Singhal V K, Kumar Puneet
Department of Botany, Punjabi University, Patiala, India.
J Biosci. 2008 Sep;33(3):371-80. doi: 10.1007/s12038-008-0057-0.
We report the occurrence of cytomixis in wild populations of Himalayan poppy (Meconopsis aculeata Royle),which is considered to be an important and threatened medicinal plant growing in the high hills of the Himalayas. The impact of cytomixis on meiotic behaviour, reduced pollen viability and heterogeneous-sized pollen grains was also studied. Cytological studies in the seven wild populations from the high hills of Himachal Pradesh revealed that all the Himalayan populations exist uniformly at the tetraploid level (2n=56) on x=14. The phenomenon of chromatin transfer among the proximate pollen mother cells (PMCs) in six populations caused various meiotic abnormalities. Chromatin transfer also resulted in the formation of coenocytes, aneuploid, polyploid and anucleated PMCs. Among individuals that showed chromatin transfer, chromosome stickiness and interbivalent connections were frequently observed in some PMCs. The phenomenon of cytomixis in the species seems to be directly under genetic control; it affects the meiotic course considerably and results in reduced pollen viability.
我们报道了喜马拉雅罂粟（Meconopsis aculeata Royle）野生种群中细胞融合现象的发生，该植物被认为是生长在喜马拉雅高山上的一种重要且濒危的药用植物。我们还研究了细胞融合对减数分裂行为、花粉活力降低以及花粉粒大小不均一的影响。对喜马偕尔邦高山上七个野生种群的细胞学研究表明，所有喜马拉雅种群在x = 14时均以四倍体水平（2n = 56）均匀存在。六个种群中相邻花粉母细胞（PMC）之间的染色质转移现象导致了各种减数分裂异常。染色质转移还导致了多核细胞、非整倍体、多倍体和无核PMC的形成。在表现出染色质转移的个体中，一些PMC中经常观察到染色体粘连和二价体间连接。该物种中的细胞融合现象似乎直接受遗传控制；它极大地影响减数分裂过程，并导致花粉活力降低。
