藠头大小孢子的发生及雌雄配子体败育的细胞学研究

MICROSPOROGENESIS, MEGASPOROGENESIS AND THE DEVELOPMENT OF MALE AND FEMALE GAMETOPHYTE IN ALLIUM CHINENSE G.DON

对栽培头4个品种大小孢子发生和雌雄配子体发育的细胞学观察表明，头小孢子母细胞减数分裂过程基本正常，四分体左右对称或四面体型，部分单核小孢子解体。散粉时，多数花粉粒空瘪，无萌发沟；部分花粉粒具单核或二核；极少数花粉粒具生殖核和营养核。花粉粒生活力低或无，无花粉管萌发。胚囊发育属葱型，部分能发育形成四核胚囊，大部分发育异常，出现二核至五核胚囊，未观察到正常七细胞八核胚囊的形成。结果表明，雌雄配子体败育导致头不结实。

The meiosis during microsporogenesis in four cultivars of Allium chinense G.Don was nearly normal. The arrangement of the microspores in tetrad was isobilateral or tetrahedra. Part of the uninucleate pollens disrupted. When the pollens were released from the loculi,most of them were hollow and had no germ furrow while the others were uninucleated or binucleated. Only a few of them had vegetable nuclei and generative unclei. In addition, pollen had low viability or had no viability, they did not grow pollen tube. The megasporogenesis was the Allium type. Part of the megaspores could form normal 4 nucleate embryo sac. Most of the megaspores developed abnormally,binucleate to 5 nucleate embryo sac were observed. No normal mature megasporogium formed. The reason of the sterility was the abnormality of microsporogenesis and megasporogenesis.