Morphophysiological and Ecological Characteristics of Melilotus officinalis (Fabaceae, Magnoliopsida) under Conditions of the Republic of Tatarstan

The morphological variability of the aerial vegetative and generative organs of Melilotus officinalis in the ecotone communities of the forest-steppe zone, the forest zone of the Republic of Tatarstan including desecrated parts of the forest zone was studied. The ascorbic acid content in various parts of the plants growing in these habitats was also analyzed. It was revealed that the realization of the morpho-physiological potential of plants was determined by the conditions of botanical-geographical zones. The sweet clover, growing on black soils under the conditions of ecotone communities of the forest-steppe zone, was found to have higher indicators of “total biomass”, “biomass of leaves”, “biomass of inflorescences”, etc., as compared to the plants from similar communities growing on gray soils of the forest zone. Under the conditions of the ecotone communities of the forest-steppe zone, the content of ascorbic acid in all parts of the plant was also higher. Melilotus officinalis, growing in the conditions of a desecrated soil layer, was characterized by the maximum realization of its biomorphological potential with a low value of the coefficient of variation (CV), which reflected a stronger homogeneity of the samples. In the plants growing under extreme conditions, a sharp increase in the concentration of ascorbic acid in all parts was observed, which could be considered as an important mechanism for the adaptation of the species to survival under conditions of a sharp temperature difference of the substrate. Along with an increase in the generative period, an important component of the species adaptation was the low correlation between the indicator “biomass of inflorescences” and the concentration of ascorbic acid in inflorescences, “biomass of inflorescences” and the concentration of ascorbic acid in the leaves, which reflected the stable process of formation of the generative system of sweet clover. All coenopopulations were characterized by an incomplete ontogenetic spectrum with an absolute maximum on the plants with the middle-age ontogenetic status (95%).

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The structure of Melilotus officinalis (L.) Pall. and Trifolium pratense L. populations on the territory of deciduous forests zone in Tatarstan Republic

Samara Journal of Science ◽

10.17816/snv201874118 ◽

2018 ◽

Vol 7 (4) ◽

pp. 103-107

Author(s):

Nina Borisovna Prokhorenko ◽

Galina Vladimirovna Demina ◽

Luiza Ravilevna Kadyrova

Keyword(s):

Reproductive Effort ◽

Trifolium Pratense ◽

Structure Study ◽

Deciduous Forests ◽

Shoot Height ◽

Melilotus Officinalis ◽

Adaptive Mechanisms ◽

Morphological Status ◽

The Republic ◽

Growing Conditions

The paper deals with the results of the Trifolium prаtense L. and Melilotus officinalis (L.) Pall. population structure study. This paper presents a comparative description of these species populations from different ecological and coenotical condition in the zone of deciduous forests in the Republic of Tatarstan. The evaluation of the morphological status of individuals in populations was carried out using such parameters as shoot height, number of shoots per plant, total number of inflorescences on a plant, dry shoots biomass, reproductive effort, photosynthetic effort, etc. Density, ontogenetic and vitality structure of populations are considered to be adaptive mechanisms of populations existence in different ecological-coenotic conditions. Studies have shown that in the composition of Melilotus officinalis populations most of the plants belong to the group of young or mature generative plants, in which the photosynthetic effort averages from 0,16 to 0,19, and the reproductive effort - from 0,12 to 0,19 in different communities. The greatest reproductive effort is observed in populations formed by plants with a low morphological status. Trifolium pratense forms populations of different vitality (prosperous, balanced, or depressed). The authors note the presence of plants of both generative and pregenerative periods in some communities, which indicates a successful seed renewal. The average values of the photosynthetic effort for Trifolium pratense in various growing conditions range from 0,20 to 0,36, and the reproductive effort - from 0,18 to 0,29. A higher reproductive effort was noted in populations at the boundary of the contact zones of deciduous forests and forest steppes.

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Time and Latitude in South Africa

International Astronomical Union Colloquium ◽

10.1017/s0252921100026816 ◽

1972 ◽

Vol 1 ◽

pp. 27-38

Author(s):

J. Hers

Keyword(s):

South Africa ◽

Cape Town ◽

Astronomical Observations ◽

Royal Observatory ◽

The Republic ◽

Astronomical Determination ◽

Limited Accuracy ◽

Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

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