Survival Rate Of Seedlings Research Articles

MORN motif-containing protein OsMORN1 and OsMORN2 are crucial for rice pollen viability and cold tolerance.

The pollen viability directly affects the pollination process and the ultimate grain yield of rice. Here, we identified that the MORN motif-containing proteins, OsMORN1 and OsMORN2, had a crucial role in maintaining pollen fertility. Compared with the wild type (WT), the pollen viability of the osmorn1 and osmorn2 mutants was reduced, and pollen germination was abnormal, resulting in significantly lower spikelet fertility, seed-setting rate, and grain yield per plant. Further investigation revealed that OsMORN1 was localized to the Golgi apparatus and lipid droplets. Lipids associated with pollen viability underwent alterations in osmorn mutants, such as the diacylglyceride (18:3_18:3) was 5.1-fold higher and digalactosyldiacylglycerol (18:2_18:2) was 5.2-fold lower in osmorn1, while the triacylglycerol (TG) (16:0_18:2_18:3) was 8.3-fold higher and TG (16:0_18:1_18:3) was 8.5-fold lower in osmorn2 than those in WT. Furthermore, the OsMORN1/2 was found to be associated with rice cold tolerance, as osmorn1 and osmorn2 mutants were more sensitive to chilling stress than WT. The mutants displayed increased hydrogen peroxide accumulation, reduced antioxidant enzyme activities, elevated malondialdehyde content, and a significantly decreased seedling survival rate. Lipidomics analysis revealed distinct alterations in lipids under low temperature, highlighting significant changes in TG (18:2_18:3_18:3) and TG (18:4_18:2_18:2) in osmorn1, TG (16:0_18:2_18:2) and PI (17:2_18:3) in osmorn2 compared to the WT. Therefore, it suggested that OsMORN1 and OsMORN2 regulate both pollen viability and cold tolerance through maintaining lipid homeostasis.

Seed and Germination Characteristics of Different Hybrids Belonging to Vitis Species

In this research, some grape cultivars are belonging to Vitis vinifera, Vitis labrusca, and interspecific grape cultivars were used for crossbreeding. The aim of the cross-breedings was to obtain individuals that could be used as a table grape, female flower type genotypes, and would be resistant to disease and cold hardy grapes. In the research, berry set (seeded and seedless berry number), seed weight (g), seed width and length (mm), floating empty seed rate (seed viability, %), seed germination rates (%), seedling survival rates (%) and shoot length (cm) were calculated in the seeds obtained as a result of cross-breeding. In this research, as a result of crossbreeding with different Vitis species and hybrids, the germination rate was significantly higher, especially when using ‘Red Globe’ and ‘Cayuga White’ cultivars as maternal parents. Although the germination rates of the seeds obtained after cross-breeding are low, the use of ‘Çavuş’ grape cultivar with female flower form in cross-breeding facilitates the work since emasculation is not necessary. It would be appropriate to increase the number of grapevines with female flowers type in breeding studies.

Ecotype variation in the endemic tree Callicarpa subpubescens on small oceanic islands: genetic, phenotypic, and environmental insights.

Callicarpa subpubescens, endemic to the Ogasawara Islands, is suggested to have multiple ecotypes in the Hahajima Islands, specifically in the central part of the Ogasawara Islands. In this study, associations between genetic groups and spatial distribution, habitat, leaf morphology, size structure, and flowering time of each genetic group were investigated on Hahajima and the satellite Imoutojima Islands. Genetic groups were identified using EST-SSR markers, revealing four ecotypes named based on morphological features: Dwarf (D), Glabrescent (G), Tall (T), and Middle (M), with M being a result of the hybridization of G and T. Ecotype D, adapted to dry environments, is characterized by small tree size, dense thick leaves with abundant hairs, and is distributed in dry scrub. Ecotype G, adapted to understory of mesic forests, lacks leaf hairs. Ecotype T, adapted to the canopy of mesic forests, has hairy leaves and is tall in tree height. Ecotype M, adapted to the canopy of mesic scrub or edges of mesic forests, has hairy leaves but with a shorter tree height than ecotype T. Flowering peaks differed among all ecotype pairs except G and M, but the flowering times more or less overlapped among all ecotypes, suggesting that pre-mating isolation among ecotypes is not perfect. Post-mating isolation is considered absent, as there were no differences in the results, germination, and survival rates of one-year seedlings among inter- and intra-ecotype crossings. The existence of such ecotypes provides valuable insights into the ongoing speciation processes adapting to the oceanic island environments.

The Influence of Minimal Cultivation Techniques on Growth Rate of Robinia pseudacacia L. Seedlings

The seed provenance, the type of substrate and its properties, as well as the watering regime in the first years after sowing are among the most important characteristics affecting the production of containerized seedlings. The objective of this study was to analyse the growth of black locust (Robinia pseudacacia L.) seedlings on different types of substrate (six mineral and two organic) with different textures and pHs under three different regimes of available water content (no-limiting, medium drought, severe drought) over a period of five months (May–October 2023), using seeds from three sources located in the southeast, south, and west of Romania. The highest seedling emergence rate (73.7%) was obtained for the medium seeds with 18.492 g weight (1000 seed weighs) (Bucharest provenance). Direct sowing in the field and containerized seedlings both showed a trend of growing in height during unlimited water and of growing in diameter during low watering. The lowest survival rate of seedlings (86.7%) occurred in the mineral substrate in the case of rendzina with additional sand (pH 8.70), and for the organic substrate, the lowest survival rate (87.0%) occurred for the peat MKS 3 substrate (pH 4.54).

Comparison of Morphological, Physiological, and Related Gene Expression Responses to Drought Stress in Five Camellia vietnamensis Cultivars

The main production area of Camellia vietnamensis (C. vietnamensis) is in the low mountain and hilly areas of southern China. The low survival rate of seedlings caused by drought is one of the main obstacles restricting the development of the C. vietnamensis industry. An exploration of the key adaptation mechanism of C. vietnamensis to drought stress is important in order to improve its drought resistance. We conducted a study on the morphological, physiological, biochemical, and drought resistance-related genes of five C. vietnamensis cultivars grown in Hainan province under varying degrees of drought stress. The results indicate that drought stress can lead to a decrease in the relative water content and photosynthetic capacity of C. vietnamensis leaves. Compared with the control, the drought damage index, malondialdehyde, relative electrical conductivity, soluble protein, soluble sugar and proline contents of the five C. vietnamensis cultivars increased with drought-stress duration and degree. With increasing drought-stress intensity, the activity of antioxidant enzymes and the content of related metabolites (total polyphenols, total flavonoids, tea saponins) gradually increased, and the expression levels of phenylpropanoid pathway-related genes (Cv4CL1, CvCAD1, CvCAD2, CvPOX1, CvPOX2, CvPOX3) were upregulated. Based on the results of the drought tolerance coefficients, principal component analysis, and hierarchical cluster analysis, we classified five C. vietnamensis cultivars into drought-tolerant cultivars (‘Haida 1’); moderately drought-tolerant cultivars (‘Haida 4’ and ‘Wanhai 4’); and drought-sensitive cultivars (‘Wanhai 3’ and ‘Wanhai 1’). The results of this study provide a theoretical basis for the promotion and cultivation of C. vietnamensis and the selection of drought-resistant cultivars.

Monitoring dan Evaluasi Kegiatan Penanaman Mangrove (Kasus: Desa Sebuntal, Kabupaten Kutai Kartanegara)

Damage to mangrove ecosystems in coastal areas could result in biotic and abiotic physical changes. This damage might occur due to natural factors or human activities. Among the damaged mangrove ecosystems in East Kalimantan Province is Sebuntal Village. The aim of this research is to monitor and evaluate the survival rate of mangrove seedlings in Sebuntal village, Kutai Kartanegara Regency. The research population used in this research was all mangrove seedlings (Avicennia spp) planted during community service activities on August 9th, 2023. The research method used in this study was the survey method. It was found that the survival rate in this study was only 8.2%. This research showed that individual mangroves' survival rates were unsuccessful due to inappropriate planting times, hydro-oceanographic patterns that are poorly studied, and poor seed preparation.

Seed thermo-priming accelerates the growth of Ceiba glaziovii (Kutze) K.Schum. seedlings

Background: Global climate changes have caused temperature increases that can harm plant development, especially the initial growth and establishment of seedlings for the recovery of degraded areas. However, there are species in which these losses are attenuated when the seeds are thermo-primed to sublethal temperatures. Therefore, the objective of the present study was to evaluate the influence of seed heat conditioning on germination and initial growth of Ceiba glaziovii (Kuntze) K. Schum seedlings, an endemic species occurring in seasonally tropical dry forest in Brazil. Methods: Seeds of C. glaziovii were exposed to 70 oC for 15, 30, 45, 60 and 90 minutes as pre-germination treatments. The control did not undergo heat treatment. Germination variables, vegetative growth, survival rate and normal leaves were evaluated. Results: Thermo-priming negatively affected the germination proportion of C. glaziovii seeds with increasing exposure time. However, it significantly enhanced vegetative growth and seedling survival rate of this species after transplanting, without impairing the formation of normal leaves. Conclusions: Thermo-priming of seeds was found to produce more vigorous seedlings of Ceiba glaziovii.

Effects of pulsed Nd:YAG laser kernel irradiation on maize (Zea mays L.): Insights into germination, gas exchange, photosynthetic pigments, and morphological modifications

Energy has always been the most concerned topic worldwide due to its large consumption. Among various types of energies, light has amazing characteristics and have interesting effects on living organisms. Interest is increasing in the use of laser kernel treatment as an environment friendly physical technique for better results in agronomic crops, but the work is still in progress. The present study was conducted with the aim to examine the application of range of Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) pulsed laser exposures (200, 400, 600, 800, 1000, 1200, 1400 J/cm2) as pre-sowing kernel treatment on seedling survival rate, leaf photosynthetic activity in relation with photosynthetic pigments and visual morphological effects at seedling to maturity stage. Results showed that the low laser exposure (200, 400 and 600 J/cm2) improved the photosynthetic activity in parallel with improvement in chlorophyll a, chlorophyll b, total chlorophyll, carotenoids as well as morphological traits. Kernel treatments with higher laser fluences (800, 1000, 1200 and 1400 J/cm2) showed irregular responses in studied attributes examined at the individual plant level. At 800 and 1000 J/cm2 improvements were found in some plants but at higher doses clear negative impacts were recorded on studied attributes. In conclusion, the lower doses of Nd:YAG pulsed laser fluences are found beneficial for induction of improvement in maize plants for better growth but higher doses were found toxic ones. In future further studies are needed to check the impacts of low laser doses on yield related attributes under field conditions and the high doses might also be used to create variants with beneficial characteristics if possible.

The use of oil palm biomass as fertilizer and its potency in agroforestry systems for peatland rehabilitation

Oil palm biomass is one of the most abundant wastes in Indonesia. The biomass can be used as fertilizer for increasing plant growth, such as paddy Inpara-2 variety and peatland rehabilitation. The study on the application of oil palm biomass as fertilizer on paddy Inpara-2 growth and its potency in agroforestry systems for accelerating peatland rehabilitation is limited. This study aimed to analyze the application of oil palm-based fertilizers on paddy Inpara-2 and investigate the scientific literature on the use of oil palm biomass as fertilizer in agroforestry systems for peatland rehabilitation. The method used was a completely randomized design with a factor (oil palm-based fertilizer) and scientific literature from the search engine database. Application of micro-lignocellulose 1% resulted in the best paddy germination percentage (100%), abnormal sprout percentage (0%), maximum growth potential (100%), mean germination time (1.95 days), seedling survival rate (100%), and seedling height (13.67 cm). We found 993 articles on oil palm biomass as fertilizer in supporting peatland rehabilitation and only three articles (0.003%) used the agroforestry system as the selected approach. Application of oil palm biomass as fertilizers can accelerate paddy Inpara-2 variety growth, and agroforestry system application could accelerate peatland rehabilitation.

Seedling survival and plantation success in the drylands of Northern Ethiopia

We studied tree seedling survival rates and plantation success of the Growth and Transformation Plan I—GTP I (2011–2015) in the drylands of Northern Ethiopia. The study was carried out in six randomly selected districts of Tigrai region that represent three agro-ecological zones: the highland, midland and lowland. A biophysical survey was conducted to assess the survival rates of tree seedlings and the success rate of the plantation interventions. The study employed both primary and secondary data sources. Results revealed that there were variations (P < 0.05) in the survival of planted tree seedlings among plantation sites of the same village, between the villages of the same district and among the districts. The regional mean survival rate of planted tree seedlings was 53%. The planting interventions were not encouraging due to lack of pre- and post-planting management, moisture stress, poor soil and site conditions, planting an unmanageable number of seedlings, weak law enforcement and lack of proper monitoring and evaluation mechanisms. In the study areas, four types of ownership were identified: private, communal, state and youth groups. Among the ownership types, private ownership had the highest rate of success, whereas community ownership had the lowest rate. For sustaining successful plantation development, watering, pre- and post-planting management of planted tree seedlings and permanent employment of guards are important.

Biogas Slurry Significantly Improved Degraded Farmland Soil Quality and Promoted Capsicum spp. Production.

This study reports on the effects of pretreated biogas slurry on degraded farm soil properties, microflora and the production of Capsicum spp. The responses of soil properties, microorganisms and Capsicum spp. production to biogas slurry pretreated soil were determined. The biogas slurry pretreatment of degraded soil increases the total nitrogen (0.15-0.32 g/kg), total phosphorus (0.13-0.75 g/kg), available phosphorus (102.62-190.68 mg/kg), available potassium (78.94-140.31 mg/kg), organic carbon content (0.67-3.32 g/kg) and pH value of the soil, while the population, diversity and distribution of soil bacteria and fungi were significantly affected. Interestingly, soil ammonium nitrogen, soil pH and soil nitrate nitrogen were highly correlated with the population of bacteria and fungi present in the pretreated soil. The soil with biogas slurry pretreatment of 495 m3/hm2 favored the seedling survival rate, flowering rate and fruit-bearing rate of Capsicum spp. and significantly reduced the rate of rigid seedlings. In this study, the application of 495 m3/hm2 biogas slurry to pretreat degraded soil has achieved the multiple goals of biogas slurry valorization, soil biofertilization and preventing and controlling plant diseases caused by soil-borne pathogenic microorganisms. These findings are of significant importance for the safe and environmentally friendly application of biogas slurry for soil pretreatment.

Influence of dry form of bacteria strains of the genus &lt;i&gt;bacillus&lt;/i&gt; on garden strawberry in maternal plants

In 2019-2022 in field experiments, stimulation of the survival rate and growth of mother plants of strawberries under the influence of pre-planting treatment with Fitop 8.1 (dry form) and Fitop 8.67 (liquid form) in working concentrations of 1 × 105 CFU / ml was proved: an increase in the survival rate of seedlings by 12.3 % and 19.5 %; an increase in the number of leaves by 29 % and 21 %; an increase in the length of the roots in both variants by 12.9 %; an increase in total plant biomass to levels of 92.9 g/plant and 94.5 g/plant. The biological effectiveness against strawberry white spot in the variants with Fitop 8.1 and Fitop 8.67 treatment was 33.1 % and 29.3м %, which is explained by the immunising effect of treatments on plants. The best effects of stimulating vegetative propagation were also noted in variants where the biological preparations Fitop 8.67 (liquid form) at a concentration of 1×105 CFU/ml and Fitop 8.1 (dry form) at concentrations of 1×105 CFU/ml and 1×106 CFU/ml were used for pre-planting treatment – the increase in the number of rosettes, on average, over three years, amounted to 3.0-3.9 rosettes/plant (20.6-27.3 %) relative to the control, where 14.4 rosettes/plant were formed, in average over three years of observation. The effects obtained in the biological product variants were at a statistically identical confidence level with the reference variant with the Phoenix humic preparation, 0.05 %. As a result, the yield of seedlings from an area of 100 m2 of the mother plantations increased significantly in the variants with Fitop 8.67 and Fitop 8.1 by 32.6 % and 55.9 % at 4229.5 seedlings/100 m2 in the control variant. In contrast, the effectiveness of Fitop 8.1 for seedlings, superior to Fitop 8.67 (liquid form) and the reference version with Phoenix, 0.05 %, has been proven.

Biological Control Ability and Antifungal Activities of Bacillus velezensis Bv S3 against Fusarium oxysporum That Causes Rice Seedling Blight

Fusarium oxysporum, a primary soil-borne fungus that affects rice seedlings globally, is responsible for rice seedling blight (RSB), which reduces seedling quality and survival rates. The synthetic fungicides used to treat this disease negatively affect human health and the environment. A biocontrol bacterial isolate, Bacillus velezensis Bv S3, isolated from the rice rhizosphere, showed a strong antagonistic effect on RSB-causing F. oxysporum. The ratio of the longest to the shortest radius of F. oxysporum following Bv S3 inoculation was 2.52 (cm/cm) in a plate standoff experiment. This was different from the other biocontrol strains. Bv S3 exhibits a wide spectrum of antifungal activity against various pathogenic fungi that cause RSB. When 10% Bv S3 liquid culture filtrate was applied, it dramatically reduced F. oxysporum spore germination and mycelial growth, with inhibition rates of 66.7%, and 45.7%, respectively, and caused hyphal malformations. Furthermore, the Bv S3 suspension (1 × 108 CFU/mL) reduced RSB by 65.5% and 76.5% in pot experiments, effectively promoted the growth of rice seedlings, and improved the activities of neutral phosphatase, urease, invertase, and catalase in rice rhizosphere soil. The active substances produced by Bv S3 were sensitive to temperature and ultraviolet irradiation, and the antifungal effect significantly increased after 90 min of exposure, with antifungal effect observed at pH 7. Bv. S3 effectively reduced the incidence of RSB and showed potential as a biocontrol agent.

Which native legume or non-legume nitrogen-fixing tree is more efficient in restoring post-landslide forests along an environmental gradient?

Under climate change, heavy precipitation is predicted to trigger frequent shallow landslides. To accelerate vegetation recovery after landslides, planting nitrogen (N)-fixing trees is a promising technique. However, a comparison of the performance of non-legume and legume N-fixing species planted across a wide range of environments after landslides has not been conducted, which is problematic for determining the most efficient tree species for restoration. We planted the seedlings of a native legume (Lespedeza bicolor) and a native non-legume (Alnus hirsuta) tree species and monitored their survival in 15 landslide forests artificially established across a variety of environments in northern Japan. The landslides were mimicked by removing standing trees and surface soil with heavy machinery from the sites. There was a significant difference in the survival rate of seedlings between the two species. The survival rate was significantly higher for L. bicolor than for A. hirsuta. Furthermore, the performance of the two species differed along the environmental gradient of post-landslide forests. Interestingly, L. bicolor seedlings survived better in the steeper post-landslide forests, probably due to less exposure to ungulate herbivory. On the other hand, the warmer air temperature and serpentine soil negatively influenced the survival of A. hirsuta, which indicates different environmental preferences of N-fixing plants in post-landslide forests. Our results suggest that for efficient forest restoration after landslides, careful selection of N-fixing plants based on slope conditions is essential.

Evaluation of survival, growth, and phytoremediation potential of Populus and Salix seedlings grown in polluted soils

The aim of this thesis was to evaluate the survival, growth, and phytoremediation potential of Populus and Salix seedlings grown in polluted soils. More specifically, the following topics were studied: (1) the survival and growth of two European aspen clones and four hybrid aspen clones grown in control soil (pristine), old creosote soil polluted with hydrocarbons, and pristine soil spiked with fresh diesel oil at three different planting densities in a greenhouse over two growing seasons (Article I); (2) the survival, growth, and hydrocarbon removal of three European aspen clones and seven hybrid aspen clones grown in hydrocarbon-contaminated soil (including polycyclic aromatic hydrocarbons (PAHs) and total petroleum hydrocarbons (TPHs)) under field conditions over 4 years (Article II); and (3) the growth and metal accumulation ability of Salix psammophila seedlings with bamboo biochar (BBC) amendment at ratios of 0–7% in soils heavily contaminated by Cd and Zn in a pot experiment over 180 days (Article III). In study I (Article I), the survival rates of European aspen and hybrid aspen clone seedlings were 70–100% in control soil, 99% in the old creosote-contaminated soil, and 22–59% in the diesel-contaminated soil across all planting densities. The heights of aspen seedlings were 5–44% and 9–38% lower and the stem dry biomass was 9–93% and 34–63% lower in diesel-contaminated and creosote-contaminated soils, respectively, compared to the control. Low plant density increased survival rates and growth compared to higher density treatments. Of all the clones, hybrid aspen clones 14 and 291 and European aspen clone R3 showed reasonable survival and growth across all treatments. Soil treatment, planting density, and clone type significantly affected survival rate, height, and stem dry biomass (p &lt; 0.05). In study II (Article II), the highest survival rates in old creosote-contaminated soils were in clone 291 (72%) among hybrid aspen clones and clone R3 (70%) among European aspen clones. Hybrid aspen clones 14 and 34 had 16–211% greater heights than other hybrid aspen clones. The height of European aspen clone R3 was also 25‒35% greater than that of other European aspen clones. However, clone type did not significantly affect seedling survival or height (p &gt; 0.05). Among hybrid aspen clones, clone 134 had the largest hydrocarbon removal at a depth of 5–10 cm and clone 191 at a depth of 10–50 cm. Clone 14 also showed potential for removing hydrocarbons at both soil depths. In European aspen clones, clone R2 had the highest hydrocarbon removal at both soil depths. However, all clones showed an ability to remove total PAHs and TPHs from the soil (but p &lt; 0.05 only at a soil depth of 5–10 cm). The reduction in hydrocarbon levels in the soil was more prominent at a soil depth of 5–10 cm than at a depth of 10–50 cm. Based on studies I and II, European aspen and hybrid aspen clones can be considered candidates for the remediation of soils polluted with PAHs and TPHs. In study III (Article III), BBC ratios of 1% and 5% resulted in only slight decreases in characteristics, especially height (0.6‒1.3%) but also total dry biomass (2‒10%), of S. psammophila seedlings compared to the control, whereas BBC 3% increased these measurements slightly (2% increase). BBC 7% reduced the height (16%) and total dry biomass (26%) of seedlings compared to the control. BBC amendment increased the accumulation of Cu, Cd, and Zn in different plant tissues, especially Cd and Zn accumulation (23‒30% and 13‒24%, respectively), in the BBC 3% treatment compared to the control. Based on these findings, S. psammophila with BBC amendment can be considered a candidate for phytoremediation. However, metal accumulation in the roots, stems, and leaves was not significantly affected by the BBC 1‒7% treatments (p &gt; 0.05), except for Pb accumulation in the roots and Cu accumulation in the stem (p &lt; 0.05). Overall, hybrid aspen, European aspen, and S. psammophila seedlings showed reasonable survival and growth, photosynthetic activity, efficient hydrocarbon removal from soil and metal accumulation ability both under greenhouse conditions and in a field experiment. Therefore, these species could be used to depollute areas affected by a range of hydrocarbons or Cd and Zn. However, future research should be conducted in the field to verify the abilities of hybrid and European aspens and S. psammophila to remediate soil contaminated by hydrocarbons, Cd, or Zn, and such studies should also use different planting densities and soil amendments over longer periods.

Understory seedlings of Quercus mongolica survive by phenological escape

Understanding understory seedling regeneration mechanisms is important for the sustainable development of temperate primary forests in the context of increasingly intense climate warming events. The poor regeneration of dominant tree species, however, is one of the biggest challenges it faces at the moment. Especially, the regeneration of the shade-intolerant Quercus mongolica seedling is difficult in primary forests, which contrasts with the extreme abundance of understory seedlings in secondary forests. The mechanism behind the interesting phenomenon is still unknown. This study used in-situ monitoring and nursery-controlled experiment to investigate the survival rate, growth performance, as well as nonstructural carbohydrate (NSC) concentrations and pools of various organ tissues of seedlings for two consecutive years, further analyze the understory light availability and simulate the foliage carbon (C) gain in the secondary and primary forest. Results suggested that seedlings in the secondary forest had greater biomass allocation aboveground, height and specific leaf area (SLA) in summer, which allowed the seedling to survive longer in the canopy closure period. High light availability and positive C gain in early spring and late autumn are key factors affecting the growth and survival of understory seedlings in the secondary forest, whereas seedlings in the primary forest had annual negative carbon gain. Through the growing season, the total NSC concentrations of seedlings gradually decreased, whereas those of seedlings in the secondary forest increased significantly in autumn, and were mainly stored in roots for winter consumption and the following year's summer shade period, which was verified by the nursery-controlled experiment that simulated autumn enhanced light availability improved seedling survival rate and NSC pools. In conclusion, our results revealed the survival trade-off strategies of Quercus mongolica seedlings and highlighted the necessity of high light availability during the spring and autumn phenological periods for shade-intolerant tree seedling recruitment.

Разработка агротехнологии получения посадочного материала, устойчивого к фитофагам и фитопатогенам

Many seedlings die early during reforestation. Traditional bareroot technologies often fail in Western Siberia. As a result, containerized technologies have become relevant as they provide higher survival rate in the harsh climatic conditions.&#x0D; The study traced the development of Scots pine (Pinus sylvestris L.) seedlings grown in a container nursery in the Kemerovo Region. The milled high-moor peat had a degree of decomposition of ≤ 15%. The seeds were treated with fungicides before planting. The seedlings underwent a double treatment against phytophages and phytopathogens during growth.&#x0D; The article introduces a new agricultural technology for ball-rooted planting stock resistant to phytophages and phytopathogens. The study revealed the developmental stages of pine seedlings and the effect of pesticides on pathogen count. After phytosanitary monitoring and preventive treatments, the seedlings were tested for the effectiveness of pesticides, fungicides, and insecticides as part of pre-planting seed treatment. Such biochemical preparations as Fitoverm (0.4%), Decis Pro, Previkur Energy, and Fitosporin increased the survival rate of the test seedlings. The biological effectiveness of the experimental treatment was 49–53 and 44–50%.&#x0D; The technology was able to improve the survival rate of pine seedlings in forest container nurseries in the harsh climate of West Siberia.

Antifungal and Plant-Growth Promotion Effects of Bacillus velezensis When Applied to Coastal to Pine (Pinus thunbergii Parl.) Seedlings

Fungal diseases such as root rot and leaf blight cause substantial losses in coastal pine (Pinus thunbergii Parl.) seedling production, which hinders afforestation/forest restoration programs. We isolated and identified Fusarium oxysporum and Alternaria alternata as the causal agents of root rot and needle blight diseases and investigated the biocontrol efficacy against the fungal pathogens and growth promotion of coastal pine seedlings using Bacillus velezensis CE 100. The bacterium produced the hydrolytic enzymes chitinase, β-1,3-glucanase, and protease enzymes, and the crude enzyme fraction of the biocontrol strain caused the deformation of the fungal cell wall and antagonized F. oxysporum and A. alternata, causing respective inhibition of spore germination by 91.0% and 85.9% and mycelial growth by 58.3% and 54.3%, at a concentration of 1000 µL/mL. Consequently, the bacterial treatment improved the survival rate of seedlings 1.9 times relative to the control group. The bacterium secreted indole-acetic acid (IAA) phytohormone and enhanced root growth and absorption of nutrients, which notably enhanced the biomass production of coastal pine seedlings. Therefore, these results provide evidence that B. velezensis CE 100 is an effective antifungal and growth-promoting bacterium that can facilitate the production of high-quality coastal pine seedlings for the restoration and establishment of coastal forests.

Joint QTL Mapping and Transcriptome Sequencing Analysis Reveal Candidate Genes for Salinity Tolerance in Oryza sativa L. ssp. Japonica Seedlings.

Salinity stress is one of the major abiotic stresses affecting crop growth and production. Rice is an important food crop in the world, but also a salt-sensitive crop, and the rice seedling stage is the most sensitive to salt stress, which directly affects the final yield formation. In this study, two RIL populations derived from the crosses of CD (salt-sensitive)/WD (salt-tolerant) and KY131 (salt-sensitive)/XBJZ (salt-tolerant) were used as experimental materials, and the score of salinity toxicity (SST), the relative shoot length (RSL), the relative shoot fresh weight (RSFW), and the relative shoot dry weight (RSDW) were used for evaluating the degree of tolerance under salt stress in different lines. The genetic linkage map containing 978 and 527 bin markers were constructed in two RIL populations. A total of 14 QTLs were detected on chromosomes 1, 2, 3, 4, 7, 9, 10, 11, and 12. Among them, qSST12-1, qSST12-2, and qRSL12 were co-localized in a 140-kb overlap interval on chromosome 12, which containing 16 candidate genes. Furthermore, transcriptome sequencing and qRT-PCR were analyzed in CD and WD under normal and 120 mM NaCl stress. LOC_Os12g29330, LOC_Os12g29350, LOC_Os12g29390, and LOC_Os12g29400 were significantly induced by salt stress in both CD and WD. Sequence analysis showed that LOC_Os12g29400 in the salt-sensitive parents CD and KY131 was consistent with the reference sequence (Nipponbare), whereas the salt-tolerant parents WD and XBJZ differed significantly from the reference sequence both in the promoter and exon regions. The salt-tolerant phenotype was identified by using two T3 homozygous mutant plants of LOC_Os12g29400; the results showed that the score of salinity toxicity (SST) of the mutant plants (CR-3 and CR-5) was significantly lower than that of the wild type, and the seedling survival rate (SSR) was significantly higher than that of the wild type, which indicated that LOC_Os12g29400 could negatively regulate the salinity tolerance of rice at the seedling stage. The results lay a foundation for the analysis of the molecular mechanism of rice salinity tolerance and the cultivation of new rice varieties.

Sensitivity of genotypically diverse rice varieties to radiation and the related changes to antioxidant enzyme activities

PurposeRadiation mutagenesis, which typically involves gamma rays, is important for generating new rice germplasm resources. Determining the appropriate radiation dose range is critical for the success of radiation mutagenesis. Clarifying the sensitivity and tolerance of genotypically diverse rice varieties to gamma irradiation as well as the radiation-induced changes to reactive oxygen species (ROS) generation and antioxidant enzyme activities is crucial for increasing the utility of radiation mutagenesis in rice breeding programs.Materials and methodsThe seeds of the following four rice varieties with different genotypes were used as test materials: indica Zhe 1613, glutinous indica Zhe 1708, japonica Zhejing 100, and glutinous japonica Zhenuo 65. Additionally,60Co was used as the source of gamma rays. The rice seeds were irradiated with 14 doses (0, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, and 750 Gy). Non-irradiated seeds were used as the control. The seedling survival rate for each variety was recorded at 3, 7, 14, and 28 days after sowing. Moreover, the median lethal dose (LD50) and critical dose (LD40) were calculated according to the seedling survival rates at 28 days after sowing. The seedling superoxide anion (O2•−), hydrogen peroxide (H2O2), and malondialdehyde (MDA) contents and the superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) activities were analyzed at 7 days after sowing.ResultsAs the radiation dose increased, the seedling survival rate decreased. The seedling survival rate also decreased significantly as the number of days after sowing increased. Among the rice genotypes, the rank-order of the radiation tolerance was as follows: indica Zhe 1613 > glutinous indica Zhe 1708 > japonica Zhejing 100 > glutinous japonica Zhenuo 65. The LD50 values were 426.7 Gy for Zhe 1613, 329.2 Gy for Zhe 1708, 318.3 Gy for Zhejing 100, and 316.6 Gy for Zhenuo 65. Increases in the radiation dose resulted in significant increases in the seedling O2•− and H2O2 contents, but only up to a certain point. Further increases in the radiation dose caused the seedling O2•− and H2O2 contents to decrease. The H2O2 content for each variety peaked when the radiation dose was very close to the LD50. We propose that the radiation dose associated with the highest H2O2 content (±50 Gy) should be used as the recommended dose for the gamma irradiation of rice. The radiation dose that resulted in peak seedling O2•− contents in the analyzed rice varieties was very close to the LD40. In all rice varieties, the MDA content increased as the radiation dose increased. The SOD, CAT, POD, and APX activities increased as the radiation dose increased within a certain range (less than 600 Gy for Zhe 1613 and 400 Gy for the other varieties), but there were slight differences among the rice varieties.ConclusionsGenotypically diverse rice varieties vary regarding their sensitivity to gamma irradiation. Our findings suggest that ROS generation and antioxidant enzyme activities are important factors associated with the radiation mutagenesis of rice. The close relationship between the activities of key antioxidant enzymes, such as SOD, POD, APX, and CAT, and the LD50 and LD40 may be exploited to enhance radiation mutagenesis through the use of plant growth regulators.