МОРФОЛОГИЧЕСКАЯ ИЗМЕНЧИВОСТЬ ДВУХ ВИДОВ МОРСКИХ ДИАТОМОВЫХ ВОДОРОСЛЕЙ NITZSCHIA VENTRICOSA И ARDISSONEA CRYSTALLINA  (BACILLARIOPHYTA)

Актуальность работы обусловлена недостаточной изученностью проблемы понимания объёма видов диатомовых водорослей, особенно в условиях in vitro. Цель исследования –– изучить морфологическую изменчивость в культурах двух видов морских пеннатных диатомовых водорослей Nitzschia ventricosa Kitton и Ardissonea crystallina (C. Agardh) Grunow при помощи методов световой и сканирующей электронной микроскопии, а также оценить в эксперименте воздействие солёности на морфологические показатели панциря A. crystallina, использующиеся при диагностике вида; сделать сопутствующие таксономические замечания. Материалом послужили изоляты (клоны и альгологически чистые культуры), полученные в условиях in vitro: изоляты N. ventricosa –– из природных популяций прибрежных районов Канарских островов, о-ва Мартиника и штата Техас (Мексиканский залив), изоляты A. crystallinа –– из бентосных проб в бухте Казачья (Севастополь, Чёрное море). Морфологическая изменчивость в культурах N. ventricosa и A. crystallinа оказалась сопоставимой с данными, полученными на материале из природных популяций. Обнаруженная вариабельность изученных изолятов позволила уточнить морфологические особенности N. ventricosa. Варьирование в одном клоне N. ventricosa по числу штрихов и фибул оказалось выше, чем обнаруженное в альгологически чистых культурах этого вида. Широкая фенотипическая вариация створок в культурах N. ventricosa и A. crystallinа сопоставима с данными, полученными in situ. Выявлена тенденция возрастания плотности расположения штрихов и ареол и уменьшения ширины клеток A. crystallinа с увеличением солёности в эксперименте. При солёности 8 ‰ вегетативное деление замедлялось, культура погибала. С повышением уровня солёности увеличивались диапазоны варьирования числа штрихов A. crystallinа.

Аннотация (alternative)

The relevance of the article is caused by insufficient knowledge of the problem of understanding of the diatoms species scope, particularly in vitro. The aim of the research is to study the morphological variability in cultures of two species of marine pennate diatoms, Nitzschia ventricosa and Ardissonea crystallina using methods of light and scanning electron microscopy. In addition we assessed the impact of salinity on morphological parameters of A. crystallina valves in the experiment, which is used in the diagnosis of the type. The material for investigation were isolates (algological pure cultures and clones) obtained in vitro. N. ventricosa isolates were received from natural populations collected at coasts of Canary Islands, Islands of Martinique and Texas (Gulf of Mexico). The clones of A. crystallina were allocated from benthic samples in Kazachya Bay (Sevastopol, the Black Sea). The culture was established with the micropipette way and grown in Petri dishes on ESAW media with natural light at a temperature of 20 ℃. We refer to a clone (strain) as vegetative offspring derived from a single cell, while the algological pure culture is a group of clones of the same species. The algological pure culture of A. crystallina (consisting of several strains) was physically separated and grown in parallel with six levels of salinity (8, 12, 17, 30, 38 and 48 ‰) for two months. To obtain the required initial salinity the medium salinity (36 ‰) was diluted with the necessary amount of distilled water, or NaCl was added. The terms of keeping of cultures in artificial conditions until the preparation of drugs were no more than 2 months longer, in order to avoid teratological changes. The species Nitzschia ventricosa was originally discovered on the coast of Hong Kong and described in 1873 by the British naturalist F. Kitton. In the Black and Azov seas’ benthos and plankton the species N. ventricosa was not observed. While studying the collected materials of the British Natural History Museum (London), the holotype of N. ventricosa was not marked by F. Kitton. The slide № 10365 from the collections of the British Museum (Collection Deby), with this type of material from Hong Kong, was studied. The material in the slide was decided to be authentic (specimina authentica). The material showed the proximity of morphometric characteristics of the valves. Data was compared to the ones given from other Pacific populations. The species Ardissonea crystallina (C. Agardh) Grunow was described by Swedish botanist C. Agardh in 1824 as Diatoma crystallinum C. Agardh. The type locality (locus typicus) are the waters of Sinus Codani, which corresponds to Kattegat Strait, located between the East coast of the Jutland peninsula and the south-western part of the Scandinavian Peninsula. Both species are widely distributed in the oceans and are found regularly in the benthos and plankton, however, they have not been studied in cultures. The following conclusions were obtained: 1. Morphological variability in cultures of N. ventricosa and A. crystallina was comparable with those obtained on the material from natural populations. 2. We managed to get both types of auxospore in the cultures that allowed us to estimate the upper limit of the size range of both types of cells. For N. ventricosa it was 616.0 µm, for A. crystallina the maximum length was 678.0 µm. 3. The variation of number of striae and fibulae in one clone of N. ventricosa was higher than in pure cultures. 4. It has been shown that A. crystallina was able to live while salinity was from 8 to 48 ‰. 5. The A. crystallina culture derived from natural population of the Black Sea, was close to the number of striae to the population from the coast of Canada (Shalёr Bay). 6. The content of the cultures at different rates of salinity for two months has not led to significant morphological changes of A. crystallina cells. There was no effect of salinity on qualitative morphological features of A. crystallina. With an increase of salinity in the experiment arrangement density of striae and areolae of A. crystallina tend to increase, and the width of the cell — to decrease. With the increase of salinity, an increase of the breadth ranges of the striae number variation was observed.

Ключевые слова

диатомовые водоросли, Nitzschia ventricosa, Ardissonea crystallina, морфологическая изменчивость

Библиографическое описание

Морской биологический журнал. - 2016. - Т. 1, № 4 https://repository.marine-research.ru/handle/299011/2638

URI

https://repository.marine-research.ru/handle/299011/2638

Коллекции

Морской биологический журнал. - 2016. - Т. 1, № 4.

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