摘要
珠心表皮下分化出一个或两个孢原细胞，但只有一个继续发育，直接起大孢子母细胞的功能．蓼型胚囊．成熟胚囊助细胞丝状器不发达，到受精前反足细胞仅体积增大但不增殖，两极核相互贴近而不融合．受精前胚珠发育过程中，珠被、珠心细胞中始终无淀粉积累；成熟胚囊各细胞中均未发现淀粉粒，但合点端胚囊壁及周围珠心细胞中具强的ＰＡＳ正反应．同一珠心中发现有双胚囊现象，另外，在四分孢子旁发现由珠心细胞起源的孢原产生，认为诺丹冰草中有无融合生殖现象存在．
One or two hypodermal archesporium cells are observed,but only one of them directly functions as megaspore mother cell. The development of embryo sac is of the Polygonum type. Thesynergids in mature embryo sac have undeveloped filiform apparatus. Before fertilization,volumeof antipodal cells increase,but no multiplications happen. Two polar-nuclei close up,but do notfuse. During the development of ovule of pre-fertilization,no starch accumulates in the integumentand nucellar cells. There are strong PAS reactions in the embryo sac and nucellar cells at the chalaza end. Double embryo sacs are found in an ovule and apospory initial cell originats from nucellar cells near tetrad,so apomixis exists in Agrophyron nordan.
出处
《内蒙古大学学报（自然科学版）》
CAS
CSCD
1996年第3期397-401,共5页
Journal of Inner Mongolia University：Natural Science Edition
基金
山西省青年科学基金
关键词
诺丹冰草
大孢子发生
无融合生殖
胚胎学
禾本科
Agropyron nordan apomixis megasporogenesis formation of female gametophyte
