辣椒自发和诱发2n花粉的形成及细胞遗传学机理

自然条件下，辣椒（Ｃａｐｓｉｃｕｍ ｆｒｕｔｅｓｃｅｎｓＬ．）小孢子形成过程中存在１％ 以下的二分体和三分体。人工诱导可使二分体、三分体的比率分别提高到４５％ 和３．２９％ ，其中２１．５２％的二分体和多数三分体由双核小孢子构成，但是，成熟花粉中仅５．６５％ 为２ ｎ 花粉。细胞遗传学研究结果表明：辣椒自发２ ｎ 花粉主要来源于减数分裂过程中的细胞质分裂异常和少部分第１ 次分裂重组，而人工诱发的２ ｎ 花粉则主要来源于由不联会造成的第１ 次分裂重组，也有部分细胞质异常分裂。

FORMATION AND CYTOGENETIC MECHANISM OF SPONTANEOUS AND INDUCED 2n POLLEN IN Capsicum frutescens L.

During microsporogenesis of Capsicum frutescens L.Var. Longum Bailey less than 1% spontaneous dyads and triads were observed.Through artificial induction,more than 45% dyads and 3.29% triads arised against total sporads,21.52% of dyads and most of triads consisted of binucleate microspores,but only 5.65% pollen grains were considered as un reduced gametes.Cytological and cytogenetic studies indicated that the predominant mechanism of induced 2n pollen formation was the first division restitution resulted from asynapsis,and aberrent cytokinesis was the other but was the main mechanism of spontaneous 2n pollen production rather than FDR.