Seedling Leaf Research Articles

Assessment of Genetic Diversity Analysis in African Yam Bean (Sphenostylis stenocarpa Hochst Ex.A.Rich Harms) using Qualitative and Quantitative Attributes

This study evaluated the genetic diversity of 18 African Yam Bean (Sphenostylis stenocarpa) accessions from the IITA germplasm in Ibadan, Nigeria, using nine qualitative traits. The experiment was conducted behind the Biological Science Block at the University of Calabar, following a Randomized Complete Block Design (RCBD) with three replicates. Qualitative traits were observed and recorded based on the descriptors for African Yam Bean, while quantitative traits were measured using metric tools like rulers, vernier calipers, and weighing scales. Data were analyzed using Analysis of Variance (ANOVA) and Least Significant Difference (LSD) tests via GenStat Discovery Edition 4 and PASW version 20.0 software. Results indicated minimal variation in morphological traits such as days to 50% seedling emergence, vine length, leaf number, leaf dimensions, peduncle and petiole length, and days to 50% flowering across accessions. Leaf color varied, ranging from light green to dark and pale green, with accession TSs 285 showing pale green leaves. Seed shapes varied from round/globular to oval or oblong, and all accessions except TSs 33 had seed cavities. Accessions TSs 266 and TSs 38 performed better in most parameters, except for days to 50% flowering and leaf count. Significant differences (P < 0.05) were observed in traits like days to 50% emergence, days to 50% flowering, leaf color, pod dehiscence, seed shape, seed cavity presence, testa splitting, and texture. However, no significant differences were noted for hypocotyl pigmentation and pod dehiscence. Accession TSs 266 excelled in traits such as vine length, terminal leaf width, peduncle length, and pod number per plant, showing optimal adaptation to the climatic and agro-geological conditions of Cross River State.

Agrobacterium-mediated Transformation of Tropical Maize Using Seedling Leaf Whorl Explants

Conventional maize transformation has largely relied on immature embryos as explants, and is thus often hampered by the limited access to high-quality immature embryos year-round. Here, we present a detailed protocol using seedling leaf whorls as alternative explants for tropical maize inbred transformation. This approach involves the use of a cassette that drives the expression of the morphogenic transcription factors (MTFs)Baby boom(Bbm) andWuschel2(Wus2), which have been shown to greatly enhance transformation efficiency. We outline here the steps required for the preparation of seedling leaf whorl explants and subsequentAgrobacteriuminfection, and describe the tissue culture regimen that results in transgenic plant regeneration. Because constitutive expression ofBbmandWus2prevents normal plant regeneration and the production of fertile plants, the cassette containing these genes must be excised. As such, we include the steps for theCre/loxP-mediated excision of the MTF gene cassette. The protocol outlines a year-round, more affordable, and efficient approach for carrying out maize transformation for crop improvement.

Sodium Bicarbonate Tolerance During Seedling Stages of Maize (Zea mays L.) Lines

ABSTRACT(1) Soil alkalinization and salinization represent a growing global challenge. Maize (Zea mays L.), with its relatively low tolerance to salt and alkali, is increasingly vulnerable to saline‐alkali stress. Identifying maize genotypes that can withstand salinity and alkalinity is crucial to broaden the base of salt‐alkali‐tolerant maize germplasm. (2) In this study, we screened 65 maize germplasm resources for alkali stress using a 60 mM NaHCO3 solution. We measured fifteen morphological and physiological indices, including seedling height, stem thickness, and leaf area. Various analytical methods—correlation analysis, principal component analysis, subordinate function analysis, cluster analysis, stepwise discriminant analysis, and ridge regression analysis—were used to assess the seedling alkali tolerance of these maize germplasm resources. The physiological indices of six tested maize varieties were analyzed in greater detail. (3) The findings revealed complex correlations among traits, particularly strong negative associations between conductivity and root traits such as length, volume, surface area, diameter, and number of branches. The 15 evaluation indices were reduced to 7 principal components, explaining 77.89% of the variance. By applying affiliation functions and weights, we derived a comprehensive evaluation of maize seedling alkali tolerance. Notably, three germplasms—Liang Yu 99, Bi Xiang 638, and Gan Xin 2818—demonstrated significant comprehensive seedling alkali tolerance. Cluster analysis grouped the 65 maize germplasm resources into four distinct categories (I, II, III, and IV). The results of the cluster analysis were confirmed by multiclass stepwise discriminant analysis, which achieved a correct classification rate of 92.3% for 60 maize genotypes regarding alkalinity tolerance. Using principal component and ridge regression analyses, we formulated a regression equation for alkali tolerance: D‐value = −1.369 + 0.002 * relative root volume + 0.003 * relative number of root forks + 0.006 * relative chlorophyll SPAD + 0.005 * relative stem thickness + 0.005 * relative plant height + 0.001 * relative conductivity + 0.002 * relative dry weight of underground parts. Under sodium bicarbonate stress, morphological indices and germination rates were significantly reduced, germination was inhibited, photosynthetic pigment levels in maize leaves decreased to varying degrees, and the activities of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) significantly increased. Alkali stress markedly enhanced the antioxidant enzyme activities in maize varieties, with alkali‐resistant varieties exhibiting a greater increase in antioxidant enzyme activities than alkali‐sensitive varieties under such stress. (4) By screening for alkali tolerance in maize seedlings, the identified alkali‐tolerant genotypes can be further utilized as suitable donor parents, thereby enhancing the use of alkali‐tolerant germplasm resources and providing theoretical guidance for maize cultivation in saline‐alkaline environments.

Mapping seedling and adult plant leaf rust resistance genes in the durum wheat cultivar Strongfield and other Triticum turgidum (L.) lines.

Durum wheat (T. turgidum L.) is threatened by the appearance of new virulent races of leaf rust, caused by Puccinia triticina, in recent years. This study was conducted to determine the leaf rust resistance in a modern Canadian durum cultivar Strongfield. Six populations derived from crosses of Strongfield with six tetraploid wheat lines, respectively, were tested at seedling plant stage with different P. triticina races. Two of the populations were evaluated for adult plant leaf rust infection in Canada and Mexico. A stepwise regression joint linkage QTL mapping and analysis by MapQTL were performed. Strongfield contributed the majority of QTL detected, contributing seven QTL detected in field tests, and eight QTL conditioning seedling resistance. A 1B QTL, QLr-Spa-1B.1, from Strongfield had a significant effect in both Canadian and Mexican field tests, and corresponded with Lr46/Yr29. The remaining field QTL were found in only the Canadian or the Mexican environment, not both. The QTL from Strongfield on 3A, QLr-Spa-3A, conferred seedling resistance to all races tested and had a significant effect in the field in Canada. This is the first report of the QLr-Spa-3A and Lr46/Yr29 as key components of the genetic resistance in Canadian durum wheat. KASP markers were developed to detect the QLr-Spa-3A for use in marker assisted leaf rust resistance breeding. The susceptible parental lines contributed QTL on 1A, 2B and 5B that were effective in Mexican field tests that may be good targets to integrate into modern durum varieties to improve resistance to new durum virulent races.

Genome wide association study of seedling and adult plant leaf rust resistance in two subsets of barley genetic resources

Leaf rust (LR) caused by Puccinia hordei is a serious disease of barley worldwide, causing significant yield losses and reduced grain quality. Discovery and incorporation of new sources of resistance from gene bank accessions into barley breeding programs is essential for the development of leaf rust resistant varieties. To identify Quantitative Trait Loci (QTL) conferring LR resistance in the two barley subsets, the Generation Challenge Program (GCP) reference set of 142 accessions and the leaf rust subset constructed using the Focused Identification of Germplasm Strategy (FIGS) of 76 barley accessions, were genotyped to conduct a genome-wide association study (GWAS). The results revealed a total of 59 QTL in the 218 accessions phenotyped against barley leaf rust at the seedling stage using two P. hordei isolates (ISO-SAT and ISO-MRC), and at the adult plant stage in four environments in Morocco. Out of these 59 QTL, 10 QTL were associated with the seedling resistance (SR) and 49 QTL were associated with the adult plant resistance (APR). Four QTL showed stable effects in at least two environments for APR, whereas two common QTL associated with SR and APR were detected on chromosomes 2H and 7H. Furthermore, 39 QTL identified in this study were potentially novel. Interestingly, the sequences of 27 SNP markers encoded the candidate genes (CGs) with predicted protein functions in plant disease resistance. These results will provide new perspectives on the diversity of leaf rust resistance loci for fine mapping, isolation of resistance genes, and for marker-assisted selection for the LR resistance in barley breeding programs worldwide.

Exploring genetic diversity and population structure in Cinnamomum cassia (L.) J.Presl germplasm in China through phenotypic, chemical component, and molecular marker analyses.

Cinnamomum cassia (L.) J.Presl, a tropical aromatic evergreen tree belonging to the Lauraceae family, is commonly used in traditional Chinese medicine. It is also a traditional spice used worldwide. However, little is currently known about the extent of the genetic variability and population structure of C. cassia. In this study, 71 individuals were collected from seven populations across two geographical provinces in China. Nine morphological features, three chemical components, and single nucleotide polymorphism (SNP) markers were used in an integrated study of C. cassia germplasm variations. Remarkable genetic variation exists in both phenotypic and chemical compositions, and certain traits, such as leaf length, leaf width, volatile oil content, and geographic distribution, are correlated with each other. One-year-old C. cassia seedling leaf length, leaf width, elevation, and volatile oil content were found to be the main contributors to diversity, according to principal component analysis (PCA). Three major groupings were identified by cluster analysis based on the phenotypic and volatile oil data. This was in line with the findings of related research using 1,387,213 SNP markers; crucially, they all demonstrated a substantial link with geographic origin. However, there was little similarity between the results of the two clusters. Analysis of molecular variance (AMOVA) revealed that the genetic diversity of C. Cassia populations was low, primarily among individuals within populations, accounting for 95.87% of the total. Shannon's information index (I) varied from 0.418 to 0.513, with a mean of 0.478 (Na=1.860, Ne =1.584, Ho =0.481, He =0.325, and PPB =86.04%). Genetic differentiation across populations was not significant because natural adaptation or extensive exchange of seeds among farmers between environments, thus maintaining the relationship. Following a population structure analysis using the ADMIXTURE software, 71 accessions were found to be clustered into three groups, with 38% of them being of the pure type, a finding that was further supported by PCA. Future breeding strategies and our understanding of the evolutionary relationships within the C. cassia population would benefit greatly from a thorough investigation of phenotypic, chemical, and molecular markers.

Direct PCR Based Detection of Macrophomina Phaseolina From Soil of Jute Field

Macrophomina phaseolina (Tassi) Goid. is a devastating fungal pathogen which infects a large number of economically important crops. In jute, it mainly causes seedling blight, leaf spot, and stem rot. The pathogen is seed borne as well as soil borne. Macrophomina phaseolina pathogen was detected in soil samples collected from jute field by a direct PCR method (dPCR) without DNA isolation using ITS2 and ITS3 region specific primers designed during the present study. The soil samples were prepared in a lysis buffer and were incubated at 650C for 15 min. The optimized buffer system was composed of 200 mM tris (hydroxymethyl aminomethane (Tris)-Cl (pH 8.0), 3.5 mM ethylene diamine tetra acetic (EDTA) (pH 8.0), 4 M NaCl and 200 μg/ml Proteinase K. Further, β-marcaptoethanol (1% v/v) was added into the buffer. Bangladesh J. Bot. 53(2): 401-404, 2024 (June)

Physiological and Structural Changes in Leaves of Platycrater arguta Seedlings Exposed to Increasing Light Intensities.

Understanding the light adaptation of plants is critical for conservation. Platycrater arguta, an endangered deciduous shrub endemic to East Asia, possesses high ornamental and phylogeographic value. However, the weak environmental adaptability of P. arguta species has limited its general growth and conservation. To obtain a deeper understanding of the P. arguta growth conditions, we examined the leaf morphology and physiology via anatomical and chloroplast ultrastructural analyses following exposure to different natural light intensities (full light, 40%, and 10%). The findings indicated that P. arguta seedings in the 10% light intensity had significantly improved leaf morphological characteristics and specific leaf area compared to those exposed to other intensities. The net photosynthetic rate, chlorophyll (Chl) content, photosynthetic nitrogen use efficiency (PNUE), and photosynthetic phosphorus use efficiency (PPUE) exhibited marked increases at a 10% light intensity compared to both 40% light and full light intensities, whereas the light compensation point and dark respiration levels reached their lowest values under the 10% light condition. With reduced light, leaf thickness, palisade tissue, spongy tissue, and stomatal density significantly decreased, whereas the stomatal length, stomatal width, and stomatal aperture were significantly elevated. When exposed to 10% light intensity, the ultrastructure of chloroplasts was well developed, chloroplasts and starch grain size, the number of grana, and thylakoids all increased significantly, while the number of plastoglobules was significantly reduced. Relative distance phenotypic plasticity index analysis exhibited that P. arguta adapts to varying light environments predominantly by adjusting PPUE, Chl b, PNUE, chloroplast area, and the activity of PSII reaction centers. We proposed that P. arguta efficiently utilizes low light to reconfigure its energy metabolism by regulating its leaf structure, photosynthetic capacity, nutrient use efficiency, and chloroplast development.

Chlorella vulgaris improves growth of Abrometiella scapigera, Abrometiella brevifolia and Abrometiella chloranta and reduces root attack by nematodes

Research objective: The aim of this study is to investigate the effects of Chlorella extract as a biofertiliser on the growth of Abrometiella spp. seedlings and to assess whether it has a repellent effect against nematodes Materials and Methods: The experiments, which began in November 2024, were conducted in the CREA-OF greenhouses in Pescia (PT), Tuscany, Italy (43°54′N 10°41′E) on Abrometiella scapigera, Abrometiella brevifolia and Abrometiella chloranta. The plants were placed in ø12 cm pots; 30 plants per thesis, divided into 3 replicates of 10 plants each. The experimental groups were: i) group without algae, irrigated with water and previously fertilised substrate; ii) group with Chlorella vulgaris, previously fertilised substrate. On 2 April 2024, plant height, leaves number, vegetative weight, root weight, root lenght, number of new plantlets, chlorophyll content, leaf area, control of the nematodes Meloidogyne javanica and Meloidogyne incognita were measured. Results and Discussion: The experiment showed that the use of Chlorella vulgaris extracts can improve the vegetative and root growth of Abrometiella scapigera, Abrometiella brevifolia and Abrometiella chloranta plants grown in pots. The treatment also led to an increase in plant height, number of leaves, length of root hairs, leaf area and number of new seedlings. The trial also showed that the use of Chlorella in plant growing media can also increase the photosynthesis rate (SPAD index) and significantly reduce the presence of nematodes, in particular Meloidogyne javanica and Meloidogyne incognita. According to some researchers, the influence of Chlorella extract on cell metabolisms is mainly due to the physiological effect of major and minor nutrients, amino acids, vitamins, and plant growth regulators on cellular metabolisms in treated plants, which increase crop yields and growth. Chlorella plants have very high photosynthesis rates, dozens of times higher than other plants. The main reason why Chlorella can grow rapidly is because it contains Chlorella Growth Factor (CGF), which is quite rich in nucleoproteins, nucleic acids, ribonucleic acids (RNA), deoxyribonucleic acids (DNA), vitamins, amino acids, polysaccharides, complex protein bodies, enzymes, glycoproteins, plant hormones, etc. Its ability to promote plant growth may be due to this factor. Conclusions: Chlorella extract significantly increased Abrometiella seedling height, leaf number and leaf area. In particular, Abrometiella seedlings treated with chlorella extract developed better root system, chlorophyll a increased significantly and the root length and number of new seedlings also improved significantly. Based on the above results that Chlorella extracts contribute to the growth and development of Abrometiella plants, we can conclude that with the treatment of Chlorella extracts, the application of chemical fertilisers in the production of succulents such as Abrometiella can be reduced.

The effects of plant growth-promoting bacteria on seed germination and seedling growth in Crassocephalum rubens

Crassocephalum rubens, a herb with potential anticancer properties, encounters challenges in production efficiency due to small seed size and elevated temperatures in cultivation areas. Our study investigates the effects of seed pelleting and plant growth-promoting bacteria (PGPB) on germination and seedling growth across temperature variations in Taiwan. Pelleted seeds demonstrate superior germination percentages linked to enhanced seed quality. Elevated temperature, particularly at 30/25 °C, enhanced germination performance, with the highest final germination percentage observed in pelleted seeds treated with water. Unexpectedly, PGPB strains— Klebsiella sp. KsGRB10 and Bacillus sp. BsGFB04—exhibited limited impact on germination rates, showing a marginal increase in seedling growth under 25/20 °C and 30/25 °C, respectively. Air temperature fluctuations influenced seedling vigor, leaf color, and physiological parameters. Remarkably, inoculation with BsGFB04 and KsGRB10 enhanced C. rubens’ tolerance to high-temperature stress conditions. Diurnal measurements in week 4, under 25/20 °C, reveal that PGPB inoculation decreased stomatal conductance and transpiration rate while maintaining the quantum yield of PSII, indicating potentially improved water-use efficiency. This study provides crucial insights into the interplay among PGPB, environmental stress, and the physiology of a wild species, paving the way for further research in the domestication of C. rubens for medicinal herb mass production.

DNAL7, a new allele of NAL11, has major pleiotropic effects on rice architecture.

dnal7, a novel allelic variant of the OsHSP40, affects rice plant architecture and grain yield by coordinating auxins, cytokinins, and gibberellic acids. Plant height and leaf morphology are the most important traits of the ideal plant architecture (IPA), and discovering related genes is critical for breeding high-yield rice. Here, a dwarf and narrow leaf 7 (dnal7) mutant was identified from a γ-ray treated mutant population, which exhibits pleiotropic effects, including dwarfing, narrow leaves, small seeds, and low grain yield per plant compared to the wild type (WT). Histological analysis showed that the number of veins and the distance between adjacent small veins (SVs) were significantly reduced compared to the WT, indicating that DNAL7 controls leaf size by regulating the formation of veins. Map-based cloning and transgenic complementation revealed that DNAL7 is allelic to NAL11, which encodes OsHSP40, and the deletion of 2 codons in dnal7 destroyed the His-Pro-Asp (HPD) motif of OsHSP40. In addition, expression of DNAL7 in both WT and dnal7 gradually increased with the increase of temperature in the range of 27-31°C. Heat stress significantly affected the seedling height and leaf width of the dnal7 mutant. A comparative transcriptome analysis of WT and dnal7 revealed that DNAL7 influenced multiple metabolic pathways, including plant hormone signal transduction, carbon metabolism, and biosynthesis of amino acids. Furthermore, the contents of the cytokinins in leaf blades were much higher in dnal7 than in the WT, whereas the contents of auxins were lower in dnal7. The contents of bioactive gibberellic acids (GAs) including GA1, GA3, and GA4 in shoots were decreased in dnal7. Thus, DNAL7 regulates rice plant architecture by coordinating the balance of auxins, cytokinins, and GAs. These results indicate that OsHSP40 is a pleiotropic gene, which plays an important role in improving rice yield and plant architecture.

Maize emergence rate and leaf emergence speed estimation via image detection under field rail-based phenotyping platform

Accurate and efficient acquisition of maize emergence rate and leaf emergence speed in the field is essential for detecting seed quality, evaluating crop field management plans, and yield assessment. This study constructs a system solution to obtain the maize seedling emergence rate and leaf emergence speed based on the field rail-based phenotyping platform and convolutional neural network. Firstly, we use the field rail-based phenotyping platform to collect a high-temporal sequence visible light images of maize plant during the seedling stage. In the first stage, an improved Faster R-CNN is used to detect maize seedlings in the plot images, and the plant ROI area is cropped as the input for the second stage network. In the second stage, the best performing ResNeSt network out of four backbone networks is chosen, using the Mask R-CNN model to segment the leaves of the input plant image, which is then used to calculate the number of leaves. We propose a quantification index for leaf emergence speed based on a weighted average combination of leaf numbers. Using the method described in this paper, we analyzed the plant images from 52 inbred lines plots of over seven consecutive days. The experimental results show that when the Intersection Over Union (IOU) is 0.50, the bbox_mAP of the maize seedling detection model is 0.969, with an accuracy rate of 99.53%. Compared with manual counting, the calculated R2 is 0.997 and RMSE is 43.382. The segm_mAP of the plant leaf segmentation model is 0.942. The differences in emergence rate and leaf emergence speed across 52 inbred lines were compared, providing new phenotyping reference indices for further exploring the genotypic differences affecting seed emergence and leafing.

An insight into the gene expression evolution in Gossypium species based on the leaf transcriptomes

BackgroundGene expression pattern is associated with biological phenotype and is widely used in exploring gene functions. Its evolution is also crucial in understanding species speciation and divergence. The genus Gossypium is a bona fide model for studying plant evolution and polyploidization. However, the evolution of gene expression during cotton species divergence has yet to be extensively discussed.ResultsBased on the seedling leaf transcriptomes, this work analyzed the transcriptomic content and expression patterns across eight cotton species, including six diploids and two natural tetraploids. Our findings indicate that, while the biological function of these cotton transcriptomes remains largely conserved, there has been significant variation in transcriptomic content during species divergence. Furthermore, we conducted a comprehensive analysis of expression distances across cotton species. This analysis lends further support to the use of G. arboreum as a substitute for the A-genome donor of natural cotton polyploids. Moreover, our research highlights the evolution of stress-responsive pathways, including hormone signaling, fatty acid degradation, and flavonoid biosynthesis. These processes appear to have evolved under lower selection pressures, presumably reflecting their critical role in the adaptations of the studied cotton species to diverse environments.ConclusionsIn summary, this study provided insights into the gene expression variation within the genus Gossypium and identified essential genes/pathways whose expression evolution was closely associated with the evolution of cotton species. Furthermore, the method of characterizing genes and pathways under unexpected high or slow selection pressure can also serve as a new strategy for gene function exploration.

Effects of Seafood Mushroom Spent Substrate Solid-State Fermentation Combined with PGPR as a Microbial Fertilizer on the Soil Environment and Growth Promotion of Cenchrus fungigraminus

PurposeCareless burning, discarding, or overfertilization of spent mushroom substrate (SMS) is environmentally harmful. The reuse of SMS resources is a matter of concern.MethodsSpent seafood mushroom substrate solid-state fermentation combined with Rhizobium pusense solution was added to soil to evaluate its environmental and Cenchrus fungigraminus seedling growth effects in pot trial experiments.ResultsThe 40% fermented seafood mushroom SMS (fresh weight) with R. pusense treatment had significantly higher total nitrogen (TN), ammonium nitrogen (AMN), organic matter, etc., and decreased soil electrical conductivity (EC) and increased pH compared with other treatment. Soil catalase (CAT), dehydrogenase (DHA), and urease (UE) activities were significantly improved; there were no differences in CAT and UE activities between 40% (T4) and 50% (T5) SMS additions. C. fungigraminus seedling height and leaf length increased gradually and were significantly different from those of the positive control. The 30–50% seafood mushroom SMS treatment increased plant TN by 5.76–10.00% and total phosphorus by 15.44–16.55%. Plant root length and root activity peaked in T4; however, plant split root number and root activity in T5 decreased by 43.96% and 26.97% compared with those in T4. According to Pearson correlation and one-dimensional regression analyses, the seafood mushroom SMS content affected fertility > enzyme activity > plant growth. Principal component analysis and redundancy analysis showed that the effect of the seafood mushroom SMS concentration on the soil environment was mainly reflected in plant aboveground and root activity.ConclusionsUnder an SMS addition amount of 40%, plant growth-promoting rhizobacteria promoted the growth of C. fungigraminus seedlings to a greater extent.

Reflectance spectra for identifying stress in different parts of leaf: a case study on oil palm seedlings

ABSTRACT In this study, the spectral responses to drought stress of different parts in the leaf of oil palm seedlings named base, middle, and tip were investigated. The ability to detect stress even before symptoms emerge requires knowledge of which part of oil palm leaves responds more quickly to the stress. The analysis of the reflectance spectra in region 650–1050 nm was conducted on respective sections of the leaves of the oil palm seedlings. The analysis revealed that the stress affects the tip of the leaf, followed by the middle and then the base. It was noticed that the greatest loss of water and chlorophyll content was at the tip of the leaf. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used for clustering, while support vector machine (SVM) and linear discriminant analysis (LDA) were applied for categorization purposes. The outcomes of the PCA and HCA showed that the separation between the samples was based on the day and stress levels at respective sections of the leaf. With this, the possession of distinct morphological and physiological features by each part of the leaf can be concluded. From the PCA loadings, it was found that the regions 699–756 nm, 833–877 nm, and 933–958 nm showed noticeable bands and can be used to distinguish between the oil palm seedlings under stress. In addition, LDA and SVM classifiers demonstrated that the prediction accuracy of the stress level in oil palm seedlings was not influenced by the location in the leaf where the spectra were acquired.

The Effects of Mycorrhiza and Seaweed Applications on Seedling Growth Parameters: Tomato and Pepper

ABSTRACT The use of mycorrhiza and seaweed are becoming significant and complementary applications in different production systems because organisms increased quality of seedlings and crop yield. This study has been conducted under growth chamber conditions to determine some of the seedling growth parameters (length (cm), stem diameter (mm), fresh weight (g plant −1), dry weight (g plant −1), root fresh weight (g plant −1), root dry weight (g plant −1), leaf area (cm2 plant−1), SPAD, photosynthesis rate (%) and color parameters). As a plant material, Cuma F1 and Mert F1 genotype seeds were sown. Endo Roots Soluble (Mycorrhiza (ERS)) and MC-Extra (Seaweed) were applied in different doses (0, 250 and 500 mg kg−1) to seedling growing vessels at a rate of 10 ml per plant. Treatment effects in tomato were found statistically significant (p ≤.01**) on stem diameter, fresh weight, dry weight. Seedling length, leaf area and SPAD results were also statistically significant (p ≤.01**), and the results of these parameters were higher in ERS. ERS increases the leaf area and SPAD measurements in tomato seedlings. The results of pepper measurements were found to be statistically significant at p ≤.05* on root fresh weight, SPAD and photosynthesis rate. The highest values of root fresh weight, SPAD were obtained from 250 mg kg−1 doses of ERS; the highest value of photosynthesis rate was measured from 500 mg kg−1 doses of ERS on pepper. The effect of 500 mg kg−1 ERS on seedling growth was found statistically significant in pepper.

Impact of Arbuscular Mycorrhizal Fungi (AMF) on nutrient uptake and the growth of <i>C. retusa<?i> and <i>S. occidentalis<?i> under phosphorus stress

This study investigates the influence of Arbuscular Mycorrhizal Fungi (AMF) on the growth of Crotallaria retusa and Senna occidentalis under three phosphorus levels (low, medium, and high). Conducted in the experimental garden of Ahmadu Bello University Zaria, the soil samples were collected from a degraded site at the Institute of Agricultural Research, sieved, and sterilized. Perforated buckets were filled with sterilized soil, and the trench method was employed for AMF application. Three phosphorus levels were tested, and seeds of C. retusa and S. occidentalis were planted in individual buckets. Daily watering and observations were carried out for twelve weeks, measuring seedling height, leaf length, width, and number of leaves. The results indicate that high phosphorus concentration (12g/bucket) constrains the growth of C. retusa, while medium concentration (6g/bucket) enhances shoot length, branches, and leaves. AMF inoculation significantly improves growth attributes, but reduced growth in C. retusa under high phosphorus suggests potential incompatibility between phosphorus and AMF. At week 6, medium phosphorus (6g/bucket) resulted in more leaves (122.17±37.61) than low and high levels. Lowest growth occurred at low phosphorus (0g/bucket). Arbuscular mycorrhizal fungi improved overall growth, but high phosphorus hindered C. retusa growth due to potential incompatibility with AMF. Overall, the study highlights the complex interplay between AMF, phosphorus levels, and plant growth, offering insights into optimizing conditions for the cultivation of C. retusa and S. occidentalis.

GmABCG5, an ATP-binding cassette G transporter gene, is involved in the iron deficiency response in soybean.

Iron deficiency is a major nutritional problem causing iron deficiency chlorosis (IDC) and yield reduction in soybean, one of the most important crops. The ATP-binding cassette G subfamily plays a crucial role in substance transportation in plants. In this study, we cloned the GmABCG5 gene from soybean and verified its role in Fe homeostasis. Analysis showed that GmABCG5 belongs to the ABCG subfamily and is subcellularly localized at the cell membrane. From high to low, GmABCG5 expression was found in the stem, root, and leaf of young soybean seedlings, and the order of expression was flower, pod, seed stem, root, and leaf in mature soybean plants. The GUS assay and qRT-PCR results showed that the GmABCG5 expression was significantly induced by iron deficiency in the leaf. We obtained the GmABCG5 overexpressed and inhibitory expressed soybean hairyroot complexes. Overexpression of GmABCG5 promoted, and inhibition of GmABCG5 retarded the growth of soybean hairy roots, independent of nutrient iron conditions, confirming the growth-promotion function of GmABCG5. Iron deficiency has a negative effect on the growth of soybean complexes, which was more obvious in the GmABCG5 inhibition complexes. The chlorophyll content was increased in the GmABCG5 overexpression complexes and decreased in the GmABCG5 inhibition complexes. Iron deficiency treatment widened the gap in the chlorophyll contents. FCR activity was induced by iron deficiency and showed an extraordinary increase in the GmABCG5 overexpression complexes, accompanied by the greatest Fe accumulation. Antioxidant capacity was enhanced when GmABCG5 was overexpressed and reduced when GmABCG5 was inhibited under iron deficiency. These results showed that the response mechanism to iron deficiency is more actively mobilized in GmABCG5 overexpression seedlings. Our results indicated that GmABCG5 could improve the plant's tolerance to iron deficiency, suggesting that GmABCG5 might have the function of Fe mobilization, redistribution, and/or secretion of Fe substances in plants. The findings provide new insights into the ABCG subfamily genes in the regulation of iron homeostasis in plants.

Gibberellin-mediated far-red light-induced leaf expansion in cucumber seedlings.

Our experiments explored the effects of far-red (FR) light on cucumber (Cucumis sativus L. 'Zhongnong No. 26') seedling growth. Our results indicated that FR light significantly promoted the growth of cucumber seedlings. Specifically, it promoted the accumulation of shoot biomass and the elongation of internodes and leaves (except the first leaf at the bottom). Further analysis showed that FR light had no effect on the accumulation contents of abscisic acid (ABA) and auxin (IAA) in seedling leaves. Still, it significantly caused the increase of the gibberellin (GA3, GA4, and GA7) contents and the decrease of GA1 content, which suggested that the leaf expansion progress under FR light may be primarily related to GA. Therefore, the cucumber seedling leaf expansion response to GA was evaluated under different light sources. The exogenous spraying of different GA4/7 contents significantly promoted the leaf expansion of cucumber seedlings under white light, while the GA biosynthesis inhibitor paclobutrazol (PAC) significantly promoted the expression of GA hydrolytic genes (GA2ox2 and GA2ox4) and decreased the content of endogenous active GA, which inhibited the leaf expansion induced by FR light. As expected, the combination of exogenous GA4/7 and PAC restored the growth promotion effect of FR light on cucumber seedling leaves. It increased the contents of endogenous active GA (GA1, GA3, GA4, and GA7), and the expression trend in GA synthetic/hydrolytic-related genes was the opposite of that of PAC was applied alone. All of the above results indicated that FR light regulates leaf expansion progress in cucumber seedlings through GA.

Foliar Application of Seaweed Extract, Zinc, and Iron Nanoparticles on Ziziphus Mauritiana Seedling Growth

This study examined the effects of foliar spraying with seaweed extract at three levels (0,1,2 ml L-1) sequentially, zinc nanoparticles at three levels (0, 10, 20 mg L-1), and nano-iron at three levels (0,20,40 mg L-1). The randomised complete block design (RCBD) factorial experiment included three levels of seaweed extract, three levels of nano-zinc, three levels of nano-iron, and three repetitions of four seedlings per experimental unit, resulting in 180 observations and 60 treatments per sector. 180 seedlings were randomly assigned treatments. Spraying marine extract at 2 ml L-1 significantly improved seedling height, stem diameter, dry weight, chlorophyll, and leaf area. It outperformed the control in seedling height, stem diameter, dry weight, chlorophyll, and leaf area. The combination of 40 mg L-1 zing and iron nanoparticles improved seedling height, stem diameter, dry weight, chlorophyll, and leaf area compared to the comparator treatment.