Figure 1.
Collection of mother plants (depository)
Figure 2.
Cultivation of birch plants in vitro in culture containers with a volume of 200 ml on light racks
Figure 3.
Sterilization of instruments
Figure 4.
Concentration of salts in nutrient media
Table 1.
The influence of the age of donor plants on the features of decontamination and morphogenesis of primary birch explants in the MS medium
| Index | Variety | Age, years | ||
|---|---|---|---|---|
| 1 | 3 | 7 | ||
| Decontamination efficiency, % | royal frost | 31.4±4.09 | 23.2±3.11 | 14.1±2.07 |
| jacquemontii | 19.5±1.99 | 11.4±2.01 | 7.4±1.86 | |
| Morphogenesis of explants, % | royal frost | 11.9±2.02 | 9.0±1.98 | 6.1±2.02 |
| jacquemontii | 6.3±0.98 | 5.1±0.88 | 3.3±1.07 | |
Table 2.
Influence of growing conditions of annual donor plants on features of decontamination and morphogenesis of primary birch explants in the MS medium
| Index | Variety | Field conditions | Depository |
|---|---|---|---|
| Decontamination efficiency, % | royal frost | 30.4±4.01 | 47.7±5.13 |
| jacquemontii | 21.2±3.12 | 39.5±4.32 | |
| Morphogenesis of explants, % | royal frost | 10.2±2.08 | 23.3±3.22 |
| jacquemontii | 7.1±0.89 | 17.2±3.06 |
Table 3.
Influence of the origin of primary bud explants on the features of decontamination and morphogenesis
| Index | Variety | Bud | ||
|---|---|---|---|---|
| apical | medial | basal | ||
| Decontamination efficiency, % | royal frost | 49.8±5.46 | 56.7±6.32 | 13.5±3.98 |
| jacquemontii | 38.3±4.05 | 48.5±5.23 | 9.1±2.86 | |
| Morphogenesis of explants, % | royal frost | 20.3±3.11 | 31.3±4.21 | 6.4±1.88 |
| jacquemontii | 16.6±3.16 | 27.6±3.09 | 3.21±2.01 | |
Table 4.
Decontamination and morphogenesis of primary birch explants with various antiseptics
| Index | Variety | NaClO | AgNO3 | C2H5OH | Blanidas 300 |
|---|---|---|---|---|---|
| Decontamination efficiency, % | royal frost | 56±6 | – | – | 78±5 |
| jacquemontii | 48±5 | – | – | 69±5 | |
| Morphogenesis of explants, % | royal frost | 31±4 | – | – | 54±3 |
| jacquemontii | 27±3 | – | – | 51±3 |
Figure 5.
Condition of explants at the fifth passage on MS medium, variety Jacquemontii
Table 5.
Dynamics of morphogenesis of birch explants on different media
| Index | Variety | Media | ||||
|---|---|---|---|---|---|---|
| MS | MS1/2 | |||||
| age, years | ||||||
| 1 | 5 | 1 | 5 | 7 | ||
| Decontamination efficiency, % | royal frost | 2.1±0.21 | 1.3±0.08 | 2.2±0.30 | 1.7±0.11 | 1.5±0.09 |
| jacquemontii | 1.6±0.10 | 1.1± 0.06 | 1.7±0.11 | 1.5±0.08 | 1.5±0.10 | |
| Morphogenesis of explants, % | royal frost | 39.5±3.09 | 12.1± 1.41 | 47±3.20 | 41.4±2.91 | 36.5±2.73 |
| jacquemontii | 33.2±2.82 | 11.0± 1.22 | 38±2.73 | 32.6±2.43 | 27.5±2.64 | |
Figure 6.
State of explants at the fifth passage on medium MS1/2, variety Jacquemontii
Table 6.
Biometric indicators of birch regenerants on different nutrient media
| Index | Cutting | Medium | ||||
|---|---|---|---|---|---|---|
| MS | MS1/2 | DKW | QL | WPM | ||
| Royal Frost | ||||||
| The number of microshoots in the conglomerate, pcs | first | 2.0±0.21 | 2.2±0.17 | 1.9±0.14 | 1.8±0.21 | 3.9±0.10 |
| fifth | 1.3±0.18 | 1.7±0.31 | 1.8±0.30 | 1.8±0.33 | 4.1±0.22 | |
| Height of regenerants, mm | first | 36.2±3.3 | 47.4±4.2 | 44.4±5.12 | 32.0±0.29 | 63.8±4.1 |
| fifth | 31.1±2.90 | 41.1± 4.3 | 32.8±3.42 | 28.4±3.1 | 61.6±4.4 | |
| The number of internodes in the main shoot of regenerates, pcs | first | 2.4±0.21 | 2.9±0.11 | 2.7±0.40 | 2.3±0.22 | 3.6±0.10 |
| fifth | 1.7±0.18 | 2.3±0.16 | 1.3±0.31 | 2.1±0.19 | 3.5±0.08 | |
| Jacquemontii | ||||||
| The number of microshoots in the conglomerate, pcs | first | 1.4±0.22 | 1.7±0.19 | 2.0±0.11 | 2.2±0.21 | 3.7±0.29 |
| fifth | 1.1±0.28 | 1.5±0.30 | 1.6±0.21 | 1.7±0.27 | 3.6±0.20 | |
| Height of regenerants, mm | first | 32.3±3.1 | 38.6±5.5 | 41.2±3.3 | 30.4±3.1 | 59.9±3.6 |
| fifth | 21.2±2.4 | 32.6±4.8 | 27.7±2.4 | 25.3±2.2 | 62.8±3.4 | |
| The number of internodes in the main shoot of regenerates, pcs | first | 2.1±0.16 | 2.6±0.24 | 2.2±0.13 | 1.9±0.21 | 3.3±0.20 |
| fifth | 1.3±0.15 | 1.8±0.19 | 1.1±0.15 | 1.8±0.22 | 3.4±0.18 | |
Figure 7.
Development of birch regenerants under unfavourable nutrient medium acidity: pH 5.1, variety Royal Frost; pH 6.0, variety Jacquemontii
Figure 8.
Development of birch regenerants at pH 5.5 nutrient medium acidity, varieties Jacquemontii (green in the centre) and Royal Frost (with burgundy colour)
Figure 9.
Symptoms of excess sulphur in the nutrient medium, Royal Frost variety
Figure 10.
Visual signs of deficiency caused by excess sulphur in the nutrient medium, variety Jacquemontii
Table 7.
The influence of combinations of nutrient media on the features of rhizogenesis of birch regenerants during long-term cultivation
| Option | Index | |||
|---|---|---|---|---|
| the length of the root system, mm | number of roots, pcs. | |||
| ...WPM–WPM... | ...MS1/2–WPM... | ...WPM–WPM... | ...MS1/2–WPM... | |
| Variety Royal Frost | 36±3 | 69±4 | 2±1 | 7±2 |
| Variety Jacquemontii | 11±3 | 37±3 | 5±2 | 14±2 |
Table 8.
The influence of combinations of nutrient media on shoot formation in birch regenerants during long-term cultivation
| Option | Index | |||
|---|---|---|---|---|
| height of a shoot, mm | number of nodes, pcs. | |||
| ...WPM–WPM... | ...MS1/2–WPM... | ...WPM–WPM... | ... MS1/2–WPM... | |
| Variety Royal Frost | 36.3±2.21 | 75.5±3.84 | 4.1±1.59 | 9.1±1.99 |
| Variety Jacquemontii | 29.4±1.98 | 65.2±3.32 | 3.3±1.42 | 7.4±2.43 |
Table 9.
The influence of cultivation conditions on the adaptation of birch plants in vitro on the 14th and 30th days of cultivation
| Adaptation conditions | Basis of the substrate | Shoot height, cm | Root length, cm | ||
|---|---|---|---|---|---|
| Royal Frost | Jacquemontii | Royal Frost | Jacquemontii | ||
| 14th day of cultivation | |||||
| Wet chamber | peat | 8.8±0.60 | 7.3±0.55 | 3.2±0.41 | 3.0±0.30 |
| perlite | 9.7±0.72 | 7.8±0.62 | 3.6±0.49 | 3.0±0.42 | |
| Bioreactor | peat | 20.1±1.91 | 17.6±1.31 | 19.3±1.65 | 13.4±1.17 |
| perlite | 23.1±2.10 | 18.4±1.76 | 20.6±1.72 | 15.7±1.22 | |
| 30th day of cultivation | |||||
| Wet chamber | peat | 15.3±1.13 | 11.7±0.81 | 7.7±0.51 | 6.4±0.30 |
| perlite | 16.1±1.33 | 12.9±1.15 | 12.6±1.12 | 9.8±0.72 | |
| Bioreactor | peat | 39.6±2.31 | 32.1±2.32 | 29.7±2.33 | 23.3±1.93 |
| perlite | 45.4±3.48 | 33.7±2.64 | 33.0±2.84 | 27.6±2.44 | |
Figure 11.
Condition of birch plants before (1, 2) and after feeding (3, 4), where 1, 3 – Royal Frost variety; 2, 4 – Jacquemontii variety
Figure 12.
Post-aseptic cutting the top, variety Royal Frost: 1 – a plant transplanted from in vitro on 22 January 2024, from which the top was separated for rooting on 7 February 2024; 2 – two new shoots grow in the decapitation zone