Heterodichogamy of a novel type in Hernandia (Hernandiaceae) and its structural basis
Heterodichogamy of a novel type in Hernandia (Hernandiaceae) and its structural basis
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DOI：
10.1086/422049
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发表时间：
2004-09-01
影响因子：
2.3
通讯作者：
Lorence, DH
中科院分区：
文献类型：
--
作者：
Endress, PK;Lorence, DH
本文首次报道了月桂科植物的异二婚现象；此外，这种异二配是一种迄今未在被子植物中报道的新类型。在雌雄同株的单性花Hernandia nymphaeifolia中，发现了两种个体，一种是上午完全雌花开放，下午雄花开放，另一种则相反。花以两雄花和一雌花的聚伞花序的复合聚伞花序排列。发育研究证实了一种较早的解释，即这些三位一体具有雄性-雄性-雌性的序列。然而，令人惊讶的是，在花期序列是相反的：大多数三合一花的序列是雄性-雌性-雄性。花发育显示雌蕊是单皮的（而不是假单瓣的）。在雄花中，有三个与雄蕊交替的初级丘（尚未被忽视），这可能与雌花中的那些丘相对应，这些丘被联合成一个环形的蜜腺，可能代表极度减少的雄蕊。由于异二婚现象在被子植物中很少见，因此在一些樟科（樟科的姐妹科）中，虽然异二婚是一种不同的类型，但很早就发现了异二婚现象。为了更好地理解植物的进化，我们还需要对其他属的开花行为进行研究。
Heterodichogamy is reported for the first time in the family Hernandiaceae (Laurales); furthermore, this heterodichogamy is of a novel type hitherto not reported in angiosperms. In Hernandia nymphaeifolia, which has unisexual flowers and is monoecious, two kinds of individuals were found: one kind with exclusively female flowers open in the morning and male flowers open in the afternoon and the other kind with the reverse behavior. The flowers are arranged in compound thyrses with cymes of two male and one female flower. Developmental studies confirm an earlier interpretation of these triads as monochasia with the sequence male-male-female. Surprisingly, though, the sequence is reversed at anthesis: most triads flower with the sequence male-female-male. Flower development shows that the gynoecium is unicarpellate (and not pseudomonomerous). In male flowers there are three rudimentary mounds (as yet overlooked) alternating with the stamens, which may correspond to those mounds in the female flowers that are united into a ring-shaped nectary and may represent extremely reduced staminodes. As heterodichogamy is an apparently rare phenomenon in angiosperms, it is of interest that heterodichogamy, although of a different type, has long been known in some Lauraceae, the sister family of Hernandiaceae. For an evolutionary understanding, the flowering behavior of the other genera of Hernandiaceae should be studied.