摘 要 ：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。
Abstract:The morphology of somatic cell chromosomes,meiotic pairing behavior in pollen mother cells(PMCs),and pollen development of Aglaonema modestum Schott ex Engl.were investigated.The results showed that:(1)the number of somatic cell chromosome for wild individuals was 2n=40 and cultivated individuals was 2n=60;(2)at diakinesis Ⅰ,cultivated individuals presented trivalent synapsis;(3)at metaphaseⅠ,20 bivalents were at the metaphase equatorial plate and 20 univalents were distributed at random,and the cultivated individuals were triploid;(4)at anaphaseⅠ,wild individuals possessed chromosome bridges,with a ratio of 10%,cultivated individuals were 3%,with lagging chromosomes,micronuclei,and fragments;(5)at the tetrad stage,the tetrads of wild individuals were normal,while cultivated tetrads and abnormal polyads;(6)pollens were spherical and trinucleate,with 2.18% of wild individual pollens abortive and 88.29% of cultivated individuals abortive;(7)each fruit of wild individuals contained one seed,while no seed was observed in the cultivated individuals.