Subtropical and flower crops breeding at the Subtropical Scientific Centre

This paper presents the results on the breeding work carried out by the Subtropical Scientific Centre of the Russian Academy of Sciences. Currently, the Centre’s breeders are doing a lot of work aimed at breeding new fine yielding cultivars of subtropical and flower crops that will be resistant to growing conditions; they include kaki persimmon, feijoa, mandarin, freesia, crown anemone, pelargonium and chrysanthemum. The sources of high-level priority traits in flower crops that are valuable for further breeding in order to improve decorative (colour, flower shape, inflorescence), economic and biological traits (flowering period, a large number of flowers in the inflorescence, storage period of cut flowers, disease resistance, high reproduction coefficient) were recorded. The aim of the research is to improve the subtropical and flower crops assortment. The objects of the research were 989 hybrid forms: 136 citrus crops, 56 persimmon, 36 feijoa, 38 tea plant, 11 pear, 24 hazel, 108 freesia, 398 crown anemone, 120 pelargonium and 62 chrysanthemum hybrids. New cultivars with a complex of valuable traits have been created as a result of the scientific work. Over the past five years, FRC SSC of RAS has created 50 new cultivars: 26 pelargonium, 15 anemone, 5 freesia, 2 chrysanthemum, 1 persimmon and 1 apple and submitted them to the State Cultivar Commission. The “State Register of Selection Achievements Authorized for Use for Production Purposes” has included 63 cultivars developed by FRC SSC RAS, including 26 pelargonium, 13 anemone, 9 chrysanthemum, 7 freesia, 4 hazel, 3 feijoa and 1 tea plant cultivars. 46 patents for breeding achievements have been obtained

Citrus genetic resources in Russia, Ukraine, Belarus: conservation and management

Citrus genetic resources including modern and old cultivars, breeding forms and wild genotypes form the basis of the global citrus industry, that is why the preservation of the biodiversity and the creation of duplicate collections all over the world is an important task. In recent decades, there has been a sharp decline in the productivity of citrus commercial plantations in the main citrus-producing countries. The risk of an abrupt reduction in genetic diversity greatly increased because of the accumulated diseases raging there and the spread of these diseases in the neighboring citrus groves. Therefore, the preservation of biodiversity in atypical citrus regions is becoming increasingly important. The aim of this study was to compare the genetic diversity of citrus crops in the basic collections of the three countries (Russia, Ukraine and Belarus), to determine the direction and prospects for the use of available genetic resources, as well as to reveal the main problems of germplasm preservation. The comparative analysis will determine the strategy for further studies on the citrus crops in atypical areas of cultivation. The collection of citrus based in the Russian Research Institute of Floriculture and Subtropical Crops contains 132 accessions, the collection of the Belarus Botanical Garden contains 100 accessions, the collection of the Grishko National Botanical Garden contains about 60 accessions. The list of species and cultivars of three collections is presented in the article. The main problems of the successful conservation and use of citrus genetic resources are insufficient use of modern tools of germplasm characterization, the absence of a unified web-database containing all available biodiversity, the lack of consensus regarding the taxonomic position of certain genotypes. Additionally, there is a need for disease control in collections, it is necessary to develop advanced test systems for rapid diagnosis of diseases. One more important task is the extension of species diversity through the exchange of material with other foreign collections

Challenges of in vitro conservation of Сitrus germplasm resources

The main problems of establishment a slow growth in vitro collection of citrus and other tree crops cultivars are high degree of fungal contamination of bud explants and low growth potential of shoots. In this regard, the aim of current research is to assess the efficiency of decontamination procedure and the possibility of tissue culture initiation and slow growth conservation of valuable lemon cultivars. The best results of surface sterilization were obtained using immersion solutions of 0.3 % Veltolen – 25 minutes or 10 % Domestos – 25–30 minutes. In these treatments, 27.7–33.0 % of aseptic explants were obtained, respectively. However, after the third subculture, the yield of aseptic viable explants decreased till 10 % as a result of secondary contamination by endophytic fungi. The addition of biocide (“Gavrish”) in a nutrient medium at a concentration of 1 ml/l helped to increase the yield of aseptic viable explants till 50 %. However, after the third subculture the photosynthetic activity and the pigments content as well as growth rate decreased. Plants dropped yellowish leaves and eventually died. Thus, 37.35 % of plantlets survived after 8 months of conservation, and only 14.6 % survived after 10 months. Even after the third month of conservation significant decrease in the viability index and the coefficient of photosynthetic activity occurred in plants. Chlorophyll a in leaves decreased from 1.59 to 1.14 mg/g during 12 months in vitro conservation. The similar tendency observed on clorophyll b and carotenoids content. The experiments were carried out for 5 years using different lemon cultivars and other citrus varieties and cultivars. Thus, micropropagation and slow growth in vitro conservation of valuable lemon cultivars are still problematic and requires new technical solutions due to the low growth potential of plantlets raised from the mature buds that is consistent with the data of other researchers

Evaluation of feijoa hybrid forms (Feijoa sellowiana Berg) according to productivity and fruit quality

The years of studying feijoa plants cultivated in the humid subtropics of the Krasnodar Territory have shown the necessity for selection of forms from seed populations with different maturity of fruits, high yields and high fruit quality. Seven promising forms have been evaluated primarily. After observation the growth dynamics of shoots B-13 for has been selected with an active growth. The average shoots length has reached 22,8 cm by the end of the growing season. Assessment of fruit cast have shown that the largest percentage of active ovaries is found in B-13 form and “Dagomysskaya” variety and (17%).Assessment of harvesting period has revealed early ripening forms (II-III decade of September – I decade of October), they include 4-10, 12-5, 13-11, IIIB-1 forms; mid-ripening forms (II-III decade of October – I decade of November) are 10-22, B-13 and late-ripening forms are 6-24, the fruits of which ripen from the 3rd decade of November till the 1st decade of December. Form B-13 has been selected as a high-yielding one: 19,2 kg / bush, and a large-fruited one – average fruits weigh 96,0 g. The forms of 4-10, B-13 have been selected according to sugar content, with 9,70 % and 8,12 % of sugar respectively. The forms of 6-24, 12-5 and B-13 are observed to contain more monosaccharides than sucrose. Two forms of 4-10 and B-13 have been selected as the best in taste with the highest percentage of monosaccharides, in particular, fructose, which gives the fruits the “sweet taste”.The fruits of form 12-5 are characterized by a highest content of vitamin “C” –75,68 mg%. Forms of 4-10 and 12-5 have the highest sugar-acid ratio which is 5,5 and 5,0, respectively, and the lowest ratio is observed in forms of 6-24 and 10-22 – 2,9 and 3,0, respectively

Selection of kaki persimmon in humid subtropics of the Krasnodar territory

The article presents the results of persimmon hybridization (Diospyros kaki L.,). A number of crossings was carried out, where the best zoned varieties such as “Djiro”, “Hiakume'” were used as maternal forms and “Zenji-Maru”, “Fuyu”, “Geili”, D.virginiana as paternal forms. A wide variety of hybrid material was obtained. In the early stages of the development of seedlings the forms were distinguished in the crossing combinations of “Djiro” x “Geili”, “Hiakume” x “Fuyu” according to indirect cultural features. Inter-specific hybrids from the combination of 'Djiro'x D.virginiana are of great value for the creation of winter-hardy hybrids

Lethal pulmonary embolism in a pregnant woman with severe acute respiratory syndrome coronavirus-2 receiving prophylactic anticoagulation: a case report

Abstract Background A limited number of studies have described thrombotic complications in pregnant women with COVID-19. Here we report on fatal pulmonary embolism in a pregnant woman with laboratory confirmed SARS-CoV-2 infection. Case presentation A 28-year-old Kazakh woman was hospitalized with muscle pain, dry cough and a temperature of 37.5 °C at the 29th week of gestation. Upon admission, a blood test demonstrated elevated neutrophil-to-lymphocyte ratio, decreased levels of erythrocytes and hemoglobin, as well as prolonged prothrombin and activated partial thromboplastin time. Within 14 days of admission, she experienced respiratory distress and underwent transfer to the intensive care unit, intubation and a cesarean section. The patient received intravenous antibiotics, antiviral medications, systemic corticosteroids and dual anticoagulation with aspirin and enoxaparin. Death outcome was reported on day 18 of illness despite aggressive supportive care. Histological analysis demonstrated that obstruction of the main pulmonary arthery and disseminated intravascular coagulation were the causes of death. Conclusions This case demonstrates that in the management of pregnancy and childbirth in patients with suspected or confirmed COVID-19 infection, special attention should be paid to coagulation system parameters and timely appropriate prophylaxis of thromboembolic complications, which has yet to be determined