EMBRAPA, Centro Nacional de Recursos Genéticos, SAIN, Parque Rural, Caixa, 70.770-Brasília-DF, Brazil.
Genetics. 1984 May;107(1):103-15. doi: 10.1093/genetics/107.1.103.
Maize kernels inheriting the indeterminate gametophyte mutant (ig) on the female side had endosperms that ranged in ploidy level from diploid (2x) to nonaploid (9x). In crosses with diploid males, only kernels of the triploid endosperm class developed normally. Kernels of the tetraploid endosperm class were half-sized but with well-developed embryos that regularly germinated. Kernels of endosperm composition other than triploid or tetraploid were abortive.-Endosperm ploidy level resulting from mating ig/ig x tetraploid Ig similarly was variable. Most endosperms started to degenerate soon after pollination and remained in an arrested state. Hexaploid endosperm was exceptional; it developed normally during the sequence of stages studied and accounted for plump kernels on mature ears. Since such kernels have diploid maternal tissues (pericarp) but triploid embryos, the present finding favors the view that endosperm failure or success in such circumstances is governed by conditions within the endosperm itself.-Whereas tetraploid endosperm consisting of three maternal genomes and one paternal genome is slightly reduced in size but supports viable seed development, that endosperm having two maternal and two paternal chromosome sets was highly defective and conditioned abortion. Thus, development of maize endosperm evidently is affected by the parental source of its sets of chromosomes.
玉米子粒从雌性方面继承了不定配子体突变（ig），其胚乳的倍性水平从二倍体（2x）到非整倍体（9x）不等。与二倍体雄性杂交时，只有三倍体胚乳类的子粒正常发育。四倍体胚乳类的子粒是半大小的，但胚胎发育良好，通常能发芽。三倍体或四倍体以外的胚乳组成的子粒是败育的。- ig/ig x 四倍体 Ig 交配产生的胚乳倍性水平也同样是可变的。大多数胚乳在授粉后不久开始退化，并保持在停滞状态。六倍体胚乳是例外；它在研究的阶段序列中正常发育，并在成熟穗上形成饱满的子粒。由于这些子粒具有二倍体母体组织（果皮）但三倍体胚胎，目前的发现倾向于认为，在这种情况下，胚乳的失败或成功是由胚乳本身的条件决定的。- 虽然由三个母体基因组和一个父本基因组组成的四倍体胚乳体积略小，但支持可育种子的发育，而具有两个母体和两个父本染色体组的胚乳则高度缺陷，并导致流产。因此，玉米胚乳的发育显然受到其染色体组的亲本来源的影响。
