Germination Period Research Articles

Effects of seed treatments on the germination of Golkoy palm (Phoenix theophrasti Greuter subsp. golkoyana Boydak)

Datça palm (Phoenix theophrasti Greuter) is the only palm taxa in the European continent. Its subspecies, Golkoy palm (Phoenix theophrasti Greuter subsp. golkoyana Boydak) was recorded only in Turkey. This subspecies, which spreads in sensitive ecosystems, needs to be carefully protected. Although there are three natural populations of Datça palm in Turkey, there is only one population of Gölköy palm. This population is under threat due to factors such as tourism, pollution, urbanization, use of groundwater and forest fires. In this respect, the continuity of the species should be ensured by taking in-situ and ex-situ protection measures immediately. One of the ex-situ conservation measures involves the propagation of the species from seed. Cold-wet stratification is applied to remove dormancy in Gölköy palm seeds. In this study, GA3, ultrasound and vacuum applications at different times were applied to remove dormancy in seeds and shorten germination time. At the end of the study that lasted for 10 weeks, it was determined that GA3, vacuum and ultrasonic applications increased the germination rate of the seeds and shortened the germination period. While the highest germination rate was reached in the seeds treated with GA3, (91.4%), the germination rate was 88.3% and 88.6%, respectively, in 60 and 120 min ultrasound applications. The germination rate of the seeds in which vacuum was applied for 60 and 120 minutes was found to be 29.9% and 48%, respectively. The lowest germination was 6.3% in the control group seeds.

Morphological characterization of seeds and germination efficiency of Pinus patula var. longepedunculata and P. pseudostrobus var. oaxacana

Pinus patula and P.pseudostrobus are species of great economic importance for different communities in the Oaxaca State due tothe wood quality and wide use in forest commercial plantations and reforestation. The objective of this research was to evaluate themorphological variation of seeds and their germination efficiency of two pine species under greenhouse conditions. In 2022,selected seeds of outstanding phenotypes was obtained from the Instituto Nacional de Investigaciones Forestales, Agrícolas yPecuarias (INIFAP); three seed samples of 10 g per species were made, the number of seeds was counted, and the equatorial (DE)and polar (DP) diameters and shape coefficient (CF=DE/DP) were measured; sowing was carried out in 49 cavity trays with amixture of mountain forest soil, vermiculite®, agrolite® and Peat Moss® with a 4:1:1:2 ratio. Germination was counted daily andvigor indicators were determined: germinative energy (EG), energy period (PE), germinative speed (VG) and germination speedindex (IVG). Data were analyzed using t-Student tests and regression analysis (α=0.05) in the SAS program. Including days aftersowing (DDS) in the model, we found that between 78 and 84 % of the existing variation in the percentage of accumulatedgermination was explained in both species. P.pseudostrobus presented more spherical (CF=0.41) and heavier seeds (24.27 mg)with an energy period of 69 % at 22 DDS; on the other hand, P.patula has elongated (CF=0.31) and light seeds (8.20 mg) with agreater energy period of 83% at 20 DDS. Both species germinate after 15 days; however, P.patula has a higher germination rateand a higher germination percentage, it is necessary to use germplasm from outstanding phenotypes to guarantee the reproductiveefficiency of the seed and subsequent seedling quality.

Assessment of Changes in Climatic Variables in Hadeja-Nguru Wetlands

The study assessed the changes in climatic variables in Hadeja Nguru wetland. Parameters evaluated includes; variations in climatic variables over a 40-year window (1979-2019) Data on climatic variables on daily basis were obtained for a period 40years and Satellite imageries of the study area were officially downloaded from the United State Geological Survey website. Paired sample T-test and chi-square test of association were used in assessing the variation in climatic factors. Result showed that indicated sparse distribution as a major effect of climate change. Decreased in crops production, land shade, destruction of harvested crops, increase in insect population and shortened seed germination period were thought to be the consequences of reduction in rainfall, excessive rainfall, irregular rainfall pattern and increase in temperatures, Food scarcity, reduction in income due to depletion of crops were also pinpointed as impacts of climate change.. Maximum and minimum temperatures, precipitation, wind speed, relative humidity and solar intensity between 1979 and 2019 were 40.07 and 36.46, 1180.36mm and 58.18mm, 2.97m/s and 2.29m/s, 0.33g/kg and 0.22g/kg and 23.68w/m2 and 20.70w/m2 respectively. There was also a significant Chi-square value (33.481a) between respondents’ effect of climate change and increase in farm sizes. The paper concluded that there were fluctuations in climatic variables. There is the need to put in place right policies to protect and preserve wetlands to enhance their sustainability and resilience to climatic changes and variability.

The synergistic effect of ascorbic and abscisic acids on enriching AVC-dominated avenanthramides in oat germination process

Avenanthramides are a group of antioxidants, of which avenanthramide C (AVC) shows the strongest antioxidant activity. Germination is conducive to the accumulation of total avenanthramides. However, it is unclear how to regulate the proportion of AVC in total avenanthramides by controlling the oat-germination process. To increase the proportion of AVC in total avenanthramides, single or combined treatments with abscisic (ABA) and ascorbic acid (Asc) during the steeping or germination period was performed. Compared to the control (541 μg/g dry weight), the 300 μM-ABA treatment during the steeping period significantly increased the proportion of AVC in total avenanthramides from 30.93 to 40.70%, which was accompanied by a remarkable increase in the content of total avenanthramides (1.8- fold). The content of total avenanthramides and the proportion of AVC within increased significantly (3.35-fold and by 9.28%, respectively) compared to the control when successively treated with 300 μM ABA during the steeping period and 20 mM Asc during the germination period. Moreover, ABA and Asc were synergistic in increasing the activities of hydroxycinnamoyl-CoA:hydroxyanthranilate N-hydroxycinnamoyl transferase (HHT) and tyrosine ammonia-lyase (TAL), but reduced the activity of peroxidase (POD), which resulted in the accumulation of AVC-dominated avenanthramides. These findings provide novel information on the bio-concentration of AVC by regulation of the oat-germination process.

Transcriptome and metabonomics combined analysis revealed the energy supply mechanism involved in fruiting body initiation in Chinese cordyceps

Chinese cordyceps was one of most valuable traditional Chinese medicine fungi. To elucidate the molecular mechanisms related to energy supply mechanism involved in the initiation and formation of primordium in Chinese cordyceps, we performed the integrated metabolomic and transcriptomic analyses of it at pre-primordium period, primordium germination period and after-primordium period, respectively. Transcriptome analysis showed that many genes related to ‘starch and sucrose metabolism’, ‘fructose and mannose metabolism’, ‘linoleic acid metabolism’, ‘fatty acids degradation’ and ‘glycerophospholipid metabolism’ were highly up-regulated at primordium germination period. Metabolomic analysis showed many metabolites regulated by these genes in these metabolism pathways were also markedly accumulated at this period. Consequently, we inferred that carbohydrate metabolism and β-oxidation pathway of palmitic acid and linoleic acid worked cooperatively to generate enough acyl-CoA, and then entered TCA cycle to provide energy for fruiting body initiation. Overall, our finding provided important information for further exploring the energy metabolic mechanisms of realizing the industrialization of Chinese cordyceps artificial cultivation.

Modification on phenolic profiles and enhancement of antioxidant activity of proso millets during germination.

Changes in phenolic profiles and antioxidant activity of three varieties of proso millet during germination were investigated. Total phenolic content (TPC) and total flavonoid content (TFC) increased significantly with prolongation in germination period. After germination for 6days, TPC of the free and bound fractions increased 6.30-8.66-fold and 77.65-116.18%, respectively. The free and bound phenolic compounds identified by UPLC-MS/MS, displayed significant variations. Feruloylquinic acid and N,N'-bis-(p-coumaroyl)-putrescine biosynthesized during germination, are reported for the first time in proso millets. Other phenolics including trans- and cis-ferulic, trans-p-coumaric, vanillic acid and ferulic acid dimers (DFAs) were increased significantly along with a new DFA (8,5'-DFA) seemingly produced during germination. The germinated proso milllets displayed superior antioxidant activity than the corresponding ungerminated samples indicating that germination could be one applicable method for improving phenolic profiles and antioxidant capacity of proso millets. Thus germinated proso millet could be exploited as a functional ingredient in several products.

Screening and validation of salt-stress responsive cg-SSR markers in wheat (Triticum aestivum L.) germplasm of Pakistan.

Soil salinity has been affecting wheat production worldwide over past few decades. Evaluation of wheat genotypes for salinity tolerance at germination and vegetative growth level is crucial. Marker assisted selection is a technique used extensively for choosing salt-tolerant genotypes from breeding populations to introduce novel genes. The current study's main goal was to discover salt-stress resistant genes; genetic divergence and genome-wide connection by using recently designed candidate gene-based simple-sequence-repeat markers (cg-SSRs). The phenotypic connection of morphological features during the germination growth stage i.e., germination period, root length/weight and shoot length/weight, and vegetative growth stages i.e., root length/weight and shoot length/weight were tested in a group of 50 wheat genotypes. Significant difference was observed in germination rate, root length and weight among control and saline treatments. Total 30 SSR markers were utilized to test salinity resistance genes in wheat genotypes. Three (10%) of which were monomorphic, one (3.34%) showed no result, and the other 26 (86%) were polymorphic. Using 30 polymorphic markers discovered total 37 alleles. The polymorphic information content (PIC), quantifies each SSR locus capacity to discriminate between wheat, varied from 0.00 to 0.38 with an average of 0.19. Association analysis revealed that 26 primers were associated with morphological features, 03 with root length and the remaining 23 with germination. Utilizing morphological data, stress tolerance index (STI) was designed concluding that Auqab-2000, Margala-99 and Ufaq showed better resistance against salinity among other wheat genotypes. Cluster analysis demonstrated that wheat genotypes have vast genetic variability.

Histone Deacetylases HD2A and HD2B Undergo Feedback Regulation by ABA and Modulate Drought Tolerance via Mediating ABA-Induced Transcriptional Repression.

Histone deacetylation catalyzed by histone deacetylase plays a critical role in gene silencing and subsequently controls many important biological processes. It was reported that the expression of the plant-specific histone deacetylase subfamily HD2s is repressed by ABA in Arabidopsis. However, little is known about the molecular relationship between HD2A/HD2B and ABA during the vegetative phase. Here, we describe that the hd2ahd2b mutant shows hypersensitivity to exogenous ABA during the germination and post-germination period. Additionally, transcriptome analyses revealed that the transcription of ABA-responsive genes was reprogrammed and the global H4K5ac level is specifically up-regulated in hd2ahd2b plants. ChIP-Seq and ChIP-qPCR results further verified that both HD2A and HD2B could directly and specifically bind to certain ABA-responsive genes. As a consequence, Arabidopsis hd2ahd2b plants displayed enhanced drought resistance in comparison to WT, which is consistent with increased ROS content, reduced stomatal aperture, and up-regulated drought-resistance-related genes. Moreover, HD2A and HD2B repressed ABA biosynthesis via the deacetylation of H4K5ac at NCED9. Taken together, our results indicate that HD2A and HD2B partly function through ABA signaling and act as negative regulators during the drought resistance response via the regulation of ABA biosynthesis and response genes.

The development and transcriptome regulation of the secondary trunk of Ginkgo biloba L.

Secondary trunk Ginkgo biloba is one of the specific germplasms of G. biloba. In this study, paraffin sectioning, high-performance liquid chromatography and transcriptome sequencing technology were used to study the development of the secondary trunk of G. biloba from the morphological, physiological and molecular levels. The results showed that the secondary trunk of G. biloba originated from the latent buds in the stem cortex at the junction of the root and stem of the main trunk. The development process of secondary trunk was divided into 4 periods: the dormancy period of the secondary trunk buds, the differentiation period, the formation period of transport tissue, and the budding period. Transcriptome sequencing was performed by comparing the germination period and elongation growth period of the secondary trunk with the normal parts of the same period where no secondary trunks occurred. Differential genes involved in phytohormone signal transduction, phenylpropane biosynthesis, phenylalanine metabolism, glycolysis and other pathways can regulate not only the inhibition of early dormant buds but also the later development of the secondary trunk. Genes related to IAA synthesis are upregulated and indole-3-acetic acid content is increased, leading to the up-regulated expression of IAA intracellular vector genes. The IAA response gene (SAUR) receives and responds to IAA signals to promote the development of the secondary trunk. Through the enrichment of differential genes and functional annotations, a key regulatory pathway map for the occurrence of the secondary trunk of G. biloba was sorted out.

Seed Dormancy and Germination Behaviour of Palmyrah: A Review

Palmyrah (Borassus flabellifer L.) is a slow growing, dioecious, drought resistant palm and considered to be native of Tropical Africa. It is cultivated as well as found growing in wild in the Indian subcontinent. It is distributed in India, Burma, Africa and Sri Lanka. Several problems are encountered in germination of seeds in palmyrah such as poor, protracted germination and prolonged nursery period. The main reasons for the failure of seeds to germinate in suitable conditions are either dead or dormant. The delayed germination of palmyrah might be due to the stony endocarp acting as a physical barrier to imbibition or imposing mechanical resistance to embryo enlargement. Against this backdrop, this review focuses on seed dormancy, pre-sowing seed treatment, nursery technology, and seed storage behaviour of palmyrah.Palmyrah (Borassus flabellifer L.) is a slow growing, dioecious, drought resistant palm and considered to be native of Tropical Africa. It is cultivated as well as found growing in wild in the Indian subcontinent. It is distributed in India, Burma, Africa and Sri Lanka. Several problems are encountered in germination of seeds in palmyrah such as poor, protracted germination and prolonged nursery period. The main reasons for the failure of seeds to germinate in suitable conditions are either dead or dormant. The delayed germination of palmyrah might be due to the stony endocarp acting as a physical barrier to imbibition or imposing mechanical resistance to embryo enlargement. Against this backdrop, this review focuses on seed dormancy, pre-sowing seed treatment, nursery technology, and seed storage behaviour of palmyrah.

Application of Cold Storage and Short In Vitro Germination for Somatic Embryos of Pinus radiata and P. sylvestris.

Somatic embryogenesis (SE) is an advanced vegetative propagation technology that, when used in combination with breeding and cryopreservation, offers the forest industry a powerful tool for the deployment of elite genotypes. Germination and acclimatization are critical and cost-intensive phases in the production of somatic plants. The efficient conversion of somatic embryos into robust plants is a necessity if a propagation protocol is to be successfully adopted by the industry. In this work, these late phases of the SE protocol of two pine species were investigated. A shortened germination protocol and more controlled acclimatization were investigated for Pinus radiata, testing embryos from 18 embryogenic cell lines. A more simplified protocol, including a cold storage phase, was also compared among 10 of these cell lines. A shortened germination period and more controlled protocols significantly improved the acclimatization of somatic embryos directly from the lab to the glasshouse. When results for all cell lines were pooled, there were significant improvements in all growth characteristics (shoot height, root length, root collar diameter, and root quadrant score). When the more simplified protocol involving cold storage was tested, improvements were seen in the root architecture. For Pinus sylvestris, the late phases of somatic embryogenesis were investigated on seven cell lines in a set of two trials (four to seven cell lines per trial). During the germination phase, a shortened and simplified in vitro period, a cold storage option and basal media were explored. Viable plants were obtained from all treatments. However, there is still the need to improve germination and related protocols together with growing regimes for Pinus sylvestris. The improvements to protocols presented here, particularly for Pinus radiata, result in greater survival and quality of somatic emblings, leading to reduced costs and increased confidence in the technology. Simplified protocols using a cold storage option show great promise and, with some further research, could lead to reductions in the cost of the technology.

Germination and Early Seedling Growth of Three Arabica Coffee Varieties at Four Seed Soaking Water Temperatures

It takes three weeks to analyze the germination percentage of Arabica coffee seeds germinated using paper and a three-day water-soaking method. This 3- week period is considered too long for seed distribution to remote areas. Thus, we need to modify this germination test needs to be modified to have a shorter test time. Temperature treatment is one method to break the seed dormancy period for faster germination. This study aimed to obtain a faster and more precise method of germination test on Arabica coffee seeds. This study employed a 3 x 4 factorial complete randomized block design with three replications in which Arabica coffee varieties of Gayo-1, Kartika-1, and Sigararutang as the first factor and the temperature of the soaking water of the seeds (25 0C, 50 0C, 75 0C, and 90 0C) as the second factor. The research was conducted at the Plant Breeding Laboratory, Indonesian Coffee and Cocoa Research Institute (ICCRI), for four months. Findings showed that the interaction between treatments was only found in seed germination percentage. Soaking in room temperature water (control) for three days was better than using water at 50 0C, 75 0C, and 90 0C on the germination percentage, sprout length, and vigor index. Observations of Arabica seed germination could be shortened to 14 days compared to the standard 21-day observation. During the seedling phase, the shoot growth and root growth of the Arabica coffee seeds soaked in water at 50 0C showed no significant difference from the control. Soaking at 75 0C and 90 0C damaged the embryo and resulted in rotten seeds. Different varieties led to different germination percentages, sprout lengths, and fresh weight of seedling shoots. The method of soaking at 50 0C for 30 minutes could be used as an alternative in germination test of Arabica coffee seeds because it showed small negative effect on germinated seed and seedling quality but it shorten thetesting time for three days.

Analysis of Fatty Acid Composition in Sprouted Grains.

A whole-grain diet is associated with the prevention of metabolic syndromes, including obesity, diabetes, and cardiovascular diseases. Sprouting improves the nutritional profile and bioactive properties of grains, which are important for use as raw ingredients in the food industry. The aim of this review was to examine the lipid and fatty acid composition of germinated grains. The methods discussed include germination and analytical procedures for determining fat and fatty acid contents of grains. The effects of sprouting on the fat content and storage stability of grains were also assessed. Lipid levels ranged from 1.43% to 6.66% in the sprouted grains. The individual fatty acid content of grains changed depending on the germination conditions (17-37 °C, 1-9 days). Limited findings showed that sprouting grains at higher temperatures (20-25 °C) and longer times generated a healthy balance of omega-6 and omega-3 fatty acids, which is beneficial to humans. Future studies are needed to determine the optimum incubation and germination periods specific to each grain to improve the omega-6/omega-3 ratio. Free fatty acids were produced more slowly and levels of oxidation products were lower in sprouted grains than in the raw ingredients when stored for a year. Additional studies are required to investigate the oxidative stability and shelf life of sprouted grains.

Effect of Acid Pretreatment of Seeds on the Germination and Early Growth of Albizia lebbek (L) Benth in Makurdi, Benue State-Nigeria

The seeds of A. lebbeck exhibit physical dormancy, which leads to poor seed germination due to a tough seed coat, which has prevented the species from being domesticated in the study area. Pre-sowing treatments are therefore necessary to increase seed germination and reduce germination period. This study aims at the evaluation of the impact of acid pretreatment on seed dormancy and growing seedlings of A. lebbeck for the establishment of plantations in Benue state, Nigeria, where it is lacking. The experiment was laid out in a completely randomized design with six pretreatments (soaked) with the used of acids. The pretreatments include: sulphuric acid (70 % H2SO4) for 2 minutes, 5 minutes, and 10 minutes; nitric acid (70 % HNO3) for 2 minutes, 5 minutes, and 10 minutes; and untreated seeds (control); and replicated thrice. Two seeds were sown in each plastic pot and later thinned to one seed per pot after germination. A total of 144 plastic pots were used. The immersion in 70 % nitric acid for 5 minutes as pretreatment of A. lebbeckyielded the highest germination percentage (50%) and immersion in nitric acid for 2 minutes had the highest emergence index (38). According to the study's findings, pre-treating A. lebbeck with 70 % nitric acid breaks dormancy better and promotes faster growth. Thus, it is recommended that pretreatment of A. lebbeck seeds with 70% nitric acid for five minutes before sowing should be adopted to grow the species faster in the study area.

Influence of basic soil treatment and moisture supply on the structural elements of soybean harvest

The article presents the results of studying the influence of methods of basic tillage and moisture availability on the elements of the structure of the soybean crop: the mass of seeds per plant, the number of beans and seeds per plant, the height of the plant, the weight of 1000 seeds and the yield of soybeans of the Volma variety, after winter wheat. It was found that on average in 2020-2022. Moisture conditions developed in such a way that among the main tillage methods, high yield structure and yield were obtained in the variant with plowing by 22-24 cm - 2.2 t/ha, slightly less yield was obtained by non-moldboard loosening by 22-24 cm - 2 0 t/ha, disking with a processing depth of 16-18 cm produced the least amount of grain - 1.9 t/ha. In addition, it was noted that the method of basic processing affects the amount and dynamics of moisture in the soil during the growing season. During the germination period, the largest moisture reserves were recorded on non-moldboard loosening, and the smallest - on disking. In the flowering phase, when soybean plants urgently need moisture to form a crop, the largest amount of it was in plowing, and the smallest - in disking.

Effects of pre-sowing treatments and seed sources on seed germination of Phytolacca acinosa Roxb.

Seed pre-treatments improve germination under diverse environmental conditions. The present study assessed the effects of pre-sowing treatments and various seed sources on seed germination of Phytolacca acinosa Roxb.- an important medicinal plant species growing in Kashmir Himalaya. Seeds were collected from five different sites of the Kashmir Himalaya, India, and were treated with 10 different pre-sowing treatments including control, gibberellic acid (GA3; 100 ppm), indole acetic acid (IAA; 50 ppm), indole butyric acid (IBA; 50 ppm), kinetin (150 ppm), potassium nitrate (KNO3; 150 ppm), thiourea (150 ppm), gibberellic acid plus scarification (GA3; 100 ppm+SC), mechanical scarification and sulphuric acid (H2SO4) treatment for 20 min. The highest seed germination (83.6%) along with the maximum seedling vigor index (SVI) of (7.92) was found in seeds treated with 150 ppm thiourea followed by scarified seeds treated with 100 ppm gibberellic acid (66.00%) and KNO3 (61.2%). The maximum germination index (GI) (0.70), mean daily germination (MDG) (6.69% seeds per day), and mean germination time (MGT) (6.58 days) were recorded for seeds treated with GA3 (100 ppm) plus scarification. Among the five seed sources, no significant differences were observed in the seed germination. However, pre-treatments, as well as the interaction effect of seed source variation and pre-treatments showed significant differences in the measured germination parameters (i.e., germination starting dates, closing dates, germination period, germination percentages, GI, and MGT). The treatment with thiourea (150 ppm), KNO3 (150 ppm), and a combination of scarification and 100 ppm GA3 are the most effective ways of enhancing the seed germination of P. acinosa. Present study will have significant implications for successful germination, large-scale cultivation, sustainable utilization, and conservation of P. acinosa by reducing its exploitation from natural wild populations.

The Isolation, Immobilization, and Characterization of Urease from The Seeds of Winged Bean (Psophocarpus tetragonolobus (L.) DC.

Urease has been utilized in the field of health and industry. Urease is commonly used in the form of free enzyme, so that the utilization is limited. Urease efficiency can be improved using immobilization enzyme. This research aimed to do the urease isolation, immobilization, and characterization from the winged bean seeds. This research was started by determining the amino-acid content of winged bean seeds using the Liquid chromatography-mass spectrometry (LCMS). The winged bean seeds were germinated and extracted. The obtained crude extract’s activity was determined using Nessler reagent and measured using UV-Vis spectrophotometer with the wavelength of 500 nm. The urease of winged bean seeds was immobilized using the alginate matrix. The optimization of urease-immobilized beads could be made through the variations of natrium alginate concentration and beads formation periods in solution CaCl2. Characterization free and immobilized urease were made using the variations of urea substrate concentration, pH, temperature, and also the repeated utilization of immobilized urease. Winged bean seeds are rich with essential amino acid, such as leucine, isoleucine, histidine, phenylalanine, and valine. The urease obtained from the winged bean seeds had the optimum activity in the germination period of 8 days. The urease immobilization showed the optimum condition in the natrium alginate concentration of 5% (w/v) and beads formation period in solution CaCl2 for 60 minutes. The characterization results of free urease and immobilization had the optimum condition at the urea substrate of 0.2 M, and pH 7. Free urease had the optimum temperature of 35 oC, while the immobilized urease had the optimum temperature of 40 oC. The immobilized urease had the utilization stability up to 5 times with the relative activity of 48%. The EDX analysis results showed that the alginate did not contain N, while alginate urease beads contained N as much as 12%.

First report of Colletotrichum spaethianum causing anthracnose disease on Bletilla striata

Bletilla striata is a traditional Chinese medicine plant. Guizhou Province is the largest producer of B. striata, with the biggest cultivation area and highest yield in China. Anthracnose is the main disease affecting the crop. In July 2021, an anthracnose outbreak occurred in Shibing County, Guizhou Province, seriously affecting the yield and quality of B. striata. Thirty samples of B. striata anthracnose were collected from Shuangjing, Niudachang, and Yangliutang towns in three main planting areas of Shibing County to clarify the causal agent of B. striata anthracnose. Fifty anthracnose strains were isolated by tissue isolation and single-conidium culture. Through morphological observation and multigene phylogenetic analysis of the internal transcribed spacer, actin, beta-tubulin, glyceraldehyde-3-phosphate dehydrogenase and chitin synthase genes, the isolated strains were identified as Colletotrichum spaethianum. The infection process of C. spaethianum on B. striata leaves was observed by cell tissue staining. The results showed that at 25°C, the conidia of C. spaethianum on B. striata leaves began to germinate after 3 h, and the peak period of conidia germination was 8 h. Appressoria formation peaked after 24 h. During 48–72 h, the hyphae randomly expanded horizontally and vertically on the host surface, gradually forming a reticular distribution. This study is the first report of C. spaethianum causing anthracnose in B. striata. Our study clarifies the infection and development process of C. spaethianum on B. striata leaves, thus providing a theoretical basis for further study on the monitoring of B. striata anthracnose.

Discontinuous low temperature stress and plant growth regulators during the germination period promote roots growth in alfalfa (Medicago sativa L.)

In high-cold regions, alfalfa is susceptible to cold damage during the seed germination. The effects of discontinuous low temperature stress and plant growth regulators (PGRs) on alfalfa were studied in response to the high day/night temperature differentials in the area. The experiments included seed germination, seedling cold tolerance and plant recovery. Variable temperatures (VT) of 0 °C/15 °C, 5 °C/20 °C and 10 °C/25 °C were set and seeds were soaked with alginate oligosaccharides (AOS), brassinolide (BR) and diethyl aminoethyl hexanoate (DA-6) during the germination period. Parameters such as seed germination and mean germination time (MGT), phenylalanine ammonia-lyase (PAL) activity and oligomeric proanthocyanidins (OPC) content of early seedlings, dry matter accumulation and root crown of the restored plants were analysed. The results showed that low variable-temperature (LVT) stress prolonged the MGT but had little inhibitory effect on germination percentage. Early seedlings adapted to LVT stress by regulating their own water and OPC content, PAL activity and other parameters. LVT induced early alfalfa seedlings to increase their underground biomass by shortening root length and increasing root diameter, and those that had accumulated more underground biomass had faster growth rates and higher total biomass when the ambient temperature rose. AOS also promoted an increase in root crown diameter and root dry weight. This research proved that LVT stress and AOS during the germination process can lead to better growth of alfalfa in high cold regions.

Alleviation of drought stress through foliar application of thiamine in two varieties of pea (Pisum sativum L.)

ABSTRACT Drought stress poorly impacts many morphological and physio-biochemical processes in plants. Pea (Pisum sativum L.) plants are highly nutritious crops destined for human consumption; however, their productivity is threatened under drought stress. Thiamine (vitamin B1) is well-known essential micronutrient, acting as a cofactor in key metabolic processes. Therefore, this study was designed to examine the protective effect of foliar application of thiamine (0, 250, and 500 ppm) on two varieties of pea plants under drought stress. Here, we conducted the pot experiment at the Government College Women University, Faisalabad, to investigate the physio-biochemical and morphological traits of two pea varieties (sarsabz and metior) grown under drought stress and thiamine treatment. Drought stress was applied to plants after germination period of 1 month. Results showed that root fresh and dry weight, shoot fresh and dry weight, number of pods, leaf area, total soluble sugars, total phenolics, total protein contents, catalase, peroxidase, and mineral ions were reduced against drought stress. However, the application of thiamine (both 250 and 500 ppm) overcome the stress and also enhances these parameters, and significantly increases the antioxidant activities (catalase and peroxidase). Moreover, the performance of sarsabz was better under control and drought stress conditions than metior variety. In conclusion, the exogenous application of thiamine enabled the plants to withstand drought stress conditions by regulating several physiological and biochemical mechanisms. In agriculture, it is a great latent to alleviate the antagonistic impact of drought stress on crops through the foliar application of thiamine.