Coastal Plain Station, University of Georgia, 31793, Tifton, GA, USA.
Theor Appl Genet. 1984 Jan;67(2-3):197-201. doi: 10.1007/BF00317033.
Microsporogenesis, reproductive behavior, pollen fertility and seed set were studied in Pennisetum basedowii Summerhayes and C. E. Hubbard, 2n = 54; P. macrostachyum (Brough.) Trin., 2n = 54; P. macrourum Trin., 2n = 36; P. polystachion (L.) Schult, 2n = 54; and P. squamulatum Fresen 2n = 54. Meiosis was regular in P. basedowii with primarily bivalent pairing. As many as 54 univalents were observed at metaphase I in P. macrostachyum. A high frequency of univalents at metaphase I in P. macrourum resulted in lagging chromosomes and micronuclei at anaphase I and telophase I, respectively. Pennisetum polystachion and P. squamulatum showed frequent multivalent chromosome associations. Studies of megasporogenesis and embryo sac development in P. basedowii showed sexual reproduction. Pennisetum macrostachyum was highly male sterile with predominantly aposporous apomictic embryo sac development. Pennisetum macrourum, P. polystachion, and P. squamulatum had only aposporous embryo sac development. Seed propagated progenies of these latter three species were uniform and matromorphic, confirming the obligate apomixis nature.
小孢子发生、繁殖行为、花粉育性和结实率在 Pennisetum basedowii Summerhayes 和 C. E. Hubbard（2n = 54）、P. macrostachyum (Brough.) Trin.（2n = 54）、P. macrourum Trin.（2n = 36）、P. polystachion (L.) Schult.（2n = 54）和 P. squamulatum Fresen（2n = 54）中进行了研究。P. basedowii 的减数分裂是规则的，主要是二价体配对。在 P. macrostachyum 的中期 I 观察到多达 54 个单价体。在 P. macrourum 的中期 I 中单价体的高频出现导致染色体滞后和分别在后期 I 和末期 I 形成微核。Pennisetum polystachion 和 P. squamulatum 表现出频繁的多价体染色体联合。在 P. basedowii 的大孢子发生和胚囊发育研究中观察到有性生殖。P. macrostachyum 高度雄性不育，主要是无孢子无融合生殖胚囊发育。P. macrourum、P. polystachion 和 P. squamulatum 只有无孢子胚囊发育。后三种物种的种子繁殖后代是均匀的和母体的，证实了其强制性无融合生殖的本质。
