Izvestiya of Saratov University.
ISSN 1816-9775 (Print)
ISSN 2541-8971 (Online)


семенная продуктивность

FREQUENCY OF APOMIXIS BEI SOME ARTEMISIA SPECIES FROM SARATOV REGION (ASTERACEAE)

We have studied the characteristics of seed reproduction Artemisia 14 species from various parts of the Saratov region. It is shown that a population of five of them (A. vulgaris, A. salsaloides, A. dracunculus, A. glauca, A. austriaca) are characterized by high (at least 20-30%) frequency of gametophytic apomixis in plants, and three species (A. abrotanum, A. absinthium, A. armenica) have lower (10-15%) frequency of gametophytic apomixis.

Tulipa sylvestris L. in the collection of the Central Siberian Botanical Garden of the SB RAS

The article presents the results of a long-term introduction of Tulipa sylvestris L. in the SB RAS Central Botanical Garden collection. Plants of the species T. sylvestris bloom abundantly and have a reproductive factor of 1–2 for the daughter bulbs. It was found that the short phase of fl owering is characterized by smooth temperature changes, the most dramatic for a long period. We also established a direct dependence of the duration of the fl owering period on the amount of precipitation during this period, the correlation coeffi cient was 0,7.

The State of the Cenopopulation Delphinium Pubiflorum (Dc.) Turcz. Ex Huth in Tatishevskiy District of the Saratov Region

Delphinium pubiflorum grows sparsely in the meadow-steppe forbgrass-shrub community on carbonate chernozem fairly rich soil. Habitat conditions correspond to moderately variable meadow-steppe hydration. The spatial structure of populations of non-uniform: there are a multitude of plants and detached instances; population density was approximately 7–8 plants per 100 m2.

The Frequency of Apomixis in Populations of Chondrilla Species in the South of Europen Part of Russia

The monitoring of the frequency of apomixis was making in popu- lations of 7 species of Chondrilla in the south of european part of Russia. It is shown that the plants of 6 examined species (C. juncea, C. graminea, C. canescens, C. brevirostris, C. latifolia и C. acantho- lepis) are characterized by their ability to seed reproduction by apo- mixis. This fact is confirmed by results of a study of seed productivity of the species of the genus Chondrilla at the regime of blossoming without pollen and cytoembryological analysis megagametophytes of the same plants.

About the Biology of the Invasive Species Hordeum jubatum L. in Bashkir Trans-Urals

The results of researches of 7 coenopopulations of North American invasivespeciesHordeumjubatumL.(Poaceae)inthe Trans-Urals of the Republic of Bashkortostan. Hordeum jubatum spreads on the steppe zone of the region. It dominates over other plants and it is share of participation in the community is 45,5–60,5%. The density of grass invasive species – 9–18 plants per 1 m2.Each plant produces 35 to 68 shoots, on average, is more than 600 shoots per 1 m2. The biomass of the type is no more than 0.25 kg/m2. Seed production is 39–54 pcs.

Embryological Features of Laburnum anagyroides Medik.

Laburnum anagyroides Medik. (Leguminosae) is a promising ornamental woody plant, which is native to the Mediterranean. It is characterized by the following indicators of seed reproduction during introduction in the Lower Volga region: potential seed productivity is 5.24 ± 0.08 ovules on 1 ovary, real seed productivity is 1.53 ± 0.05 seeds per 1 fruit, the reproduction efficiency coefficient is 29.2%. Seeds quickly pass into a state of deep physical rest and cannot independently leave this state in spring.

Construction of Consciousness and Implementation of Seed Productivity of Various Varieties of Branch Onion (Allium ramosum L., Amaryllidaceae Jaume St.-Hil.) in the Conditions of the Moscow Region

Allium ramosum L. – type species of the subgenus Butomissa (Salisb.), Section Butomissa. The species has a fairly high seed productivity, which varies widely. This article presents the results of a study of seed productivity under the conditions of artificial phytocenosis of the Moscow Region in four commercial varieties of A. ramosum. In alluvial meadow soils, fruit setability was 88.9–95.8%, real seed productivity was fixed at 3.5–18.5 g/plant, 1000 seeds weight was 4.2–5.9 g. Average insemination was noted 3, 0–5.9 pieces/fruit.

Special features of fruiting in some Clematis L. cultivars from the collection of the Nikita Botanical Gardens

The article presents the results of studying the fruiting in 9 clematis cultivars under the conditions of the southern coast of Crimea. Morphometric characteristics of seeds, their weight and germination capacity are given. Potential and real seed production was assessed. It was found that the studied cultivars are characterized with high potential seed production, on average from 38.1 to 116.9 ovules per fruit, but relatively low real seed production, on average from 1.3 to 8.3 seeds per fruit.