Fine-mapping and primary analysis of candidate genes associated with seed coat color in mung bean(Vigna radiata L.)

Seed coat color affects the appearance and commodity quality of mung beans(Vigna radiata L.).The substances that affect mung bean seed coat color are mainly flavonoids,which have important medicinal value.Mapping the seed coat color gene in mung beans would facilitate the development of new varieties and improve their value.In this study,an F2 mapping population consisting of 546 plants was constructed using Jilv9(black seed coat)and BIS9805(green seed coat).Using bulk segregated analysis(BSA)sequencing and kompetitive allele-specific PCR(KASP)markers,the candidate region related to seed coat color was finally narrowed to 0.66 Mb on chromosome(Chr.)4 and included eight candidate genes.Combined transcriptome and metabolome analyses showed that three of the eight candidate genes(LOC106758748,LOC106758747,and LOC106759075)were differentially expressed,which may have caused the differences in flavonoid metabolite content between Jilv9 and BIS9805.These findings can provide a research basis for cloning the genes related to seed coat color and accelerate molecular markerassisted selection breeding in mung beans.

Preparation of Tartary Buckwheat Seed Coating Agent and Its Effect on Germination

To mitigate the wastage of seed resources and reduce the usage of pesticides and fertilizers, seed coating agentshave gained popularity. This study employs single-factor and multi-index orthogonal experimental design methodsto investigate the seed coating formula and physical properties of Tartary buckwheat. The specific effects ofeach component on Tartary buckwheat seed germination are analyzed. The findings reveal that the seed coatingagent formulated with 1.5% polyvinyl alcohol, 0.15% sodium alginate, 0.2% op-10, 0.1% polyacrylamide, 8% colorant,3% ammonium sulfate, 1% potassium dihydrogen phosphate, and 0.15% carbendazim exhibits the mosteffective coating. It demonstrates optimal physical properties and promotes seed germination efficiently. The suspensionrate of this seed coating agent reaches 91.12%, with a mere 2.13% coating shedding rate and 2.5% coatingseed rot rate. Furthermore, it achieves a germination percentage of 99.17%, which is 20.84% higher than the lowestgroup. The germination potential and index are also significantly higher than the lowest group, with anincrease of 20.84% and 26.56%, respectively. Additionally, the vitality index is 553.08, a 15.75% increase comparedto the lowest group. The application of seed coating agents helps reduce seed resource loss, increase plant numbers,and ultimately enhance agricultural yields. This finding holds practical significance in agriculturalproduction.

Biochar-Based Seed Coating as an Effective Strategy to Reduce Seed Predation When Restoring Forests on Degraded Land

As ecosystem degradation becomes more widespread, there is a growing need for efficient and effective forest restoration methods. Direct seeding is one such method that can be used to cover a relatively large area, particularly places with difficult-to-access terrain. One major obstacle hampering successful restoration via direct seeding is seed predation, as seeds are damaged or eaten. We tested the effectiveness of encrusting six species of native seeds with biochar-based coating in reducing the seeds’ chances of being predated on degraded hillsides and landslide scars in Hong Kong. The six seeded species are native trees and shrubs, including both late-successional and pioneer species that are present in forests and shrublands. Our results show that biochar-based seed coats were able to significantly reduce overall seed predation by 5.77% (SE = 1.41, p < 0.05). Additionally, we found varied effectiveness of the biochar-based seed coats across species and seed morphology. Of the six species that were included, four of them had significantly reduced seed predation after encrusting with biochar-based seed coats, while two other species were not significantly affected by the biochar-based seed coats. When we investigated seed predation against seed morphology, we found that while the species with larger seeds were more likely to be predated when sown without any biochar-based seed coat, the effectiveness of the biochar-based seed coat to reduce predation also increased with larger seeds. Our results suggest that encrusting seeds with biochar-based seed coats is an effective means of reducing seed predation.

Effects of Different Seed Coating Agents on the Quality of"Grey-matter"Hybrid Rice Seeds

[Objectives]This study was conducted to select suitable mixed seed coating agents for improving the quality of"grey-matter"hybrid rice seeds.[Methods]Three different mixed seed coating agents(A,B,C)were used to coat the seeds of two varieties(Taiyou 390 and Zhenliangyou 8612)of hybrid rice with different"grey-matter"content(5%,15%,25%),and the results were investigated and compared.[Results]The combinations of treatment B(seed coating agent A+Linong)and treatment C(Manshijin+seed coating agent A)could significantly improve indexes including seed germination potential,germination rate,seed vigor,seedling height,fibrous roots and fresh weight of the two varieties with a"grey-matter"content greater than 15%,but had no significant effects on main root length,dry weight,leaf number and tiller number,and the effects of treatment B was better than those of treatment C.That is to say,mixed seed coating agent B(seed coating agent A+Linong)was suitable for use as a seed coating agent to improve the quality of"grey-matter"seeds.[Conclusions]This study provides a reference plan for the safe use of mixed seed batches with"grey-matter"deterioration.

Control Effect of 35% Thiamethoxam-prochloraz FS to Plant Diseases and Insect Pests at Rice Seedling Stage and Safety Evaluation

The prevention and control effect of 35% thiamethoxam-prochloraz FS to rice thrips and rice bakanae disease and its influence on the quality of rice seedlings were studied. The results show that when 100 kg of rice seeds were coated with 200 g of 35% thiamethoxam-prochloraz FS,the control effects to rice thrips were 93.0% and 84.7% 15 and 20 days after sowing, and the control effect to rice bakanae disease was 90.8% 30 days after sowing. As 100 kg of rice seeds were coated with 250 g of 35% thiamethoxam-prochloraz FS, the control effects to rice thrips were 98.2% and 94.9% 15 and 20 days after sowing, and the control ef- fect to rice bakanae disease was 94.6% 30 days after sowing. 35% thiamethoxam- prochloraz FS is safe to rice seedlings and can effectively promote the growth of rice seedlings.

Genetic study on seed coat characteristics in multiploid watermelon

[ Objective] This study is to provide basis for the genetic improvement of triploid watermelon cultivars from seed coat characteristiscs by analyzing its genetic properties. [ Method ] Genetic effects of seed coat characteristics and their related characteristics in tdploid watermelon were analyzed by additive dominant genetic model based on 36 F1 hybrids which were crossed by six female parents of four ecotypes and six male parents of same ecotype according to North Carolina II crossing design. [ Result] The seed coat number characteristics was controlled by additive effects, dominant effects and error variance of genetic together. The additive effects of the length and width of abortive seed coat were significant, and the error variance was significant or highly significant. It was observed that there was a significant negative correlation of additive effects between the seed coat number and fringe soluble sugar. Also there was a significant negative correlation of dominant effects between lycopenes, dry matter and the seed coat number. However, there was a highly significant positive correlation in additive effects between the length and width of abortive seed coat. [ Conclusion ] The results provide guidance for genetic breeding of triploid watermelon cultivars.

Effect of Seed Coat on Drying Kinetics of Kidney Bean Seed

Kidney bean seed was dried in a laboratory scale fixed bed. The effect of seed coat on drying dynamic characteristics and the changes of seed coat structure were investigated. A mathematical model was established to simulate the drying process and determine the moisture diffusivity. Numerical results agree well with the experimental data. The average moisture diffusivity of the seed with separated coat is 1.67 times larger than that of the seed with coat, and the moisture diffusivity of seed cotyledon is 3.2 times larger than that of the seed coat. It is proved that the seed coat is the most main resistance of mass transfer and is also one of the key points of the optimization of heat and mass transfer for seed drying.

Effects of Different Treatment Methods on Germination Rate of Hard Seeds of Wild Lotus corniculatus L

Birdsfoot trefoil （Lotus corniculatus L.） is high in nutritional value and adapted to slightly acidic, droughty, infertile, or wet soils. However, the impermeable seed coat restricts water imbibition and results in poor seed germination and subse- quent stand establishment. The aim of this study was to identify the dormancy mechanism of Birdsfoot trefoil seeds, and investigate the suitable pretreatment to overcome the poor seed germination. Germination behavior was characterized by using the final germination percentage and the mean germination time. The results indicated that coat thickness of dormant seeds was significant larger. The average hard seed rate was up to 92.3%. It was found that mechanical scarification, chemi- cal scarification with concentrated sulfuric acid （98% H_2SO_4）, and gibberellic acid soaking following freezing below zero temperature were effective in reducing hard- seededness and lead to increases of seed germination.

Effect of Trace Elements in Seed Coating Agent on Peanut Growth

[Objective] This study aimed to investigate the effect of trace elements in peanut seed coating agent. [Method] Different concentrations of trace elements Fe and B were added into peanut coating agent, then the germination rate and plant height of the seeds treated by different agents were measured to decide the best formula. [Result] The germination rate and plant height of the seeds treated with seed coating agent was obviously increased. Adding trace elements Fe and B could increase the peanut yield, and 1.5% Fe and 1% B gave the best result. [Conclusion] This study will provide reference for modifying the seed coating agent formula.

Preparation of a Novel Highly Effective and Environmental Friendly Wheat Seed Coating Agent

A novel environmental friendly wheat seed coating agent was prepared from the natural polymer,biological pesticide,microfertilizer,microelements and other additives.The laboratory and field test results showed that it could enhance the yield up to 16% and reduce its input cost to 1/6 as compared with the conventional wheat seed coating agent.It is safe without causing any pollution and would have significant economic and environmental benefits.

Seed Germination Traits of Loquat (Eriobotrya japonica Lindl.) as Affected by Various Pre-Sowing Treatments (Cutting of Cotyledons, Removal of Perisperm, Moist Chilling and/or Exogenous Application of Gibberellin)

The purpose of this study was to investigate the effects of various presowing treatments on the germinability(final germination percentage)and germination rate of loquat seeds in order to increase seedling production in nurseries(applied research)as well as provide answers for important physiological issues related to loquat seeds and their seed coat(basic research).Three experiments were carried out with various pre-sowing treatments.These treatments included full or partial removal of seed coat(perisperm),partial cutting of cotyledons as well as moist chilling at 5℃ for 13 days and/or soaking the seeds in water or 250 ppm gibberellic acid(GA_(3))solution for 24 h.According to the results,cotyledons excision resulted in delayed germination,regardless of the presence or absence of the seed coat in comparison with the decoated seeds that demonstrated the highest germination rate amongst them.In addition,even the partial excision of seed coats affected positively both the germinability and the germination rate,compared to the control-intact seeds.Furthermore,control-intact seeds had a higher germination percentage when exposed to moist chilling independently of the application or not of gibberellin;while the combination of gibberellin application and moist chilling improved both the percentage and the rate of germination of decoated seeds.In conclusion,the role of perisperm(seed coat)in the germination procedure of loquat seeds seems to be important,indicating the existence of seed coat-imposed dormancy on loquat seeds.Finally,the existence of a mild endogenous embryo-dormancy on loquat is also discussed.

Improvements of Fiber Yield and Fiber Fineness by Expressing the iaaM Gene in Cotton Seed Coat

Cotton,the most important natural fiber crop in the world,is a mainstay in China's economy.However,for over two decades,cotton yields both in China and U.S.have been at a plateau.

Effects of imidacloprid and thiamethoxam as seed treatments on the early seedling characteristics and aphid-resistance of oilseed rape

Seed treatments with the neonicotinoid insecticides imidacloprid and thiamethoxam were evaluated to determine whether the chemicals at effective concentrations for aphid control would influence the germination and early growth of oilseed rape,Brassica napus.Treatment with imidacloprid or thiamethoxam did not affect the cumulative germination rate,but significantly inhibited establishment potential by suppressing root system development in the cotyledon stage.However,these alterations in seedling development in the thiamethoxam-treated seeds appeared not to be detrimental as leaves developed;in contrast,for the seedlings with imidacloprid as seed treatment agent,a significantly decreased shoot/root ratio was still evident at the late two-leaf stage.After two leaves developed,chlorophyll content per leaf in the thiamethoxam treatment was significantly higher than that of the control,while chlorophyll content per leaf in the imidacloprid treatment remained close to that in the control.Most other parameters,i.e.,height,leaf area,weight of stem,leaf or root,and other growth indexes,between the treatments and the control showed no significant difference.Additionally,it was found that storage time of the treated seeds had a significant effect on cumulative germination rate.Treatment 30 d before planting significantly reduced germination relative to that of the control.All of the plants treated with neonicotinoids were shown to have significant anti-aphid characteristics that persisted until the end of the trial.

Ultrastructural studies of seed coat and cotyledon during rapeseed maturation

Brassica napus L.(B.napus)is an important oil crop worldwide and it rapidly accumulates oil at late stage of seed maturation.However,little is known about the cellular mechanism of oil accumulation and seed color changes during the late stage of rapeseed development.Here,we analyzed the ultrastructure of seed coat,aleurone and cotyledon in embryos of B.napus from 25 to 70 days after flowering(DAF).The pigments,which were deposited on the cell wall of palisade cells in seed coat,determined dark black color of rapeseed.The chloroplasts degenerated into non-photosynthetic plastids which caused the green cotyledon to turn into yellow.The chloroplasts in aleurone and cotyledon cells respectively degenerated into remnants without inner and outer envelope membranes and ecoplasts with intact inner and outer envelope membranes.From 40 to 70 DAF,there were degraded chloroplasts without thylakoid,oil bodies contacting with plastids or protein bodies,big starch deposits of chloroplasts degrading into small particles then disappearing,and small endoplasmic reticulum(ER)in aleurone and cotyledon cells.Additionally,there were decreases of chlorophyll content and dramatic increases of oil content in rapeseed.These results suggested that the rapid oil accumulation was independent on the NADPH synthesized by photosynthesis of chloroplasts and probably utilized other sources of reductant,such as the oxidative pentose phosphate pathway during the late stage of rapeseed development.The triacylglycerol assembly presumably utilizes the enzymes in the plastid,cytosol or oil body of cotyledon and aleurone cells.

Identification of quantitative trait loci and candidate genes controlling seed pigments of rapeseed

Rapeseed(Brassica napus L.)is an important source of edible vegetable oil and feed protein;however,seed pigments affect the quality of rapeseed oil and the feed value of the residue from oil pressing.Here,we used a population of rapeseed recombinant inbred lines(RILs)derived from the black-seeded male parent cultivar Zhongyou 821 and the yellow-seeded female parent line GH06 to map candidate genes controlling seed pigments in embryos and the seed coat.We detected 94 quantitative trait loci(QTLs)for seed pigments(44 for embryos and 50 for seed coat),distributed over 15 of the 19 rapeseed chromosomes.These included 28 QTLs for anthocyanidin content,explaining 2.41–44.66% of phenotypic variation;24 QTLs for flavonoid content,explaining 2.41–20.26% of phenotypic variation;16 QTLs for total phenol content,accounting for 2.74–23.68% of phenotypic variation;and 26 QTLs for melanin content,accounting for 2.37–24.82% of phenotypic variation,indicating that these traits are under multigenic control.Consensus regions on chromosomes A06,A09 and C08 were associated with multiple seed pigment traits,including 15,19 and 10 QTLs,respectively,most of which were major QTLs explaining>10% of the phenotypic variation.Based on the annotation of the B.napus"Darmor-bzh"reference genome,67 candidate genes were predicted from these consensus QTLs regions,and 12 candidate genes were identified as potentially involved in pigment accumulation by RNA-seq and qRT-PCR analysis.These preliminary results provide insight into the genetic architecture of pigment biosynthesis and lay a foundation for exploring the molecular mechanisms underlying seed coat color in B.napus.

Genetic Analysis and Molecular Mapping of Two SMV-Resistance Traits in Soybean:Adult-Plant Resistance and Resistance to Seed Coat Mottling

Soybean mosaic virus （SMV） could lead to adult-plant system diseases, and cause mottling of soybean seeds. Genetic analysis and molecular mapping were conducted using an F2 population and derived F3 families from two crosses of Dongnong 3C624 （susceptible）x Dongnong 8143 （resistant） and Dongnong 3C628 （susceptible）× Tie 6915 （resistant）. Simple sequence repeat （SSR） markers with bulked segregation analysis （BSA） were used to conduct genetic mapping of the resistance to SMV1 in the segregating populations. The results indicated that resistance to SMV1 in adultplants and the resistance to seed coat mottling in Dongnong 8143 and Tie 6915 was separately controlled by one single dominant gene. The two dominant genes were identified to be linked on the MLG F by Mendel＇s genetics and SSR genetic mapping. The order and distance of markers DPRSMV1 and DSRSMV1 were Sat 229-6.9 cM-DSRSMV1-4.6 cM-Sat_317-3.6 cM-DPRSMV1-5.2 cM-Satt335. The order and distance of markers TPRSMV1 and TSRSMV1 was Satt160-16.1 cM-TPRSMV1-7.3 cM-Satt516-2.0 cM-TSRSMV1-4.5 cM-Sat_133. This research provides the useful information for breeders to select the two types of SMV resistance simultaneously in soybean breeding through molecular marker-assisted selection （MAS）.

Enhancement of seed germination in Macaranga peltata for use in tropical forest restoration

We used pre-sowing treatments v/z., soaking seeds in concen- trated sulphudc acid （CSA）, gibberellic acid （GA）, combined treatment of CSA ＋ GA and mechanical scarification to overcome seed dormancy and enhance synchronous germination of Macaranga peltata seeds. We analysed percent seed germination data by logistic regression and con- finned that except in GA treatment, time and acid concentration together were crucial for enhancing germination. The combination treatment of CSA and GA resulted in higher percent germination （up to 74%） than either treatment used separately, but produced defective seedlings （26%）. Mechanical scarification of seed coat had the greatest impact in enhanc- ing germination （78%） and reducing imbibition time （6 days） against the control （0%）. Germination studies and SEM analysis confirmed that seed germination in M. peltata was inhibited by seed coat dormancy.

Vascular bundle connection between seed stalk and seed coat of Caragana arborescens

The purpose of this study was to investigate the morphology, transmission route of photosynthetic products in the seed stalk of Caragana arborescens Lam. at various stages after flowering and evaluate the role of the seed stalk in seed maturation using scanning electron microscopy. We found that the mature seed stalk mainly consisted of vessels,sclerenchymatous cells and parenchymatous cells. Elongated cells formed a ring at the junction between the seed stalk and seed, and a large hollow was produced by two layers of sclerenchymatous cells in the interior seed, which functions to sustain seed growth. The opening in the center of the ring was closed during an early stage of seed development, and the opening enlarged as the seed matured.There were two routes for material transport, which started from the seed stalk： one from the seed coat to the embryo,and another directly entering the embryo. Vessels, which are abundant in the seed stalk, are the pathway for absorption of nutrients by the seeds. The vessels were densely packed in the seed stalk, and secondary thickening of the cell wall of the vessels was characterized by net thread thickening, while the secondary thickening of the cell wall of the vessels within the seed was characterized by screw thread thickening. The morphological characteristics of the vessels were adaptive to its functions.

Influence of Seed Coating Formulations on Maize Production

Effects of four coating formulations on maize production were studied.The results showed that all coating formulations had some effects on improving maize seedlings,strengthening the resistance againt diseases and pests and increasing the yields in different degrees,especially Paxil which increased the corn yield by 12.0%,significantly higher than the control.

Comparison of Five Selection Procedures for Seed Coat and Hilum Color in Interspecific Crossing of Soybeans

Five selection procedures for seed coat and hilum color were studied with F4 progenies in two interspecific crossing of soybeans. The seed coat and hilum color indicated that pedigree, 5% and 10% mass selection method were equally successful, and were better than picking-pod and 25% mass selection in cross S17. However, no significant differences in seed coat and hilum color were found in cross G18.