雌雄异型异熟是植物从雌雄同花向雌雄异株进化过程中的一种过渡类型,目前发现存在于13个科20个属植物中。其群体中包括雌先型和雄先型两种交配类型,两种交配类型植株的同步性和互不干扰性可有效地避免自交。一般认为雌雄异型异熟植株的交配类型是固定不变的,但也在一些植物中发现了彼此间的转化;植株内雌雄花开放时间有的完全错开,有的部分重叠。经典遗传学认为交配类型受1对显/隐性的等位基因控制,且当群体达到平衡时两种交配类型的比例可达平衡状态(1∶1),这在胡桃属和山核桃属上得到了验证,但在其他同类植物分子生物学方面的研究还是空白。雌雄异型异熟植物的性别决定为饰变型,其性别分化不仅受性别决定基因的遗传控制,而且还受植物激素的诱导调控,但不同植物上激素诱导性别分化的作用存在差异。解剖学研究表明同一交配类型上的雌雄花发育和成熟时间均存在差异。
Heterodichogamy, which is dispersed and reported in 20 genera from 13 families of flowering plants, is one ofthe evolutionary pathways from monoecy to dioecy. Heterodichogamous populations usually contain two sexual morphs,protogynous and protandrous, which are synchronous and reciprocal, and thus can reduce selfing rate. Generally, matingtype is stable for an individual.Whereas,transitions among sexual phenotypes are reported in several species, though therate is very low. There are separate completely between sexual functions(male-female flowering) within individual treesin many heterodichogamous plants, while partly overlaps have been found in several species. The inheritance pattern ofmating system that a dominant-recessive Mendelian factor of one locus and two alleles determines mating type, and twogenetic morphs co-occurs, typically at a ratio of 1 ∶1 in a population has been confirmed in Juglans and Carya. However,little information at molecular level in other heterodichogamous species is available to support this hypothesis. Pattern ofsex determination in heterodichogamous plants is trim variant. Sex differentiation of those plants is not only geneticallycontrolled by genes of sex determination, but also is inductively regulated by phytohormones. However, hormonal functionfor sex differentiation is quite different among different species. Anatomical data from an individual plant revealed that de-velopmental progress of female and male as well as ripening time is asynchronous. However, data from other sources is veryfew. Therefore, it is urgent that more evidences should be expoited to elucidate the mechanism of heterodichogamy.