Mother Plant Research Articles

Development of sex-specific molecular markers for early sex identification in Hippophae gyantsensis based on whole-genome resequencing

Hippophae gyantsensis is a dioecious plant endemic to the Qinghai-Tibet Plateau and is significant for ecological restoration and sand stabilization. Its fruit is rich in bioactive compounds that offer economic potential. However, the inability to distinguish sexes before flowering and prolonged maturation hinder breeding and cultivation. We performed whole-genome resequencing on male and female plants, identified large insertion/deletion (InDel) variants, and developed two sex-specific primers (Higy_04 and Higy_06). These primers enable rapid, accurate PCR-based sex identification. All sex-specific sites were located on chromosome 2, suggesting its potential role as the sex chromosome. Additionally, we found a 1:1 sex ratio among offspring from the same mother plant, consistent with Mendelian inheritance, indicating that sex segregation is mainly genetically controlled. This work lays the foundation for developing molecular markers applicable across the entire genus Hippophae and contributes to understanding sex chromosome formation and adaptive evolution within the genus.

RITA® Temporary Immersion System (TIS) for Biomass Growth Improvement and Ex Situ Conservation of Viola ucriana Erben & Raimondo

Viola ucriana Erben & Raimondo is a rare and endangered taxon, endemic to a limited area on Mount Pizzuta in northwestern Sicily, Italy. Its population is significantly threatened by anthropogenic activities, including fires, overgrazing, and habitat alterations. Temporary immersion systems (TISs) have proven effective for large-scale propagation in various protected species, offering potential for ex situ conservation and population reinforcement of V. ucriana. This study aimed to establish a bioreactor-based micropropagation protocol for shoot multiplication and compare the efficacy of a TIS with that of conventional solid culture medium (SCM). Three different plant growth regulators (PGRs) were also compared: 6-benzylaminopurine (BA), zeatin, and meta-topolin-9-riboside (mTR). The starting material originated from seeds collected from mother plants in their natural environment. The best growth outcomes (in terms of shoot multiplication, shoot length, and relative growth rate) were achieved using THE RITA® TIS, with BA (0.2 mg/L) and mTR (0.5 or 0.8 mg/L) outperforming SCM. Anomalous or hyperhydric shoots were observed with all zeatin treatments (especially with 0.8 mg/L) in both the TIS and SCM, suggesting that this cytokinin is unsuitable for V. ucriana biomass production. The rooting phase was significantly improved by transferring propagules onto rockwool cubes fertilized with Hoagland solution. This approach yielded more robust roots in terms of number and length compared to the conventional agar-based medium supplemented with indole-3-butyric acid (IBA). Flow cytometry analysis confirmed the genetic fidelity of the regenerants from the optimal PGR treatments, showing that all plantlets maintained the diploid ploidy level of their maternal plants. Over 90% of the in vitro derived plantlets were successfully acclimatized to greenhouse conditions. This paper represents the first report of V. ucriana biomass multiplication using a RITA® bioreactor. The stability of the regenerants, confirmed by nuclei quantification via cytofluorimetry, provides guidance in establishing a true-to-type ex situ population, supporting conservation and future reinforcement efforts.

Establishment of a Suitable Protocol for Clonal Propagation of Stevia (Stevia rebaudiana) and Creating its Advanced Lines using Gamma-Ray

A suitable protocol was developed for in vitro clonal propagation of Stevia rebaudiana Bertoni from shoots tip and nodal explant. Experiments were conducted to standardize the culture media composition with plant hormone for multiple shoot proliferation and rooting for obtaining plantlets with uniform characteristics like the mother plant in terms of growth and habits. The best response towards multiple shoot regeneration was observed from nodal explants on Murashige and Skoog (MS) basal media fortified with 3.0 mg/L Benzyl amino purine (BAP). In this combination, an average of 14 shoots were regenerated from the shoot tip and 16 shoots were regenerated from nodal explant. Multiple shoots were increased up to two to three times higher when they were sub-culture in the same media combination. Plantlets produced profuse rooting within 10 to 16 days after transfer to MS supplemented with different concentrations of Indole-3-butyric acid (IBA), Alpha naphthyl acetic acid (NAA) and Indole-3-acetic acid (IAA) (0.5-2.5 mg/l). Best root development was obtained in MS containing 1.5 mg/l IBA. Rooted plantlets were transferred to soil for hardening. About 90% of plantlets were successfully established to the field condition. For the induction of the mutation, radio sensitivity tests were performed by determining lethal dose-50 (LD50) after irradiating the explants by gamma ray. The LD50 was 45 gray (Gy) for shoot tip explants whereas 55 gray (Gy) for nodal explants. Some morphological changes occurred in the treated explants which is significant for induction of mutation. J. of Sci. and Tech. Res. 6(1): 99-107, 2024

Environmental drivers of seed persistence and seedling trait variation in two Neltuma species (Fabaceae)

Abstract The endemic tree Neltuma caldenia Burk. and the shrub Neltuma flexuosa var depressa F.A. Roig (Fabaceae; subfam: Mimosoideae) are two promising species from the central region of Argentina, with high potential for use in the restoration of disturbed environments, for extensive livestock grazing and apiculture. Both species have seeds with physical dormancy. Ecological study of native species is important from the point of view of rehabilitation of degraded areas by natural regeneration or via seed-based programmes. The objective of this study was to evaluate soil seed bank persistence and seedling traits to understand variation among different populations of each of the study species growing along an ecological gradient and to identify potential components driving this variation. Home environments influenced seed bank persistence, which was higher in populations originating from more arid and unpredictable environments where it could act as a bet-hedging strategy between years and seasons. We also observed differences associated with seedling growth traits between the species and populations. Populations with higher seed persistence were associated with greater seedling growth in N. caldenia. The rapid elongation rate of N. caldenia seedlings growing in large populations and unstable environments could help their ability to escape drought by accessing deeper soil moisture and would confer a high relative competitive ability. In contrast, N. f. var depressa displayed higher seed persistence, which was associated with more arid and unstable conditions and correlated with lower seedling growth, possibly due to an inbreeding depression effect, resulting from the presence of mother plants in low-densities or being isolated from other individuals. There was no effect of population size on seed persistence. To better understand seed persistence and associated seedling trait variation, future studies need to consider the genotype, environment and landscape conditions.

Emerging Diseases in Spain Strawberry Crops: Neopestalotiopsis Leaf and Crown Rot and Fusarium Wilt.

In recent years, strawberry cultivation in Spain has been increasingly affected by new and re-emerging fungal diseases. The most significant emerging diseases in Spain include those caused by Neopestalotiopsis spp. Maharachch., K.D.Hyde & Crous and Fusarium oxysporum f. sp. fragariae Winks & Y.N. Williams. These pathogens are difficult to control due to their pathogenic variability (presence of pathotypes and/or races), the lack of knowledge about the susceptibility of the different cultivars, the limited availability of effective fumigants, and the absence of sufficient information about their sources of inoculum. Both pathogens can cause root and crown rot, leading to plant collapse and significant losses for strawberry producers. Several factors have contributed to the rise of these diseases in Spain: (i) the gradual ban on key soil fumigants has left the crop vulnerable; (ii) there has been a notable diversification in the origin of mother plants used in cultivation, with plants now sourced from various countries, increasing the risk of long-distance pathogen spread; (iii) the introduction of numerous new strawberry varieties, which exposes more genotypes to pathogenic infections; and (iv) changes in planting times, leading to younger and more vulnerable plants being exposed to heat stress, as well as an increase in disease susceptibility. Neopestalotiopsis spp. and Fusarium oxysporum f. sp. fragariae have also become major threats to strawberry crops worldwide, spreading through nursery plants and the movement of plant material. The latest research findings in Spain on both pathogens are highlighted in this manuscript.

Cytogenomic evaluation of regenerated Aralia elata using PLOP-FISH and flow cytometry

Aralia elata is closely related to Panax ginseng and contains high levels of saponins and other medicinal compounds. Successful A. elata micropropagation is commercially significant; however, the genomic stability of tissue culture-derived regenerants is unclear. In this study, callus-derived regenerated A. elata plants were obtained, and their cytogenomic constitutions were assessed. Using RepeatExplorer, pre-labeled oligonucleotide probes (PLOPs) were developed with newly mined tandem repeats from < 1× NGS whole-genome short reads, fluorescence in situ hybridization (FISH) was performed using six repeat probes, including three universal PLOPs, and genomic DNA content was estimated using flow cytometry. Regenerated A. elata plants (50) exhibited consistent ploidy, repeat distribution, and genome sizes compared with those exhibited by the mother plant. Six repeat probes were detected using FISH. Tandem repeat AeTR49 was identified as an excellent cytogenetic marker for homologous chromosomes, and AeTR161 and AeTR178 were localized in the centromeric and telomeric sections, respectively. Genomic DNA content (2C) was estimated at 2.46 ± 0.04 pg in the mother plant and 2.41 ± 0.05 pg in regenerated plants, with no significant variations in genome size or chromosome length. These results demonstrate that cytogenomics can be used to effectively evaluate chromosome-level genomic stability in regenerated A. elata plants.

Activation of Cryptic Secondary Metabolite Biosynthesis in Tobacco BY-2 Suspension Cells by Epigenetic Modifiers.

Cultured plant cells often biosynthesize secondary metabolites to a lesser extent relative to the mother plants. This phenomenon is associated with epigenetic alterations of the biosynthetic gene(s). Here we investigated the effectiveness of epigenetic modifiers, such as inhibitors of histone deacetylase (HDAC) and DNA methyltransferase (DNMT), to activate cryptic secondary metabolite biosynthesis in tobacco (Nicotiana tabacum) BY-2 cells. The BY-2 suspension cells cultured with an HDAC inhibitor, suberoyl bis-hydroxamic acid, exhibited strong biosynthesis of four compounds that were originally present at trace concentrations. The induced compounds were identified as caffeoylputrescine (1), 4-O-β-D-glucopyranosylferulic acid (2), 5-O-caffeoylquinic acid (3), and feruloylputrescine (4). Biosynthetic activation of compounds 1-4 was reproduced by two other HDAC inhibitors. Treatment of the cells with a DNMT inhibitor (zebularine) also activated the biosynthesis of compounds 1-4, but had a limited effectiveness relative to the HDAC inhibitors, indicating that histone acetylation levels are involved more than DNA methylation levels in the epigenetic regulation of the biosynthesis of compounds 1-4 in the BY-2 cells. Following our previous demonstration using cultured cells of a monocotyledonous plant, this study demonstrates the utility of epigenetic modifiers to activate cryptic secondary metabolite biosynthesis in cultured cells of a dicotyledonous plant.

Efficient nitrogen fertilization for sustainable sago palm (Metroxylon sagu Rottb.) cultivation in Tropical Peatland

ABSTRACT Tropical peatlands degraded by agricultural use with intensive drainage require restoration through rewetting, preferably while agricultural use continues. Sago palm (Metroxylon sagu Rottb.), a starch crop that can grow in high water table peatlands, is suitable for this objective. However, the optimal method of sago palm cultivation on peat soil has not yet been established. To establish an efficient nitrogen (N) fertilization method for sustainable production of sago palm in peatland, the fate of 15N-labelled urea applied to sago palm after transplanting and the effect of controlled-release N fertilizer applied before transplanting on sago palm growth were examined in field experiments in Malaysia. The rate of mineralization of soil organic N was also measured to evaluate the capacity of soil N as another N source for sago palms. The application of chemical fertilizers after transplanting did not improve plant growth or total N uptake. After 1 year, only 2–5% and 9–22% of the fertilized N was detected in aboveground parts (mother plant and suckers) and soil, respectively. The N supplying potential of peat soils exceeded the N requirements of sago palms. In contrast, N application at the nursery stage increased leaf length, number of leaves, aboveground biomass, and leaf chlorophyll content after transplanting. These results suggest that concentrating fertilization at the nursery stage would be an efficient method for sago palm cultivation in tropical peatlands.

Warm temperature perceived at the vegetative stage affects progeny seed germination in natural accessions of Arabidopsis thaliana.

Temperatures perceived early in the life cycle of mother plants can affect the germination of the offspring seeds. In Arabidopsis thaliana, vernalisation-insensitive mutants showed altered germination response to elevated maternal temperature, hence revealing a strong genetic determinism. However, the genetic control of this maternal effect and its prevalence across natural populations remain unclear. Here, we exposed a collection of European accessions of A. thaliana to increased temperature during the vegetative phase and assessed germination in their progeny to identify the genetic basis of transgenerational germination response. We found that genotypes with rapidly germinating progeny after early maternal exposure to elevated temperature originated from regions with low-light radiation. Combining genome-wide association, expression analysis and functional assays across multiple genetic backgrounds, we show a central role for PHYB in mediating the response to maternally perceived temperature at the vegetative stage. Differential gene expression analysis in leaves identified a similar genetic network as previously found in seed endosperm under elevated temperature, supporting the pleiotropic involvement of PHYB signalling across different tissues and stages. This provides evidence that complex environmental responses modulated by the maternal genotype can rely on a consistent set of genes yet produce different effects at the different stages of exposure.

High-frequency shoot regeneration, assessment of genetic fidelity, and histochemical analysis of forskolin production in Coleus forskohlii Briq.

Forskolin, a diterpenoid found in the roots of Coleus forskohlii, has generated significant interest in the medical field due to its various therapeutic uses. This study aimed to establish an effective system for regenerating C. forskohlii plants, ensuring a year-round supply of plant material and forskolin production. We tested different concentrations of cytokinins, either alone or combined with auxin, to see their impact on shoot multiplication and growth. We found that a medium supplemented with 1.5mg L-1 of meta-topolin (mT) resulted in the highest number of shoots (~ 12.66) and leaves (~ 20) within about 5days. When mT (1mg L-1) was combined with a low amount of auxin (0.05mg L-1 NAA), we obtained an even greater number of leaves (~ 23). The shoot regeneration capacity was consistent over five subculture passages, showing minimal variation in mean shoot length and number. During acclimatization, around 91% of the plantlets grown in vermiculite + sand survived. The photosynthetic pigment concentration in the plantlets modestly increased in the first 10days and reached its highest level after 30days. Genetic fidelity assays using inter simple sequence repeats (ISSRs) confirmed the similarity between the in vitro derived plantlets and the mother plant. Micro-morphological features of in vitro and ex-vitro acclimated plantlets also matched those of the mother plant, further confirming genetic accuracy. Histochemical staining with vanillin confirmed the presence of forskolin in the in vitro roots, indicated by the violet coloration in the cells. Forskolin quantification was also validated by HPLC where in vitro derived roots were documented to undergo an almost ~ 1.8-fold in comparison to that of the mother plant. This established protocol can effectively address resource scarcity for commercial-scale forskolin production and sustainable conservation techniques.

Demonstration of Local Honeybee Flora “Mentesie” (&amp;lt;i&amp;gt;Becium grandflorum&amp;lt;/i&amp;gt;) Propagation Techniques in Wag - Himra Zone, Ethiopia

The demonstration of local honeybee flora &amp;quot;Mentesie&amp;quot; (&amp;lt;i&amp;gt;Becium grandiflorum&amp;lt;/i&amp;gt;) propagation techniques was carried out over two rainy seasons in the Gazgibla district, Debreweyla watershed closure area of the Northeastern Amhara region. The shrub has numerous benefits for the community, including honey production, fuel use, and soil and water conservation. However, it has been gradually declining. To preserve these valuable shrubs, various propagation techniques were tested. The objectives of the experiment were to demonstrate the propagation techniques of &amp;lt;i&amp;gt;Becium grandiflorum&amp;lt;/i&amp;gt; to beekeepers and to generate wider demand for its plantation among beekeepers and extension workers. The experiment compared two selected propagation techniques with local farmers’ traditional planting practices, under the guidance of forestry researchers. The treatments included seeds and cuttings. Seeds were collected from mature fruits, and cuttings were taken early in the morning from natural, mature, young, and healthy mother plants at a height of 40 cm during 2020/21. These materials were packed in perforated polyethylene bags. The average mean of flower numbers, branch numbers, and canopy cover for the enhanced propagation techniques (seedlings with pots) were 4107, 21.81, and 92.5, respectively. These values were higher than those for the comparative propagation technique, which had flower numbers of 2462, branch numbers of 19.4, and a canopy cover of 92.5. There were significant differences (p&amp;lt;0.05) among the propagation techniques in terms of canopy cover, height, number of flowers, and branches per plant. Farmers recognized the higher flower biomass, canopy cover, and potential for greater plant height of the enhanced techniques, which are beneficial for bee forage and soil and water conservation. Therefore, planting seedlings using pots were found to be the best method for the wider production of &amp;lt;i&amp;gt;B. grandiflorum&amp;lt;/i&amp;gt; in its natural growing areas.

Diaspore Dimorphism, Awn Hygroscopicity and Adaptive Significance in a Winter Annual Bromus tectorum (Poaceae).

Bromus tectorum, a winter annual plant, produces dimorphic diaspores: complex diaspores with multi-awns and simple diaspores with one awn. However, there is no information available about the role of awns and the germination characteristics of dimorphic diaspores. Dispersal germination and awns hygroscopicity of the dimorphic diaspores were assessed. The complex diaspore with multi-awns can easily be dispersed long distances from the mother plant by mammals. The simple diaspores with one awn are tightly attached to the mother plant. Caryopses from the two types of diaspores exhibited non-deep physiological dormancy at maturity, which can be released by dry storage and GA3 treatment. The awns have hygroscopic activity and can move in response to changes in moisture, moving the complex diaspore (the seed) into the soil. The seedling emergence from complex diaspores was significantly higher than those from simple diaspores at all burial depths. Germination of caryopses on the soil surface was poor. The optimal planting depth for both types of diaspores' emergence is 1-2 cm. The distinct characteristics of dimorphic diaspores and the beneficial influence of hygroscopic awns on dispersal, germination, and seedling establishment have significant ecological implications for B. tectorum's successful reproduction in unpredictable cold deserts.

Cryopreservation of Fegra Fig (Ficus palmata Forssk.) and Genetic Fidelity of the Recovered Micropropagated Plants

Cryopreservation allows for the long-term storage of biological materials, ensuring their viability for future use and preserving biodiversity. This study aimed to develop an efficient protocol for the long-term in vitro conservation of fegra fig. In vitro precultured shoot tips of fegra fig with 0.3 M sucrose showed the highest regrowth percentage (100%) before plunging into liquid nitrogen. After plunging into liquid nitrogen, the regrowth percentage was 43.33%. Following cryopreservation, the recovered shoots were rooted and acclimatized to ex vitro conditions. The genetic fidelity of the acclimatized 8-week-old fegra fig plantlets after cryopreservation with their mother plant was tested using randomly amplified polymorphic DNA (RAPD), inter simple sequence repeats (ISSR), and start codon targeted (SCoT) molecular markers. Genetic similarity between the stored plantlets with their mother plant was 100% ensuring uniformity and true-to-type regenerated plants following cryopreservation. This study presents, for the first time, an efficient protocol for the genetic conservation of fegra fig.

Effect Of Different Doses Of IBA On Success, Survivability And Growth Of Lemon Using Leaf Cut Method Under Glass House And Field Condition

An experiment was conducted at the Horticulture division of Bangladesh Institute of Nuclear Agriculture (BINA), Mymensingh during the period from March, 2024 to June, 2024 to evaluate the quick propagation techniques from lemon leaves by using IBA under glass house and field condition. The experiment was consisted of two factors such as Environmental condition: (i) glass house and field condition and (ii) Different doses of IBA: D0 (Control), D1 (1000ppm IBA for 3mins) D2 (1500ppm IBA for 3mins) and D3 (2000ppm IBA for 3mins). Mature leaves were collected from BINA Lebu-1 mother plants. Collected leaves were exposed by different doses of IBA solution separately and also a control. The experiment was laid out in RCBD with three replications. Total 24 treatment combinations of the environmental condition and IBA levels. IBA exposed leaves of lemon were planted in the unit plots on 8 March, 2024 in the afternoon with spacing of 15cmx15cm (row to row and leaf to leaf distance). Different environmental condition showed significantly influenced on almost all the mentioned parameters studied concerned with growth and growth contributing characteristics. The highest percentage of success (66.34%), survivability (56.86 and %) and canopy volume (0.055m3) were found in glass house condition and the lowest % success (50.35%) % survivability ( 44.26%) and canopy volume (0.028m3) were found in field condition. The glasshouse condition took the minimum time for root and shoot (43.22 and 70.82 days respectfully) initiation. The application of 1500ppm IBA for 3mins took the minimum time for root and shoot (21.83 and 31.00 days respectfully) initiation and the maximum success ( 97.70 %), survivability (92.77%) and canopy volume (0.088m3).The maximum time took for root and shoot (51.08 and 66.08 days respectfully) initiation and the minimum success ( 48.35 %), survivability (45.59%) and canopy volume (0.008m3) were found from control treatment. The combined effect of environmental condition and IBA was statistically significant on the success, survivability and growth of lemon. The treatment in glasshouse condition with 1500ppm IBA solution for 3mins took the minimum time for root and shoot (18.00 and 51.44 days respectfully) initiation and the maximum success (98.70 %), survivability (96.90%) and canopy volume (0.015m3) as compare to control. Therefore, the overall results indicate that glasshouse condition with 1500ppm IBA solution for 3 mins might be an efficient and eligible practice for developing mutant from leaves. Therefore, the overall results indicate that glasshouse condition with 1000ppm IBA solution for 3mins might be an efficient and eligible practice for quick propagation techniques from leaves

Detection of Viruses and Elimination of Sweet Potato Feathery Mottle Virus in High-Yielding Varieties of Sweet Potato (Ipomoea batatas) from Ethiopia

Sweet potato (Ipomoea batatas L. Lam.) is a major source of food in many parts of Ethiopia. In recent years, viral diseases have become the main threat to sweet potato production in Ethiopia. Previous virus survey studies carried out from 1986 to 2020 reported eight viruses infecting sweet potato in Ethiopia. Consequently, obtaining and multiplying virus-free planting materials have been difficult for farmers and commercial multipliers. This study was conducted to detect viruses infecting the five sweet potato varieties used as source plants and compare the virus elimination efficiency between meristem cultures from untreated and heat-treated mother plants and production of virus-free sweet-potato-planting materials. Seven common viruses were tested for, using grafting to Ipomoea setosa, enzyme-linked immunosorbent assay (ELISA) and reverse-transcription polymerase chain reaction (RT–PCR) before and after elimination procedures as screening and confirmatory methods. The sweet potato feathery mottle virus (SPFMV) elimination efficiencies of meristem cultures from untreated (grown at 25 ± 1 °C) and heat-treated (grown at 39 ± 1 °C) potted plants of sweet potato varieties were evaluated and compared. Sweet potato feathery mottle virus (SPFMV) was detected in 12 of the 15 source plants tested. Triple infections of SPFMV, sweet potato chlorotic stunt virus (SPCSV), and sweet potato virus C (SPVC) were detected in one of the fifteen plants. This study reports the detection of SPVC for the first time in sweet potato plants from Ethiopia. The cutting of meristems from heat-treated plants further increased the percentage of virus-free plantlets by ca 10% to ca 16%, depending on the plant variety. Elimination efficiency also seemed to vary among varieties: the greatest difference was observed for ‘Tola’, and the least difference was observed for ‘Guntute’. The present study provided protocols for detecting viruses and generating virus-free sweet-potato-planting materials in Ethiopia.

Environmental Pollutant Anthracene Induces ABA-Dependent Transgenerational Effects on Gemmae Dormancy in Marchantia polymorpha.

Anthracene, a polycyclic aromatic hydrocarbon (PAH) from fossil fuel combustion, poses significant environmental threats. This study investigates the role of abscisic acid (ABA) in the anthracene tolerance of the liverwort Marchantia polymorpha using mutants deficient in ABA perception (Mppyl1) or biosynthesis (Mpaba1). In this study, we monitored the role of ABA in the anthracene tolerance response by tracking two ABA-controlled traits: plant growth inhibition and gemmae dormancy. We found that the anthracene-induced inhibition of plant growth is dose-dependent, similar to the growth-inhibiting effect of ABA, but independent of ABA pathways. However, gemmae dormancy was differentially affected by anthracene in ABA-deficient mutants. We found that gemmae from anthracene-exposed WT plants exhibited reduced germination compared to those from mock-treated plants. This suggests that the anthracene exposure of mother plants induces a transgenerational effect, resulting in prolonged dormancy in their asexual propagules. While Mppyl1 gemmae retained a dormancy delay when derived from anthracene-exposed thalli, the ABA biosynthesis mutant Mpaba1 did not display any significant dormancy delay as a consequence of anthracene exposure. These results, together with the strong induction of ABA marker genes upon anthracene treatment, imply that anthracene-induced germination inhibition relies on ABA synthesis in the mother plant, highlighting the critical role of MpABA1 in the tolerance response. These findings reveal a complex interplay between anthracene stress and ABA signaling, where anthracene triggers ABA-mediated responses, influencing reproductive success and highlighting the potential for leveraging genetic and hormonal pathways to enhance plant resilience in contaminated habitats.

Grapevines grown from canes having spent 10 months in space: study of their downy mildew susceptibility

The control of plant diseases represents a significant challenge in agriculture, particularly with the current emphasis on reducing pesticide use, necessitating alternative approaches. Among them, resistant plant breeding programs offer a promising alternative. Considering the stressful conditions in space, space conditions emerge as an innovative method for advancing crop improvement. This study explored the unique potential of the International Space Station (ISS) environment to induce beneficial modifications in grapevine, resulting in plants with reduced susceptibility to diseases. Canes of two Vitis vinifera L. cultivars, Cabernet Sauvignon (CS) and Merlot (Me), have undergone a 10-month space journey on-board the ISS, while others stayed on Earth (Ground Control, GC). We conducted a 2-year analysis of the response to downy mildew (Plasmopara viticola) of plants developed from ISS and GC canes, called Mother plants. The disease development of progenies produced from Merlot Mother plants was also evaluated. A higher proportion of individuals with low-susceptibility was noted in the ISS Mother group compared to the controls for both cultivars. This trend was also observed for the Merlot progenies. Finally, 11% of Merlot individuals (Mother and progenies, and for the 2 years of study) were distributed in the low susceptibility class. This study suggests that grapevine canes exposure to ISS conditions resulted in an enhanced percentage of plants showing reduction of susceptibility to downy mildew.

Разработка природоподобной технологии размножения низкорослых подвоев косточковых культур в закрытом грунте

Abstract. The creation of technologies in accordance with the directions for the introduction of environmentally friendly, resource-saving developments into agriculture is relevant. Accelerated reproduction of planting material of the "basic" and "proven" categories is considered equally important, which requires optimization of reproduction by green cuttings. Green cutting allows to significantly quickly increase the yield of cuttings from one mother plant, reducing the area of the mother plantations by 4-5 times. Its advantage is the genetic uniformity of own-root plants, contributing to the elimination of plant infection with diseases and pests, ensuring a shorter growing period, successful combination with other stages of recovery: microclonal reproduction, reproduction by green grafting. In the protected ground conditions, studies were carried out (2019-2023) to isolate the most effective drug for the reproduction of healthy mother rootstock bushes for small-stone crops: AI 5 B, 3-20, AI-1.10-18, 3-107 (FSBSI NCFSCHVW breeding); VSL-2 (Crimean EBS breeding). The effect of the drugs was compared: plant growth regulators: Indolyl-3-butyric acid (IMC, SP), Phytactive Extraplus, CE; microbiological fertilizers: Sporex, Zh, Ultrex, Zh; Sporion, Zh, control (water). It was found that the treatment of BCI and the phytactive Extraplus reduced the period of appearance of primary roots by 4.5 and 5 days, depending on the rootstock. The largest percentage of rooted ones was obtained using the microbiological preparation Ultrex (3-47 % more than the control variant, depending on the rootstock genotype), also in this variant, due to its positive effect on root formation of more than 2 mm, increased stress resistance, more standard planting material was obtained by 90 % relative to the control ones. Key words: basic mother plantings, green cuttings, plant growth regulators, preparations based on microorganisms and their waste products, the percentage of yield of standard rootstocks for sweet cherries and cherries.

Reproductive Biology in the Possible Last Healthy Population of Parodia rechensis (Cactaceae): Perspectives to Avoid Its Extinction.

All 32 Brazilian species of Parodia Speg (Cactaceae) occurring in Rio Grande do Sul State are considered threatened, according to the IUCN criteria. Until 2021, Parodia rechensis (CR) was known by only two small populations. However, a new population with over 400 individuals was discovered in 2021, prompting the study of its reproductive biology as a way to promote its conservation. Anthesis, breeding system, and natural pollination were studied in the field. The breeding system was studied by applying controlled pollination treatments to plants excluded from pollinators (bagged). Germination features were studied at the Seed Bank of the Porto Alegre Botanical Garden under controlled temperatures (20, 25, and 30 °C). The anthesis is diurnal and lasts for up to four days. The flowers offer pollen as the sole resource to the pollinators. The study species is unable to set fruit and seed without the agency of pollinators and has self-incompatible (unable to set fruit and seeds when pollinated with pollen of the same individual) characteristics that can considerably restrict its reproduction. Native bees of Halictidae and Apidae (Hymenoptera) are the main pollinators, with a smaller contribution of Melyridae (Coleoptera) and Syrphidae (Diptera). Natural fruit set is moderate (≤64%, per individual), but the species presents vegetative growth, producing several branches from the mother plant. Seeds showed the optimum germination rate at 20 °C and an inhibition of 75% in germinability at 30 °C. Our findings suggest the need to manage the species' habitat to guarantee the permanency of the plants and healthy populations of pollinators as well. Our findings raise concerns about the germination and establishment of new individuals in the context of rising temperatures caused by climate change. Suggestions for the possible management of the extant populations are made.

Reducing red light proportion in full-spectrum LEDs enhances runner plant propagation by promoting the growth and development of mother plants in strawberry.

Full-spectrum light-emitting diodes (LEDs) have gradually replaced narrow-spectrum LEDs and are widely used in plant factories with artificial lighting (PFALs). However, the specific effect of LED light quality on dry mass allocation in runner plant propagation remains unclear. Hence, we cultivated "Akihime" strawberries as mother plants for 115 days to conduct runner plant propagation experiment under white LEDs (W100), white and red LEDs (W84R16 and W55R45), red and blue LEDs (RB100), and red, blue and green LEDs (RB80G20) in PFALs, and determined key factors affecting dry mass accumulation and allocation among mother plants and runner plants based on growth component analysis. The results showed that the net photosynthetic rate and total leaf area in mother plants in W100 increased by 11% and 31%, respectively, compared with W55R45. In comparison to W84R16 and W55R45, W100 increased the dry mass (23%-30%) of runner plants mainly by increasing the total dry mass (TDM) (23%) of strawberry plants, without significantly affecting the fraction of dry mass partitioning to runner plants. However, the number of runners in W55R45 was 5.1 per plant, representing only 78% of that in W100. Compared with RB100, RB80G20 significantly increased the number of runner plants and runner numbers by 16% and 19% to 13.0 per plant and 5.8 per plant, respectively. The partial replacement of blue light with green light in RB80G20 induced a shade avoidance response in runner plants, resulting in a 55% increase in the total leaf area of runner plants compared with RB100. Data from growth component analysis showed that compared with red and blue LEDs, white LEDs increased the TDM of runner plants by 83% by increasing the plant TDM accumulation (44%) and the fraction of dry mass partitioning to runner plants (37%). Additionally, the dry mass (g) of runner plants per mol and per kilowatt-hour under in W100 were 0.11 and 0.75, respectively, significantly higher than other treatments. Therefore, reducing red light proportion in full-spectrum LEDs is beneficial for strawberry runner plant propagation in PFALs.