THE INFLUENCE OF ROOTSTOCK ON THE FROST RESISTANCE OF SWEET CHERRIES DURING THE THAW

Studies on the frost resistance of sweet cherries were carried out in 2019–2020 in the FSBSI of the Federal Horticultural Research Center for Breeding, Agrotechnology and Nursery in laboratory conditions by artificial freezing in the climate chamber TH-6 JEIO TECH-1000. Objects of research: Tyutchevka and Chermashnaya varieties grafted on 8 clonal rootstocks (Colt, Izmailovsky, AVCH-2, V-5-88, VC-13, Moskoviya, VSL-2, Stepnoy Rodnik). The aim of the research is to study the effect of clonal rootstocks on the frost resistance of cherry buds and tissues during the thaw and to identify the most frost-resistant scion-rootstock combinations for the 3rd component. It was found that after freezing at t = -20 °C during the thaw, the safety of flower buds in the Tyutchevka variety in both years of research was more than 80 %, and in the Chermashnaya variety — from 20 to 30 %, depending on the year. The limits of changes in the frost resistance of generative buds of varieties depending on the rootstock are shown: in the Tyutchevka variety — from 66.8 % (V-5-88) to 96.4 % (Izmailovsky), and in the Chermashnaya variety — from 7.7 % (V-5-88) to 65.5 % (AVCH-2). When using the AVCH-2 and Izmailovsky clonal rootstocks, the safety of flower buds increased by 30 % compared to the Colt rootstock. The most frost-resistant scion –rootstock combinations for each variety were identified: Tyutchevka/Izmailovsky and Tyutchevka/Stepnoy Rodnik, which preserved more than 90 % of the living rudiments; Chermashnaya/AVCH-2 (65.5 %) and Chermashnaya/Izmailovsky (40.1 %). Vegetative buds and tissues of annual branches were practically free of freezing in the studied varieties when grafted on the rootstocks of Stepnoy Rodnik and AVCH-2. In the Chermashnaya variety, damage of about 1 point of the phloem and vascular bundle under the buds was noted when grafting on rootstocks V-5-88 and Colt.

Successful Cryopreservation of Dormant Buds of Blackcurrant (Ribes nigrum L.) by Using Greenhouse-Grown Plants and In Vitro Recovery

The cryopreservation of dormant buds can be a feasible method for preserving germplasm of cold-tolerant woody plants. In the present study, we evaluated the effects of pre-desiccation, thawing method, and the rehydration of bud sections on the post-cryopreservation recovery of dormant blackcurrant buds in vitro. The estimated recovery of small- and medium-sized buds was 80.1 and 62.7% respectively for desiccated buds and 67.8 and 72.3% respectively for non-desiccated buds. The pre-desiccation of bud sections enhanced the number of the shoots regenerated from vegetative buds (2.3 vs. 4.7). The estimated recovery of fast-thawed buds was better after 14-day than after 7-day rehydration (85 vs. 59%). In slowly thawed buds the difference between 14-day and 7-day rehydration was not significant (73 vs. 62%). The estimated recovery of vegetative and flower buds was 77.7 and 41.1% respectively after 7-day rehydration, and 95.2 and 43.6% respectively after a 14-day rehydration period. The rehydration of bud sections was not necessary for the in vitro recovery of non-desiccated, fast-thawed buds. Of the 23 blackcurrant cultivars cryopreserved using non-desiccated dormant buds collected from a greenhouse, the estimated recovery of 22 cultivars ranged between 42 and 90%.

Whole-transcriptome analysis of differentially expressed genes in the mutant and normal capitula of Chrysanthemum morifolium

Background Chrysanthemum morifolium is one of the most economically important and popular floricultural crops in the family Asteraceae. Chrysanthemum flowers vary considerably in terms of colors and shapes. However, the molecular mechanism controlling the development of chrysanthemum floral colors and shapes remains an enigma. We analyzed a cut-flower chrysanthemum variety that produces normal capitula composed of ray florets with normally developed pistils and purple corollas and mutant capitula comprising ray florets with green corollas and vegetative buds instead of pistils. Results We conducted a whole-transcriptome analysis of the differentially expressed genes (DEGs) in the mutant and normal capitula using third-generation and second-generation sequencing techniques. We identified the DEGs between the mutant and normal capitula to reveal important regulators underlying the differential development. Many transcription factors and genes related to the photoperiod and GA pathways, floral organ identity, and the anthocyanin biosynthesis pathway were differentially expressed between the normal and mutant capitula. A qualitative analysis of the pigments in the florets of normal and mutant capitula indicated anthocyanins were synthesized and accumulated in the florets of normal capitula, but not in the florets of mutant capitula. These results provide clues regarding the molecular basis of the replacement of Chrysanthemum morifolium ray florets with normally developed pistils and purple corollas with mutant ray florets with green corollas and vegetative buds. Additionally, the study findings will help to elucidate the molecular mechanisms underlying floral organ development and contribute to the development of techniques for studying the regulation of flower shape and color, which may enhance chrysanthemum breeding. Conclusions The whole-transcriptome analysis of DEGs in mutant and normal C. morifolium capitula described herein indicates the anthocyanin deficiency of the mutant capitula may be related to the mutation that replaces ray floret pistils with vegetative buds. Moreover, pistils may be required for the anthocyanin biosynthesis in the corollas of chrysanthemum ray florets.

The morphogenesis of vegetative buds of Picea species (Pinaceae), introduced in the taiga zone (Karelia)

The observations were carried out in the Botanical garden of the Petrozavodsk state University, located in the taiga zone. Objects of research served 1 native and 5 introduced species: Picea abies (L.) Karst., P. obovata Ledeb., P. mariana Britt., P. glauca (Mill.) Вritt., P. pungens Engelm., P. omorica (Pane) Purk. The study of morphogenesis in vegetative buds was carried out axial shoots from the middle part of the crown since the beginning of the bud swelling until the cessation of laying primordial needles (May to September). The growing shoots are cut off after 2-3 days and were fixed in a mixture of alcohol and glycerin. For the start date of a stage, took the time when it was noted in not less than 30% of the buds. It is established that intrarenal development of vegetative organs from the native species P. abies was studied and introduced species of the genus Picea characterized by similar phases: rest, laying cover scales and laying primordial needles. Morphogenesis of vegetative buds of P. abies on the timing ahead of the development of the bud in the introduced species, which indicates a much greater insistence of the latter to temperature. The duration of the morphogenesis of the buds in all studied types varies slightly (days 131-137). However, the morphogenesis of vegetative buds of native species for 1-4 weeks ahead in terms of development of the buds in introduced species with a similarity of morphogenesis of the bud (P. abies and P. glauca), the value of the annual increment of the shoots is almost the same.

Whole-transcriptome analysis of differentially expressed genes in the mutant and normal capitula of Chrysanthemum morifolium

Background: Chrysanthemum morifolium is one of the most economically important and popular floricultural crops in the family Asteraceae. Chrysanthemum flowers vary considerably in terms of colors and shapes. However, the molecular mechanism controlling the development of chrysanthemum floral colors and shapes remains an enigma. We analyzed a cut-flower chrysanthemum variety that produces normal capitula composed of ray florets with normally developed pistils and purple corollas and mutant capitula comprising ray florets with green corollas and vegetative buds instead of pistils.Results: We conducted a whole-transcriptome analysis of the differentially expressed genes (DEGs) in the mutant and normal capitula using third-generation and second-generation sequencing techniques. We identified the DEGs between the mutant and normal capitula to reveal important regulators underlying the differential development. Many transcription factors and genes related to the photoperiod and GA pathways, floral organ identity, and the anthocyanin biosynthesis pathway were differentially expressed between the normal and mutant capitula. A qualitative analysis of the pigments in the florets of normal and mutant capitula indicated anthocyanins were synthesized and accumulated in the florets of normal capitula, but not in the florets of mutant capitula. These results provide clues regarding the molecular basis of the replacement of Chrysanthemum morifolium ray florets with normally developed pistils and purple corollas with mutant ray florets with green corollas and vegetative buds. Additionally, the study findings will help to elucidate the molecular mechanisms underlying floral organ development and contribute to the development of techniques for studying the regulation of flower shape and color, which may enhance chrysanthemum breeding.Conclusions: The whole-transcriptome analysis of DEGs in mutant and normal C. morifolium capitula described herein indicates the anthocyanin deficiency of the mutant capitula may be related to the mutation that replaces ray floret pistils with vegetative buds. Moreover, pistils may be required for the anthocyanin biosynthesis in the corollas of chrysanthemum ray florets.

Study of frost resistance of cherry variety Turgenevka during on different rootstocks winter thaws

Relevance. The study of the resistance of garden cultures to unfavorable abiotic factors of the winter period is a priority direction of scientific studies, because the low winter hardiness can annul advantages the varieties on other signs. Concerning in the middle zone of Russia, studies on the resistance of cherry to frost during the thaw period remain relevant.Methods. The studies were carried out in the laboratory of physiology of fruit plant resistance at VNI-ISPKin2017-2018. The object of research was the Turgenevka cherry variety on new clonal root-stock of the Institute breeding were studied. Control - Turgenevka on the Rubin stock. For artificial freezing in early December the material was prepared for III and IV components of frost hardiness.Results. As a result of artificial freezing, the Turgenevka cherry variety was characterized by frost resistance of vegetative buds and tissues of annual shoots during a three-day winter thaw of + 2°C with a decrease in temperature of -25°C (III component of frost resistance). Inthiscase, thehighest frost resistance of the generative buds of the Turgenevka variety on rootstock 74340, 82987 is shown. After a three-day thaw of +2°C and repeated hardening with a subsequent decrease in temperature to -30°C in March (IV frost resistance component), the Turgenevka variety on the rootstock 74332, 74363, 82987 was characterized by frost resistance of vegetative buds, bark and wood of annualshoots. Moreover, in the studied scion-rootstock combinations, low frost resistance of the generative kidneys was revealed. Only in the studied variety on the rootstock 82987 was the largest percentage of living flower primordia revealed. The conducted studies revealed the Turgenevka variety in a rootstock of 82987 with the greatest potential for frost resistance during the winter thaws.

Whole-transcriptome analysis of differentially expressed genes in the mutant and normal capitula of Chrysanthemum morifolium

Background Chrysanthemum morifolium is one of the most economically important and popular floricultural crops in the family Asteraceae. Chrysanthemum flowers vary considerably in terms of colors and shapes. However, the molecular mechanism controlling the development of chrysanthemum floral colors and shapes remains an enigma. We analyzed a cut-flower chrysanthemum variety that produces normal capitula composed of ray florets with normally developed pistils and purple corollas and mutant capitula comprising ray florets with green corollas and vegetative buds instead of pistils. Results We conducted a whole-transcriptome analysis of the differentially expressed genes (DEGs) in the mutant and normal capitula using third-generation and second-generation sequencing techniques. We identified the DEGs between the mutant and normal capitula to reveal important regulators underlying the differential development. Many transcription factors and genes related to the photoperiod and GA pathways, floral organ identity, and the anthocyanin biosynthesis pathway were differentially expressed between the normal and mutant capitula. A qualitative analysis of the pigments in the florets of normal and mutant capitula indicated anthocyanins were synthesized and accumulated in the florets of normal capitula, but not in the florets of mutant capitula. These results provide clues regarding the molecular basis of the replacement of Chrysanthemum morifolium ray florets with normally developed pistils and purple corollas with mutant ray florets with green corollas and vegetative buds . Additionally, the study findings will help to elucidate the molecular mechanisms underlying floral organ development and contribute to the development of techniques for studying the regulation of flower shape and color, which may enhance chrysanthemum breeding. Conclusions The whole-transcriptome analysis of DEGs in mutant and normal C. morifolium capitula described herein indicates the anthocyanin deficiency of the mutant capitula may be related to the mutation that replaces ray floret pistils with vegetative buds. Moreover, pistils may be required for the anthocyanin biosynthesis in the corollas of chrysanthemum ray florets.

p-COUMARATES OF BETULA PENDULA (BETULACEAE) VEGETATIVE BUDS SESQUITERPENE ALCOHOLS

The composition of coumarates sesquiterpene alcohols of Betula pendula Roth. birch vegetative buds was determined. Fraction was isolated from buds extract by preparative liquid chromatography. The extract was isolated by sequential extraction of an alcoholic extract of the buds with methyl tert-butyl ether. The new sesquiterpene derivatives were first detected in the birch vegetative buds. The structure of 6-hydroxyisocaryophyllene [(1R,4Z,6R,9S)-8-methylene-11,11-dimethylbicyclo[7.2.0]undec-4-ene-6-ol] trans-p-coumarate isolated from the birch buds was determined by NMR spectroscopy. The physico-chemical characteristics and NMR data of 6-hydroxyisocaryophyllene p-coumarate and others coumarates are demonstrated. The gas chromatographic retention indices of all identified compounds were determined. Birch buds contain derivatives of trans-coumaric acid. The antimicrobial activity of sesquiterpene alcohols coumarates was evaluated. The antimicrobial activity of sesquiterpene alcohols coumarates in relation to the following microorganisms: Escherichia coli, Proteus mirabilis, Staphylococcus aureus, Staphylococcus pneumonia and Klebsiella pneumonia was evaluated. The fraction of sesquiterpene alcohols coumarates showed activity against Staphylococcus epidermidis.

Study of maximum frost resistance of cherry scion/stock combinations

The research was carried out on the basis of the laboratory of stability of physiology of fruit plants at All-Russian research Institute of Breeding of Fruit Crops in 2017-2018. The object of research was the scion/stock combinations of Novella and Turgenevka cherries/82987, C-2-180, 74332, 74340, 74336, 74324 breeding of the Institute. In the study of winter hardiness of cherry, special attention was paid to the ability of varieties to withstand low temperatures in mid-winter. The aim of the research was to study the maximum frost new scion/stock combinations of cherries by artificial freezing and selection of the hardiest of them. The results of the research noted that in the recovery period of organic dormancy in late December, when the cherry plants acquire the maximum hardened state, study scion/stock combinations were characterized by high resistance to frost of bark and wood of annual branches. They noted frost resistance of vegetative buds with reversible damage. Significant differences in the freezing vegetative buds, bark and wood between scion/stock combinations of sweet cherries are shown. Novella and Turgenevka cherry varieties on clonal rootstocks 74332, 74336, characterized by the greatest potential frost resistance of vegetative buds and tissues of annual branches at lower t= -35°C (winter hardiness component II) at the end of December. It is shown that all cherry scion/stock combinations have a low potential frost resistance of generative buds. After exposure to t= -35°C, living rudiments of flower buds preserved only in cherry scion/stock combinations Novella/74332, Turgenevka/74340, 74336 (from 4.0 to 15.4 %). According to the results of artificial freezing scion/stock combination Novella/74332 and Turgenevka / 74332, 74336 were revealed, which were characterized by the maximum frost resistance of generative, vegetative buds, bark and wood.