对授粉后不同发育阶段扇脉杓兰(Cypripedium japonicum Thunb.)果实的生长动态进行了观察和分析,并分别采用TTC 法和常规石蜡切片法研究了种子生活力及其胚胎发育过程。观察结果显示:扇脉杓兰果实形态成熟时间约为110 d,其中,授粉后0 ~20 d 为第1 次迅速生长期,授粉后20 ~30 d 为第1 次缓慢生长期,授粉后30 ~50 d 为第2 次迅速生长期,授粉后50 ~110 d 为第2 次缓慢生长期;果实纵径和横径的生长动态变化过程相似,但横径的生长动态曲线较纵径平缓,形态成熟时果实的纵径和横径分别为48. 87 和13. 59 mm。成熟种子由内外2 层种皮和球形胚构成,不具胚乳,内外种皮间具空气腔;败育种子只具有内种皮和外种皮而无种胚。胚胎发育类型为石竹型,种胚自受精形成合子到发育为成熟球形胚约需95 d。种胚发育时合子第1 次不均衡横裂形成基细胞和顶细胞;基细胞发育为胚柄细胞,胚柄细胞高度液泡化,在胚胎发育的过程中不进行分裂并逐渐退化消失;顶细胞不参与胚柄形成,并且经过有丝分裂最终形成球形胚;内珠被在种子成熟时发育成为1 层致密的紧贴胚体的内种皮。种胚纵径和横径的生长动态变化相似,成熟球形胚的纵径和横径分别为208. 71 和106. 19 μm。扇脉杓兰种子生活力较高,有生活力的种子占56%。根据研究结果推测:自然状态下扇脉杓兰种子萌发率较低,可能与致密的种皮、种子中较小的胚体以及无胚乳导致的营养成分不足有关。

Fruit growth dynamics of Cypripedium japonicum Thunb. at different development stages after pollination were observed and analyzed. And seed viability and embryo development process were also studied by TTC and normal paraffin section methods, respectively. The observation results show that morphological mature time of C. japonicum fruit is about 110 d, in which, after pollination, 0-20 d is the first fast growth period, 20-30 d is the first slow growth period, 30-50 d is the second fast growth period and 50-110 d is the second slow growth period. Growth dynamic changes of vertical and horizontal diameters of C. japonicum fruit are similar but dynamic growth curve of horizontal diameter is gentler than that of vertical diameter, and fruit vertical and horizontal diameters at morphological mature stage are 48. 87 and 13. 59 mm, respectively. The mature seeds are consisted of endopleura, exopleura and sphere embryo without endosperm, and air cavity exists between endopleura and exopleura. While, abortive seeds only possess endopleura and exopleura, without sphere embryo. The embryo development type of C. japonicum is caryophyllad type, and the time from forming zygote after fertilization to developing the mature sphere embryo is about 95 d. During development stage of seed embryo, the first unequal transverse fissure of zygote forms basal cell and terminal cell. Basal cell develops into suspensor cell with highly vacuolated, which does not further divide and degenerate and disappear gradually. Terminal cell is not involved in suspensor forming and finally forms sphere embryo through mitosis. The inner integument develops into one layer of impermeable endopleura clunged to embryo at seed mature stage. Dynamic growth changes of vertical and horizontal diameters of seed embryo are similar, and vertical and horizontal diameters of mature sphere embryo are 208. 71 and 106. 19 μm, respectively. Seed viability of C. japonicum is higher with 56% viable seeds. According to these research results, it is conjectured that germination rate of C. japonicum seed is low under natural state, which relates to compact seed coat, smaller embryo and nutritional components deficiency due to no endosperm.