Статьи – Формирование гинецея у Buddleja davidii (Buddlejaceae)

Формирование гинецея у Buddleja davidii (Buddlejaceae)

Ботанический журнал №7 / 2014 г. – С. 729-748

База данных цитирования: РИНЦ

Рубрика: Оригинальные статьи
УДК: 581.466 581.3

Авторы: Шамров И. И.

Аннотация:
Гинецей Buddleja davidii (Buddlejaceae) изменяется в ходе развития. Уже на самых ранних стадиях (во время дифференциации плацент) нижняя и средняя части завязи представлены синасцидиатной зоной. Верхняя часть завязи образована открытой симпликатной зоной. Дистальную часть гинецея составляют лопасти рыльца и столбик с чертами ранней специализации. В дальнейшем происходит усложнение в строении симпликатной зоны, которая к моменту опыления становится закрытой. В завязи формируются септы трех разновидностей: базальная, медианная и апикальная. Семязачатки располагаются со смещением на наружных и внутренних ветвях угловых плацент, при этом их положение в завязи изменяется с трансверсального на продольное...

Ключевые слова: морфогенез, гинецей, плацентация, Buddleja davidii, Buddlejaceae, Scrophulariaceae, Orobanchaceae и Gesneriaceae

Название на английском: THE GYNOECIUM FORMATION IN BUDDLEJA DAVIDII (BUDDLEJACEAE)

Аннотация на английском:
The gynoecium of Buddleja davidii changes during its development. At the earliest stages (during the placenta differentiation) already, the lower and middle portions of the ovary are presented by synascidiate zone. The upper part of the ovary is formed by open symplicate zone. Distal portion of the gynoecium is composed by stigma lobes and style with features of early specialization. Later on, a complication takes place in the structure of symplicate zone, the latter getting closed by the pollination time. Three types of septa arise in the ovary: basal, median and apical. The ovules are arranged with displacement on external and internal branches of angular placentae, with their position in the ovary changing from transverse plane to longitudinal one. At the poles of the ovary, the placentae are sterile. Free spaces are formed there and filled by ovules of lower and upper tiers. In the proximal area of the synascidiate zone, placentae become composite median by approach of individual angular placentae. The placental obturators become differentiated through the ovary, on surfaces of both fertile and sterile placentae, despite their different functioning. The gynoecium of B. davidii is characterized by combination of central-axial and trans-septal modes of ovule innervation. Peripheral (lateral and dorsal median) vascular bundles go through the ovary wall to terminate in the style. Lateral bundles reach the middle part of the style and dorsal ones reach the stigma. Central-axial innervation of ovules is characteristic of synascidiate (complex amphicrybrate vascular bundle due to fusion of four ventral bundles) and the lower area of symplicate (ventral vascular bundles of each carpel pair together in homocarpellate bundles) zones. In the middle and upper areas of symplicate zone, the trans-septal innervation of the upper row of ovules is observed. Departing from the lateral peripheral bundles are branches extending from the ovary wall through the septum into the placenta to form heterocarpellate ventral bundles. Thus, gynoecium of B. davidii develops according to syncarpous type, and the presence of the median septum throughout the ovary allows to consider its development as a typical variation of this type. Similar and different features in the gynoecium structure of Buddlejaceae and possibly related Scrophulariaceae, Orobanchaceae and Gesneriaceae (order Scrophulariales), are discussed. Gynoecium structure differs greatly between the Orobanchaceae and Scrophulariaceae. In the Orobanchaceae, the gynoecium is predominantly paracarpous, while in the Scrophulariaceae it is mainly syncarpous. The gynoecium structure in the Buddlejaceae (Dickison, 1994; present study), Scrophulariaceae (Hartl, 1956) and some members of Gesneriaceae (Saintpaulia ionantha, Streptocarpus reinoldii - see Teryokhin, Nikiticheva, 1981 ) has a number of similarities: the presence of synascidiate zone at the bottom or lower and middle parts of the ovary (it is sterile at the proximal area), symplicate zone in the middle or middle and upper parts of the ovary (sterile at the top), central-angular placentation in synascidiate and closed symplicate zones (in the open symplicate area the placentae become simple angular). This is also evidenced by the formation of a special complex bundle formed in the center of the ovary due to fusion of four ventral bundles: Scrophulariaceae ( Striga orobanchoides - Tiagi, 1962; possibly Striga elegans - Teryokhin, Nikiticheva, 1981), Buddlejaceae ( Sanango racemosum - Dickison, 1994; Buddleja davidii - present study), perhaps Gesneriaceae ( Streptocarpus reinoldii - Teryokhin, Nikiticheva, 1981). The gynoecium type can be defined as syncarpous. This type includes two variations depending upon the median septa presence in the symplicate zone: typical variation (median septa are formed), or symplicate variation (median septa missing).

Ключевые слова на английском: morphogenesis, gynoecium, placentation, Buddleja davidii, Buddlejaceae, Scrophulariaceae, Orobanchaceae and Gesneriaceae

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Ботанический журнал - Статьи - Формирование гинецея у Buddleja davidii (Buddlejaceae)

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