Ovule development, megasporogenesis, megagametogenesis, embryogenesis, endosperm development and seed germination of Audouinia capitata are described. In sharp contrast to the relatively high incidence of abortion and non-viability of microspores demonstrated previously, no pre-anthesis aberrations occur in the megagametophyte. In many fertilized ovules the primary endosperm nuclei remain undivided, enlarge considerably for up to five weeks and eventually degenerate, accompanied by abortion of the zygote. A low incidence of abortion is evident after the fifth week. Abortions after 11 weeks of development are identifiable in mature fruits. A substantial number of mature seeds are devoid of, or contain low densities of, protein bodies. After germination, the radicles of these seeds stop growing soon after emergence from the fruits. It is suggested that abortion is regulated by inter-ovular competition for available nutrients, or by a strongly fixed, genetically controlled system. This strategy could have been selected to allow for the economization of reserves in the 6-ovuled, indehiscent ovaries that act as dispersal units. Possible explanations are suggested for abortion rates in excess of those implied by a fixed general system of one seed per indehiscent fruit. When accepting a seed:ovule ratio of 1:6 as full realization of the seed-setting potential, and ignoring all nonsexual factors, the pre-emergent reproductive success is only 9%. This deficiency is a contributing factor in the rarity of the species. Saadknopontwikkeling, megasporogenese, megagametogenese, embriogenese, endospermontwikkeling en saadontkieming van Audouinia capitata word beskryf. Geen voor-antese-afwykings word in die megagametofiet waargeneem nie, wat in skrille teenstelling is met die voorheen-aangetoonde, relatiewe hoë voorkoms van aborsie en lae kiemkrag van mikrospore. In baie bevrugte saadknoppe bly die primêre endospermkerne onverdeeld, neem vir tot so lank as vyf weke aansienlik in grootte toe en degenereer uiteindelik, met ’n gelyktydige abortering van die sigoot. Na die vyfde week is daar ’n lae voorkomssyfer van aborsie. Aborsies wat na 11 weke van ontwikkeling voorkom, is identifiseerbaar in volwasse vrugte. In die endosperm van ’n aansienlike aantal volwasse sade word geen proteïenliggaampies, of slegs lae digthede daarvan, waargeneem. Na ontkieming van dergelike sade word alle groei deur die kiemwortels, kort na verskyning buite die sade, gestaak. Daar word voorgestel dat aborsie beheer word deur tussen-saadknop-mededinging vir beskikbare nutriente, of deur ’n streng-neergelegde, geneties-beheerde sisteem as ’n aanpassingstrategie vir ekonomisering van reserwes in die vrugbeginsel met ses saadknoppe wat nie-oopspringend is en as verspreidingseenheid optree. Moontlike verklarings word aangebied vir aborsie-tempo’s wat hoër is as dié in ’n algemene sisteem van een saad per nie-oopspringende vrug. Indien ’n saad:saadknop-verhouding van 1:6 as ’n voile verwesenliking van die saadset-potensiaal beskou word, en alle nie-geslagtelike faktore geignoreer word, is die voor-opkoms-voortplantingsukses slegs 9%. Hierdie tekortkoming is ’n bydraendefaktor tot die skaarsheid van die spesie.
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