Effects of Seed Maturity of Turf-Type Tall Fescue on the Seed Vigor and the Optimal Harvesting Time

By assay of accelerated aging germination, germination index, vigor index, seedling length, seedling weight, electric conductivity, dehydrogenase activity, ATP content and acid phosphoesterase activity during seed development of turf-type tall fescue, the seed vigor of tall fescue were studied. Combining with seed moisture content and yield, the optimal harvesting time of tall fescue was determined. The results indicated that the seed vigor increased continuously along with seed maturity, and the higher seed vigor was achieved at 19th day after perk anthesis and maintained continuously until 31st day after peak anthesis. At 25th day after peak anthesis, the highest yield of 3 533 kg ha-1 and the good quality of seeds of tall fescue were harvested with 32.19% moisture content. From 22nd to 31st day after peak anthesis, the seed yield of 3 300 kg ha-1 and the good quality seeds of tall fescue were harvested with 40 - 12. 43% moisture content, and the span was the optimal harvesting time.

Time lag characteristics of sap flow in seed-maize and their implications for modeling transpiration in an arid region of Northwest China

Plant capacity for water storage leads to time lags between basal stem sap flow and transpiration in various woody plants. Internal water storage depends on the sizes of woody plants. However, the changes and its influencing factors in time lags of basal stem flow during the development of herbaceous plants including crops remain unclear. A field experiment was conducted in an arid region of Northwest China to examine the time lag characteristics of sap flow in seed-maize and to calibrate the transpiration modeling. Cross-correlation analysis was used to estimate the time lags between stem sap flow and meteorological driving factors including solar radiation（R_s） and vapor pressure deficit of the air（VPD_（air））. Results indicate that the changes in seed-maize stem sap flow consistently lagged behind the changes in R_s and preceded the changes in VPD_（air） both on hourly and daily scales, suggesting that light-mediated stomatal closures drove sap flow responses. The time lag in the maize＇s sap flow differed significantly during different growth stages and the difference was potentially due to developmental changes in capacitance tissue and/or xylem during ontogenesis. The time lags between stem sap flow and R_s in both female plants and male plants corresponded to plant use of stored water and were independent of total plant water use. Time lags of sap flow were always longer in male plants than in female plants. Theoretically, dry soil may decrease the speed by which sap flow adjusts ahead of shifts in VPD_（air） in comparison with wet soil and also increase the speed by which sap flow adjusts to R_s. However, sap flow lags that were associated with R_s before irrigation and after irrigation in female plants did not shift. Time series analysis method provided better results for simulating seed-maize sap flow with advantages of allowing for fewer variables to be included. This approach would be helpful in improving the accuracy of estimation for canopy transpiration and conductance using meteorological measurements.

2CP-1型玉米小区播种机设计与试验

针对众多中小型育种单位育种条件和需求,设计研发了一种可以实现精密播种和快速清仓换种功能的人力式2CP-1型玉米小区播种机并进行了试验。通过建立单粒玉米种子X-Y平面力系图,对影响排种器排种性能各因素的影响大小、影响方式进行了分析,以指导排种器主要设计参数的取值;采用排种器外壳体绕排种轮在90°范围内往复旋转的方式实现快速清仓;通过传动尺寸链控制播种株距,可方便实现对不同需求株距进行扩展。试验结果表明,设计的2CP-1型玉米小区播种机作业稳定可靠,粒距合格指数(扁平窝眼型腔排种轮)达到95.7%,播种深度合格率达到93.3%,平均清仓换种时间16.6 s,满足设计要求。

Study on Seedling Quality of Double-cropping Late Rice Sowed at Different Dates in Guangdong

[Objective] The aim was to study seedling quality of rice sowed at different dates so as to provide theoretical basis for determining the best seeding time.[Method] By investigating the characters of shoot and root of different varieties sowed at different dates,the best seeding time of double-cropping late rice was determined.[Result] The first leaf sheath height and the second leaf length shared significantly positive correlation,which fit the quadratic equation well.The effects of different sowing dates on shoot and root of three rice varieties appeared significant difference.[Conclusion] The best seeding time of Tianyou428 was in June 25-July 2 and that of Tianyou998 and Yuxiangyouzhan was in July 2-9.

Photodissociation Dynamics of 2-1odotoluene Investigated by Femtosecond Time-Resolved Mass Spectrometry

The photodissociation dynamics of 2-iodotoluene following excitation at 266 nm have been investigated employing femtosecond time-resolved mass spectrometry. The photofragments are detected by multiphoton ionization using an intense laser field centered at 800 nm. A dissociation time of 3804-50 fs was measured from the rising time of the co-fragments of toluene radical （C7H7） and iodine atom （I）, which is attributed to the averaged time needed for the C-I bond breaking for the simultaneously excited nσ and ππ＊ states by 266 nm pump light. In addition, a probe light centered at 298.23 nm corresponding to resonance wavelength of ground-state iodine atom is used to selectively ionize ground-state iodine atoms generated from the dissociation of initially populated hσ＊ and ππ＊ states. And a rise time of 4004-50 fs is extracted from the fitting of time-dependent I＋ transient, which is in agreement with the dissociation time obtained by multiphoton ionization with 800 nm, suggesting that the main dissociative products are ground-state iodine atoms.

The Optimal Time for Harvesting the Seeds of Gui 39722, the Female Parent of a Maize Hybrid Guidan 0810

To determine the optimal time for harvesting the seeds of Gui 39722, which is the female parent of a newly-developed maize hybrid Guidan 0810, the cobs of Gui 39722 were harvested 31 （the first stage）, 34 （the second stage）, 37 （the third stage）, 40 （the fourth stage）, 43 （the fifth stage） and 46 （the sixth stage） d after pollination and oven dried at 38 ~C to constant weight. Then, the 1 000-ker- nel weight, germination rate and the agronomic traits of three-leaf seedlings were measured and compared. The results showed that the seeds of Gui 39722 harvest- ed 43 d after pollination （the fifth stage） had the greatest germination rate, seedling height, vigor index, root dry weight, shoot dry weight and germination potential, and high 1 000-kernel weight （very close to the highest level）, root length, number of roots per seedling and root-shoot ratio. Therefore, 43 d after pollination was the op- timal time for harvesting the seeds of Gui 39722, when the effective accumulated temperature after pollination reached 780.7 ℃ and the ear leaf dried. The seeds harvested at this stage had the highest yield and the best quality. Field sampling revealed that 89.00% to 95.00% （with an average of 91.15%） of the seedlings of six stages of seeds grew well.

Application of oxygen-sensing technology to measure seed quality of Ginkgo biloba

Germination tests are currently the most widely used method to evaluate seed quality of Ginkgo biloba L., but they are time-consuming and labor intensive. Oxygen-sensing technology, based on the principle of fluorescence quenching to detect oxygen and assess seed quality was used to rapidly evaluate seed quality of two varieties (Shandong Tancheng 202 and Zhejiang Dafoshou) of G. biloba from five mother plants. Fifteen samples of three vigor levels were produced by accelerated aging treatments. This process was applied in duplicate. A portable oxygen-sensing detector was employed to measure oxygen content during seed germination in a closed system at 25 A degrees C each day until day 14. Four oxygen metabolism indices were calculated: oxygen consumption index, oxygen consumption rate, critical oxygen concentration, and theoretical germination time (T (GT)). Additionally, we tested laboratory germination and field emergence. The results of a one-way analysis of variance and correlation analysis showed that T (GT) was the candidate index to evaluate seed quality of G. biloba. Therefore, the T (GT) value was used to validate the reliability of oxygen-sensing evaluation for Zhejiang Dafoshou seeds kept under four storage conditions. The trend in the change in oxygen metabolism agreed completely agreement with that of seed germination under all storage conditions. The oxygen-sensing test reliably and rapidly assessed seed quality of G. biloba. The germination rate of Zhejiang Dafoshou was accurately predicted by T (GT).

Analysis of Internal Moisture Change of Camphor Seeds during Drying by Low-Field NMR

In this study,low-field nuclear magnetic resonance(LF-NMR)was used to collect the transverse relaxation signals of camphor seeds that had been dried at different temperatures and for different durations.The transverse relaxation time of the hydrogen nucleus was obtained by SIRT(Simultaneous Iterative Reconstruction Technique)inversion,and the correlation between the moisture content on dry basis and the amplitude of NMR signal of camphor seeds sampled at different drying stages was analyzed.The results showed that water existed in three main forms strongly bound water,weakly bound water and free water in camphor seeds.During the drying process,the peak position of strongly bound water remained unchanged,but the peak positions of weakly bound water and free water fluctuated.Drying rate increased with drying temperature increasing.In addition,there was a very significant linear relationship between the total NMR signal amplitude and moisture content on dry basis,and the correlation coefficient reached 0.984 4.

Identification of a novel seed size associated locus SW9-1 in soybean

Seed size is one of the vital traits determining seed appearance, quality, and yield. Untangling the genetic mechanisms regulating soybean 100-seed weight (100-SW), seed length and seed width across environments may provide a theoretical basis for improving seed yield. However, there are few reports related to QTL mapping of 100-SW across multiple ecological regions. In this study, 21 loci associated with seed size traits were identified using a genome-wide association of 5361 single nucleotide polymorphisms (SNPs) across three ecoregions in China, which could explain 8.12%–14.25% of the phenotypic variance respectively. A new locus, named as SW9-1 on chromosome 9 that explained 10.05%–10.93% of the seed weight variance was found significantly related to seed size traits, and was not previously reported. The selection effect analysis showed that SW9-1 locus has a relatively high phenotypic effect (13.67) on 100-SW, with a greater contribution by the accessions with bigger seeds (3.69) than the accessions with small seeds (1.66). Increases in seed weight were accompanied by increases in the frequency of SW9-1T allele, with >90% of the bred varieties with a 100-SW >30 g carrying SW9-1T. Analysis of SW9-1 allelic variation in additional soybean accessions showed that SW9-1T allele accounting for 13.83% of the wild accessions, while in 46.55% and 51.57% of the landraces and bred accessions, respectively, this results indicating that the SW9-1 locus has been subjected to artificial selection during the early stages of soybean breeding, especially the utilization of SW9-1T in edamame for big seed. These results suggest that SW9-1 is a novel and reliable locus associated with seed size traits, and might have an important implication for increasing soybean seed weight in molecular design breeding. Cloning this locus in future may provide new insights into the genetic mechanisms underlying soybean seed size traits.

Variation in seed and seedling traits and their relations to geo-climatic factors among populations in Yunnan Pine(Pinus yunnanensis)

Differences in seed germination and seedling growth among populations of Pinus yunnanensis Franch. were quantified to provide information for use in the regeneration, reforestation, and improvement of this species. Seed germination and seedling growth traits at the nursery stage were investigated at the population level. We evaluated relationships between pairs of measured traits as well as the association between measured traits and geo- climatic variables including longitude, latitude, elevation, temperature and precipitation. Seedling growth showed significant differences although a low magnitude of variation was found in the seed germination traits among the populations. Some populations with strong and stable growth （e.g., the Baoshan population） may be selected as superior seed sources for regeneration and reforestation. Germination percentage was negatively correlated with elevation, and positively with precipitation. In addition, germination index, vigor index and seedling height were positively correlated with precipitation. Seed germination index, cotyledon number and length, and seedling diameter were significantly and positively correlated with seed weight. Strong correlations between pairs of traits will be helpful in early evaluations for the selection of certain prominent traits.

Effect of GA_(3) Concentration and Soaking Time on Seed Germination Characteristics of Blueberry

This study aims to explore the effect of GA_(3) concentration and soaking time on seed germination characteristics of blueberry.To be specific,big(B),medium-sized(M),and small(S)blueberry seeds were soaked in 0,100,200,and 300 mg/L GA_(3) solution for 18 h and 200 mg/L GA_(3) solution for 0,24,and 48 h,respectively.The results showed that 300 mg/L GA_(3) had significant effect on the germination of B and M seeds(P<0.01)and enabled the germination 4~5 d and 7~8 d earlier,respectively.Soaking with 200 mg/L GA_(3) for 24 h was conducive to the germination of B and M seeds(P<0.05).However,GA_(3) concentration and soaking time had no obviously promoting effect on the germination of S seeds.The interactions between GA_(3) concentration and seed size and between soaking time and seed size were significant(P<0.01).

Impact of time lags on diurnal estimates of canopy transpiration and canopy conductance from sap-flow measurements of Populus cathayana in the Qinghai–Tibetan Plateau

Recently, canopy transpiration （Ec） has been often estimated by xylem sap-flow measurements. However, there is a significant time lag between sap flow measured at the base of the stem and canopy transpiration due to the capacitive exchange between the transpiration stream and stem water storage. Significant errors will be introduced in canopy conductance （gc） and canopy transpiration estimation if the time lag is neglected. In this study, a cross-correlation analysis was used to quantify the time lag, and the sap flowbased transpiration was measured to pararneterize Jarvistype models of gc and thus to simulate Ec of Populus cathayana using the Penman-Monteith equation. The results indicate that solar radiation （Rs） and vapor pressure deficit （VPD） are not fully coincident with sap flow and have an obvious lag effect; the sap flow lags behind Rs and precedes VPD, and there is a 1-h time shift between Eo and sap flow in the 30-min interval data set. A parameterized Jarvis-type gc model is suitable to predict P. cathayana transpiration and explains more than 80% of the variation observed in go, and the relative error was less than 25%, which shows a preferable simulation effect. The root mean square error （RMSEs） between the predicted and measured Ec were 1.91×10^-3 （with the time lag） and 3.12×10^-3cm h^-1 （without the time lag）. More importantly, Ec simulation precision that incorporates time lag is improved by 6% compared to the results without the time lag, with the mean relative error （MRE） of only 8.32% and the mean absolute error （MAE） of 1.48 × 10^-3 cm h^-1.

Influence of size of seed grains and sintering condition on varistor properties of ZnO-Bi_2O_3-TiO_2-Sb_2O_3 ceramics

Varistor ceramics of ZnO Bi 2O 3 TiO 2 Sb 2O 3 system have been fabricated by introducing pre fabricated ZnO seed grains with different size distributions respectively. The results show that the varistor properties were significantly influenced by the size of introduced seed grains, and introducing larger seed grains is more advantageous to the modification of microstructure and the improvement of varistor properties. The varistor properties were considerably improved with a moderately increased sintering temperature or time, whereas degraded apparently when the sintering temperature or time was excessively increased. Compared with the sintering time, the sintering temperature plays a more critical role in determining the varistor properties. By introducing pre fabricated ZnO seed grains into the original powders, low voltage ZnO varistor ceramics possessing the desired electrical properties have been produced with a sintering temperature of about 1 210 ℃ and a sintering temperature of 2～2.5 h. [

Effects of Low-Power Microwave Fields on Seed Germination and Growth Rate

Experiments were conducted to investigate the effects of low power microwave radiation on germination and growth rate in seeds. In the present paper, the bioeffects of low power (non-thermal intensity) microwave modulated with 1 KHz square wave have been studied. Experiments were performed in X-band frequencies using klystron based microwave test bench. Microwave parameters like frequency, power, exposure time and power density were varied while irradiating seed samples to study their influence on germination. The seed samples used for the experiment included wheat (Triticum aestivum), bengal gram (Cicer arietinum), green gram (Vigna radiate) and moth bean (Vigna Aconitifolia). Seed germination %, plant height, root length and dry matter % (biomass %) were recorded and compared with control seeds. The effects of different treatments were found to be stimulating the germination and seedling vigour of plants especially in power and exposure time treatments while increase in frequency and power density has reduced the seed germination and seedling vigour. The effect also varied with the nature of seeds.

Real-time crash prediction on freeways using data mining and emerging techniques

Recent advances in intelligent transportation system allow traffic safety studies to extend from historic data-based analyses to real-time applications. The study presents a new method to predict crash likelihood with traffic data collected by discrete loop detectors as well as the web-crawl weather data. Matched case-control method and support vector machines （SVMs） technique were employed to identify the risk status. The adaptive synthetic over-sampling technique was applied to solve the imbalanced dataset issues. Random forest technique was applied to select the contributing factors and avoid the over-fitting issues. The results indicate that the SVMs classifier could successfully classify 76.32% of the crashes on the test dataset and 87.52% of the crashes on the overall dataset, which were relatively satisfactory compared with the results of the previous studies. Compared with the SVMs classifier without the data, the SVMs classifier with the web-crawl weather data increased the crash prediction accuracy by 1.32% and decreased the false alarm rate by 1.72%, showing the potential value of the massive web weather data. Mean impact value method was employed to evaluate the variable effects, and the results are identical with the results of most of previous studies. The emerging technique based on the discrete traffic data and web weather data proves to be more applicable on real- time safety management on freeways.

A Numerical Algorithm Based on Quadratic Finite Element for Two-Dimensional Nonlinear Time Fractional Thermal Diffusion Model

In this article,a high-order scheme,which is formulated by combining the quadratic finite element method in space with a second-order time discrete scheme,is developed for looking for the numerical solution of a two-dimensional nonlinear time fractional thermal diffusion model.The time Caputo fractional derivative is approximated by using the L2-1formula,the first-order derivative and nonlinear term are discretized by some second-order approximation formulas,and the quadratic finite element is used to approximate the spatial direction.The error accuracy O(h3+
t2)is obtained,which is verified by the numerical results.

Lychee seed saponins improve cognitive function and ameliorate hippocampal neuronal injury in Alzheimer disease rat model induced by Aβ_(25-35) through AKT/GSK3β pathway

OBJECTIVE Lychee seed,a famous traditional Chinese medicine,recently were reported to improve the learning and memory abilities in mice.However,it is still unclear whether lychee seed saponins(LSS)can improve the cognitive function and associated mechanisms.METHODS In present studies,we established the Alzheimer disease(AD)model by injecting Aβ25-35 into the lateral ventricle of rats.Then the spatial learning and memory abilities of LSS-treated rats were evaluated with the Morris water maze,meanwhile the protein expressions of AKT,GSK3β and Tau in the hippocampal neuron were analyzed by immunohistochemistry and Western blotting.RESULTS The results showed LSS can improve the cognitive functions of AD rats through shortening the escape latency,increasing the number across the platform,platform quadrant dwell time and the percentage of the total distance run platform quadrant.The protein expression of AKT was significantly up-regulated and that of GSK3β and Tau were decreased remarkably in the hippocampal CA1 area.CONCLUSION Our study is the first to show that LSS significantly improve the cognitive function and prevent hippocampal neuronal injury of the rats with AD by activation of the PI3K/AKT/GSK3βsignaling pathway,suggesting LSS may be developed into the nutrient supplement for the treatment of AD.

Relationship between miR-7-5p expression and ^(125)I seed implantation efficacy in pancreatic cancer and functional analysis of target genes

Objective The aim of this study was to investigate the relationship between miR-7-5p expression and intertissue-^(125)I irradiation sensitivity in pancreatic cancer tissues and to analyze the function of target genes.Methods Thirty-seven patients with unresectable pancreatic ductal adenocarcinoma(PDAC)treated with radioactive ^(125)I seed implantation were enrolled.RT-PCR was used to detect the expression level of miR-7-5p in cancer tissues and analyze the relationship between miR-7-5p expression and ^(125)I radiation sensitivity.Bioinformatic software and online tools were used to predict the miR-7-5p target genes and analyze their functional annotation and pathway enrichment.Results Radioactive ^(125)I seed implantation was followed up for 2 months.The objective response rate of the miR-7-5p high expression group was 65.0%(13/20),whereas the objective response rate of the miR-7-5p low expression group was 5.88%(1/17),and the difference between the two groups was statistically significant(χ^(2)=13.654,P<0.001).A total of 187 target genes were predicted using three databases.GO functional annotation showed that target genes were mainly involved in cellular response to insulin stimulus,regulation of gene expression by genetic imprinting,cytosol,peptidyl-serine phosphorylation,bHLH transcription factor binding,cargo loading into vesicles,cellular response to epinephrine stimulus,and nucleoplasm.KEGG pathway enrichment analysis showed that target genes were mainly involved in the ErbB signaling pathway,HIF-1 signaling pathway,axon guidance,longevity regulatory pathway,endocrine resistance,glioma,choline metabolism in cancer,and EGFR tyrosine kinase inhibitor drug resistance.Molecular complex detection analysis by Cytoscape revealed that PIGH,RAF1,EGFR,NXT2,PIK3CD,PIK3R3,ERBB4,TRMT13,and C5orf22 were the key modules of miR-7-5p target gene clustering.Conclusion The expression of miR-7-5p in pancreatic cancer tissues positively correlated with the radiosensitivity of ^(125)I seeds.Via targeted gene regulation,miR-7-5p acts on the network of multiple signaling pathways in PDAC and participates in its occurrence and development.Thus,miR-7-5p may become a predictive index of ^(125)I seed implantation therapy sensitivity in PDAC patients.

Temporal transcriptomics reveal the molecular mechanism of dormancy and germination regulated by temperature in Paris polyphylla seed

The mature seed of Paris polyphylla var.chinensis(PPC)is morphophysiologically dormant and develops differently under warm and cold temperatures.To elucidate the molecular mechanisms underlying temperature-dependent regulation of PPC seed dormancy and germination,we investigated the dynamic changes in PPC seed transcript levels under warm and cold temperature stratifications(WS and CS,respectively)by time-resolved RNA sequencing,focusing on genes related to hormone metabolism and signaling and cell wall remodeling(CWRM)and encoding transcription factors/regulators(TFs/TRs).A total of 48765 and 47836 differentially expressed genes(DEGs)were associated with WS and CS,respectively.Of these,17581 and 16652 DEGs,respectively,unique to WS and CS,and 5386 were common to both temperature stratifications across nine analyzed growth stages.The expression of hormone metabolism and signaling,TF/TR,and CWRM genes were closely associated with temperature.More genes related to gibberellin(GA),cytokinin,auxin,and brassinosteroid biosynthetic were upregulated in WS as compared to CS seeds,while genes related to dormancy release and germination were downregulated in WS seeds.However,only GA and abscisic acid levels were altered in PPC seeds breaking morphophysiological dormancy(MPD).Overall,37 TF and five TR families were upregulated whereas 24 TF and 16 TR families were downregulated in WS as compared to CS seeds.Most CWRM families were highly expressed under WS as compared to CS,suggesting that they promote endosperm weakening and embryo growth of WS seeds and facilitate MPD release and germination.A coexpression analysis revealed positive correlations between TFs/TRs and DEGs involved in hormone metabolism and signaling and CWRM.These results provided a basis for investigating the interaction between the endosperm and underdeveloped embryo in the regulation of PPC seed germination and seedling emergence.

Blossoming Characteristics in Black Cumin Genotypes in Relation Seed Yield Influenced by Sowing Time

Black cumin (Nigella sativa L.;Family-Ranunculaceae) is an important spice crop. Mature seeds are consumed for edible and medical purposes and also used as a food additive and flavour. Seed of black cumin has great potentiality as spice crop due to nutritive and medicinal values. The experiments were carried out at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur during 2011 to 2012 to determine optimum planting time for seed production of black cumin. The experiment was two factorials. Factor A: 4 genotypes were V1: Exotic, Iran;V2: BARI kalozira-1;V3: Local, Faridpur and V4: Local, Natore. Factor B: sowing date: D1: 16 October;D2: 1 November;D3: 16 November and D4: 1 December. Therefore, treatment combinations were 16 in total. So, in 3 replications total plot was 48. Result revealed that significantly the highest 2.37 t/ha in V1, followed by V2 (1.96 t/ha). V2 and V3 (1.97 t/ha) were statistically similar and maximum yield was obtained from D2 (2.65 t/ha). In combined effect, maximum yield 3.00 t/ha was obtained in V1D2.. Investigation on time of sowing revealed that performance of black cumin was better in earlier sowings (16 October, 1 November) than later ones. The highest yield (4g plant-1;2.65 tha-1) was obtained when the crop was sown on 1 November. Among the genotypes, the exotic one with sowing in 1 November gave the highest seed yield (4.54 g·plant-1;3.00 t·ha-1).