Use of factors of photoperiod duration and growth regulators to increase the yield of mixoploid plants in C0 generation in meadow clover (Trifolium pratense L.)

It has been established that the studied mode of cultivation of meadow clover under controlled environmental conditions, with continuous illumination with an intensity of 18-20 thousand lux and a constant temperature of + 25 °C, causes significant morphological changes in meadow clover. Compared with the optimal (control), the proposed growing regime halves the development time of plants and by the same amount reduces the severity of morphological traits, while simultaneously causing apical dominance in 54% of plants. Spraying plants with phytohormone in the form of naphthylacetic acid in all studied concentrations reduced the growing season by 4-8 days and increased pollen fertility by 8-10%. The optimal concentration of naphthylacetic acid (NLA) was revealed to suppress the growth of secondary meristems in meadow clover under the conditions of an experimental plant growing regime. The most significant effect on the manifestation of apical dominance was shown by the use of naphthylacetic acid at a concentration of 0.001%. The combined use of the proposed growing regime and treatment with naphthylacetic acid at a concentration of 0.001% increased the yield of plants with apical dominance from 54.5% to 76%. The developed method has shown high efficiency for the creation of tetraploid forms of meadow clover. When growing clover C0 generation and selection of mixoploid plants, the yield of mixoploids increased 5.4 times, the survival rate of seedlings increased by 21%, the time to obtain one generation and the selection of mixoploids decreased by 58%.

Use of alpha-naphthylacetic acid in ovary thinning and preharvest fruit drop reduction in apple trees

Chemical thinning of apple ovaries in intensive orchards is highly relevant. This farming practice reduces manual labour, decreases the fructification interval and improves apple quality. Growth regulators, including alpha-aphthylacetic acid, also reduce preharvest fruit drop allowing for an optimal harvest capacity. The research aimed to study the impact of different alpha-naphthylacetic acid application rates on ovary thinning and preharvest fruit drop. Assays were conducted in 2019—2020 in a leached-chernozem experimental apple orchard of the Michurin Federal Research Centre in Tambov Region. Assay 1 studied the treatment impact on apple tree thinning at rates 100, 200, 300 and 400 ml/ha in 8—12 mm fruits, assay 2 (treatment 2 weeks prior to expected harvest) — on reducing preharvest apple drop at rates 200, 300 and 400 ml/ha. The treatments significantly reduced the number of ovaries in the Zhigulevskoe/62-396 cultivar and increased mean apple fruit weight. Such increase was an important yield-rising factor in the 300 and 400 ml/ha treatments. Alpha-naphthylacetic acid treatments in 8—12 mm fruits had a significant lowering impact on total leaf nitrogen content. The treatments also induced a significant reduction in preharvest apple fruit drop, with the best effect at rate 300 ml/ha. No explicit impact of alpha-naphthylacetic acid on fructification interval was observed in the study period.

In vitro Barnardia japonica (Thunb.) Schult. et Schult. fil. micropropagation by direct regeneration

In vitro micropropagation of rare Far Eastern species Barnardia japonica by the direct regeneration method was studied for the first time. The effect of different concentrations of 6-benzylaminopurine and kinetin in combination with auxins on the regeneration potential of young seedlings using Murashige and Skoog media was estimated. It was found that the largest number of new plants (61 new shoots on average) is formed when explants are cultivated on the medium with a high concentration of kinetin (10 mg/L) and a minimum of α-naphthylacetic acid (0.1 mg/L). The resulting plants are rooted easily on a hormone-free medium of the same mineral composition. The least effective for the mass production of plants by direct regeneration was a medium with a combination of 2 mg/L kinetin and 1 mg/L α-naphthylacetic acid. The developed approach can be applied for the effective propagation of Barnardia japonica and returning the species to its natural habitat.

Agrobacterium-mediated transformation of Amaranthus cruentus L. epicotyls by the ARGOS-LIKE transgene

The present study describes the results of our research in Agrobacterium-mediated transformation of epicotyl segments of Amaranthus cruentus variety “Bagryanyi” by the ARGOS-LIKE transgene of Arabidopsis thaliana controlled by the 35S promoter. For shoot regeneration from epicotyl segments after Agrobacterium-mediated transformation, Murashige-Skoog (MS) medium containing 13 μM 6-benzylaminopurine and 1 μM α-naphthylacetic acid was used. For the selection of transgenic shoots, 10 mg/L of hygromycin B was added to the MS medium.

Multi-omics Analysis Reveals Whether and how Naphthylacetic Acid Affects the Quality of Rehmannia Glutinosa

Background: Rehmannia glutinosa (R.glutinosa) is an important medicinal plant. The tuberous root of R.glutinosa is often used as herbal medicine. Naphthylacetic acid (NAA) as expansin can improve its yield, but knowledge about gene regulation and metabolome in its root is limited.Results: Full-length transcriptome, next generation transcriptome(NGS), small RNA and degradome sequencing and metabolomics were used to elucidate whether and how NAA affected its quality.30 differential expression metabolites (DEMs) (11 upregulated, 19downregulated) were identified, but catalpol and Rehmannioside D as quality standards were unchanged in its tuberous roots under control and NAA conditions (CKs and NTs); Their NGS identified 1,113 differentially expressed transcripts (DETs) (596 upregulated, 517downregulated) verified by RT-qPCR; Small RNA sequencing identified 78miRNAs (11known, 67 novel), of which 3 were differentially expressed miRNAs (1upregulated, 2downregulated). Among them, 274 differentially expressed miRNAs target transcripts (DEMTs) were predicted found and then validated by degradome sequencing; DETs and DEMTs were mainly related to metabolism. 4 miRNA-mRNA interaction pairs that regulates 4 metabolites (2 negatively correlated, 2 positively correlated) were identified; DETs, DEMs, differentially expressed miRNAs and DEMTs involved in phenylpropanoid biosynthesis regulated metabolites.Conclusions: The identification of DETs, DEMs, differentially expressed miRNAs and DEMTs could help to elucidate the regulatory networks and molecular mechanisms important for NAA-improving root quality of R.glutinosa.