Seedling Root Length Research Articles

Regulation of nanofungicide based on ZIF-8 on the growth and metabolism of rice seedlings

Nanopesticides have received increasing attention in modern agricultural production. Before large-scale application, it is necessary to evaluate the environmental risks and safety of nanopesticides. Different pesticides are encapsulated into different nanomaterials, which have varying effects on the growth and metabolism of different non-target crops. In this work, a novel acid-responsive nanoparticles (Nps) coating the fungicide boscalid (Bos) based on the metal-organic framework material zeolitic imidazolate framework-8 (ZIF-8) was constructed (Bos@ZIF-8). Nps had good slow-release performance and fungicidal activity against Rhizoctonia solani (R. solani). The growth and metabolic regulation of rice seedlings after treatment with Bos@ZIF-8 Nps were investigated. The height and the root length of rice seedlings were measured. Metabolites, including saccharides, amino acids, organic acids, flavonoids, and various functional enzymes, were analyzed. Bos@ZIF-8 Nps, especially at low and medium concentrations, exhibited a positive trend in regulating crop growth and metabolism, and offset the partial negative effects of Bos due to the introduction of zinc ions. This work provides a reference for the large-scale application of nanopesticides in agricultural production.

Plant growth promoting rhizobacteria incorporated soilless substrates – A potential arena for high quality nursery production of ornamentals

Nursery raising of ornamental flowering annuals using soilless substrates is becoming a lucrative industry worldwide. Pakistan, being an agricultural country, still doesn't have its own cheaper and sustainable soilless substrates for high quality nursery production. Therefore, a study was conducted at University of Agriculture, Faisalabad, Pakistan and Purdue University, West Lafayette, IN, USA, for development and evaluation of a cheaper, sustainable, and easily available soilless substrate using agricultural by-products along with its value addition by inoculating it with plant growth promoting rhizobacteria. For this purpose, coco-coir, rice hulls ash and composted sugarcane pressmud were combined in ratio of 1:1:1; v/v/v and were inoculated with Bacillus (MN-54), Enterobacter (MN-17) and Trichoderma species in 108 CFU mL−1 and 107 CFU mL−1 solutions. These inoculated treatments along with uninoculated treatment, a negative control (sand: silt; 1:1, v/v) were evaluated for their physico-chemical and nursery raising aspects for ‘Inca’ marigold and ‘Giant Dahlia Flowered’ zinnia. The study revealed that Enterobacter MN-17 (107 CFU mL−1) inoculated substrate had highest water holding capacity (72.9 %), total porosity (81.04 %) and organic matter contents (92.9 %). Whereas, Trichoderma spp. (108 CFU mL−1) inoculated substrate had better electrical conductivity (1.59 dS m−1) and pH (5.64) and resulted in highest final germination percentage (93.6 %), with greatest seedling vigor index (2195), seedling shoot length (10.2 cm), root length (12.5 cm) and leaf total chlorophyll contents (57.4 SPAD) in marigold. However, in zinnia, Enterobacter MN-17 (107 CFU mL−1) inoculated substrate resulted in highest germination percentage (98.3 %), greatest seedling vigor index (3302), seedling root length (15.8 cm) and leaf total chlorophyll contents (55.8 SPAD), whereas same strain with 108 CFU mL−1 took shortest time for mean germination (3.8 days). In conclusion, substrate enriched with Enterobacter MN-17 (107 CFU mL−1) or Trichoderma spp. (108 CFU mL−1) may be used to produce high quality ornamental flowering annuals nursery.

Seed priming of stored seeds on seed germination, vegetative performance, flowering, and proline content in chili under water stress condition

Chili seeds mostly have been stored for a long period; therefore, the seed quality may be affected. Prior to planting, reinvigoration by priming treatments becomes an important treatment. The purpose of this study was to evaluate how priming affected seed germination, vegetative performance, flowering, and proline content in chili cv. "Inata Agrihorti" under water stress treatment. The research was carried out in the Physiology Laboratory and Shade House in Batu East Java, Indonesia from December 2022 to March 2023, A factorial Randomized Block Design with three replications was set up in this study that consisted of two factors. First factor was stored seeds (2 and 5 years) duration of chili cv. Inata Agrihorti, and the second factor was priming treatments (Phenol Ethyl Glycol 6000, Gibberellic acids, Phenol Ethyl Glycol 6000 + Gibberellic acids, and distilled water as a control). The reinvigoration of stored seeds by priming treatments significantly improved germination percentage, germination time, root length, and proline content of early seedlings’ stages either under water stress or distilled water treatment as a control. The interaction of priming treatment and stored seeds was also recorded in improving the vegetative performance, flower number, and proline content of chili plants derived from reinvigorated seeds under water stress or normal watering treatment. Under water stress and/or normal conditions, primed seeds of 2-year-old stored seeds produced larger values of these variables than primed seeds of 5-year-old stored seeds. To improve yield, seed invigoration of stored seeds of chili cv Inata Agrihort through - 1.5 MPa Phenol Ethyl Glycol 6000 treatment was recommended.

Effect of Iron (Fe) heavy metal content at different pH on the germination of seven soybean varieties in Indonesia

Greater use of acid soil has expanded the area under cultivation for soybeans; however, acid soil is associated with heavy mineral toxicity, including Iron (Fe). This investigation looked at how well soybean seeds germinated in media containing heavy metal Fe and how the pH of the media affected the viability of soybean seeds. This research was conducted at the Seed and Plant Breeding Laboratory at the University of Lampung, Indonesia. The experimental design was a randomized block design. The first factor was seven soybean local varieties – Grobogan, Anjasmoro, Derap 1, Detap 1, Dena 1, Deja 1, and Dega 1 – and the second factor was heavy metal Fe solution pH of 6–7 and 4.5 and without heavy metal Fe (control). Seed viability in heavy metal Fe medium was assessed using radicle emergence, germination capacity or percentage, germination speed, number of normal seedlings, normal seedling hypocotyl length, main root length of regular seedlings, and normal shoot dry weight. This research found that heavy metal Fe affected soybeans’ seeds’ viability in pH 6–7 and 4.5. The observed data showed that all seeds’ viability variables in media with heavy metal Fe, both in pH 6–7 and in pH 4.5, differ from the control media. The seed viability in media heavy metal Fe pH 6–7 was not significantly different from the control media, but in pH 4.5, the difference is significant. Soybean varieties’ characteristics also influence how heavy metal Fe in different pH affects seed viability. Overall, Anjasmoro, Deja, Grobogan, and Dega were the types that consistently demonstrated resistance or adaptation to heavy metal Fe existence, while Dena, Derap, and Detap are susceptible to heavy metal Fe existence. Seed viability in Iron medium is not always related to seed physical performance; therefore, before planting soybean in acid soil, it is recommended to conduct a seed viability test.

Titanium dioksit nano partiküllerinin ayçiçeği fide çıkışı üzerine olumlu etkileri

Seed germination and seedling emergence is the main step of cultivation and improving them could yield high performance in the field. Improved seedling emergence means less sensitivity to biotic and abiotic stress factors. It is possible to enhance seedling emergence via different technologies. Nanoparticles are one of the improving technology and their impact on crop cultivation are improving day by day. The seeds of hybrid-snack type cultivar Ahmetbey and for seed treatment agent TiO₂ nanoparticles were used in this experiment. This study was conducted to observe the impact of seed treatment with different titanium dioxide (TiO₂) nanoparticles (NPs) concentrations (6, 12, and 24 mg Lˉ¹) with dimensions of 20-50 nm during 8 hours on the emergence and seedling growth performance of snack-type sunflower cultivar Ahmetbey. Four replicates of 50 seeds in each treatment were sown in plastic trays 4 cm deep and placed in a growth chamber at 20 ± 2 °C 45 μM photons m-² s-¹ light for 16 h. Mean emergence time (MET), emergence percentage, seedling vigor, root-to-shoot length ratio, shoot length, and root length seedling fresh and dry weight were measured. Emergence percentage, shoot length, root length, and fresh and dry weight of seedlings increased with TiO₂ NPs treatments. The results revealed that 8-hour priming with water has a low impact on seeds of cv. Ahmetbey compared to any treatment of TiO₂ NPs. In conclusion, it is proved that the improving effects of 8 hour priming of sunflower seeds with TiO₂ NPs solutions on sunflower seedling emergence.

Regulatory effects of Hemin on prevention and rescue of salt stress in rapeseed (Brassica napus L.) seedlings

BackgroundSalt stress severely restricts rapeseed growth and productivity. Hemin can effectively alleviate salt stress in plants. However, the regulatory effect of Hemin on rapeseed in salt stress is unclear. Here, we analyzed the response and remediation mechanism of Hemin application to rapeseed before and after 0.6% (m salt: m soil) NaCl stress. Experiment using two Brassica napus (AACC, 2n = 38) rapeseed varieties Huayouza 158R (moderately salt-tolerant) and Huayouza 62 (strongly salt-tolerant). To explore the best optional ways to improve salt stress resistance in rapeseed.ResultsOur findings revealed that exogenous application of Hemin enhanced morph-physiological traits of rapeseed and significantly attenuate the inhibition of NaCl stress. Compared to Hemin (SH) treatment, Hemin (HS) significantly improved seedlings root length, seedlings height, stem diameter and accumulated more dry matter biomass under NaCl stress. Moreover, Hemin (HS) significantly improved photosynthetic efficiency, activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and decreased electrolyte leakage (EL) and malondialdehyde (MDA) content, thus resulting in the alleviation of oxidative membrane damage. Hemin (HS) showed better performance than Hemin (SH) under NaCl stress.ConclusionHemin could effectively mitigate the adverse impacts of salt stress by regulating the morph-physiological, photosynthetic and antioxidants traits of rapeseed. This study may provide a basis for Hemin to regulate cultivated rapeseed salt tolerance and explore a better way to alleviate salt stress.

Respons Pertumbuhan Bibit Budset Tebu (Saccharum officinarum L.) Varietas VMC 86-550 pada Beberapa Konsentrasi dan Frekuensi Aplikasi Pupuk Organik Cair (POC) Urine Sapi

Sugarcane (Saccharum officinarum L.) is an important plantation commodity as the main raw material for producing sugar consumed in Indonesia. One of the varieties cultivated is VMC 86-550, but one of the technical obstacles to its cultivation is the slow and non-uniform growth of the seeds. Therefore, one effort to maximize the growth of budset seed varieties requires proper nutrition and contains growth-promoting hormones. Therefore, this study aims to determine the response of giving liquid organic fertilizer (LOF) from cow urine to the growth of VMC 86-550 sugarcane seedlings using the budset method. To find out the purpose, this study used a factorial randomized block design with a concentration factor of LOF of cow urine consisting of five levels (0%, 10%, 15%, 20%, and 25%). The second factor is the application frequency which consists of once every 2 weeks and once every 4 weeks, so there were 10 treatments and repeated three times. This study used a completely randomized factorial design and was analyzed using ANOVA if there was a significant influence followed by Duncan Multiple Range Test (DMRT) at a 5% level using SPSS 20 software. Observation variables included plant height, stem diameter, number of leaves, number of tillers, and root length of sugarcane seedlings up to 90 HST. The results showed that the addition of cow urine LOF had an effect on the growth of sugarcane seedlings, both from the concentration and frequency of application, but the combination of the two did not have a significant effect on all observation variables.

2-hydroxymelatonin (2-OHM), a major melatonin metabolite, confers multiple stress tolerance in pepper at seed germination stage

Besides affecting or regulating several crucial processes in plants’ growth and development, melatonin is also highly effective at reducing the oxidative damage induced by various abiotic stressors and therefore it is regarded as a new master plant hormone. The interaction of melatonin with several oxygenated compounds results in the formation of various metabolites that also exhibit melatonin-like functions. Although 2-hydroxymelatonin (2-OHM) is one of the principal melatonin metabolites found in plants, its possible roles in plant life are yet to be fully revealed. This study investigated the impact of 2-OHM treatment on pepper seed germination and seedling growth under various abiotic stress conditions. Pepper seeds treated with 50 µM 2-OHM were subjected to germination and emergence tests under chilling, salt, and water stress conditions. The results demonstrated that 2-OHM treatment significantly enhanced seed germination and seedling emergence performance compared to untreated seeds under stress conditions. The 2-OHM-treatemant resulted in higher final seed germination (FGP) and seedling emergence percentage (FEP) and root length under chilling and water stress conditions. Exogenously applied 2-OHM also significantly shortened the seed germination and emergence periods under chilling conditions as indicated by higher mean germination (MGT) and emergence rates (MET). Additionally, the 2-OHM treatment improved root length, FEP and MET under salt stress. In general, the 2-OHM treatment effectively reduced malondialdehyde (MDA) and hydrogen peroxide (H2O2) levels while increasing proline content and amplifying the activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) under all stress conditions. In conclusion, the 2-OHM treatment significantly improved seed germination and seedling performance and enhanced stress resilience in pepper at germination stage. This study highlights the potential of 2-OHM as an effective natural compound to enhance crop productivity and alleviate the adverse effects of abiotic stressors in agricultural practices. Future experiments will also assist in elucidation of 2-OHM intervened stress mitigation procedure in pepper.

Physiological quality of ‘BRS’ passion fruit seeds grown at different altitudes and storage environments

The aim of this work was to study the physiological quality of ‘BRS’ passion fruit seeds grown at different altitudes stored in cold chamber and in natural environment for six months. Hybrid passion fruit seeds (BRS Gigante Amarelo, BRS Sol do Cerrado and BRS Rubi do Cerrado) grown at three altitudes (104; 711; 1016 meters) in the southern region of the state of Espírito Santo were used. Germination was carried out in germitest paper rolls, placed in BOD-type germination chambers at temperature of 20-30 ºC. The following parameters were analyzed: germination, germination speed index, shoot and root length and dry mass of seedlings. The experimental design used was completely randomized in a factorial scheme with split plot in time 4x(3x3) (four bimonthly analyses x three hybrids x three altitudes), with two independent storage environments and three replicates of 100 seeds. Hybrid Passiflora edulis f. flavicarpa seeds can be stored in natural environment or cold chamber. Hybrid yellow passion fruit seeds grown at altitudes of 104 and 711 meters show higher germination and vigor percentages. Hybrid ‘Gigante Amarelo’ seeds had lower averages for variables under study, regardless of altitude. Hybrid ‘Rubi do Cerrado’ seeds grown at altitude of 1016 meters and hybrid ‘Sol do Cerrado’ seeds grown at altitudes of 104 and 711 meters have higher germination and vigor percentages and can be stored for 180 days in natural environment or cold chamber without viability loss. Flavicarpa can be stored in natural environment or cold chamber. Hybrid yellow passion fruit seeds grown at altitudes of 104 and 711 meters show higher germination and vigor percentages. Hybrid ‘Gigante Amarelo’ seeds had lower averages for variables under study, regardless of altitude. Hybrid ‘Rubi do Cerrado’ seeds grown at altitude of 1016 meters and hybrid ‘Sol do Cerrado’ seeds grown at altitudes of 104 and 711 meters have higher germination and vigor percentages and can be stored for 180 days in natural environment or cold chamber without viability loss. Passiflora edulis f. flavicarpa can be stored in natural environment or cold chamber. Hybrid yellow passion fruit seeds grown at altitudes of 104 and 711 meters show higher germination and vigor percentages. Hybrid ‘Gigante Amarelo’ seeds had lower averages for variables under study, regardless of altitude. Hybrid ‘Rubi do Cerrado’ seeds grown at altitude of 1016 meters and hybrid ‘Sol do Cerrado’ seeds grown at altitudes of 104 and 711 meters have higher germination and vigor percentages and can be stored for 180 days in natural environment or cold chamber without viability loss. Hybrid ‘Gigante Amarelo’ seeds had lower averages for variables under study, regardless of altitude. Hybrid ‘Rubi do Cerrado’ seeds grown at altitude of 1016 meters and hybrid ‘Sol do Cerrado’ seeds grown at altitudes of 104 and 711 meters have higher germination and vigor percentages and can be stored for 180 days in natural environment or cold chamber without viability loss. Hybrid ‘Gigante Amarelo’ seeds had lower averages for variables under study, regardless of altitude. Hybrid ‘Rubi do Cerrado’ seeds grown at altitude of 1016 meters and hybrid ‘Sol do Cerrado’ seeds grown at altitudes of 104 and 711 meters have higher germination and vigor percentages and can be stored for 180 days in natural environment or cold chamber without viability loss.

Characterization of seed micro-morphometry and optimization of germination assay conditions of Bergenia ciliata - a highly valued medicinal plant

Bergenia ciliata, a valuable medicinal perennial herb, belongs to the family Saxifragaceae. It bears very minute seeds which exhibit poor viability, germination potential and storability. Thus, the present study aimed to analyze the seed characters and germination biology of this medicinal herb. The study revealed that seeds were irregular shaped and dark brown coloured with average length ∼0.93 mm and width ∼0.31 mm. Test weight of seeds ranged between 42.6 and 56.4 mg, and moisture content varied from 7.05 to 10.46%. To standardize the conditions required for germination, the experiment was conducted under different regimes of temperature either in the light or in the dark. Results revealed that mean germination time was shortest and germination percentage highest (94%) when seeds were incubated at 20 °C with light. Seed imbibition pattern was studied at 24 h intervals starting from day zero, and it was found that changes in seed dimensions were small during the first 24 h but were greatest between 24 and 48 h. The experiment also revealed that average length of 8-day old seedling was 4.71 mm whereas it was 5.92 mm with better proportion of root length in 10-day old seedlings.

Strontium alleviated the growth inhibition and toxicity caused by cadmium in rice seedlings

Cadmium (Cd) contamination of rice is an urgent ecological and agricultural problem. Strontium (Sr) has been shown to promote plant growth. However, the effect of Sr on rice seedlings under Cd stress is currently unclear. In this work hydroponic experiments were used to assess the impact of Sr on rice seedling growth under Cd stress. The findings demonstrated that foliar application of 0.5 mg L−1 Sr had no discernible impact on the development of rice seedlings. However, Sr significantly alleviated growth inhibition and toxicity in rice seedlings when threatened by Cd. Compared with the Cd treatment (Cd, 2.5 mg L−1), the root length, shoot height, and whole plant length of rice seedlings in the Cd + Sr treatment (Cd, 2.5 mg L−1; Sr, 0.5 mg L−1) increased by 4.96 %, 12.47 % and 9.60 %, respectively. The content of Cd in rice decreased by 23.34 % (roots) and 5.79 % (shoots). Sr lessened the degree of membrane lipid peroxidation damage (lower MDA concentration) among the seedlings of rice under Cd stress by controlling the activities of antioxidant enzymes and GSH content. By changing the expression of antioxidant enzyme-encoding genes and downregulating the heavy metal transporter gene (OsNramp5), Sr reduced accumulation and the detrimental effects of Cd on rice seedlings. Our study provides a new solution to the problem of Cd contamination in rice, which may promote the safe production of rice and benefit human health.

The Physiological Mechanism of Melatonin Enhancing the Tolerance of Oat Seedlings under Saline–Alkali Stress

Exogenous melatonin (MT) regulates plant growth and mitigates stress in response to stress. To analyze the machinery of exogenous melatonin, which improves salt and alkaline tolerance in oats, MT’s function was identified in the oat seed germination stage in our previous study. In this study, morphogenesis, photosynthetic physiology, hormone levels, and ion homeostasis were evaluated using the same MT treatment concentration. The results revealed that compared to the S45 treatment, the 100 μmol·L−1 MT treatment efficiently increased the seedling height and main root length of oat seedlings; promoted secondary root development; enhanced the root volume and root surface area; maintained a higher photosynthetic pigment content (carotenoids; chlorophyll a; chlorophyll b); raised the leaf photosynthetic rate (Pn), intercellular CO2 concentration (Ci), conductance to H2O (Gs), and transpiration rate (Tr); enhanced the light energy absorption and conversion of leaves; increased the leaf GA3, Tryptamine (TAM), and IAA contents; and decreased ABA levels. Hierarchical cluster analysis revealed that MT treatment also increased the contents of P, K, Ca, Mn, Cu, Mg, Fe, Zn, Mo, Cd, Al, Se, Ni, Co, and Ti; decreased the Na/K ratio; and maintained cellular ionic homeostasis in oat seedlings under saline–alkali stress, as compared with the untreated group. These findings showed that MT treatment enhanced the adaptation of oat to saline–alkali stress through regulating the physiological process of seedling growth. This suggests that MT plays a different role in improving saline–alkali tolerance in the germination and seedling stages of oat.

Active permanent greening - a new slope greening technology based on mineral solubilizing microorganisms.

With social and economic development and the associated large-scale exploitation of natural resources, the number of slopes has significantly increased. As slope instability can lead to serious geological disasters, the ecological protection and reconstruction of slopes has become a hot topic of common global concern. In order to achieve scientific slope management and overcome the difficulty of maintaining slope greening in the long term, this study explored eight strategies (A, B, C, AB, AC, BC, ABC, CK), involving different patented mineral solubilizing microorganisms (MSMs), and analyzed the field application of active permanent greening (APG) based on MSMs. The results revealed that MSMs significantly increased the content of effective metal ions and available nutrients in soil and enhanced soil enzyme activity. Among all strategies, strategy A showed significant superiority, with soil effective calcium, magnesium, potassium, nitrogen, phosphorus and organic matter contents increasing by 51.62%, 55.41%, 30.42%, 39.77%, 181.69% and 76.92%, respectively, while urease, sucrase and peroxidase activities increased by 89.59%, 74.68% and 85.30%. MSMs strongly promoted the growth of Amorpha. Strategy A showed the best performance, with plant seedling height, ground diameter, leaf area, root length, and root volume increasing by 95.75%, 47.78%, 124.14%, 108.83%, and 139. 86%, respectively. According to a comprehensive evaluation using the entropy-analysis hierarchy process, strategy A has great potential for application. The field test results verified that APG has significantly better greening performance than the traditional greening method, with high vegetation cover and stable soil layer. The results of this study provide a reliable practical basis and technical reference for the development, promotion, and application of APG.

Evaluation of Morphological Characteristics, Yield Potential, and Essential Oil Composition of Ocimum sanctum Genotypes for Crop Improvement

Ocimum sanctum, also known as Holy Basil, is an aromatic herb with a long history of use in traditional medicine. It is native to tropical and subtropical regions of Asia and is now cultivated worldwide. Plants have erect, much-branched sub-shrub with simple opposite green or purple leaves that are strongly scented and hairy stems and leaves has a strong, characteristic aroma that occurs mainly because of the volatile oils present.
 In this experiment, 30 genotypes of Ocimum sanctum were evaluated for morphological, yield and quality traits. At nursery stage, germination percentage, seedling shoot length and seedling root lengths were recorded. Among the accessions. OS-22 exhibited the highest germination percentages (82%), Seedling shoot and root length were highest in Os-18 and OS 21 (35 cm and 11 cm) respectively. In the main field, the accessions were characterized for qualitative traits viz growth habit, leaf colour and stem colour. The accessions were grouped into two, based on growth habit. Based on stem and leaf colour the accessions were grouped into five and four groups respectively. In case of quantitative traits, plant height achieved maximum in the accession OS 22 (88cm) followed by OS 17(75cm). The accessions OS-15 and OS-22 exhibited more extensive plants spread, while OS-21 and OS-13 had higher number of primary branches. Accessions OS-20 and O S-23 recorded more number of leaves (409 and 422) and the accessions O S-22 and OS-11 recorded highest fresh leaf weight (370.2 g & 301.67 g). The essential oil recovery and oil yield was highest in the accession OS 20 (green type) followed by OS 22 (purple type). Characterization of oil in GCMS revealed that the key component was eugenol, which showed highest content in accession Os-20 (46 %). This study can be used for further crop improvement studies and breeding programs.

Application of Endophytic Trichoderma harzianum to Alleviate the Adverse Impact of Chromium in Lupinus albus L

The present study was conducted to understand the role of interactive usage of Trichoderma harzianum to alleviate the adverse impact of chromium (Cr) stress for sustainable production of the legume plants (Lupinus albus L.) with special reference to physiological mechanism. The exogenous application of T. harzianum significantly enhanced seed germination and plant growth, along with all physiological and biochemical attributes examined in lupin plant. The germination percentage of lupin seeds treated with conidia suspension of T. harzianum was 100% with 37% increase as compared to the control. T. harzianum inoculation increased seedling height (41.3%) and root length (75.6%). Treatment of T. harzianum also resulted in significant enhancement in the photosynthetic attributes like chlorophyll pigment synthesis (13.75% increase as compares to the control), reflecting a significant enhancement in the net photosynthetic rate. Results of our study demonstrated that L. albus have improved tolerance to inhibitory concentrations of Cr when inoculated with T. harzianum. So, we suggest the application of T. harzianum, which could be used to improve the quality and yield of lupin (L. albus) plants in Cr-contaminated areas and in fertile soils.

Phosphorus Addition Reduces Seedling Growth and Survival for the Arbuscular Mycorrhizal Tree Cinnamomum camphora (Lauraceae) and Ectomycorrhizal Tree Castanopsis sclerophylla (Fagaceae) in Fragmented Forests in Eastern China.

Global changes in nutrient deposition rates and habitat fragmentation are likely to have profound effects on plant communities, particularly in the nutrient-limited systems of the tropics and subtropics. However, it remains unclear how increased phosphorus (P) supply affects seedling growth in P-deficient subtropical fragmented forests. To explore this, we applied P to 11 islands in a subtropical Chinese archipelago and examined the results in combination with a contemporary greenhouse experiment to test the influence of P addition on seedling growth and survival. We measured the growth (i.e., base area) and mortality rate of seedlings for one arbuscular mycorrhizal (AM) and one ectomycorrhizal (EcM) tree species separately and calculated their relative growth rate and mortality when compared with P addition and control treatment on each island. We also measured three functional traits and the biomass of seedlings in the greenhouse experiment. Results showed that P addition significantly increased the mortality of AM and EcM seedlings and reduced the growth rate of EcM seedlings. The relative growth rate of AM seedlings, but not EcM seedlings, significantly decreased as the island area decreased, suggesting that P addition could promote the relative growth rate of AM seedlings on larger islands. The greenhouse experiment showed that P addition could reduce the specific root length of AM and EcM seedlings and reduce the aboveground and total biomass of seedlings, indicating that P addition may affect the resource acquisition of seedlings, thereby affecting their survival and growth. Our study reveals the synergistic influence of habitat fragmentation and P deposition, which may affect the regeneration of forest communities and biodiversity maintenance in fragmented habitats.

SALINITY STRESS AS AN ABIOTIC FACTOR AT GERMINATION STAGE ON DRY BEAN (Phaseolus vulgaris L.) CULTIVARS

The study focused on germination parameters as the most critical stage of plant development in dry bean cultivars under different salt treatment. For two used cultivars (Akman-98, Karaman-2016) the data on germination percentage, mean germination time, seedling shoot length, seedling root length, seedling length and seedling vigor indexes were reached under the different salinity levels of irrigation water (0 mM, 25 mM, 50 mM, 100 mM, 150 mM, and 200 mM of NaCl) in Petri plates. The data indicates that these parameters could be used as screening the dry bean cultivars against salt stress levels. This study was carried out in a Completely Randomized Design (CRD) with a total of 12 treatments (6 salinity x 2 cultivars) for the germination and seedling data each comprising of three replicates. The results demonstrated that; i) From the overall observation of the germination characters, at 100 mM and over salt treatments showed decreasing in the germination percentage, the seedling length and the seedling vigor index in the mean of the cultivars, ii) Significantly decreasing in the seedling shoot length were observed in the mean of the cultivars at just after 25 mM and gradually at all salt concentrations, iii) Although the root length showed increasing in 25 and 50 mM treatments than the control plants, a sudden decrease occurred after 100 mM salt treatment in the mean of the cultivars and in each cultivars separately, iv) The mean germination time were sharply in increasing starting with 25 mM treatment in the mean of the cultivars, v) Except the seedling shoot length, in the mean of all the salt treatments between the cultivars did not show statistically differences in the calculated parameters, vi) Any correlation was found between the salt concentrations and the cultivars.

Reinvigoration of corn seeds (common, popcorn, sweet and super sweet) by hydroconditioning

Hydroconditioning has been tested in some crops as an attempt to improve seed performance in the field. Minimum germination standards for corn (Zea mays L.) seeds in Brazil varies from 85% for common, 70% for popcorn and sweet and 60% for super sweet one, due to genotypic effect on physiological seed quality. This study aimed to evaluate the effects of periods of hydroconditioning (0, 30, 60, 90 and 120 minutes) and gas insufflation techniques (atmospheric air, concentrated oxygen and none) on seed germination and vigor of corn seeds of different physiological qualities (high and low) and types (common, popcorn, sweet and super sweet). The experiment was carried out in a 5x3x2 factorial design for each corn type, with four replicates. The evaluated parameters comprised water content, germination and electrical conductivity of seeds; main root and seedling length and dry mass of seedlings. Positive effects of the hydroconditioning were observed on seed reinvigoration of corn of all qualities and types and the best results were achieved with hydroconditioning with air or oxygen insufflation, during 60 to 90 minutes, which is therefore recommended to reinvigorate seeds of common, popcorn, sweet and super sweet corn.

Growth Promoting Potential of Phosphate Solubilizing Enterobacter Cloaca and Enterobacter Hormaechei on Maize and Cowpea Seedlings

Introduction: Phosphorus plays a range of functions in the proper growth and development of plants. Numerous microbial species, including bacteria, fungi, actinomycetes, and even algae have been found to play a crucial role in the solubilization of phosphate. This study was therefore aimed at exploring the growth-promoting potential of phosphate solubilizing Enterobacter species on maize and cowpea seedlings. Methods: Five strains that showed remarkable phosphate solubilization potential were used for the study. The bacterial isolates consist of three strains of Enterobacter cloaca and two strains of Enterobacter hormaechei. Growth promotion studies were carried out under laboratory conditions (in blotters) and green house (soil environment). In the blotter study, percent germination, germination index, germination time, germination rate, and vigor index were estimated, while shoot and root lengths, number of leaves, and wet weight were estimated in the greenhouse study. Results: In both seedlings, percent germination, germination index, and vigor index showed significantly higher values in seeds primed with the isolates than in the water-treated seeds (p≤ 0.05). Throughout the period of planting, the shoot and root lengths of the isolate-treated seedlings showed significantly higher values than the untreated control setups. This observation was irrespective of the maize and cowpea seedlings. In both seedlings, shoot and root lengths were directly proportional to days of growth. The bacterial strains showed significantly higher growth promoting potential on the seedlings. Conclusion: Therefore, the availability of these phosphate solubilizing microorganisms in the soil could enhance the growth of the seeds.

Multiannual Assessment of Quality of Plantago major L. Seed Progeny from Kyshtym Radiation Accident Area: Weather-Dependent Effects.

The effects of low-dose radiation that are observed in plant populations in radioactively contaminated areas are variable. One of the reasons is the influence of fluctuating weather conditions and the interaction of radiation with weather factors. This article summarizes results of 12-year research on the viability and radioresistance of greater plantain (Plantago major L.) seed progeny growing in the East Ural Radioactive Trace (EURT) zone and in control (nonradioactive) areas, with consideration of weather conditions' variability. The EURT was formed by the Kyshtym accident, which occurred in 1957 at the Mayak Production Association. Absorbed dose rates of P. major parental plants in the pollution gradient were 14.5-165.9 μGy h-1, which correspond to a low-dose range. Seed progeny quality was evaluated as seed weight, the survival rate, and root length of 21-day seedlings. Interannual variability in the studied parameters was high, and their ranges overlapped between EURT groups of seeds and control groups in most cases. The number of significant correlations between the parameters of seed quality and weather conditions was higher in EURT groups than in control populations. In the control groups of seeds, 88.9% of correlations were negative, whereas in the EURT groups, 78.5% were positive.