Effects of Nitric Oxide on the Germination of Wheat Seeds and Its Reactive Oxygen Species Metabolisms Under Osmotic Stress

Effects of sodium nitroprusside (SNP), a nitric oxide (NO) donor, on the germination and metabolism of reactive oxygen species were surveyed in wheat (Triticum aestivum L.) seeds. Germination of wheat seeds and even the elongation of radicle and plumule were dramatically promoted by SNP treatments during the germination under osmotic stress. Meanwhile, activities of amylase and EP were enhanced, thus leading to the degradation of storage reserve in seeds. After osmotic stress was removed, higher viability of wheat seeds was also maintained. In addition, the activities of CAT, APX and the content of proline were increased by SNP treatment simultaneously, but activities of LOX were inhibited, and both of which were beneficial for improving the antioxidant capacity during the germination of wheat seeds under osmotic stress. It was also shown that the increase of the activity of amylase induced by SNP in embryoless half-seeds of wheat in the beginning period of germination (6 h) might be indirectly related to GA(3).

Investigation on a Regulatory Framework for Seed Transportation of Spartina alterniflora in the Presence of Tidal Currents:A Case Study of Zhanhua District,Binzhou,China

Seed movement is a key hub for the management of Spartina alterniflora.Seed transport patterns under varying dominant wind directions and initiation rates were evaluated by tidal model combined with ecological model.Before the simulation,S.alterniflora distribution in the research area was determined and seed deposition rate was measured experimentally.Research findings indicated that:1)Wind direction affected the primary direction of seed dispersal for S.alterniflora.2)A positive correlation was discovered between wind speed and the distance traveled by S.alterniflora seeds,such that seeds showed the longest displacement under prevailing summer winds,with maximum displacement of up to 25 m.3)Starting velocity played a key role in the determination of the extent of S.alterniflora seed dispersal.Specifically,when initiation flow velocity reached 0.1 m s^(-1),seed transport range was maximized.Furthermore,as time progressed,seed transport range continued to expand.

Optimization of sowing date and seeding rate for high winter wheat yield based on pre-winter plant development and soil water usage in the Loess Plateau,China

Sowing date and seeding rate are critical for productivity of winter wheat(Triticum aestivum L.).A three-year field experiment was conducted with three sowing dates(20 September(SD1),1 October(SD2),and 10 October(SD3)) and three seeding rates(SR67.5,SR90,and SR112.5) to determine suitable sowing date and seeding rate for high wheat yield.A large seasonal variation in accumulated temperature from sowing to winter dormancy was observed among three growing seasons.Suitable sowing dates for strong seedlings before winter varied with the seasons,that was SD2 in 2012–2013,SD3 in 2013–2014,and SD2 as well as SD1 in 2014–2015.Seasonal variation in precipitation during summer fallow also had substantial effects on soil water storage,and consequently influenced grain yield through soil water consumption from winter dormancy to maturity stages.Lower consumption of soil water from winter dormancy to booting stages could make more water available for productive growth from anthesis to maturity stages,leading to higher grain yield.SD2 combined with SR90 had the lowest soil water consumption from winter dormancy to booting stages in 2012–2013 and 2014–2015; while in 2013–2014,it was close to that with SR67.5 or SR112.5.For productive growth from anthesis to maturity stages,SD2 with SR90 had the highest soil water consumption in all three seasons.The highest water consumption in the productive growth period resulted in the best grain yield in both low and high rainfall years.Ear number largely contributed to the seasonal variation in grain yield,while grain number per ear and 1 000-grain weight also contributed to grain yield,especially when soil water storage was high.Our results indicate that sowing date and seeding rate affect grain yield through seedling development before winter and also affect soil water consumption in different growth periods.By selecting the suitable sowing date(1 October) in combination with the proper seeding rate of 90 kg ha–1,the best yield was achieved.Based on these results,we recommend that the current sowing date be delayed from 22 or 23 September to 1 October.

The effects of grain texture and phenotypic traits on the thin-layer drying rate in maize(Zea mays L.) inbred lines

To explore the relation of maize grain texture and phenotypic traits with grain thin-layer drying rate,we observed the ultra-structure of maize grain,and tested three traits about the maize grain texture and four phenotypic traits.The vitreous part percentage was different（P〈0.05） among different maize inbred lines.There was a significant relationship between the drying rate with grain texture and phenotypic traits.Main factors that influenced the drying rate were different during different drying stages.New results observed that empirical constants（k and N） in drying equation were different for seed of the 30 inbred lines of maize.The k of simplified diffusion equation and N of page equation were significantly influenced by both grain texture and phenotypic traits.These results could be used as guideline parameters for drying maize seeds having different grain characteristics during different drying stages.

Effects of Seeding Rate and Light on the Seed Yield and Bioactive Ingredient Contents of Vernonia anthelmintica

[Objectives]This study was conducted to investigate the effects of seeding rate and light on the seed yield and active ingredients of Vernonia anthelmintica.[Methods]With V.anthelmintica L.Willd as the research object,the seed yield was determined by staged harvesting combined with the actual cutting and measuring method;and the caffeoylquinic acids(CQA)were used as the characterization indexes,and high performance liquid chromatography was used to determine the contents of 3,4-CQA,3,5-CQA and 4,5-CQA of V.anthelmintica seeds under different seeding rate+light treatments,so as to compare the changes in seed yield and chemical composition of V.anthelmintica under different seeding rates and light factors.[Results]In Moyu County,Hetian and similar areas,the suitable planting rate of V.anthelmintica was in the range of 13.5-15.0 kg/hm^(2).For different harvesting purposes,the optimal seeding rate and light conditions of V.Anthelmintica were different.[Conclusions]The seeding rate and light conditions can be used to interfere with the seed yield and quality of V.anthelmintica.

Relations Between Photosynthetic Parameters and Seed Yields of Adzuki Bean Cultivars (Vigna angularis)

The study comparatively examined the leaf photosynthetic capacities of different adzuki bean cultivars, high-yield 2000-75 and Jihong 9218, and low-yield Hongbao 1 and Wanxuan 1 from flowering to ripening. It showed that after flowering, the leaves of the cultivars gradually aged, the leaf chlorophyll （Chl.）, soluble protein （SP） contents, net photosynthetic rates （Pn）, transpiration rates （Tr） and stomatal conductance （G） of the cultivars tended to decline, but the leaf intercellular CO2 concentration （Ci） of the cultivars tended to rise. The leaf photosynthetic capacities of the cultivars decreased gradually from the lower to the upper nodes. The dry seed yields of the cultivars were positively correlated with their leaf Chl., SP, Pn, and Tr and Gs, and negatively associated with their leaf Ci. At the late growth stages, the high-yield cultivars maintained higher leaf Chl. contents, SP contents, Pn, Tr, and Gs than the low-yield cultivars, indicating that leaf photosynthetic capacity was one of important yield-affecting factors of adzuki bean. Therefore, it was important for a crop at the crucial stage of yield formation to maintain a high leaf chlorophyll content and a high leaf photosynthetic capacity and delay leaf aging.

Spatial distribution of Agriophyllum squarrosum Moq. (Chenopodiaceae) in the straw checkerboards at a revegetated land of the Tengger Desert, northern China

The present study focuses on straw checkerboards established in the Shapotou Desert Research and Experimental Station at the southeastern edge of the Tengger Desert and their effects on the species richness and the abundance of Agriophyllum squarrosu Moq. Specifically, detailed analyses on the spatial distribution of A. squarrosum and the related soil properties were carried out at a small scale in the straw checkerboards. A. squarrosum is an excellent pioneer plant for revegetation in desert areas. However, the distribution pattern of A. squarrosum and the influencing factors have not been sufficiently delineated. The results showed that the species richness and the abundance of A. squarrosum were decreased exponentially from the border to the center of the straw checkerboards. At the micro-geomorphological scale, the soil texture, soil organic matter （SOM）, soil nutrients （nitrogen, phosphorus and potassium）, and soil infiltration rate in the topsoil tended to increase from the center to the border within a straw checkerboard, while soil moisture presented an opposite tendency. The soil seed bank ofA. squarrosum, soil bulk density, electrical conductivity, sand content, CaCO3 accumulation, and pH showed no significant difference （P〉0.05） between the border and the center of the straw checkerboards. Multiple linear regression analysis indicated that the abundance of A. squarrosum was mainly determined by the concentrations of SOM, nitrogen, and the infiltration rate, implying that nutrient acclimation was the optimal competitive strategy ofA. squarrosum for surviving in a barren natural environment of an arid desert region.

The Variation of β-glucan and Protein Content in Barley as Affected by Agronomic Practices

The influences of N application rate, timing, sowing date and seeding rate on β-glucan and protein content in barley grains were studied through the field experiments in Hangzhou, China during 1997 -2001. Protein content increased with N application rate and with N proportion applied at late stage. β-glucan content also responded significantly to N application rate and timing, but with different pattern with protein content. Of three N rate treatments, the medium N rate (135 kg ha-1) had the highest β-glucan content, being significantly higher than low N rate (90 kg ha-1) and no difference with high N rate (180 kg ha-1). A-mong three N timing treatments, two times of N top-dressing at both tillering and booting stage had significantly higher β-glucan content than once N top-dressing at tillering or booting stage. Sowing date has the dramatic effect on both β-glucan and protein content. Protein content decreased with the delayed sowing, and kernel weight showed opposite tendency. Either earlier or later sowing caused increased β-glucan content relative to sowing in early November, which is the normal date for barley sowing locally. Seeding rate had no significant influence on both β-glucan and protein content.

Field mold stress induced catabolism of storage reserves in soybean seed and the resulting deterioration of seed quality in the field

Excessive rainfall provides a favorable condition for field mold infection of plants, which triggers field mold(FM) stress. If FM stress occurs during the late maturation stage of soybean seed, it negatively affects seed yield and quality. To investigate the responses of soybean seed against FM stress and identify the underlying biochemical pathways involved, a greenhouse was equipped with an artificial rain producing system to allow the induction of mold growth on soybean seed. The induced quality changes and stress responses were revealed on the levels of both transcriptome and metabolome. The results showed that soybean seeds produced under FM stress conditions had an abnormal and inferior appearance, and also contained less storage reserves, such as protein and polysaccharide. Transcriptional analysis demonstrated that genes involved in amino acid metabolism, glycolysis, tricarboxylic acid, β-oxidation of fatty acids, and isoflavone biosynthesis were induced by FM stress. These results were supported by a multiple metabolic analysis which exhibited increases in the concentrations of a variety of amino acids, sugars, organic acids, and isoflavones, as well as reductions of several fatty acids. Reprogramming of these metabolic pathways mobilized and consumed stored protein, sugar and fatty acid reserves in the soybean seed in order to meet the energy and substrate demand on the defense system, but led to deterioration of seed quality. In general, FM stress induced catabolism of storage reserves and diminished the quality of soybean seed in the field. This study provides a more profound insight into seed deterioration caused by FM stress.

Effect of Flood Stress on Soybean Seed Germination in the Field

Flooding is an abiotic stress that impacts soybean [Glycine max (L.) Merr.] growth and reduces seed germination. Effect of flooding on soybean plant grown at different growth stage has been previously conducted and reported. However, soybean seed germination responses to flood stress are largely unknown. The objective of this study was to elucidate flooding influence on soybean seed germination after planting in the field. The research showed that seed germination rate (SGR) of each genotype, without flood stress, was significantly different and ranged between 64.7% to 84.0% and 69.0% to 90.7% while using untreated and fungicide-treated seed (P < 0.0001), respectively. Results indicated that fungicide treatment improved soybean seed survival and germination in the field. The average of SGR of high-yielding soybean group was significantly higher than those of non-high-yielding soybean (P < 0.0001). The results indicated that high-yielding trait of each genotype was correlated with seed germination and survival. Under flood stress in the field, SGR means of untreated and fungicide-treated seed significantly decreased over eight flooding treatment times (P Flooding effect on germination between untreated and fungicide-treated seed was not significantly different (P = 0.1559). Furthermore, comparing the high-yielding and flood-tolerant soybean groups showed no difference in their SGR means over eight flooding treatment times (P = 0.7687 and P = 0.8490), indicating that soybean seed germination did not depend on genotype, yield, and flood tolerance trait, and seed treated by fungicide did not increase its germination in the field under the flood stress. Hence, it is necessary to develop new soybean seed pelleting to improve seed germination in the field under flooding conditions.

Policy Adjustments Required to Balance China's International Payments——A theoretical analysis of China's excess foreign exchange reserves

The paper deals with the rapid growing twin surpluses and surging foreign exchange reserves in China’s international accounts withessed in recent years.It observes the characteristics of the phenomenon against the standard economic theory and empirical experiences.Then it offers explanation factors:the combined effects of processing trade and foreign direct investments,China’s opening development model underpinned by the intra-product specialization of the contemporary globalization era,and the undervalued exchange rate for the Chinese currency.

FSH/LH Ratio as a Predictor of the IVF Outcome in Young Women

In Vitro Fertilization (IVF) is the treatment for many causes of infertility. Many studies were done to investigate different factors that can affect the success rate. This study was conducted to evaluate if cycle day 3 (CD3) follicle-stimulating hormone (FSH)/luteinizing hormone (LH) ratio can be a predictor for the IVF outcome in young sub-fertile females ≤ 35 years with normal baseline FSH. This is a retrospective case control study conducted at the Centre of Fertility and Andrology Care (CFAC) in Egypt where 235 sub-fertile women underwent IVF. Patients were grouped based on CD3 FSH/LH ratio. Group A consisted of ≤35-year-old women with FSH/LH ratio ≤35-year-old women with FSH/LH ratio ≥ 2. The primary outcomes include the fertilization rate, implantation rate and the clinical pregnancy rate. The secondary outcomes include duration and the total dose of gonadotrophin used. We found that, there was no significant difference in the total dose of gonadotropin used during the IVF cycle. Also, there was no significant difference in the number of retrieved and fertilized oocytes and the number of good embryos. Clinical pregnancy rate was the same in both groups. In conclusion, in patients younger than 35 years, CD3 FSH/LH ratio is not a predictor for IVF outcome.

Effects of Sowing Date and Sowing Rate on Yield of Rice Developed from Seedlings Dry-raised in Aperture Disk

[Objectives]This study was conducted to find out the best sowing date and sowing rate of rice.[Methods]Based on the technique of dry seedling raising in aperture disk,the effects of sowing date and sowing rate on rice yield were studied.[Results]Sowing date and sowing rate per hole had obvious effects on tillering dynamics,growth process,number of panicles per unit area,number of filled grains per panicle and yield of rice developed from dry-raised seedlings.The comprehensive analysis showed that the highest yield was 10285.5 kg/hm 2 with the sowing date of May 20 and sowing rate of 5 grains/hole.[Conclusions]This study provides theoretical support and data support for the popularization and application of rice developed from seedlings dry raised in aperture disk.

Intra-specific variations of two Leymus chinensis divergence populations in Songnen Plain, Northeast China

Population demography, seed production, biomass allocation, net photosynthesis and transpiration of two Leymus chinensis divergent populations and between two years in Songnen plain, northeast China were compared. Strong differences between the dry 1997 and moist 1998 occurred in vegetative shoot and sexual shoot densities, sexual differentiation and tiller densities, as well as in the lengths of inflorescence, seed numbers per inflorescence, seed weights and biomass allocation in each population respectively ( P < 0.01). While strong differences between the two populations occurred in vegetative shoot densities, sexual shoot densities, sexual differentiation and seed weights in each year ( P < 0.01). The differences between the two populations in tiller densities and in biomass allocation to sexual shoots were significant ( P <0.05). But there were no significant differences between the two populations in the lengths of inflorescence, seed numbers per inflorescence and biomass allocation to rhizomes and vegetative shoots ( P >0.05). Excepting the transpiration rate in the early June, the differences between the two populations in net photosynthesis and transpiration rate of vegetative shoots and sexual shoots were strongly significant in the early June and July respectively ( P <0.01). Relative stable variations in population demography and physiological traits between the two populations indicated that they are divergently in the Songnen Plain.

Studies on the Growth Habits and Characteristics of Two Polyploid Indica-Japonica Hybrid Rice with Powerful Heterosis

Based on a series of polyploid indica-japonica hybrid plant lines obtained from a new breeding strategy of using double predominance of wide cross and polyploidization to breed super flee, two polyploid indica-japonica hybrids, PSR073 and PSR120 were studied in their growth periods to show the powerful heterosis in a larger scale and to study the characteristics of polyploid indica-japonica hybrids more elaborately. The leaf age, tiller growth, flowering habits, and agronomic traits of them were observed to analyze their growth habits and characteristics. The results showed that the.agronomic traits of PSR073 and PSR120, such as the plant height, panicle length, grain length, grain width, and 1000-grain weight, all acquired obvious predominance of polyploidy, and that the seed setting rate was more than 83%. No significant difference was observed between the two tetraploids and common diploids in the leaf age, tiller growth, and flowering habits. It was concluded that the characteristics of the two powerful heterosis polyploid hybrids were different from those of the polyploid rice reported earlier. Wide cross and polyploidization had no negative effects on their growth habits and characteristics; on the contrary these had powerful heterosis. This had provided theoretic and practical evidences for their application to agricultural production.

Distribution of the Classification Traits in the F_2 Progeny of Two Crosses of indica/japonica in Rice (Oryza sativa)

Comparison of seed setting rate, plant height and Cheng's morphological traits were made between the F_2 progeny of indica-japonica hybrids, 02428/Pei'ai 64 and Taichung 65/Teqing. There existed resemblance normal distribution in plant height, and the distribution had no relationship with the seed setting rate and plant height in F_1 progeny, suggesting that there were no gametic selection for the plant height in the F_2 progeny of indica-japoniea hybrids. An average seed setting rate of the F_2 was equal to the F_1 populations in the recombination of 02428/Pei'ai 64 in which there was an excellent cross compatibility, but the remarkable increase in the seed setting rate from the F_1 to F_2 in Taichung 65/Teqing, indicating that gametic selection only took place in the indica-japonica crosses with low cross compatibility while null or little in the hybrids with high compatibility. There were many intermediate types among the leaf pubescence, color of hull at heading, and length of the first and second panicle internode, and these Cheng's morphological traits was distributed normally; there were also a little intermediate types in hull hairness and phenol reaction with bi-peak distribution; while length to width ratio of grain was inclined to the japonica types obviously showing a skewed distribution in the F2 population. Although Cheng's morphological traits in F_2 populations had inconsistent distribution types, Cheng's morphological traits index showed normal distribution, which suggested that intermediate types, i.e. indicalinous or japonicalinous, were primary in F_2 population.

Physiological Mechanism of Thermotolerance in Wheat (<i>Triticum aestivum</i>Lin.) Seedlings

A research work was performed under sub-tropical condition (24&deg;8'N, 90&deg;0'E) at Bangabandhu Sheikh Mujibur Rahman Agricultural University with three wheat genotypes (BARI Gom 25, BARI Gom 26 and Pavon 76) to observe the mobilization of seed reserve and seedling growth under normal (15&deg;C/25&deg;C) and elevated (25&deg;C/35&deg;C) temperature in growth chamber. The effect of high temperature on wheat seedling was observed in terms of mobilized seed reserve, respiration and transpiration efficiency and seedling growth. At 35&deg;C temperature, maximum mobilization of seed reserve was observed in BARI Gom varieties (BARI Gom 25 and 26) but the respiration efficiency was higher in Pavon 76 in comparison to other genotypes. Maximum loss of respiration and transpiration at 35&deg;C temperature was found to produce low seedling growth in Pavon 76. It appeared from the result that at high temperature the maximum mobilized seed reserve and subsequently minimum loss of respiration and transpiration collectively contributed a positive role for better seedling growth in BARI Gom 25 and BARI Gom 26. Therefore the better mobilized seed reserve and subsequently minimum loss of respiration and transpiration during seedling development are indicators of the thermo tolerance in growing wheat seedling.

Factors Influencing the Outcrossed Seed-Setting Obstacles of Photo-thermo Sensitive Genie Male Sterile Rice

Using photo-thermo sensitive genie male rice (PTGMS) Pei' ai 64S, W7415S, W6154S, N26S, Annong S, Nongken 58S, 7001S and 5088S as female parents and conventional indica lines 8258 and U89 as male parents, the factors affecting outcrossed seed-setting were analyzed. The PTGMS had obstacles in outcrossed seed setting influenced by inheritance and environment at varying degrees. Environmental temperature was regarded as the main factor that resulted in the outcrossed seed-setting obstacles. The sensitive stage was at the early stage of grain filling for outcrossed seed setting. There existed remarkable differences at the sensitivity stage, the duration of sensitive period, the sensitive level and the effective level of outcrossed seed-setting obstacles caused by environmental temperature among different PTGMS lines. Therefore, attention should be paid to outcrossed seed-setting obstacles in selection and utilization of PTGMS lines.

Effects of Different Processing Methods on Germination Rate of Wada Alfalfa Seeds

[Objective] To find a processing method to increase germination rate of Wada alfalfa seeds. [Method] Five processing methods were used to treat Wada alfaffa seeds, including immersion in hot water, immersion in 98% concentrated sulfuric acid, immersion in 100 g/L potassium nitrate, immersion in hot water after rubbing seed capsule, immersion in 30% （ V~ V） hydrogen peroxide. After treatment, germination energy, germination rate, germination index and vitality index were detected. [ Result] The Wada alfaffa seeds immersed in 25℃ water for 25 min after rubbing seed capsule had the highest germination rate （81.3%）, followed by that of seeds immersed in 100 g/L potassium nitrate for 2 h, that of seeds immersed in 50℃ water, and that of seeds immersed in 30% hydrogen peroxide for 5 min in order. The worst germination appeared in the seeds im- mersed in 98% concentrated sulfuric acid. [ Conclusion] Immersion in 25℃ water for 25 min after rubbing seed capsule is the best method to increase germination rate of Wada alfaffa seeds.

The Association between Germination Vigour and Biochemical, Physiological, Subcellular Changes in Bambara Groundnut Seeds after Seed Scarification

Seed storage reserves and organelles after scarification(chemical,mechanical,control)of bambara groundnut with different seed coat colours(cream,light brown and brown)were examined in relation to germination vigour.Seed storage proteins,oil and sugar content,starch granules and protein bodies,germination vigour index(GVI)and mean germination time(MGT)were measured.There were significant(p<0.05)effects of seed scarification on protein body diameter,seed oil content and sugar content.Chemical scarification resulted in seeds having larger starch granules,followed by the control and mechanical scarification that resulted in seeds having smaller starch granules.Mechanical scarification had the highest(p>0.05)protein density,followed by chemical scarification and control seeds that had the lowest protein density.Seeds from the control had the highest oil content,followed by seeds from mechanical scarification and seeds from chemical scarification that had the lowest oil content.Seeds from the control and chemical scarification had larger diameter of protein bodies and sugar content.Seed coat colour significantly(p<0.05)influenced the area and diameter of protein bodies,starch granule area,seed sugar content.Brown seeds produced larger protein bodies and the highest oil content,while light brown seeds had larger area of starch granules and the highest sugar content.Seed storage reserves had an influence on bambara groundnut germination vigour.While favouring dark coloured seeds such as light brown and brown,bambara groundnut seed users should adapt chemical seed scarification to enhance germination vigour of this crop.