Vegetative Compatibility and Virulence Diversity of <i>Verticillium dahliae</i> from Okra (<i>Abelmoschus esculentus</i>) Plantations in Turkey and Evaluation of Okra Landraces for Resistance to <i>V. dahliae</i>

Forty-four V. dahliae isolates were collected from symptomatic vascular tissues of okra plants each from a different field in eight provinces located in the eastern Mediterranean and western Anatolia regions of Turkey during 2006- 2009. Nitrate-nonutilizing (nit) mutants of V. dahliae from okra were used to determine heterokaryosis and genetic relatedness among isolates. All isolates from okra plants were grouped into two vegetative compatibility groups (VCGs) (1 and 2) and three subgroups as 1A (13.6%, 6/44), 2A (20.5%, 9/44) and 2B (65.9%, 29/44) according to international criteria. Pathogenicity tests were performed on a susceptible local okra (A. esculentus) landrace in greenhouse conditions. All isolates from VCG1A and VCG2B induced defoliation (D) and partial defoliation (PD) symptoms, respectively. Other isolates from VCG2A gave rise to typical leaf chlorosis symptoms without defoliation. The obtained data showed that the virulence level of V. dahliae isolates from okra was related to their VCG belongings. Eighteen okra landraces from diverse geographical origins were screened for resistance to VCG2B and VCG1A of V. dahliae. The results indicated that all landraces were more susceptible to highly virulent VCG1A-D pathotype displaying D or PD symptoms depending on their susceptibility levels with a mean disease severity index of 3.52 than to less virulent VCG2B-PD pathotype of V. dahliae displaying PD and ND symptoms with a mean disease severity index of 2.52. Significant differences were observed among the landraces; however, none of them exhibited a level of resistance. Okra landraces; Çorum, Hatay Has and Şanlıurfa displayed the lowest level of susceptibility or little tolerance to both D and PD pathotypes. VCG2B of PD was prevailing in the surveyed areas and VCG1A of D was the most virulent of the VCGs identified. Introduction of resistant genotypes to Turkish okra germplasm from different sources and breeding new resistant okra cultivars are critical for the sustainability of okra production.     

Multivariate analysis and the choice of parents for hybridization in Okra (Abelmoschus esculentus (L.) Moench)

Summary Thirty okra genotypes of diverse eco-geographical origin were grown in single-row plots in a randomised complete block design. The data collected on 14 characters were subjected to analysis of variance. By multivariate analysis (Mahalanobis D² technique), the genetic divergence among the genotypes were quantitatively measured. The genotypes were grouped into five clusters by this technique. There was no relationship between clustering pattern and eco-geographic distribution. The effects of genetic divergence on the choice of parental stock in hybridization was discussed.     

<i>Aspergillus tubingensis</i> Causes Leaf Spot of Cotton (<i>Gossypium hirsutum</i> L.) in Pakistan

Cotton (Gossypium hirsutum L.) is a key fiber crop of great commercial importance. Numerous phytopathogens decimate crop production by causing various diseases. During July-August 2018, leaf spot symptoms were recurrently observed on cotton leaves in Rahim Yar Khan, Pakistan and adjacent areas. Infected leaf samples were collected and plated on potato dextrose agar (PDA) media. Causal agent of cotton leaf spot was isolated, characterized and identified as Aspergillus tubingensis based on morphological and microscopic observations. Conclusive identification of pathogen was done on the comparative molecular analysis of CaM and β-tubulin gene sequences. BLAST analysis of both sequenced genes showed 99% similarity with A. tubingensis. Koch’s postulates were followed to confirm the pathogenicity of the isolated fungus. Healthy plants were inoculated with fungus and similar disease symptoms were observed. Fungus was re-isolated and identified to be identical to the inoculated fungus. To our knowledge, this is the first report describing the involvement of A. tubingensis in causing leaf spot disease of cotton in Pakistan and around the world.     

Inhibitory Effect of <i>N</i>, <i>N</i>-Dimethylhexadecylamine on the Growth of White-Rot Fungus <i>Trametes versicolor</i> (L.) in Wood

Wood is an organic material that is a source of carbon of organisms called Wood-decay fungi, and to preserve the wood, various toxic compounds to man and the environment have been used. To analyze the effect of N,N-Dimethylhexadecylamine (DMHDA) on wood attacked by the rotting fungus Trametes versicolor L. We used an in vitro system to expose the fungus T. versicolor to different concentrations of the DMHDA (50, 150 and 450 μM). We quantified the diameter of mycelial growth and laccase activity, also, under these experimental conditions we studied morphological details of the organisms using different scanning equipment including scanning electron microscopy. The growth of T. versicolor exposed to DMHDA for 60 days, showed a concentration-dependent dose behavior, also, the electron microscopy analysis revealed that the morphology and mycelial density was affected by the DMHDA, showing a formation of atypical morphological and thickener folds. Finally, the pieces of wood treated with DMHDA and exposed to the fungus had a lower mass loss, after a period of 60 days of exposure, the values obtained were 0.7, 1.0 and 0.5 g of mass lost for the control, LoC and LoDMHDA treatments respectively. Wood-rot fungi have represented economic losses worldwide, the strategies used have been supported by toxic compounds for the environment. The DMHDA both in the Petri dish system and as a wood preservative was shown to significantly inhibit the growth of T. versicolor.     

Integrated Nutrient Management Improves Productivity and Quality of Sugarcane (<i>Saccharum Officinarum</i> L.)

Sugarcane is one of the major important sugar yielding crops in Bangladesh. As an exhaustive crop, sugarcane removes a huge amount of plant nutrients from the soil. However, the combined use of organic and inorganic fertilizers can be a good approach to deal with nutrient depletion and promote sustainable crop production as well as improve soil health. Therefore, an attempt was made to identify the most fruitful and profitable integrated nutrient management on the aspects of growth, yield and quality of sugarcane in two consecutive growing seasons. Seven treatments: T₁=Control, T₂=165:55:120:30:10:2.5:4 kg N:P:K:S:Mg:Zn:B ha⁻¹, T₃=Poultry Litter (PL) at 5 t ha⁻¹+95:51:87:9:10:2.5:4 kg N:P:K:S:Mg:Zn:B ha⁻¹, T₄=Cow Dung (CD) at 15 t ha⁻¹+ 36:52:60:17:10:2.5:4 kg N:P:K:S:Mg:Zn:B ha⁻¹, T₅=Press Mud (PM) at 15 t ha⁻¹+10:50:43:0:10:2.5:4 kg N:P:K:S:Mg:Zn:B ha⁻¹, T₆=Mustard Oil Cake (MOC) at 0.5 t ha⁻¹+140:54:115:25:10:2.5:4 kg N:P:K:S:Mg:Zn:B ha⁻¹ and T₇=GM (Green Manure) at 5 t ha⁻¹+140:53:100:28:10:2.5:4 kg N:P:K:S:Mg:Zn:B ha⁻¹ were used in this experiment. Two years data showed that treatment T₃ produced the maximum amount of tillers, total dry matter yield, millable sugarcane, cane yield and sugar yield, followed by the T₄ treatment. The highest stalk heights were recorded in the T₃ treatment, which was statistically similar to all other treatments except T₁ and T₂. The juice quality parameters viz., brix and pol in cane were found significant in treatment T₃ while the highest purity was obtained in the T₇ treatment. All the data of Jaggery (goor) quality parameters, the highest sucrose content, color transmittance, Jaggery (goor) recovery and the lowest ash content of Jaggery (goor) were observed in the T₃ treatment, which was statistically similar to the T₄ treatment in both seasons. The highest cost of production was obtained from the T₆ treatment while the highest gross return, net return and BCR were recorded in the T₃ treatment. No significant changes were found in one cycle of sugarcane in initial and post-harvest soil characteristics viz., pH, organic carbon, total N, and available P, K and S contents due to integrated use of different fertilizer packages. From the experimental findings, it was concluded that treatment T₃ followed by T₄ treatment would be the better productive and profitable integrated nutrient management technology for ensuring higher yields and quality of sugarcane without soil fertility degradation in the High Ganges River Floodplain soils.     

Distribution,Etiology, Molecular Genetics and Management Perspectives of Northern Corn Leaf Blight of Maize (<i>Zea mays</i> L.)

Maize is cultivated extensively throughout the world and has the highest production among cereals. However, Northern corn leaf blight (NCLB) disease caused by Exherohilum turcicum, is the most devastating limiting factor of maize production. The disease causes immense losses to corn yield if it develops prior or during the tasseling and silking stages of crop development. It has a worldwide distribution and its development is favoured by cool to moderate temperatures with high relative humidity. The prevalence of the disease has increased in recent years and new races of the pathogen have been reported worldwide. The fungus E. turcicum is highly variable in nature. Though different management strategies have proved effective to reduce economic losses from NCLB, the development of varieties with resistance to E. turcicum is the most efficient and inexpensive way for disease management. Qualitative resistance for NCLB governed by Ht genes is a race-specific resistance which leads to a higher level of resistance. However, some Ht genes can easily become ineffective under the high pressure of virulent strains of the pathogen. Hence, it is imperative to understand and examine the consistency of the genomic locations of quantitative trait loci for resistance to NCLB in diverse maize populations. The breeding approaches for pyramiding resistant genes against E. turcicum in maize can impart NCLB resistance under high disease pressure environments. Furthermore, the genome editing approaches like CRISPR-cas9 and RNAi can also prove vital for developing NCLB resistant maize cultivars. As such this review delivers emphasis on the importance and current status of the disease, racial spectrum of the pathogen, genetic nature and breeding approaches for resistance and management strategies of the disease in a sustainable manner.     

Conventional Breeding and Molecular Markers for Blast Disease Resistance in Rice (<i>Oryza sativa</i> L.)

Monogenic lines, which carried 23 genes for blast resistance were tested and used donors to transfer resistance genes by crossing method. The results under blast nursery revealed that 9 genes from 23 genes were susceptible to highly susceptible under the three locations (Sakha, Gemmeza, and Zarzoura in Egypt); Pia, Pik, Pik-p, Piz-t, Pita, Pi b, Pi, Pi 19 and Pi 20. While, the genes Pii, Pik-s, Pik-h, Pi z, Piz-5, Pi sh, Pi 3, Pi 1, Pi 5, Pi 7, Pi 9, Pi 12, Pikm and Pita-2 were highly resistant at the same locations. Clustering analysis confirmed the results, which divided into two groups; the first one included all the susceptible genes, while the second one included the resistance genes. In the greenhouse test, the reaction pattern of five races produced 100% resistance under artificial inoculation with eight genes showing complete resistance to all isolates. The completely resistant genes: Pii, Pik-s, Piz, Piz-5 (=bi2) (t), Pita (=Pi4) (t), Pita, Pi b and Pi1 as well as clustering analysis confirmed the results. In the F₁ crosses, the results showed all the 25 crosses were resistant for leaf blast disease under field conditions. While, the results in F₂ population showed seven crosses with segregation ratio of 15 (R):1 (S), two cross gave segregated ratio of 3 R:1 S and one gave 13:3. For the identi- fication of blast resistance genes in the parental lines, the marker K3959, linked to Pik-s gene and the variety IRBLKS-F5 carry this gene, which was from the monogenic line. The results showed that four genotypes; Sakha 105, Sakha 103, Sakha 106 and IRBLKS-F5 were carrying Pik-s gene, while was absent in the Sakha 101, Sakha 104, IRBL5-M, IRBL9-W, IRBLTACP1 and IRBL9-W(R) genotypes. As for Pi 5 gene, the results showed that it was present in Sakha 103 and Sakha 104 varieties and absent in the rest of the genotypes. In addition, Pita-Pita- 2 gene was found in the three Egyptian genotypes (Sakha 105, Sakha 101 and Sakha 104) plus IRBLTACP1 monogenetic. In F2 generation, six populations were used to study the inheritance of blast resistance and specific primers to confirm the ratio and identify the resistance genes. However, the ratios in molecular markers were the same of the ratio under field evaluation in the most population studies. These findings would facilitate in breeding programs for gene pyramiding and gene accumulation to produce durable resistance for blast using those genotypes.     

Aluminum Toxicity: A Case Study on Tobacco (<i>Nicotiana tabacum</i> L.)

Aluminum is an abundant metal in the earth’s crust that turns out to be toxic in acidic environments. Many plants are affected by the presence of aluminum at the whole plant level, at the organ level, and at the cellular level. Tobacco as a cash crop (Nicotiana tabacum L.) is a widely cultivated plant worldwide and is also a good model organism for research. Although there are many articles on Al-phytotoxicity in the literature, reviews on a single species that are economically and scientifically important are limited. In this article, we not only provide the biology associated with tobacco Al-toxicity, but also some essential information regarding the effects of this metal on other plant species (even animals). This review provides information on aluminum localization and uptake process by different staining techniques, as well as the effects of its toxicity at different compartment levels and the physiological consequences derived from them. In addition, molecular studies in recent years have reported specific responses to Al toxicity, such as overexpression of various protective proteins. Besides, this review discusses data on various organelle-based responses, cell death, and other mechanisms, data on tobacco plants and other kingdoms relevant to these studies.     

Characterization and Candidate Gene Analysis of the Yellow-Green Leaf Mutant <i>ygl16</i> in Rice (<i>Oryza sativa</i> L.)

Leaf color mutants are ideal materials for studying many plant physiological and metabolic processes such as photosynthesis, photomorphogenesis, hormone physiology and disease resistance. In this study, the genetically stable yellow-green leaf mutant ygl16 was identified from mutated “Xinong 1B”. Compared with the wild type, the pigment concentration and photosynthetic capacity of the ygl16 decreased significantly. The ultrastructural observation showed that the distribution of thylakoid lamellae was irregular in ygl16 chloroplasts, and the grana and matrix lamellae were blurred and loose in varied degrees, and the chloroplast structure was disordered, while the osmiophilic corpuscles increased. The results of the genetic analysis and mapping showed that the phenotype of ygl16 was controlled by a pair of recessive nuclear gene. The gene located in the 56Kb interval between RM25654 and R3 on the long arm of chromosome 10. The sequencing results showed that the 121st base of the first intron of the candidate gene OsPORB/FGL changed from A to T in the interval. qRT-PCR results showed that the expression of chlorophyll synthase-related genes in the mutant decreased.     

Phenotype Analysis and Fine Mapping of the Male Sterile Mutant <i>ms10</i> in Rice (<i>Oryza sativa</i> L.)

There is a positive correlation between fertility and yield, and the decrease of fertility is bound to a greatly reduced crop yield. Male sterile mutants can be used in hybrid rice. Therefore, rice male sterility has an important value in research and application, and the study of related mutants is also very vital. The mutant ms10 (male sterile 10) reported in this study was induced by ethyl methane sulfonate (EMS) in the indica maintainer line Xinong 1B. There was no significant difference between the ms10 and wild type in the vegetative growth stage. However, in the reproductive growth stage, ms10 showed that the plant became shorter, the anther became smaller and the color became lighter, and finally showed the phenotype of male sterility in comparison to the wild type. I₂-KI staining showed that the pollen was malformed and only a little was active. Scanning electron microscopy observation showed that the exine waxy layer of the ms10 anther decreased, suggesting that the protective effect on pollen was decreased. This may be one of the reasons leading to the phenotype of male sterility. Finally, the pollen showed shrinkage and collapsed, and the structure of germinating pore cover disappeared. This may be the result of sterility. Genetic analysis showed that the male sterility phenotype of the mutant was controlled by a single recessive nuclear gene. MS10 was mapped between the molecular markers IND37 and IND51 on chromosome 4, with a physical distance of 178.6 kb. These results lay the foundation for further studies on MS10.     

Genome-Wide Identification of Candidate Genes Associated with <i>β</i>-glucan Traits in a Hulled and Hulless Barley (<i>Hordeum vulgare</i> L.) Population

Barley grain is a valuable source of β-glucan, which is an important component of dietary fiber with significant human health benefits. Although the genetic basis of β-glucan biosynthesis has been widely studied, a genome-wide association study (GWAS) is still required for a scan of the candidate genes related to the complex quantitative trait based on the high-quality barley reference genome. In this study, a GWAS was conducted using a population composed of 87 barley landraces (39 hulled and 48 hulless, β-glucan from 2.07% to 6.56%) with 191,098 nucleotide polymorphisms (SNPs) markers to cover the chromosomes with the highest density. The population was divided into four sub-populations (POP1~POP4), and the β-glucan content in POP2 was significantly higher than that in other groups, in which most of the hulless barley landraces are from Qinghai-Tibet Plateau in China. Among seven SNP markers identified by GWAS, two (SNP2 and SNP3) of them showed positive correlation to β-glucan trait and the remaining five (SNP1, SNP4, SNP5, SNP6 and SNP7) showed the negative relationship. Two candidate genes linked to SNP7, HORVU7Hr1G000320 and HORVU7Hr1G000040, belong to the nucleotide triphosphate hydrolase superfamily which is probable to affect the activities of β-glucan synthase. Another candidate gene associated with SNP1, HORVU1Hr1G000010, is possibly involved in sugar response. In conclusion, our results provide new insights into the genetic basis of β-glucan accumulation in barley grains, and the discovery of new SNP markers distributed in each chromosome and the associated candidate genes will be valuable for the breeding of functional barley varieties with high β-glucan.     

Agro-Morphological Characterization and Genetic Dissection of Linseed (<i>Linum usitatissimum</i> L.) Genotypes

Linseed is a multipurpose crop and the crop needs further improvement to increase production and yield due to its high value and demand. This study aimed to assess the extent and pattern of genetic variability of forty linseed genotypes based on diverse agro–morphological and yield attributes. The field experiment was conducted following a Randomized Complete Block Design with three replications. Linseed germplasm showed a wide range of phenotypic expression, genetic variability and heritability for 30 studied traits. A low to high phenotypic coeffi- cient of variation (PCV) and genotypic coefficient of variation (GCV) were observed. The lowest genotypic (σ² g) and phenotypic variances (σ² p) were found in capsule diameter (CD), length of calyx (LC), capsule length (CL), seed length (SL), and seed breadth (SB). High broad-sense heritability (h²_b) with high genetic advance as a percentage of mean (GAM) were observed in days to germination started (DGS), days to 80% emergence (DE), plant height at 28 and 40 DAS, number of flowers (NFPP), filled capsules (NFCPP) and yield per plant (YPP) indicating additive gene action exists for these characters. Hierarchical cluster analysis separated 40 genotypes into five clusters, where Clusters I to V assembled with 13, 4, 4, 5 and 14 genotypes, respectively. Considering yield and yield attributes, Cluster-IV (G3, G4, G6, G10 and G31) genotypes showed promising while, Cluster-II (G2, G16, G35, G36) and Cluster-III (G1, G33, G39 and G40) genotypes were dominant on plant morphological traits. Based on principal component analysis (PCA), few characters such as YPP, NFPP, NFCPP, days to first flowering and capsule formation, early emergence, days to branch initiation and plant heights at different growth stages revealed important and effective traits for consideration in the selection of linseed breeding programs.     

Rice (<i>Oryza sativa</i> L.) Breeding among Hassawi Landrace and Egyptian Genotypes for Stem Borer (<i>Chilo agamemnon</i> Bles.) Resistance and Related Quantitative Traits

Rice stem borer (Chilo agamemnon Bles.) is a primary insect pest of rice and is a major limiting factor to rice production. Breeding for insect-resistant crop varieties has been an economic way of integrated pest management (IPM) as it offers a viable and ecologically acceptable approach. This study was aimed to evaluate rice genotypes for their resistance against rice stem borer. Seven parental genotypes with twenty one F1 crosses were evaluated for genotypic variation in field experiments. Analysis of variance revealed significant differences for the studied traits in almost all crosses and parents. In addition, the mean squares of parents versus their crosses were signifi- cant for stem borer resistance and other associated traits. Moreover, both general combining ability (GCA) and specific combining ability (SCA) variances were highly significant for all characters studied in the F1 generation. Based on GCA, 4 genotypes (Sakha101, Gz6903-3-4-2-1, Gz9577-4-1-1 and Hassawi) exhibited highly significant negative values for stem borer resistance (–0.53, –1.06, –0.18 and –0.49, respectively) indicating they are the best combiners for stem borer resistance. Based on SCA analysis, nine cross combinations showed highly significant negative effects for stem borer resistance. Similarly, the cross Giza178 Hassawi was the best combination with significantly highest value for early maturity. In addition, seven crosses showed highly significant negative SCA for plant height trait. On the other hand, for panicle length, number of primary branches/panicle, panicle weight and 1000-grain weight, seven, four, eight and six crosses showed highly significant positive SCA, respectively. The result further revealed that the non-additive dominance genetic variance was higher than the additive variance for all evaluated traits indicating that non-additive genetic variances have a role in their inheritance. The broad-sense heritability estimates were high for all the studied traits. The stem borer resistance was significantly correlated with panicle weight and 1000-grain weight, which also showed a highly significant correlation with grain yield/plant. Thus these traits can be effectively employed in a breeding program to confer resistance against stem borer infestation in rice. It was further supported by biplot analysis, which clustered these potentially important traits into two quadrants showing their importance in any future breeding program to control stem borer infestation. This study has contributed valuable information for evaluation of genetic diversity in the local rice germplasm and its utilization in futuristic rice genetic improvement programs.     

Estimation of Growth and Photosynthetic Performance of Two C₄ Species (<i>Pennisetum spicatum</i> (L.) Körn. and <i>Zea mays</i> L.) under a Low Temperature Treatment

Pearl millet (Pennisetum spicatum (L.) Körn.) and maize (Zea mays L.) are C₄ grass species grown for feeding humans and animals in Almadinah Almunawwarah, which is in the western part of Saudi Arabia. During the winter, the mean temperature, which drops to 14°C, represents a major problem for the growth of these species in this region. Therefore, the objectives of this research were to investigate the growth response and the photosynthetic performance of P. spicatum and Z. mays under a low temperature stress. The treatments involved daytime and nighttime temperatures of 14/12°C (low temperature) and 24/22°C (optimum temperature). The results indicated that low temperature significantly reduced all growth and physiological parameters, including seed germination, leaf expansion, leaf area, shoot length and root length of the two species compared to those of the control. Additionally, the low temperature significantly decreased the light-saturated assimilation rate (A_sat), quantum yield (ϕ), saturated rate of carbon dioxide uptake (A_max) and efficiency of carboxylation on both species compared to those of the control. Moreover, the values of Fv/Fm and the chlorophyll contents of both species were significantly reduced by low temperature compared to those of the control. It can be concluded that both species had little tolerance to low temperatures.     

<i>In Vitro</i> and <i>in Silico</i> Insights on the Biological Activities,Phenolic Compounds Composition of <i>Hypericum perforatum</i> L. Hairy Root Cultures

Three Hypericum perforatum hairy root lines (HR B, HR F and HR H) along with non-transformed roots were analyzed for phenolic compounds composition and in vitro enzyme inhibitory properties. In silico molecular modeling was performed to predict the interactions of the most representative phenolic compounds in HR clones with enzymes related to depression, neurodegeneration and diabetes. Chromatographic analyses revealed that HR clones represent an efficient source of quinic acid and hydroxybenzoic acids, epicatechin and procyanidin derivatives, quercetin and kaempferol glycosides, as well numerous xanthones. In vitro antidepressant activity of HR extracts through monoamine oxidase A (MAO-A) inhibition was attributed to the production of oxygenated and prenylated xanthones. The neuroprotective potential of HR extracts was related to the accumulation of quercetin 6-C-glucoside, epicatechin, procyanidins and γ-mangostin isomers as potential inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Vanillic acid and prenylated xanthones in HR clones as promising inhibitors of tyrosinase additionally contributed to the neuroprotective activity. Five preeminent xanthones in HR (γ-mangostin, mangiferin, garcinone C, garcinone E and 1,3,7-trihydroxy-6-metoxy-8-prenyl xanthone) along with the flavonol quercetin 6-C-glucoside effectively inhibited α-amylase and α-glucosidase indicating the antidiabetic properties of HR extracts. Transgenic roots of H. perforatum can be exploited for the preparation of novel phytoproducts with multi-biological activities.     

Improvement of Selected Morphological,Physiological, and Biochemical Parameters of Banana (<i>Musa acuminata</i> L.) Using Potassium Silicate under Drought Stress Condition Grown <i>in vitro</i>

Drought stress has become more common in recent years as a result of climate change impacts on the production of banana crops and other fruit trees. The growth and productivity of Musa spp are severely impacted by the gradual degradation of water resources and the erratic distribution pattern of annual precipitation amount. The aim of the work includes increased drought tolerance in light of water scarcity in the world as a result of the bananas’ being gluttonous for water needs. This investigation was carried out from 2019 to 2020 to study the effect of potassium silicate on morphological growth and biochemical parameters of Musa acuminata L under drought stress by PEG. As a result, drought stress reduced the morphological characteristics such as shoots number, shoot length, roots number, and survival percentage and biochemical characteristics such as chlorophyll a, b, carotenoids, stomatal status, and RWC. While proline content increased in the leaf of M. acuminata L. Media complemented with K₂SiO₃ (2 to 6 mM) either individually or in combination with PEG led to an improvement in all morphological and biochemical characteristics. The activities of CAT, POD, and PPO enzymes increased signifi- cantly compared to control. Furthermore, the lowest PPO, CAT, and POD activity were achieved. Additionally, K₂SiO₃ treatments under drought stress successfully enhanced the leaf stomatal behavior. Our results suggest that K₂SiO₃ can help to maintain plant integrity in the tested cultivar under drought stress.     

Bioinformatics and Functional Analysis of High Oleic Acid-Related Gene Gm<i>SAM22</i> in Soybean [<i>Glycine max</i> (L.) Merr.]

High yield, high quality, stable yield, adaptability to growth period, and modern mechanization are the basic requirements for crops in the 21st century. Soybean oleic acid is a natural unsaturated fatty acid with strong antioxidant properties and stability. Known as a safe fatty acid, it has the ability to successfully prevent cardiovascular and cerebrovascular disorders. Improving the fatty acid composition of soybean seeds, can not only speed up the breeding process of high-quality high-oil and high-oleic soybeans, but also have important significance in human health, and provide the possibility for the development of soybean oil as a new energy source. Hence, the aim of this study was to analyze the high oleic acid elated gene GmSAM22 in soybean. In this research the soybean oleic acid-related gene GmSAM22 was screened out by Genome-wide association analysis, a 662 bp fragment was acquired by specific PCR amplification, and the pMD18T cloning vector was linked by the use of a seamless cloning technique. Bioinformatics analysis of the signal peptide prediction, subcellular localization, protein hydrophobicity, transmembrane region analysis, a phosphorylation site, protein secondary and tertiary structure and protein interaction analysis of the protein encoded by the SAM22 gene was carried out. The plasmid of the gene editing vector is pBK041. The overexpression vector was transformed from pCAMBIA3301 as the base vector, and overexpression vector were designed. Positive plants were obtained by genetic transformation by the pollen tube channel method. Fluorescence quantitative PCR was performed on the T₂ generation plants to detect the relative expression levels in different tissues. Southern Blot was used to detect the presence of hybridization signal. Screening genes BAR, 35S, and NOS in plants were identified by conventional PCR. 10 seeds with high and low oleic acid content were chosen for quantitative PCR identification, and finally, the concentration and morphology of soybean fatty acids were identified by near-far infrared spectroscopy. On 10 seeds with an upper and lower oleic acid content, a quantitative fluorescence analysis was done. In Southern blot hybridization, the SAM22 gene was integrated into the recipient soybean plant in hands of a sole copy. Fluorescence quantitative PCR appeared that the average relative expression of the SAM22 gene in roots, stems, leaves, and seeds was 1.70, 1.67, 3.83, and 4.41, respectively. Positive expression seeds had a 4.77% increase in oleic acid content. The level of oleic acid in the altered seeds was reduced by 4.13% when compared to CK, and it was discovered that the GmSAM22 gene could be a regulatory and secondary gene that promotes the conversion of stearic acid to oleic acid in soybean. There has not been a discussion of gene cloning or functional verification. The cloning and genetic transformation of the soybean SAM22 gene can effectively increase the content of oleic acid, which lays a foundation for the study of soybean with high oleic acid.     

Biochar Application Enhanced Post-Heading Radiation Use Efficiency in Field-Grown Rice (<i>Oryza sativa</i> L.)

It has been shown that adding biochar to soil can improve nitrogen (N)uptake and utilization in rice (Oryza sativa L.). However, there is a lack ofresearch on the physiological alterations of rice as a result of the changes in nitrogen uptake due to the addition of biochar. This study conducted field experimentsin 2015 and 2016 with the goal of testing the hypothesis that the application ofbiochar would enhance radiation use efficiency (RUE) of rice by improving theplant’s ability to take in and utilize nitrogen. Our results demonstrated that theapplication of biochar (20 t ha⁻¹) induced no significant effects on pre-headingspecific leaf weight (SLW), nitrogen uptake (NUpre), and leaf area index (LAI)at heading, the ratios of LAI/NUpre and SLW/Nupre, or pre-heading RUE. However, biochar application significantly increased post-heading nitrogen uptake(NUpost), ratios of NUpost/SLW and NUpost/LAI, and post-heading RUE. Theseresults indicate that the application of biochar can improve the plant’s nitrogenuptake and RUE in field-grown rice during the post-heading period, which con-firms our hypothesis.