|
ИСТИНА |
Войти в систему Регистрация |
ИСТИНА ИНХС РАН |
||
Peculiarities of microgametophyte development in several species and cultivars of poplarстатья Краткое сообщение
- Автор: Polevova Svetlana V.
- Журнал: Skvortsovia
- Том: 6
- Номер: 2
- Год издания: 2020
- Издательство: Ботанический сад УрО РАН
- Местоположение издательства: Екатеринбург
- Первая страница: 64
- Последняя страница: 64
- Аннотация: Sporoderm development has been studied in two species and two hybrids of poplar. Allstudied plants have passed the same stages of microsporogenesis and sporoderm development.Differences were observed only in duration of certain stages and hence dates. Simultaneousmicrosporogenesis in poplars takes place during about one or two weeks of cold winter period,in late January and early February. Trembling aspen (Populus tremula L.) is a native speciesin Moscow Region. Pollen development in this species takes place some two weeks earlier thanin the introduced white poplar (P. alba L.) and cultivated hybrids (P. × nevensis Nasim. andP. × berolinensis K.Koch). Duration of stages in the sporoderm development considerablydiffers. Formation of thin callous wall results in the swift development of primexine over theentire surface of the microspore, ultimately ending up with production of thin, though fivelayer exine consisting of tectum, bacules, and foot layer of ectexine along with two layers ofendexine. During the stage of volume enlargement of pollen grain prior to ripening, the exinekeeps thinning across all of its layers, becoming fragmentary in some areas. At the same time,intine is forming at this stage, which also takes a fairly long period. As a result of theseprocesses, tubular elements of the powerful exocytosis are preserved in the outer layer of theintine over the entire surface of the pollen grain. The inner intine layer remains homogeneous.The multi-layer intine is typical for aperture areas, which, in combination with the fragmentation of the exine, makes poplar pollen grains omniaperturate – in terms of both the structure of the sporoderm and mode of its formation.
- Добавил в систему: Полевова Светлана Вячеславовна