Cytoembryological evaluation, meiotic behavior and pollen viability of Paspalum notatum tetraploidized plants

Abstract This study evaluated the mode of reproduction, the meiotic behavior and the pollen viability of three tetraploid plants (2n=4x=40) originated from somatic chromosome duplication of Paspalum notatum plants. The plant WKS 3 changed the mode of reproduction after duplication and became apomictic. The plants WKS 63 and WKS 92 confirmed sexual mode of reproduction identical to that of the original genotype. The analyzed plants presented meiotic abnormalities related to tetraploidy, and the chromosome pairing were variable, but it did not hinder the meiotic products, which were characterized by regular tetrads and satisfactory pollen fertility, ranging from 88.7 to 95.7%. Results show that all plants are meiotically stable and that they can be used in intraspecific crosses in the breeding program of Paspalum notatum.

摘要 本研究评估了3株由巴哈雀稗（Paspalum notatum）体细胞染色体加倍获得的四倍体植株（2n=4x=40）的繁殖方式、减数分裂行为与花粉活力。其中WKS 3号植株经染色体加倍后改变了原有繁殖模式，转变为无融合生殖型；WKS 63与WKS 92号植株则保留了与原始基因型一致的有性繁殖方式。供试植株均出现与四倍体特性相关的减数分裂异常，染色体配对情况存在变异，但未对减数分裂产物造成不良影响；其减数分裂产物表现为规则四分体，花粉育性介于88.7%至95.7%之间。研究结果表明，所有供试植株均具备减数分裂稳定性，可应用于巴哈雀稗育种项目中的种内杂交工作。