对二者的体细胞染色体、花粉母细胞减数分裂染色体配对行为和花粉发育过程进行了观察。结果表明:(1)野生植株为二倍体2n...采用常规压片法和去壁低渗法,以生长于广西凭祥和广东深圳的广东万年青(Aglaonema modestumSchott ex Engl.)为材料,对二者的体细胞染色体、花粉母细胞减数分裂染色体配对行为和花粉发育过程进行了观察。结果表明:(1)野生植株为二倍体2n=40,栽培植株为三倍体2n=60;(2)野生种的小孢子母细胞减数分裂前期I终变期均为二价联会,栽培种偶见三价联会;(3)中期I,野生种为20个二价体排列在赤道板上,未见单价体,栽培种的20个二价体排列于赤道板上,20个单价体随机分布于两极,证实其为三倍体;(4)后期I,野生种二价体分离,出现单染色单体桥和断片,几率为10%,栽培种几率为3%,还存在落后染色体,部分不能进入两极的落后染色体和染色体断片在末期I形成微核;(5)四分体时期,野生种未观察到异常孢子,栽培种出现大量败育的四分体或多分体;(6)小孢子进入正常的发育分化,通过两次有丝分裂形成三细胞型花粉。野生种成熟花粉败育率为2.18%,栽培种为88.29%;(7)野生种正常结实,栽培种果实中未发现种子,为高度不育。展开更多
This paper reports three newly recorded species, Diphascon modestum Binda, Pilato and Dastych, 1984, Diphascon nobilei Binda 1969, and Diphascon triodon Maucci, 1996, of the genus Diphascon （Tardigrada; Hypsibiidae）...This paper reports three newly recorded species, Diphascon modestum Binda, Pilato and Dastych, 1984, Diphascon nobilei Binda 1969, and Diphascon triodon Maucci, 1996, of the genus Diphascon （Tardigrada; Hypsibiidae） from China. Five specimens of Diphascon modestum were collected from Taibai Mt. （34°18′N, 107°42′E） at 2,500 m above the sea level （a.s.l.）, two specimens ofDiphascon nobilei were collected from Tonggu County, Jiangxi Province （28°31′N, 114°26′E） at 900 m a.s.l, and one specimen ofDiphascon triodon was collected from Linzhi County, Tibet （29°40′N, 94°23′E） at 3,500 m a.s.l. All specimens are deposited at the College of Life Sciences, Shaanxi Normal University, China. A key to the Chinese species of Diphascon was also given.展开更多
文摘采用常规压片法和去壁低渗法,以生长于广西凭祥和广东深圳的广东万年青(Aglaonema modestumSchott ex Engl.)为材料,对二者的体细胞染色体、花粉母细胞减数分裂染色体配对行为和花粉发育过程进行了观察。结果表明:(1)野生植株为二倍体2n=40,栽培植株为三倍体2n=60;(2)野生种的小孢子母细胞减数分裂前期I终变期均为二价联会,栽培种偶见三价联会;(3)中期I,野生种为20个二价体排列在赤道板上,未见单价体,栽培种的20个二价体排列于赤道板上,20个单价体随机分布于两极,证实其为三倍体;(4)后期I,野生种二价体分离,出现单染色单体桥和断片,几率为10%,栽培种几率为3%,还存在落后染色体,部分不能进入两极的落后染色体和染色体断片在末期I形成微核;(5)四分体时期,野生种未观察到异常孢子,栽培种出现大量败育的四分体或多分体;(6)小孢子进入正常的发育分化,通过两次有丝分裂形成三细胞型花粉。野生种成熟花粉败育率为2.18%,栽培种为88.29%;(7)野生种正常结实,栽培种果实中未发现种子,为高度不育。
基金supported by scientific research foundation project of Shaanxi Institute of Education (No. 07KJ37Q)
文摘This paper reports three newly recorded species, Diphascon modestum Binda, Pilato and Dastych, 1984, Diphascon nobilei Binda 1969, and Diphascon triodon Maucci, 1996, of the genus Diphascon （Tardigrada; Hypsibiidae） from China. Five specimens of Diphascon modestum were collected from Taibai Mt. （34°18′N, 107°42′E） at 2,500 m above the sea level （a.s.l.）, two specimens ofDiphascon nobilei were collected from Tonggu County, Jiangxi Province （28°31′N, 114°26′E） at 900 m a.s.l, and one specimen ofDiphascon triodon was collected from Linzhi County, Tibet （29°40′N, 94°23′E） at 3,500 m a.s.l. All specimens are deposited at the College of Life Sciences, Shaanxi Normal University, China. A key to the Chinese species of Diphascon was also given.
