Search articles

The article presents the results of study the effect of the light day duration on the embryological features of apomixis in Poa pratensis L. (Poaceae). The plants were grown under different day length (15 (control), 10 and 24 hours). The some embryological characteristics (frequency of ovules with a few embryo sacs, frequency of the parthenogenetic proembryo and a frequency and range of the gametophyte anomalies) were analyzed.

As a result of cytoembryological analysis of megagametophytes of Chondrilla it was found out, that the plants of six species examined (C. juncea, C. graminea, C. canescens, C. brevirostris, C. latifolia and C. acantholepis) are characterised by the ability for seed reproduction by apomixis. It was discoverd that the frequency of disclosure of cytoembryological signs of apomixis considerably varies year by year and on the interpopulation level. C.

The parameters for introduction in in vitro culture of Tamatix laxa and T. ramosissima, including sterilization method, mineral and hormonal composition of the medium used, are defined. It is proved that the most efficient method of sterilization (the percentage of viable explants is over 60%) is the treatment with soap solution, 70% ethanol, 10% Belizna detergent, 5% solution of Lizoformin-2000 detergent and subsequent washing with sterile distilled water three times. The lower concentration of sterilizing agents improves the material sterilization.

The article presents the results of studying of pollen-ovules ratios (P/O), the quality and size of the pollen in wild cereals with different mode of reproduction (sexual: Alopecurus pratensis L., Elymus caninus L., Glyceria fluitans (L.) R. Br., Poa annua L., Zerna riparia (Rehm.) Nevski; facultative apomict: Dactilis glomerata L., Koeleria cristata (L.) Pers., Festuca valesiaca Schleich.

It is shown that the plants of the five investigated species (C. juncea, C. graminea, C. ca-nescens, C. brevirostris, C. latifolia) are characterized by a high degree of defectiveness of pollen (60–80%) and the presence of cytoembryological marker signs gametophytic atomixis. This indicates a high probability of their ability to seed reproduction by apomixis. It is established that the frequency of detection of these signs varies significantly among years and between-population level. It is revealed that C.

During the research of seed productivity of 6 willow species growing in Saratov region the ability to the parthenocarpic fruit formation was found out for the first time. Correlation was not found out between the ability of Salix plants to parthenocarpy and the ability of reproduction with the help of gametophyte apomixis.

During cytoembryological investigation of Toillius europaeus L., Adonis wolgensis Stev. and Anemoides ranunculoides (Ranunculaceae) the features of game- tophyte apomixis was found for the first time. The proporcion of ovules with the features of gametophyte apomixis was maked 16,32±6.12 in Trollius europaeus population, 5.82 ±1.82 in Adonis wolgensis population, 3.22 ±1.13% in Anemoides ranunculoides population.

The article is dedicated to cytoembryology investigation of two cereals species: HierochO glabra (two populations from Kamchatka) and H. repens (one population from Lower Volga region). The plants of these populations are characterized by high frequency of ovules with few (2-4) megagametophytes (5,7; 8,6 и 25%, respectively). This point to the apoarhespory - development of unreduced embryo sacs from somatic nucellus cells.

During the cytoembriological investigation of the species of Fabaceae family, growing in the different areas of Saratov region the ability of gametophyte apomixic was found out of 4 species of Fabaceae. This way of reproduction of Fabaceae family was noticed for the first time.