Physiological and biochemical parameters of drought tolerance of some genotypes of garden roses

To identify drought resistance of the studied genotypes of garden roses during the period of maximum probability of drought on the Southern Coast of the Crimea, the water regime, proline concentration, enzyme activity and chlorophyll fluorescence induction parameters under controlled dehydration were studied. Analysis of water regime parameters showed that under conditions of water stress, the best water-holding and recovery capabilities were shown by leaves of cv. ‘Borisfen’ and R. hugonis species. Species R. indica, R. bracteata, R. rouletti, R. foetida showed instability of water regime under conditions imitating dry weather. Studies of changes in biochemical parameters revealed that under relatively mild wilting conditions after removal of stress, metabolic processes are restored in R. hugonis, R. bracteata, R. indica and cv. ‘Borisfen’. Wilting under conditions imitating dry weather does not cause irreversible metabolic disturbances in R. hugonis, R. bracteata, and cv. ‘Borisfen’. Under different wilting conditions, cv. ‘Borisfen’and R. foetida species had relatively stable functioning of FS II. Simulation of dry weather led to irreversible disturbances in the oxygen-releasing complex and thylakoid destruction in R. gallica during the stressor, and in R. indica and R. bracteata species - after recovery of water availability. The highest drought tolerance is in in cv. ‘Borisfen’and R. hugonis sprcies

Quantification of some ornamental plant species carbon dioxide absorption for various moisture conditions

The study of carbon dioxide gas exchange of leaves of Prunus laurocerasus L., Laurus nobilis L. and Viburnum tinus L. under various environmental conditions was carried out. The greatest resistance to drought and the ability to absorb CO2 under hydrothermal stress was found in Viburnum tinus plants. It was determined that the inhibition of the processes of CO2 absorption with increasing water scarcity begins in the studied species with a decrease in soil moisture to 35% field capacity. Under conditions of soil drought, the amount of CO2 absorbed by Prunus laurocerasus leaves is reduced by 10 times, Laurus nobilis – by 7 times, Viburnum tinus – by 2 times. The positive carbon dioxide gas exchange of Prunus laurocerasus, Laurus nobilis and Viburnum tinus in the hot dry period, when the amount of CO2 absorption exceeds its release during respiration by 1–5.1, 1.5–3.7 and 1.1–6.2 times, respectively, indicates a significant potential these species for optimizing the urban ecosystems of the southern regions of Russia. The developed predictive models allow us to perform a quantitative assessment of the ability of plants to absorb carbon dioxide under various environmental conditions

Comparative introduction study of

The article presents the results of a comparative introduction study and cultivar evaluation of 7 of common lilac cultivars in the collections of three botanical gardens (the Nikita Botanical Gardens, the Central Siberian Botanical Garden and the Donetsk Botanical Garden) located in zones with conditionally subtropical, temperate continental and continental climate. It is established that the cultivars retain their decorative features in the conditions of introduction and show ecological plasticity, increasing their growing season with an increase in the vegetation period, as well as reducing the area of the leaf blade with a decrease in the average annual precipitation

Physiological and biochemical parameters of drought tolerance of some genotypes of garden roses

To identify drought resistance of the studied genotypes of garden roses during the period of maximum probability of drought on the Southern Coast of the Crimea, the water regime, proline concentration, enzyme activity and chlorophyll fluorescence induction parameters under controlled dehydration were studied. Analysis of water regime parameters showed that under conditions of water stress, the best water-holding and recovery capabilities were shown by leaves of cv. ‘Borisfen’ and R. hugonis species. Species R. indica, R. bracteata, R. rouletti, R. foetida showed instability of water regime under conditions imitating dry weather. Studies of changes in biochemical parameters revealed that under relatively mild wilting conditions after removal of stress, metabolic processes are restored in R. hugonis, R. bracteata, R. indica and cv. ‘Borisfen’. Wilting under conditions imitating dry weather does not cause irreversible metabolic disturbances in R. hugonis, R. bracteata, and cv. ‘Borisfen’. Under different wilting conditions, cv. ‘Borisfen’and R. foetida species had relatively stable functioning of FS II. Simulation of dry weather led to irreversible disturbances in the oxygen-releasing complex and thylakoid destruction in R. gallica during the stressor, and in R. indica and R. bracteata species - after recovery of water availability. The highest drought tolerance is in in cv. ‘Borisfen’and R. hugonis sprcies

The results of introduction study of old garden roses in different natural and climatic zones

The introduction study of old garden roses has been done in the conditions of the forest-steppe zone continental climate ( 69 cultivars) and in xeromorphous edaphoclimatic conditions of the subtropical zone (85 cultivars and varieties). The valuable characters of old garden roses in each zone have been determined. The increasing tendency for flower doubleness and their quantity has been educed in a subtropical zone. The long-term introduction study of 21 cultivars in both zones has been done and as the result of it 14 cultivars have been recommended for a wide use in greening

WATER RELATION FEATURES OF NERIUM OLEANDER L. UNDER PROGRESSIVE SOIL DROUGHT STRESS

Abstract. Aim. Study the ecophysiological reaction of Nerium oleander L. on effect of progressive soil drought. Estimate the optimal and threshold values of environmental factors limiting photosynthesis rate of Nerium oleander L. plants. Materials and Methods. As the research materials, were used the young plants of Nerium oleander L. For continuous automatic recording of CO2/H2O gas exchange of intact leaves we used PTM-48A Photosynthesis Monitor. Results. It was established that N.oleander begins sense a water stress deficit during the critical period of active growth by reducing soil moisture content up to 35% field capacity (FC). Net photosynthesis (PN) and stomata conductance (gs) decreased under progressive soil drought stress and dropped to zero under condition: soil water beneath 2-4%VWC (6-11% FC) during more than 24 hours, leaves temperature – more than 37°C and PAR – more than 1300-1700 µmol/(m2 s). Optimal light and temperature conditions for intensive growth: leaf temperature from 23 to 36.5°C, light regime: full sunlight in the range PAR 850-1600 µmol/(m2 s) when soil moisture 45-75% FC. Conclusion. Genotypic characteristics of N. oleander plants in supporting optimal on accordance with the environmental conditions water balance were determined. One of the specific adaptation reaction for N. oleander to extreme drought conditions in case of complex influence of water stress (soil water content at level of wilting range (<6% FC) during more than 48 hours), high levels of irradiance and overheating is the accelerated senescence and exfoliation not only old but also young leaves resulting in the loss of ornamental value cultivar

Identifying the rose varieties and natural forms using ISSR-markers

Identifying among varieties and natural forms of roses were carried out using ISSR thechnics to determine kinship. It was studied 6 foreign varieties, 16 varieties bred in Nikitsky Botanical Garden, as well as 2 natural forms (Rosa canina and Rosa chinensis). Despite some samples breaking into three clades, many of them don’t belong to any of these groups due to the lack of relative ties, that confirms the high genetic diversity in the studied material. The revealed molecular genetic differences in rose forms and varieties can be used to identify and certify cultivars promising for their complex resistance to the continental climate conditions

Modelling of Climate Change’s Impact on <i>Prunus armeniaca</i> L.’s Flowering Time

This study presents the results of the development of numerical models for predicting the timing of apricot flowering, including using experimental data on the emergence of plants from a state of deep dormancy. The best results of approximation of the process of accumulation of the necessary cooling in the autumn–winter period were obtained using the sigmoidal function. Models that take into account the combined effect of temperature and photoperiod on the processes of spring development showed a high accuracy of the process of accumulation of thermal units. Based on the results of testing, two models were selected with an accuracy of 3.0 days for the start of flowering and the absence of a systematic bias, which can be considered a good quality assessment These models describe well the interannual variability of apricot flowering dates and can be used to predict these dates. The discrepancy is no more than 2–4 days in 87–89% of cases. Estimates of the timing of flowering and the end of deep dormancy are very important for increasing the profitability of fruit production in the South of Russia without incurring additional costs, by minimizing the risks associated with irrational crop placement and the selection of varieties without taking into account the specifics of climate change. When constructing a system of protective measures and dates of treatments, it is also necessary to take into account the calendar dates of the shift in the development of plants

Genetic diversity analysis of Rose varieties from Grandiflora group based on ISSR molecular markers

Kinship and genetic diversity determination among six rose varieties from the Grandiflora group were carried out using ISSR thechnics. The studied varities were divided into 3 clades: I) ‘Lezginka’, ‘Queen Elizabeth’ and ‘Koralovy surpriz’ varieties; II) ‘Gurzuf’ and ‘Love’ varieties; III) ‘Komsomolsky ogonek’ variety formed a separate branch. This division into clades was confirmed by a statistical comparison of morphometric characters. On the basis of the obtained data, it can be concluded that the analysis using the selected primer group is well-suited for differentiation rose varieties into groups, which makes it possible, for one thing, to determine the genetic distance between varieties, and for another, to use these data in the future by certification of the varieties promising by resistance characters to the continental climate conditions