Building a Resilient Wheat Seed System to Resist Rust Risks in Ethiopia

This study is a review of existing reports and summary of some field experiences aiming at building of a resilient wheat seed system to resist rust risks in Ethiopia. Practical gaps in the wheat seed system were identified with regard to understanding of seed system factors that build, or undermine resilience to rust risks. The study has recognized that the formal seed multiplication schemes are too slow to respond to the ever increasing frequencies of wheat rust outbreaks. Therefore, it is indicated that new approaches such as pre-release and farmer based seed multiplication schemes are helpful in insuring availability of seed of rust resistant wheat varieties to the small farmers.

Role of Crystal Seed in Aluminum Hydroxide Crystallization from Ammonia System with Added NH_(4)Al(SO_(4))_(2)·12H_(2)O

A method to promote aluminum hydroxide crystal growth through pickling Al(OH)_(3)as seed in the ammonia system was proposed to overcome these defects.The experimental results show that,under the conditions of pickling time of 15 min,the acid concentration of 10%,the addition of 70 g/L pickling-Al(OH)_(3)seed,and the coarse granular Al(OH)_(3)products(d0.5=85.667)can be obtained.The characterization results show that the phase of the product is gibbsite,consistent with the seed.Moreover,the steps and ledges can be formed on pickling Al(OH)_(3)seed surface under the ammonia system,effectively promoting crystal growth.During crystal growth,the roughness of the crystal surface was first increased and then decreased,and the lamellar structure was deposited on the crystal seed surface.The final particles are approximately round,the surface is compact and dense.The growth of the product is surface reaction controlled.In addition,the content of the AlO_(6)unit is increased and contributed to Al(OH)_(3)crystal growth.

Rodent abundance triggered switch between the relative mutualism and predation in a rodent-seed system of the subtropical island forest

Density-dependent non-monotonic species interactions are important in maintaining ecosystem stability and function,but empirical evidences are still rare.Rodents,as both seed dispersers and seed predators,have dual effects on plant regeneration and may result in non-monotonic rodent-plant interactions.According to the non-monotonic models,the relative positive or negative effects of rodents on seedling establishment can be measured based on the positive or negative association of seedling recruitment rate and rodent abundance.In this study,we investigated the fates of acorns of Quercus serrata by tracking tagged seeds on 21 fragmented subtropical islands in the Thousand Island Lake,China.We found that the proportion of germinated seeds of all released seeds showed a dome-shaped association with rodent abundance per seed.The proportion of removed seeds and cached seeds showed a saturated-and a weak dome-shaped association with rodent abundance per seed,respectively.Our results demonstrated a clear empirical evidence that rodent abundance per seed triggered a switch between the relative mutualism and predation in a rodent-seed system.Our study implied that the observed non-monotonic interactions between plants and animals may play a significant role in maintaining biodiversity and ecosystem function.We appeal for more investigations of the complex non-monotonic interactions in various ecosystems.

Spatial structure and species composition of soil seed banks in moving sand dune systems of northeast China

Soil seed banks can provide a mechanistic for understanding the recruitment dynamics and can inform conservation management of ecosystems. To investigate the contribution of soil seed banks to vegetation restoration in moving sand dune systems, we compared seed structure and species similarity between soil seed banks and standing vegetation among moving sand dunes, ecotones and dune slacks in northeast China. Average seed density in dune slacks was greater than in ecotones or moving sand dunes. Seed density in the soil layer of 0-10 cm was greater than at 10-20 cm both in the moving sand dunes and the eco- tones, but seed densities were similar at depths of 10-20 and 20-30 cm in moving sand dunes. Moreover, the spatial autocorrelation of seed density on moving sand dunes was weak but was strong on the ecotones and dune slacks. The species in the soil seed bank of moving sand dune systems were nearly all annuals, and the low similarity was mainly due to the lack of perennial species that were common in standing vegetation. Consequently, vegetation restoration cannot mainly rely on the soil seed banks in the movingsand dunes and more attention should be paid to protection of the dune slacks because they are the main source of seed disperse and seedling recruitment in moving sand dune systems.

Effect of Shade on Seed Protein, Oil, Fatty Acids, and Minerals in Soybean lines Varying in Seed Germinability in the Early Soybean Production System

The cause of poor seed quality (germination) of soybean produced in the Early Soybean Production System in the midsouth U.S.A. is still not completely understood. Temperature, solar radiation, and soybean genotype may all be important factors involved. The objective of this research was to evaluate seed composition, mineral level, and nitrogen assimilation in high and low germinability soybean plant introductions in a full-sunlight (unshaded) and a low-light intensity (shaded) environments. Shade netting was employed in field plots that reduced light intensity by about 50% and air temperature by about 10?F/6?C (10%). A two-year field experiment was conducted on soybean accessions with high germinability (PI 587982A and PI 603723), low germinability (PI 80480 and PI 84976-1), and on soybean cultivars (DSR-3100 RR STS and Pella 86). Results showed that shade resulted in higher total oil, linoleic and linolenic acids, and lower protein and oleic acid. Shade also resulted in lower nitrogen assimilation, leaf chlorophyll concentration, but unshade resulted in higher total seed boron, iron, and nitrogen concentrations. Seed structural boron was positively correlated with germination and protein. Structural boron percentage was consistently higher under shade than under unshade in PI 80480, PI 84976-1, DSR-3100 RR STS, and Pella 86, but consistently higher under unshade than under shade in higher germinability lines PI 587982A and PI 603723, suggesting that different distribution mechanisms of structural boron exist between genotypes. The positive correlation between germination and structural B and between protein and structural B signify a possible role of B in seed quality traits. Our research demonstrated that light intensity, combined with temperature, can alter seed constituents. Higher germinability lines had higher germination rates and lower percentages of hardseededness, desirable traits for soybean seed.

Cloud Seedability Study with a Dual-Model System

In this research, one-dimensional stratiform a novel dual-model system, cold cloud model （1DSC） coupled to Weather Research and Forecast （WRF） model （WRF-1DSC for short）, was employed to investigate the effects of cloud seeding by silver iodide （AgI） on rain enhancement. Driven by changing environmental conditions extracted from the WRF model, WRF-1DSC could be used to assess the cloud seeding effects quantitatively. The employment of WRF- 1DSC, in place of a one-dimen- sional two-moment cloud seeding model applied to a three-dimensional mesoscale cloud-resolving model, was found to result in massive reduction of computational resources. Numerical experiments with WRF-1DSC were conducted for a real stratiform precipitation event ob- served on 4-5 July 2004, in Northeast China. A good agreement between the observed and modeled cloud system ensured the ability of WRF-1DSC to simulate the observed precipitation process efficiently. Sensitivity tests were performed with different seeding times, locations, and amounts. Experimental results showed that the optimum seeding effect （defined as the percentage of rain enhancement or rain enhancement rate） could be achieved through proper seeding at locations of maximum cloud water content when the updraft was strong. The optimum seeding effect was found to increase by 5.61% when the cloud was seeded at 5.5 km above ground level around 2300 UTC 4 July 2004, with the maximum AgI mixing ratio （As） equaling 15 ng kg-1. On the other hand, for an overseeded cloud, a significant reduction occurred in the accumulated precipitation （-12.42%） as Xs reached 100 ng kg^-1. This study demonstrates the potential of WRF- 1DSC in determining the optimal AgI seeding strategy in practical operations of precipitation enhancement.

Coleoptile Purple Line Regulated by A-P Gene System Is a Valuable Marker Trait for Seed Purity Identification in Hybrid Rice

In plants,a large number of anthocyanin biosynthetic genes encoding enzymes and regulatory genes encoding transcription factors are required for anthocyanin synthesis.Coleoptile purple lines are two purple lines on both sides of coleoptiles after seed germination.However,the molecular mechanism of coleoptile purple line is not clear in rice so far.In this study,two major dominant genes,coleoptile purple line 1(OsCPL1,also known as OsC1)and coleoptile purple line 2(OsCPL2),were isolated via map-based cloning,and both of them were required for anthocyanin biosynthesis of coleoptile purple line in rice.The knockout and complementation experiments confirmed that OsC1 was required for purple color in most organs,such as coleoptile line,sheath,auricle,stigma and apiculus,whereas OsCPL2 was just required for coleoptile purple line.OsC1 was predominantly expressed in coleoptiles,flag leaves,and green panicles,and highly expressed in young leaves,whereas OsCPL2 was predominantly expressed in coleoptiles,and extremely lowly expressed in the other tested organs.Loss-of-function of either OsC1 or OsCPL2 resulted in significant reduction of transcript levels of multiple anthocyanin biosynthesis genes in coleoptiles.Coleoptile purple line was further used as a marker trait in hybrid rice.Purity identification in hybrid rice seeds via coleoptile purple line just needed a little water,soil and a small plate and could be completed within 5 d.Molecular marker and field identification analyses indicated that coleoptile purple line was reliable for the hybrid seed purity identification.Our findings disclosed that coleoptile purple line in rice was regulated by two major dominant genes,OsC1 and OsCPL2,and can be used as a simple,rapid,accurate and economic marker trait for seed purity identification in hybrid rice.

Long-Term No-Tillage Direct Seeding Mode for Water-Saving and Drought-Resistance Rice Production in Rice-Rapeseed Rotation System

To study the effects of long-term no-tillage direct seeding mode on rice yield and the soil physiochemical property in a rice-rapeseed rotation system, a comparative experiment with a water-saving and drought-resistance rice （WDR） variety and a double low rapeseed variety as materials was conducted under no-tillage direct seeding （NTDS） mode and conventional tillage direct seeding （CTDS） mode for four years, using the CTDS mode as the control. Compared with the CTDS mode, the actual rice yield of WDR decreased by 8.10% at the first year, whereas the plant height, spikelet number per panicle, spikelet fertility, 1000-grain weight, grain yield, actual yield, and harvest index increased with no-tillage years, which led to the actual yield increase by 6.49% at the fourth year. Correlation analysis showed that the panicle length was significantly related to the actual yield of WDR. Compared with the CTDS mode in terms of the soil properties, the pH value of the NTDS mode decreased every year, whereas the contents of soil organic matter and total N of the NTDS mode increased. In the 0-5 cm layer of the NTDS mode, the soil bulk decreased, whereas the contents of soil organic matter, total N, and available N increased. In the 5-20 cm layer of the NTDS mode, the available N and K decreased, whereas the soil bulk, contents of soil organic matter, and total N increased. In summary, the NTDS mode increased the rice yield, and could improve the paddy soil fertility of the top layer.

Synthesis of ZSM-22 in Static and Dynamic System Using Seeds

ZSM-22 was synthesized using various sources of silica, organic template 1,6-diaminohexane, under hydrothermal conditions, with and without agitation during crystallization. Subsequently, the crystallized material was used as seeds to accelerate the crystallization process. Characterization of the ZSM-22 samples was performed by XRD, ATG/DTG and FT-IR. It was found that it is possible to synthesize ZSM-22 employing colloidal silica and pyrolytic silica as silicon sources only if the system is stirred during crystallization. The crystallization time for these systems was 13 hours, longer times of crystallization do not significantly increase the crystallinity of the sample. The addition of seeds significantly accelerates the crystallization of ZSM-22, reducing the crystallization time to only 7 hours, with stirring and with systems employing colloidal silica.

Pectin methylesterase inhibitors GhPMEI53 and AtPMEI19 improve seed germination by modulating cell wall plasticity in cotton and Arabidopsis

The germination process of seeds is influenced by the interplay between two opposing factors,pectin methylesterase(PME)and pectin methylesterase inhibitor(PMEI),which collectively regulate patterns of pectin methylesterification.Despite the recognized importance of pectin methylesterification in seed germination,the specific mechanisms that govern this process remain unclear.In this study,we demonstrated that the overexpression of GhPMEI53is associated with a decrease in PME activity and an increase in pectin methylesterification.This leads to seed cell wall softening,which positively regulates cotton seed germination.AtPMEI19,the homologue in Arabidopsis thaliana,plays a similar role in seed germination to GhPMEI53,indicating a conserved function and mechanism of PMEI in seed germination regulation.Further studies revealed that GhPMEI53 and AtPMEI19 directly contribute to promoting radicle protrusion and seed germination by inducing cell wall softening and reducing mechanical strength.Additionally,the pathways of abscicic acid(ABA)and gibberellin(GA)in the transgenic materials showed significant changes,suggesting that GhPMEI53/AtPMEI19-mediated pectin methylesterification serves as a regulatory signal for the related phytohormones involved in seed germination.In summary,GhPMEI53 and its homologs alter the mechanical properties of cell walls,which influence the mechanical resistance of the endosperm or testa.Moreover,they impact cellular phytohormone pathways(e.g.,ABA and GA)to regulate seed germination.These findings enhance our understanding of pectin methylesterification in cellular morphological dynamics and signaling transduction,and contribute to a more comprehensive understanding of the PME/PMEI gene superfamily in plants.

The structure-directing role of heterologous seeds in the synthesis of zeolite

Zeolites have been widely used as catalysts,ion-exchangers,and adsorbents in chemical industries,detergent industry,steel industry,glass industry,ceramic industry,medical and healthfield,and environmentalfield,and recently applied in energy storage.Seed-assisted synthesis is a very effective approach in promoting the crystallization of zeolites.In some cases,the target zeolite cannot be formed in the absence of seed zeolite.In homologous seed-assisted synthesis,the structure of the seed zeolite is the same to that of the target zeolite,while the structure of the seed zeolite is different to that of the target zeolite in the heterologous seed-assisted synthesis.In this review,we briefly summarized the heterologous seed-assisted syntheses of zeolites and analyzed the structure-directing effect of heterologous seeds and surveyed the“common composite building units(CBUs)hypothesis”and the“common secondary building units(SBUs)hypothesis”.However,both hypotheses cannot explain all observations on the heterologous seed-assisted syntheses.Finally,we proposed that the formation of the target zeolite does need nuclei with the structure of target zeolite and the formation of the nuclei of the target zeolite can be promoted by either the undissolved seed crystals with the same CBUs or SBUs to the target zeolite or by the facilitated appropriate distribution of the specific building units due to the presence of the heterologous seed that does not have any common CBUs and SBUs with the target zeolite.

Design and Kinematic Analysis of a Driving Roller-type No-till Seeding and Hole-forming System

Conventional no-till seeders should cut or remove crop straw and residue,when in operation and thus present a number of problems,including high performance requirements for the cutting component,high power consumption,dust raising and interference from intertwined straw.In view of this,in this study,a driving roller dibbling-type no-till seeding and hole-forming(DGR-NT-SHF)system was designed to be capable of penetrating soil and creating holes without requiring any special preparation of the surface covering.The core mechanism of this system consisted of a land wheel-driven driving roller and a duckbill-type roller seeder,which were internally tangent to one another.The rotating roller rolled the straw into a thin layer,and the duckbills extended from the roller and penetrated this thin layer of straw and subsequently formed the holes and planted the seeds.Based on kinematic analysis,a mathematical model was established to depict the relations between the rear angle of the duckbill(α),the front angle of the duckbill(β),the angular velocity of the duckbill-type roller seeder(ω0),the angular velocity of the roller(ω1),and the aperture of the duckbill outlet on the roller(θ).In contrast to a driven roller-type no-till seeding and hole-forming DNR-NT-SHF system,several parameters of the DGR-NT-SHF system were established for planting seeds at a plant spacing that was an integral multiple of 100 mm:the radius of the duckbill-type roller seeder,200 mm;radius of the roller,400 mm;α,23°;andβ,5°.Based on the analysis of the models using the MATLAB Image Processing Module with a relation betweenω1 and the number of outlets on the roller as the constraint,the optimal number of outlets on the roller and theω1/ω0 ratio were determined to be 21 and 4/7,respectively.Kinematic simulation on a digital prototype was performed using computer aided three-dimensional interactive application(CATIA)to observe the motion of the DGR-NT-SHF system,when the duckbills on the duckbill-type roller seeder were open and to determine the locations of the duckbills relative to the outlets.To ensure the duckbills could be successfully opened,the chord length of the outlets was ultimately determined to be 71 mm.The prototype test results showed that the DGR-NT-SHF system met the design requirements and that the operation was straightforward and reliable.In addition,compared to the DNR-NT-SHF system,the DGR-NT-SHF system performed better in penetration and exerted no impact on the duckbills,thus providing an effective technical option for no-till seeding.

Targeted mutations of BnPAP2 lead to a yellow seed coat in Brassica napus L.

The yellow seed trait is preferred by breeders for its potential to improve the seed quality and commercial value of Brassica napus.In the present study,we produced yellow seed mutants using a CRISPR/Cas9 system when the two BnPAP2 homologs were knocked out.Histochemical staining of the seed coat demonstrated that proanthocyanidin accumulation was significantly reduced in the pap2 double mutants and decreased specifically in the endothelial and palisade layer cells of the seed coat.Transcriptomic and metabolite profiling analysis suggested that disruption of the BnPAP2 genes could reduce the expression of structural and regulated genes in the phenylpropanoid and flavonoid biosynthetic pathways.The broad suppression of these genes might hinder proanthocyanidin accumulation during seed development,and thereby causing the yellow seed trait in B.napus.These results indicate that BnPAP2 might play a vital role in the regulatory network controlling proanthocyanidin accumulation.

Influence of Crop Nutrition on Grain Yield,Seed Quality and Water Productivity under Two Rice Cultivation Systems

The system of rice intensification （SRI） is reported to have advantages like lower seed requirement,less pest attack,shorter crop duration,higher water use efficiency and the ability to withstand higher degree of moisture stress than traditional method of rice cultivation.With this background,SRI was compared with traditional transplanting technique at Indian Agricultural Research Institute,New Delhi,India during two wet seasons （2009-2011）.In the experiment laid out in a factorial randomized block design,two methods of rice cultivation [conventional transplanting （CT） and SRI] and two rice varieties （Pusa Basmati 1 and Pusa 44） were used under seven crop nutrition treatments,viz.T 1,120 kg/hm2 N,26.2 kg/hm2 P and 33 kg/hm2 K;T 2,20 t/hm2 farmyard manure （FYM）;T 3,10 t/hm2 FYM＋ 60 kg/hm2 N;T 4,5 t/hm2 FYM＋ 90 kg/hm2 N;T 5,5 t/hm2 FYM＋ 60 kg/hm2 N＋ 1.5 kg/hm2 blue green algae （BGA）;T 6,5 t/hm2 FYM＋ 60 kg/hm2 N＋ 1.0 t/hm2 Azolla,and T 7,N 0 P 0 K 0 （control,no NPK application） to study the effect on seed quality,yield and water use.In SRI,soil was kept at saturated moisture condition throughout vegetative phase and thin layer of water （2-3 cm） was maintained during the reproductive phase of rice,however,in CT,standing water was maintained in crop growing season.Results revealed that CT and SRI gave statistically at par grain yield but straw yield was significantly higher in CT as compared to SRI.Seed quality was superior in SRI as compared to CT.Integrated nutrient management （INM） resulted in higher plant height with longer leaves than chemical fertilizer alone in both the rice varieties.Grain yield attributes such as number of effective tillers per hill,panicle length and panicle weight of rice in both the varieties were significantly higher in INM as compared to chemical fertilizer alone.Grain yields of both the varieties were the highest in INM followed by the recommended doses of chemical fertilizer.The grain yield and its attributes of Pusa 44 were significantly higher than those of Pusa Basmati 1.The seed quality parameters like germination rate and vigor index as well as N uptake and soil organic carbon content were higher in INM than those in chemical fertilizer alone.CT rice used higher amount of water than SRI,with water saving of 37.6% to 34.5% in SRI.Significantly higher water productivity was recorded in SRI as compared to CT rice.

Systematic Analysis and Innovation for Development Policies of Beijing Seed Industry at Transformation Stage

At transformation stage,seed Industry is not only a fundamental and strategic industry during the construction of World City,but also part of urban and modern agriculture in Beijing. Based on the analysis of the theory of industrial economics and system theory,the article constructs the seed industry policy analysis model,systematically analyzes the support points of national level and the city of Beijing seed industry policy,and studies policy input,mechanism,output and effects by way of systematic analysis,as well as proposes polices and suggestions on promotion of development for Beijing seed industry and on construction of new seed industry from talent incentive,platform construction,seed trading and enterprise cultivation.

The convection cooling system of the Yakutsk permafrost seed repository

Temperature is critical to maintaining seed viability under long-term storage conditions. It has been common practice to use refrigeration systems to maintain required storage temperatures. A seed repository constructed in permafrost in Yakutsk, Russia is the first seed storage facility that relies solely on natural cold. This paper describes the design and performance of the cooling system of the repository. An innovative aspect of the cooling system is that it utilizes the patterns of temperature wave propagation in permafrost. Predicted and measured ground temperatures for the first year of operation are presented and analyzed. Results indicate that convection air cooling systems can be used to control the temperature regime in underground facilities in permafrost.

Seed Morphology of Some Species of <i>Indigofera</i>(Fabaceae) from Saudi Arabia (Identification of Species and Systematic Significance)

Seeds of 18 species of Indigofera L. were examined with the scanning electron microscope and the light microscope. Macro- and micromorphological characters, including seed shape, colour, size, surface, epidermal cell shape, anticlinal boundaries, outer periclinal cell wall and relief of outer cell walls, are presented. Two types of basic anticlinal cell wall boundaries and two types of relief outer cell walls are recognized and two different shapes of the outer periclinal cell wall are described. A key for the identification of the investigated taxa based on seed characters is provided.

Effects of the grazing systems on germinable soil seed bank of desert steppe

We studied a soil seed bank in the Stipa breviflora desert steppe under three grassland management systems, namely continuous grazing, rotational grazing, and no grazing, from 1999 until 2007. The germinable seed bank species in rotational, continuous and no gazing were 11, 9 and 8 species, respectively. Rotational grazing increased the number of seed bank plant species and perenni- al grasses. The density of germinal soil seed bank was significantly higher in the enclosed area （19,533.33 seeds/m2） than those in rotational （3,233.33 seeds/mz） and continuous grazing areas （2,553.60 seeds/m2）. The vertical distribution of the soil seed bank had a similar trend： 75.06%-83.19% of the seeds are distributed in the top 0-5 cm soil layer, 14.16%-21.68% in the 5-10 cm lay- er, and 2.65%-4.95% in the 10-15 cm layer, which varied between the grazing treatments. Density of the soil seed bank was sig- nificantly higher in the enclosed area, and there was no significant difference between rotational and continuous grazing. The Margalef and Shannon-Wiener indices for the soil seed bank were higher for rotational grazing treatment than for continuous grazing. The Sorensen＇s similarity index for the soil seed bank between the enclosed and rotational grazing areas reached 0.857.

Use of Unmanned Aerial System (UAS) Phenotyping to Predict Pod and Seed Yield in Organic Peanuts

Peanut (Arachis hypogaea L.) is a highly nutritious food that is an excellent source of protein and is associated with increased coronary health, lower risk of type-2 diabetes, lower risk of breast cancer and a healthy profile of inflammatory biomarkers. The domestic demand for organic peanuts has significantly increased, requiring new breeding efforts to develop peanut varieties adapted to the organic farming system. The use of unmanned aerial system (UAS) has gained scientific attention because of the ability to generate high-throughput phenotypic data. However, it has not been fully investigated for phenotyping agronomic traits of organic peanuts. Peanuts are beneficial for cardio system protection and are widely used. Within the U.S., peanuts are grown in 11 states on roughly 600,000 hectares and averaging 4500 kg/ha. This study’s objective was to test the accuracy of UAS data in the phenotyping pod and seed yield of organic peanuts. UAS data was collected from a field plot with 20 Spanish peanut breeding lines on July 07, 2021 and September 27, 2021. The study was a randomized complete block design (RCBD) with 3 blocks. Twenty-five vegetation indices (VIs) were calculated. The analysis of variance showed significant genotypic effects on all 25 vegetation indices for both flights (p < 0.05). The vegetation index Red edge (RE) from the first flight was the most significantly correlated with both pod (r = 0.44) and seed yield (r = 0.64). These results can be used to further advance organic peanut breeding efforts with high-throughput data collection.

Effects of Intercropping Systems of Castor Bean, Maize and Common Bean on Their Growth and Seed Yield in the Soudano Guinea Zone of Cameroon

Field trial was carried out in the Soudano-Guinean zone of Cameroon to investigate the effect of intercropping systems of castor bean with common bean and maize on their growth and yield. Randomized complete block design with three replications was used and five treatments： castor bean in monoculture or in association with common beans or maize, common bean in monoculture and in association with castor bean, maize in monoculture and in association with castor bean. The growth parameters and seed yield were evaluated. Castor beans associated with either maize or common bean grew faster compared to the monoculture system. In addition common bean exhibited fast growth and high seed yield when associated to castor bean, while, no significant difference was observed for maize. In conclusion, the culture of castor bean in association with common bean or maize is advantageous for the peasants in the Adamawa Cameroon region.