Seed Germination Vigor Research Articles

Evaluation of cucumber seed germination vigor under salt stress environment based on improved YOLOv8.

Seed germination vigor is one of the important indexes reflecting the quality of seeds, and the level of its germination vigor directly affects the crop yield. The traditional manual determination of seed germination vigor is inefficient, subjective, prone to damage the seed structure, cumbersome and with large errors. We carried out a cucumber seed germination experiment under salt stress based on the seed germination phenotype acquisition platform. We obtained image data of cucumber seed germination under salt stress conditions. On the basis of the YOLOv8-n model, the original loss function CIoU_Loss was replaced by ECIOU_Loss, and the Coordinate Attention(CA) mechanism was added to the head network, which helped the model locate and identify the target. The small-target detection head was added, which enhanced the detection accuracy of the tiny target. The precision P, recall R, and mAP of detection of the model improved from the original values of 91.6%, 85.4%, and 91.8% to 96.9%, 97.3%, and 98.9%, respectively. Based on the improved YOLOv8-ECS model, cucumber seeds under different concentrations of salt stress were detected by target detection, cucumber seed germination rate, germination index and other parameters were calculated, the root length of cucumber seeds during germination was extracted and analyzed, and the change characteristics of root length during cucumber seed germination were obtained, and finally the germination activity of cucumber seeds under different concentrations of salt stress was evaluated. This work provides a simple and efficient method for the selection and breeding of salt-tolerant varieties of cucumber.

SlWRKY37 targets SlLEA2 and SlABI5-like7 to regulate seed germination vigor in tomato

Seed germination is a critical phase for the life cycle and propagation of higher plants. This study explores the role of SlWRKY37, a WRKY transcription factor in tomato, in modulating seed germination. We discovered that SlWRKY37 expression is markedly downregulated during tomato seed germination. Through CRISPR/Cas9-mediated editing, we demonstrate that SlWRKY37 knockout enhances germination, while its overexpression results in a delay compared to the wild type. Transcriptome analysis revealed 679 up-regulated and 627 down-regulated genes in Slwrky37-CRISPR deletion mutants relative to the wild type. Gene ontology (GO) enrichment analysis indicated these differentially expressed genes are linked to seed dormancy, abscisic acid homeostasis, and protein phosphorylation pathways. Bioinformatics and biochemical assays identified SlABI5-like7 and SlLEA2 as key transcriptional targets of SlWRKY37, integral to tomato seed dormancy regulation. Additionally, SlWRKY37 was found to be post-translationally phosphorylated at Ser65, a modification crucial for its transcriptional activation. Our findings elucidate the regulatory role of SlWRKY37 in seed dormancy, suggesting its potential as a target for gene editing to reduce seed dormancy in tomato breeding programs.

Laboratory Safety Evaluation and Weed Control Potential of Pre- and Post-Emergence Herbicides for Quinoa

In this study, we aimed to identify suitable herbicides for quinoa fields in Anhui Province and explore the value of their potential application in order to achieve the sustainable weed management of the crop and tackle the global issue of unregistered herbicides in quinoa fields. Employing a pre-emergence seed soaking method, we evaluated the effects of different herbicides, such as anilofos, prometryn, pendimethalin, and atrazine on the germination inhibition rate of quinoa seeds, as well as their impacts on the growth indicators of quinoa seedlings. Our findings show that, while these herbicides initially suppressed quinoa seed germination, this effect decreased over time, allowing for the successful germination of all seeds, suggesting the existence of a recovery mechanism in quinoa. An increase in herbicide concentration was correlated with significant decreases in the germination vigor and index of quinoa seeds, along with a decrease in plant height, root length, and fresh weight. Notably, anilofos, prometryn, pendimethalin, and atrazine demonstrated significant inhibitory effects on quinoa seedlings, thus providing critical insights into the sensitivity of quinoa to these chemicals. Greenhouse pot experiments showed that pre-emergence herbicides, such as napropamide, pretilachlor, s-metolachlor, and anilofos, and post-emergence herbicides, including fluroxypyr, penoxsulam, clethodim, quizalofop-P-ethyl, oxaziclomefone, metamifop, benzobicyclon, nicosulfuron, and pinoxaden, are safe for quinoa and suitable for further field trials, broadening the options for integrated weed management strategies. The results of the mixture experiments indicated that penoxsulam and metamifop are safe for quinoa at a ratio of 1:4.6, and their combined activities against dominant weeds in quinoa fields in Anhui Province, such as Digitaria sanguinalis, Cyperus iria, and Amaranthus viridis, were higher than those of single-agent doses, with fresh weight inhibition rates ranging from 66.98% to 92.16% and selectivity indexes ranging from 176.88 to 3282.17. Therefore, this mixture offers a promising approach to enhanced weed control in a sustainable manner.

YOLOv8-Peas: a lightweight drought tolerance method for peas based on seed germination vigor.

Drought stress has become an important factor affecting global food production. Screening and breeding new varieties of peas (Pisum sativum L.) for drought-tolerant is of critical importance to ensure sustainable agricultural production and global food security. Germination rate and germination index are important indicators of seed germination vigor, and the level of germination vigor of pea seeds directly affects their yield and quality. The traditional manual germination detection can hardly meet the demand of full-time sequence nondestructive detection. We propose YOLOv8-Peas, an improved YOLOv8-n based method for the detection of pea germination vigor. We constructed a pea germination dataset and used multiple data augmentation methods to improve the robustness of the model in real-world scenarios. By introducing the C2f-Ghost structure and depth-separable convolution, the model computational complexity is reduced and the model size is compressed. In addition, the original detector head is replaced by the self-designed PDetect detector head, which significantly improves the computational efficiency of the model. The Coordinate Attention (CA) mechanism is added to the backbone network to enhance the model's ability to localize and extract features from critical regions. The neck used a lightweight Content-Aware ReAssembly of FEatures (CARAFE) upsampling operator to capture and retain detailed features at low levels. The Adam optimizer is used to improve the model's learning ability in complex parameter spaces, thus improving the model's detection performance. The experimental results showed that the Params, FLOPs, and Weight Size of YOLOv8-Peas were 1.17M, 3.2G, and 2.7MB, respectively, which decreased by 61.2%, 61%, and 56.5% compared with the original YOLOv8-n. The mAP of YOLOv8-Peas was on par with that of YOLOv8-n, reaching 98.7%, and achieved a detection speed of 116.2FPS. We used PEG6000 to simulate different drought environments and YOLOv8-Peas to analyze and quantify the germination vigor of different genotypes of peas, and screened for the best drought-resistant pea varieties. Our model effectively reduces deployment costs, improves detection efficiency, and provides a scientific theoretical basis for drought-resistant genotype screening in pea.

Effects of microplastics on seed germination and seedling physiological characteristics of Spinacia oleracea under alkali stress.

Microplastics, a type of new environmental pollutant, have received much attention for their negative effects on organisms and environment. We examined the effects of microplastics on seed germination and seedling physiological characteristics of spinach (Spinacia oleracea) under alkali stress, taking polystyrene microspheres with a diameter of 100 nm (200, 400, 800, 1600 mg·L-1) as the microplastic treatment, and mixed NaHCO3 and Na2CO3 as alkaline salt solution (5, 10, 20, 40 mmol·L-1) according to the molar ratio of 1:1. The results showed that the presence of MPs (≥400 mg·L-1) inhibited seed germination, and that the length of roots and shoots increased at low while decreased at high concentration of MPs. Different concentrations of alkali alone could inhibit seed germination, root and bud elongation. With the increases of MPs concentration, SOD activity of spinach seedlings gradually decreased, while POD activity firstly increased and then decreased, and chlorophyll content increased at low concentration (200 mg·L-1) and decreased significantly at medium and high concentration (≥400 mg·L-1). Different alkali stresses reduced chlorophyll content of spinach seedlings, and the effects on SOD and POD were 'promotion at low concentration and inhibition at high'. In the treatments of microplastics (200, 800 mg·L-1) and alkali (5, 20 mmol·L-1) combined exposure, germination of spinach seeds was inhibited, and chlorophyll content decreased. The activities of SOD and POD in spinach seedlings were reduced under the combined exposure except the treatment of 200 mg·L-1 MPs and 5 mmol·L-1 alkali. Compared to the alkali stress, the combination of low concentration of MPs (200 mg·L-1) and alkali could improve germination rate, germination index, germination vigor and vigor index of seeds, and significantly promoted the elongation of roots and shoots, while the addition of high concentration of MPs (800 mg·L-1) reduced the germination rate, germination index, germination vigor and vigor index of seeds and inhibited the growth of roots and buds. The different concentrations of combined exposure inhibited the activities of SOD and POD and decreased the content of chlorophyll in spinach seedlings.

An improved multi-objective brainstorming algorithm with the application of rapeseed germination characteristics optimization

As one of the most important raw materials for daily edible oil, the annual production and quality of oilseed rape have a great impact on the daily lives of people and the development of the country. The germination quality of rapeseed directly affects the future yield and quality of oilseed rape, and seed germination vigor (SGV) and chlorophyll content (CC) are important factors affecting the quality of rapeseed germination. It is very necessary to make the rapeseeds have optimal germination characteristics and seed germination vigor at the early stage of germination by controlling the combination of each decision variable at the segmented harvest. The two objectives are coupled with each other to form a complex multi-objective optimization problem, which is important in the current research field of the rapeseed problem. To solve this problem, a modified brainstorming optimization algorithm based on OPTICS clustering, named MOPCBSO, is proposed in this study. The algorithm uses optics clustering as a new clustering method, chaotic mutation as a new updating method for individuals, and introduces an elite strategy and a tracking strategy. 19 benchmark test functions and nonparametric tests are adopted to examine the performance of the MOPCBSO compared with other optimization algorithms. The results show that the proposed algorithm has significant advantages over other algorithms in terms of convergence and comprehensiveness, demonstrating the effectiveness of the algorithm improvement. To optimize rapeseed germination characteristics, mathematical models are built, in which, cut-down time, after-ripening time and stubble height are selected as decision variables, while chlorophyll concentration and seed germination vigor in seeds as the target characteristics. The data of oliseed rape field trials were collected from 2020 to 2021 in Huanggang City, Hubei Province. Finally, the optimal solution for the germination characteristics of rapeseeds was obtained by the MOPCBSO, which provided an effective basis for the subsequent rapeseed production experiments.

Transcriptomic and QTL Analysis of Seed Germination Vigor under Low Temperature in Weedy Rice WR04-6

Low temperature is one of the major factors affecting rice germination, and low temperature germination (LTG) is an important agronomic trait. Although significant progress has been made in the study of rice LTG, the molecular mechanism of LTG remains poorly understood. To explore more rice LTG gene resources, we first demonstrated that weedy rice WR04-6 (Oryza sativa f. spontanea) had significantly higher LTG ability at 10 °C than the cultivated rice Qishanzhan (QSZ Oryza sativa L. ssp. indica). RNA-seq was used to investigate the gene expression of WR04-6 and QSZ at 10 °C for 10, 12 and 14 days after imbibition (DAI) of seed germination. The results of Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment revealed that the differentially expressed genes (DEGs) between WR04-6 and QSZ were mainly concentrated on the response to starch catabolic processes and the response to abscisic acid (ABA). This is consistent with the results of α-amylase activity, ABA and gibberellins (GA) treatment. A recombinant inbred line (RIL) population derived from a cross between WR04-6 and QSZ and its high-density SNP genetic map were used to detect quantitative trait loci (QTL) for LTG rates. The results showed that two new QTLs were located on chromosome 3 and chromosome 12. Combined with the mapped QTLs and RNA-seq DEGs, sixteen candidate genes potentially associated with LTG were identified. Validation of the expression of the candidates by qRT-PCR were consistent with the RNA-seq data. These results will enable us to understand the genetic basis of LTG in weedy rice and provide new genetic resources for the generation of rice germplasm with improved LTG.

Identifikasi Penanda Masak Fisiologis untuk Panen Benih Mentimun (Cucumis sativus L.)

Identification of Physiological Cooking Markers for Cucumber (Cucumis sativus L.) Seed Harvest. Cucumber (Cucumis sativus L.) has a wide adaptability to the environment. Cucumber production in Indonesia has decreased every year. The availability of quality seeds is one of the important factors in increasing the productivity of cucumber plants. This study aims to identify physiological ripening markers, especially in cucumber fruit. This study used a one-factor randomized block design method with 4 levels of treatment at harvesting age of cucumbers, namely 24, 27, 30, and 33 days after flower blooming. The variables observed in this study were; a) identification of fruit and seed maturity markers; 1) fresh weight of fruit (g), 2) fresh weight of 100 seeds (g), 3) oven dry weight of 100 seeds (g), 4) seed moisture content (%), and 5) fruit color development; b) testing of seed quality; 1) seed germination (%) and 2) seed germination vigor (%).The results showed that the right harvest time based on the character of the fruit and seeds to produce quality seeds for cucumber plants was 27 days after the flowers bloom. The character of the fruit at that time was shiny green with a yellow tinge and reached the maximum fresh weight, while the character of the seeds at that time was bright yellow seeds, with a fresh weight of 100 seeds was 3,95g and an oven dry weight of 100 seeds was 1,51g reaching the maximum weight. And seed moisture content at the age of 27 with the lowest percentage. The quality of cucumber seeds harvested when physiologically ripe was obtained with the highest average values such as seed germination (93.17%) and simultaneous growth vigor (81.83%).

Pepper heat shock transcription factor A1d contributes to seed thermotolerance and germination vigor

Pepper (Capsicum annuum L.) is an important economic vegetable and have a high value in the medicinal, chemical additive and other industries. However, heat stress during seed germination and the loss of seed vigor during seed conservation affect the seed germination, development, yield, and economic value of pepper. To fulfill the demands of industries, it is crucial to explore the potential molecular mechanism of pepper seed thermotolerance and vigor for developing good quality pepper seeds. In the present study, we found that pepper CaHsfA1d gene is highly expressed in seed development, and its expression decreased with entering the germination state. Heat induced a declined expression of CaHsfA1d gene during seed germination. However, overexpression of CaHsfA1d in Arabidopsis significantly improved seed thermotolerance, and enhanced the transcript levels of thermotolerant (AtHsfA2 and AtHsp18.2) and antioxidative (AtGSTU5) genes during seeds germination after heat stress. In addition, CaHsfA1d transgenic Arabidopsis seeds showed enhanced resistance to accelerated aging and signifying their possible role in seed germination vigor. Research on seed germination under environmental stresses and seed vigor are new topics in pepper seed science, and our study provides a reference for further studying the mechanism of pepper seed defense and crop resistance breeding.

WSVAS: A YOLOv4 -based phenotyping platform for automatically detecting the salt tolerance of wheat based on seed germination vigour.

Salt stress is one of the major environmental stress factors that affect and limit wheat production worldwide. Therefore, properly evaluating wheat genotypes during the germination stage could be one of the effective ways to improve yield. Currently, phenotypic identification platforms are widely used in the seed breeding process, which can improve the speed of detection compared with traditional methods. We developed the Wheat Seed Vigour Assessment System (WSVAS), which enables rapid and accurate detection of wheat seed germination using the lightweight convolutional neural network YOLOv4. The WSVAS system can automatically acquire, process and analyse image data of wheat varieties to evaluate the response of wheat seeds to salt stress under controlled environments. The WSVAS image acquisition system was set up to continuously acquire images of seeds of four wheat varieties under three types of salt stress. In this paper, we verified the accuracy of WSVAS by comparing manual scoring. The cumulative germination curves of wheat seeds of four genotypes under three salt stresses were also investigated. In this study, we compared three models, VGG16 + Faster R-CNN, ResNet50 + Faster R-CNN and YOLOv4. We found that YOLOv4 was the best model for wheat seed germination target detection, and the results showed that the model achieved an average detection accuracy (mAP) of 97.59%, a recall rate (Recall) of 97.35% and the detection speed was up to 6.82 FPS. This proved that the model could effectively detect the number of germinating seeds in wheat. In addition, the germination rate and germination index of the two indicators were highly correlated with germination vigour, indicating significant differences in salt tolerance amongst wheat varieties. WSVAS can quantify plant stress caused by salt stress and provides a powerful tool for salt-tolerant wheat breeding.

Analysis of Effect of Compound Salt Stress on Seed Germination and Salt Tolerance Analysis of Pepper (Capsicum annuum L.).

To determine the salt tolerance and physiological mechanism of pepper (Capsicum annuum L.) at the germination stage, the Hongtianhu 101 and Xinxiang 8 varieties, which have large differences in salt tolerance, are employed as the study materials. Six mixed salt concentrations of 0, 3, 5, 10, 15, and 20 g/L derived using equal molar ratios of Na2CO3, NaHCO3, NaCl, CaCl2, MgCl2, MgSO4, and Na2SO4 are used. To determine their effects, the related indexes of seed germination, seedling growth, and physiology are measured, and salt tolerance is comprehensively evaluated using membership function analysis. The results show that as the mixed salt concentration increases, the germination potential, germination index, germination rate, seed germination vigor index, root length, and root fresh weight of the two cultivars significantly decrease, whereas the relative salt rate gradually increases. The hypocotyl length and fresh weight aboveground increase first and then decrease, while the malondialdehyde (MDA), proline (Pro) content, catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) activity decrease and then increase. The germination potential, germination index, germination rate, seed germination vigor index, root length, root fresh weight, MDA and Pro content, and CAT activity of the Hongtianhu 101 seeds are higher than those of Xinxiang 8 for all salt concentrations employed here. However, hypocotyl length, fresh weight aboveground, and relative salt rate are lower in Hongtianhu 101 than in Xinxiang 8. The comprehensive evaluation of salt tolerance reveals that the total weighted values of the two membership function indexes increase first and then decrease as the mixed salt concentration increases. Compared with 5 g/L, which has the highest membership function value, the index under salt concentrations of 3 g/L, 10 g/L, and 15 g/L decreases by 4.7%-11.1%, 25.3%-28.3%, and 41.4%-45.1%, respectively. This study provides theoretical guidance for the breeding of salt-tolerant varieties of pepper and an analysis of the physiological mechanisms involved in salt tolerance and salt-tolerant cultivation.

Solid matrix priming improves cauliflower and broccoli seed germination and early growth under the suboptimal temperature conditions.

Seed priming is an effective method for imparting stress tolerance to plants. This study aimed to analyze the effects of solid matrix priming (SMP) on cauliflower and broccoli seed germination and early seedling growth under suboptimal temperature conditions. The SMP method used in this study included the following steps: (1) mixing seeds with vermiculite and water at a ratio of 2:3:2.5 (w/w/v) and incubating for 2 days in the dark at 20°C; (2) drying the SM-primed seed; (3) germinating the SM-primed and the nonprimed seeds at 10, 15, 20, and 25°C; (4) analyzing the antioxidant enzyme activities of SM-primed and nonprimed germinating broccoli and cauliflower seeds in the early germination stage at 10, 15, 20, and 25°C; and (5) testing the emergence of SM-primed and nonprimed control seeds in the early spring glasshouse. The results showed that the SMP improved seed germination vigor and early seedling growth and increased the activities of peroxidase and ascorbate peroxidase in the germinating cauliflower and broccoli seeds under the suboptimal temperature conditions in the early germination stage compared with nonprimed seeds. It was observed that the suboptimal temperature conditions (i.e., 10 and 15°C) suppressed SM-primed and nonprimed seed germination and early seedling growth of cauliflower and broccoli. Inside a greenhouse, the SMP improved the emergence of cauliflower and broccoli seeds during the early spring season. SMP is an effective method for improving seed germination and the emergence of cauliflower and broccoli under suboptimal temperature conditions.

Responses of the germination and phytochemical content of Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe. (Anatolian black pine) seeds to salt stress

The germination stage, which is known to be the most sensitive period of plant development, is very sensitive to salt stress. To determine how salt stress affected the germination behaviour of Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe, the seeds were germinated at gradually increasing salt concentrations. The detrimental effect of the salt stress increased parallelly to the salt concentration. The morphological and physiological changes were analysed in each application to detect the effect of the increasing salt concentrations on the germination stage, and the results were evaluated. The root and stem length, germination percentage, seed germination vigour index and seed mass decreased with the increasing concentration. The amount of volatile and phenolic compounds increased up to 100 mM of salt concentration, while similar parameters decreased at other salt concentrations. The gradual destruction of the habitats of these plants, which create sustainable living conditions with their ability to adapt to the ever-changing climatic conditions, and the increasing ecological negativities make it challenging for the quality of life and viability of these plants. The study was aimed at defining the responses to salt stress by examining the changes in the germination behaviour and phytochemical content, and the amount of Anatolian black pine seeds with an increasing soil salinity.

Comparison of the Changes in Seed Germination Vigour with Prolonged Postharvest Storage for Hordeum vulgare Varieties, Hope and Sierra Malting Barley Varieties, in Zimbabwe

To ensure production of quality malt that conforms to brewing requirements, the barley used should have minimal postharvest dormancy and be able to germinate rapidly and uniformly. The objective of the study was to compare the changes in seed germination, vigour trends, and storage stability of two-row Zimbabwean commercially grown malting barley varieties (Hope and Sierra), as the postharvest storage time increased. The two varieties were stored for 12 months, and at monthly intervals, germination index, capacity, and energy were determined. In addition, other quality parameters (protein content, screening, moisture content, water sensitivity, and insect damage index) were also assessed. Hope’s germination index improved with an increase in storage time from 8.67 at the beginning of the study to 9.18 at the end of the study, while that for Sierra diminished with storage from 9.35 to 6.71. Generally, water sensitivity improved with postharvest storage for both varieties. However, the germination energy for Hope diminished with increased postharvest storage compared to Sierra. Hope variety is the more suitable variety for extended postharvest storage than Sierra. However, Sierra variety is more suitable for early malting postharvest storage.

Screening of rice cultivars for Cr-stress response by using the parameters of seed germination, morpho-physiological and antioxidant analysis

Rice is the most important crop for the majority of population across the world with sensitive behavior toward heavy metals such as chromium (Cr) in polluted regions. Although, there is no information on the Cr resistancephenotyping in rice. Herein, two different groups of rice cultivars (normal, and hybrid) were used, each group with 14 different rice cultivars. Firstly, seed germination analysis was conducted by evaluating various seed germination indices to identify the rice cultivars with greatest seed germination vigor. Furthermore, exposure of chromium (Cr) toxicity to 28 different rice varieties (NV1-NV14, HV1-HV14) caused noticeable plant biomass reduction. Subsequently, NV2, NV6, NV10, NV12, NV13 (normal type), HV1, HV4, HV8, and HV9 (hybrid types) were pragmatic as moderately sensitive varieties, while NV3, NV4, NV9, and NV14 (normal type), HV3, HV6, HV7, and HV13 were observed as moderately tolerant. Although, NV7, and HV10 were ranked most sensitive cultivars, and NV11, and HV14 were considered as most tolerant varieties as compared to the other rice (both groups) genotypes. Afterward, Cr induced reduction in chlorophyll pigments were significantly lesser in HV14 relative to NV11, NV7, and especially HV10, and as a result HV14 modulated the total soluble sugar level as well as reduced ROS accumulation, and MDA contents production by stimulating the antioxidant defense mechanism conspicuously which further reduced the electrolyte leakage as well. Our outcomes provide support to explore the Cr tolerance mechanism in cereal crops as well as knowledge about rice breeding with increased tolerance against Cr stress.

Deciphering Novel Transcriptional Regulators of Soybean Hypocotyl Elongation Based on Gene Co-expression Network Analysis.

Hypocotyl elongation is the key step of soybean seed germination, as well an important symbol of seedling vitality, but the regulatory mechanisms remain largely elusive. To address the problem, bioinformatics approaches along with the weighted gene co-expression network analysis (WGCNA) were carried out to elucidate the regulatory networks and identify key regulators underlying soybean hypocotyl elongation at transcriptional level. Combining results from WGCNA, yeast one hybridization, and phenotypic analysis of transgenic plants, a cyan module significantly associated with hypocotyl elongation was discerned, from which two novel regulatory submodules were identified as key candidates underpinning soybean hypocotyl elongation by modulating auxin and light responsive signaling pathways. Taken together, our results constructed the regulatory network and identified novel transcriptional regulators of soybean hypocotyl elongation based on WGCNA, which provide new insights into the global regulatory basis of soybean hypocotyl elongation and offer potential targets for soybean improvement to acquire cultivars with well-tuned hypocotyl elongation and seed germination vigor.

Influence of film-coated Materials on Germination and Seedling Vigor of film-Coated Chinese Cabbage Seeds

Influence of film-coated Materials on Germination and Seedling Vigor of film-Coated Chinese Cabbage Seeds

Genome‐wide association analysis of drought resistance based on seed germination vigor and germination rate at the bud stage in common bean

AbstractCommon bean (Phaseolus vulgaris L.) is an important food legume. However, drought influences its entire growth and development process and can cause yield losses. The influence of drought stress is the most severe in the bud stage. The major objective of our study was to identify a series of loci involved in drought stress response in the bud stage using association analysis. In this study, 361 common bean germplasms were used to investigate germination vigor (GV) and germination rate (GR) under distilled water and drought stress conditions. The common bean showed large variations in GV and GR, with GV ranging from 6.67 to 100% and 0 to 73.33% and GR ranging from 66.67 to 100% and 0 to 100% in distilled water and under drought stress, respectively. A genome‐wide association study (GWAS) of 361 accessions was conducted using 3,724,159 single nucleotide polymorphisms (SNPs) and revealed 2 and 11 candidate SNPs associated with relative germination rate (RGR) and relative germination vigor (RGV), respectively. Three loci were collocated with loci previously reported as being related to drought tolerance. A total of 180 candidate genes were identified, many of which were related to ion transport and oxidation‐reduction reactions. A major haplotype for RGV was identified on chromosome 6. These results provide new insight into the genetic basis of drought tolerance in common bean at the bud stage and provide candidate SNPs and genes that can be used to accelerate the drought tolerance improvement of common bean.

Low Doses of Cuscuta reflexa Extract Act as Natural Biostimulants to Improve the Germination Vigor, Growth, and Grain Yield of Wheat Grown under Water Stress: Photosynthetic Pigments, Antioxidative Defense Mechanisms, and Nutrient Acquisition.

The present study was conducted to investigate the effects of Cuscuta reflexa extract (CRE) on the activities of germination enzymes, seed germination vigor, biomass production, physio-biochemical attributes, and seed yield of water-stressed wheat plants. Different levels of CRE (0, 10, 20, 30, 40, and 50%), including water soaking, were used as seed priming. Water stress negatively affected the seed germination, germination enzyme activities, growth, yield, and different physio-biochemical attributes of wheat plants. Low doses of CRE (10, 20, and 30%) ameliorated the adverse effects of water stress on seed germination attributes, and activities of germination enzymes, but negative impacts were recorded at higher doses (40 and 50%) of CRE. Water-stressed wheat plants grown from seeds pre-treated with low doses of CRE also showed better growth and yield as compared with non-treated ones, and that was associated with an improvement in water relations, photosynthetic pigments, nutrient acquisition, reduced lipid peroxidation, and better antioxidative defense mechanisms. The maximum increase in seed yield was 14.77 and 12.32%, found in plants grown from seeds treated with 20% and 10% CRE, respectively. In conclusion, it is suggested that using low doses of CRE as seed priming can contribute to better wheat yield under water stress, especially in semi-arid and arid areas.

Effect of Saline-Alkali and Drought Stress on Seed Germination of Haloxylon Ammodendron*

Based on the problems of desertification and salinization in the Qaidam Basin, this paper studies the coupled stress of saline-alkali and drought conditions on the seed germination of Haloxylon ammodendron from Qaidam provenance, and clarifies the comprehensive effect of salt, alkali and drought stress on Haloxylon ammodendron seed germination vigor. It provides a reference for the research on the resistance of Haloxylon ammodendron and provides a theoretical basis for improving the breeding efficiency of Haloxylon ammodendron population in the area of bad situation.