Breeding and Cultivation Techniques of a New Spring Wheat Variety Kechun 140103

Kechun 140103 is a new spring wheat variety with high and stable yield bred by Keshan Branch of Heilongjiang Academy of Agricultural Sciences.This paper summarizes the breeding process,characteristics,yield performance and cultivation techniques of Kechun 140103,in order to promote the popularization and application of the variety.

ACC and MACC Biosynthesis and Ethylene Production in Water-Stressed Spring Wheat

Changes of ACC and MACC levels, ACC synthase activity as well as ethylene production in the leaves of two spring wheat (Triticum aestivum L.) cultivars 8139 (with relatively low drought-resistance) and 504 (with relatively high drought-resistance) during water stress were determined. The levels of ACC and MACC in both cultivars decreased in the first 24 It of water stress and increased in the second 24 It while the activities of ACC synthase increased continuously throughout the entire period of treatment (48 h), As water stress progressed, ethylene production decreased continuously in cv. 8139 but remarkably increased earlier and decreased later in the cv. 504. Moreover, the decrease in RWC of stressed leaves was greater and the changes in ACC and MACC levels as well as ACC synthase activity were higher in the drought-sensitive cv. 8139 than in the drought-resistant cv, 504 during water stress. The levels of ACC and MACC, activities of ACC synthase and productions of ethylene in the stressed leaves in two cultivars were significantly altered by the application of MGBG (an inhibitor of SAMDC) and AOA (an inhibitor of ACC synthase) where their effects on these items were almost opposite. They were increased by the former inhibitor but reduced by the latter. All of these results suggested that the level of ethylene production in plants did not depend on the level of ACC during water stress. The increase in the level of ethylene in the drought-resistant cultivar during the earlier period of water stress might be a phenomenon of adaptation to water stress and be correlated with the development of the drought-tolerance in plants and playing role in the transduction of stress signal. The role of MACC, however, was primarily in the regulation of ethylene production under water stress.

A Simplified Model with Soil Water Limitation on Spring Wheat Growth

The authors constructed a simplified model of spring wheat (Triticum aestivum L.) carbon assimilation and dry matter accumulation (DMA) process which consisted of two independent variables, day length (L) and total daily radiation (TDR). Leaf water potential (Ψ) was incorporated into the simplified growth model based on the assumption that both light use efficiency (α) and CO 2 conductance of assimilation (g c) were depressed by water limitation. Finally,Ψ was estimated from a regression equation in which the independent variables were relative soil water content in the upper 80 cm (θ R,80 ), ambient temperature (T a), vapor pressure deficit (VPD), the cumulative leaf water potential below thresholds of -1.5 MPa (Ψ c,1.5 ). Some applications in research program of field experiment of atmosphere_land surface processes in Heihe River region were tested. The simulated data agreed well with the data observed at Linze oasis in 1989 for various levels of water supply and at Zhangye oasis in 1992 in the field. The analysis and simulation using the model demonstrated that the simplified growth model could describe very well the DMA process of spring wheat with and without water limitation in the region of HEIFE (Heihe field experiment).

The Effects of Simulated Acid Rain on Photosynthetic Characteristics of Spring Wheat Leaves at the Jointing Stage

In order to investigate the effect of acid rain on photosynthetic characteristics of spring wheat,spring wheat at the jointing stage was sprayed with simulated acid rain at different pH levels of 1.5,2.5,3.5,4.5 and 5.6,and then,the photosynthetic parameters of spring wheat leaf was monitored.The results indicated that the pH value of simulated acid rain was positively and very significantly correlated with the net photosynthetic rate,stomata conductance,transpiration rate,water use efficiency and the chlorophyll relative content,whereas very significantly and negatively correlated with intercellular CO2 concentration.Due to acid rain,the net photosynthetic rate,stomata conductance,transpiration rate and the chlorophyll relative content decreased by 4.08%-67.04%,17.44%-58.44%,12.08%-48.08% and 12.16%-37.23% respectively,while intercellular CO2 concentration increased by 9.01%-14.29%.After simulated treatment with acid rain,the net photosynthetic rate had high significant positive correlation with stomata conductance,transpiration rate,water use efficiency,and the chlorophyll relative content,but high significant negative correlation with intercellular CO2 concentration.At the same time,transpiration rate was observed to be very significantly and positively correlated to stomata conductance and chlorophyll relative content,being significantly and positively correlated with water use efficiency,and very significantly and negatively correlated with intercellular CO2 concentration.In a word,the influence of simulated acid rain on photosynthetic characteristics of spring wheat leaf became more and more obvious with the increase of hydrogen ion concentration.

Experimental Study on the Utilization of Shallow Groundwater for Spring Wheat

[Objective]The paper aimed to study effect of shallow groundwater at different depths on crop water requirement and crop evaporation in spring wheat field.[Method]Five treatments of shallow groundwater table at different depth were designed to do evaporation experiment for spring wheat in 2008-2009.[Result]The groundwater at different depths had great impact on crop growth and field evaporation;its supply accounted for 0-52% of actual evapotranspiration.Atmospheric evaporation and crop rooting depth were the major factors to affect the uptake of groundwater at shallow table,and the supply of deep groundwater was controlled by groundwater table.[Conclusion]The study reveled the pattern of evapotranspiration of spring wheat and evaporation of shallow groundwater at different depth,in order to supply basis for the rational and effective utilization of shallow groundwater as well as optimization of the irrigation scheduling for spring wheat.

Effects of zinc on cadmium uptake by spring wheat (Triticum aestivum, L.): long-time hydroponic study and short-time ^(109)Cd tracing study

To investigate effects of Zn on Cd uptake by spring wheat (Triticum aestivum, L.) in solution culture, long-time hydroponic experiment (1 month) (Experiment 1) and short-time Cd isotope (109Cd) tracing experiment (24 h) (Experiment 2) were conducted. In Experiment 1, spring wheat (cv. Brookton) was grown in nutrient solution at uniform cadmium concentration of 20μ mol/L and 10 zinc concentrations (0, 1, 5, 10, 20, 100, 200, 500, 1000, 2000 μ mol/L). In Experiment 2, spring wheat seedlings,pre-cultivated in complete nutrient solution, were treated with 109Cd of uniform activity and the same series of Zn concentrations as those in Experiment 1 for 24 h. Cd concentrations in shoots and roots in Experiment 1 increased marginally but not consistently with Zn increasing at Zn rates of 1～200 μmol/L, and then decreased significantly at high rates (＞200 μ mol/L). In Experiment 2, the response of 109Cd activities in shoots and roots to increasing Zn was greatly similar to the response of Cd concentrations to Zn increasing in Experiment 1. The results of the two experiments indicated that the short-time and long-time exposure of spring wheat to Zn had similar effects on Cd accumulation.

Root carbon consumption and grain yield of spring wheat in response to phosphorus supply under two water regimes

In semiarid areas, cereal crops often alocate more biomass to root at the expense of aboveground yield. A pot experiment was conducted to investigate carbon consumption of roots and its impact on grain yield of spring wheat （Triticum aestivum L.） as affected by water and phosphorus （P） supply. A factorial design was used with six treatments namely two water regimes （at 80–75% and 50–45% ifeld capacity （FC）） and three P supply rates （P1=0, P2=44 and P3=109 μg P g–1 soil）. At shooting and lfowering stages, root respiration and carbon consumption increased with the elevate of P supply rates, regardless of water conditions, which achieved the minimum and maximum at P1 under 50–45% FC and P3 under 80–75% FC, respectively. However, total aboveground biomass and grain yield were higher at P2 under 80–75% FC; and decreased with high P application （P3）. The results indicated that rational or low P supply （80–75% of ifeld water capacity and 44 mg P kg–1 soil） should be recommended to improve grain yield by decreasing root carbon consumption in semiarid areas.

Using CropSyst to Simulate Spring Wheat Growth in Black Soil Zone of Northeast China

Available water and fertilizer have been the main limiting factors for yields of spring wheat, which occupies a large area of the black soil zone in northeast China; thus, the need to set up appropriate models for scenario analysis of cropping system models has been increasing. The capability of CropSyst, a cropping system simulation model, to simulate spring wheat growth of a widely grown spring cultivar, 'Longmai 19', in the black soil zone in northeast China under different water and nitrogen regimes was evaluated. Field data collected from a rotation experiment of three growing seasons (1992-1994) were used to calibrate and validate the model. The model was run for 3 years by providing initial conditions at the beginning of the rotation without reinitializing the model in later years in the rotation sequence. Crop input parameters were set based on measured data or taken from CropSyst manual. A few cultivar-specific parameters were adjusted within a reasonable range of fluctuation. The results demonstrated the robustness of CropSyst for simulating evapotranspiration, aboveground biomass, and grain yield of 'Longmai 19' spring wheat with the root mean square errors being 7%, 13% and 13% of the observed means for evapotranspiration (ET), grain yield and aboveground biomass, respectively. Although CropSyst was able to simulate spring production reasonably well, further evaluation and improvement of the model with a more detailed field database was desirable for agricultural systems in northeast China.

Screening and evaluation for antibiosis resistance of the spring wheat accessions to the grain aphid,Sitobion miscanthi(Takahashi)(Hemiptera:Aphididae)

Resistant cultivar deployment is an effective method for cereal aphid management.Under greenhouse conditions,preliminary antibiosis resistance screening was conducted on 114 Ethiopian and 22 Chinese spring wheat accessions.After performing a bioassay to determine antibiosis resistance,aphid feeding behaviour and phenolic acid content analyses were performed on the aphid resistant wheat accessions by electrical penetration graph(EPG)and high performance liquid chromatography(HPLC),respectively.Among the wheat accessions,two high resistances,27moderate-resistances,and 35 low-resistances to Sitobion miscanthi were identified.The antibiosis resistance test showed prolonged pre-adult and pre-reproductive periods,shorter reproductive periods,lower fecundity,an intrinsic rate(rm)of increase,and a finite rate(λ)of increase of S.miscanthi on Lunxuan 145,Wane,Lunxuan 6,204511,Lunxuan 103and 5215 than those on the aphid-susceptible accession Beijing 837.The changes for the parameters of aphid feeding behaviour,including spending a longer time in the penetration and phloem salivation phases and less time in the phloem sap-feeding phase on the resistant wheat accessions,indicated that the aphid resistance may occur during the phloem phase and may be due to difficulties in the mechanical probing of the mesophyll cells.Additionally,the HPLC analysis showed higher contents of:1)ferulic acid in Lunxuan 145,Lunxuan 103 and Lunxuan 6;2)p-coumaric acid in Lunxuan145;3)vanillic acid in Lunxuan 145,Wane and Lunxuan 6;4)syringic acid in Lunxuan 103;and 5)caffeic acid in 5215.The contents of some phenolic acids within wheat leaves,such as p-courmaric acid and vanillic acid showed significant positive correlation with the duration of aphid development,but negative correlation with the aphid fecundity.The concentrations of these acids may be the causes of antibiosis resistance to S.miscanthi.The identification of grain aphid-resistant wheat accessions in our study will be helpful in future breeding program for pest control.

Fertilization Management for Improving Quality Properties of Spring Wheat in Northeast China

Fertilization management to improve quality properties of spring wheat cultivars has received little research attention inNortheast China. In this study, the effects of different fertilization management regimes on the quality properties of springwheat cultivar New Kehan 9 (Triticum aestivum L.) were investigated for two years. The results showed that fertilizationconsistently increased wheat yield, and the highest yield was obtained with addition of N, P and NPK fertilizers. The NPKtreatment resulted in 50% more yield than the unfertilized plot. The average increases in protein content from NPK and NP atseeding + N at anthesis over no fertilization and NP fertilizers at seeding were 2.7% and 0.90% respectively. The highestprotein yields were achieved in NPK and NPK + N treatments, and the lowest protein yield was observed in the no fertilizertreatment due to both low protein content and grain yield. Fertilization increased gliadins content, but decreased gluteninscontent, thus the gliadins/glutenins ratios were higher in the fertilization treatments. The most obvious effect of fertilizationon kernel quality was the significant increase of hardness percentage. Although the dough rheological properties werenot strongly changed by fertilization, dry gluten and wet gluten were significantly increased, and the highest breadvolume and bread score were found in the NPK treatment in both years. The application of 3% urea at anthesis, or applying45 kg ha-1 of potassium sulphate at seeding, with urea and diammonium phosphate as basal applications, significantlyincreased protein yield and improved quality properties of this wheat cultivar.Key words: Fertilization, Yield, Protein contents, Protein fractions, Quality, Spring Wheat

EflFect of long-term ozone fumigation on growth development and yield of spring wheat in open-top field chamber

The experimental plants were grown in open-top chamber and exposed to 0.26 ppm of ozone for six hrs. per day from seedling stage till ripening. The results showed that the height of plants, rates of earing, flowering, grain forming, ripening and the weight/1000 kernels all declined in fumigated plants in comparison with the controls. The yield lost 76.7%. The actual actions of ozone were that it caused foliar injury and chlorophyll destruction accelerating leaf senescence, reduction of assimilation products. O3 was unfavorable injurious to transport and accumulation of substances to the grains after flowering.

A preliminary study on simplified simulation model of spring wheat growth

In the model developed in this paper, taking the characters and requirements of meteorological services into account, some conventional meteorological observations which are easy to be obtained have been ch.osen, and mathematical equations describing micro-growth processes of crops have been established on the basis of the field experiments, laboratorial analysis and computer's modelling tests with time interval of ten-days for several years (1987-1989), in accordance with the known biological and physical rules and corresponding reference literatures. It is a preliminary simplified simulation model of spring wheat growth in optimal water and nutrient conditions. The field experiments show that simulation results of this simplified model are satisfactory. The potential operational application and theoretical sense are significant in the meteorological forecast of yield and in the assessment of influences of climatic change on agriculture.

Study on Somaclonal Variation of Spring Wheat

Somaclonal variation of calli and regenerated plants of spring wheat were detected by using technique RAPD in the study. Calli at different culture stages and regenerated plants derived from young spikes and immature embryos were used as materials. Molecular variation could be reflected from electrophoresis pattern of RAPD fragments at different culture stage in calli, and in regenerated plants derived from different explants, even no phenotype variations were found. Somaclonal variation in calli and in regenerated plants appeared regularly: A higher frequency of variation in hybrids F2 was detected than that of the cultivar that is stable genetically. High variation frequency of RAPD fragments appeared in calli when cultured 75 days. The identical variations of RAPD fragments were observed in calli and in the regenerated plants induced from different genotype or explants. The variation frequency detected is higher in regenerated plants than that of in calli. RAPD could be applied easily and simply to determine variation in level of DNA at each stage cultured in vitro.

Analysis on Main Traits of Spring Wheat Landraces in Tibet

In this study, 9 main traits of 774 spring wheat landraces in Tibet were investigated and analyzed. The results show that spring wheat landraces in Tibet have high plant height （with an average of 126.1 cm） and long growth period （with an average of 135.2 d）, with an average spike length of 9.5 cm, average effective tiller number per plant of 5.9, average spikelet number per spike of 19.9, average kernel number per spikelet of 3.5, average spikelet number per spike of 51.8, aver- age kernel weight per spike of 2.0 g, and average 1 000-grain weight of 38.1 g. Specifically, kernel number per spikelet of 2 landraces is larger than 6.0, spikelet number per spike of 2 landraces is larger than 100, kernel weight per spike of 2 landraces is larger than 4.0 g, 1 000-grain weight of 11 tandraces is larger than 50 g. There is abundant genetic diversity in those traits except in growth period, and the coefficient variation of 9 traits is in a decreasing order of effective tiller number per plant 〉 kernel weight per spike 〉 kernel number per spike 〉 spike length 〉 kernel number per spikelet 〉 1 000-grain weight 〉 plant height 〉 spikelet number per spike 〉 growth period. There is different relevance among different traits. Growth period is extremely significantly positively related to yield traits; grain number traits are extremely significantly positively relative to plant height and spike length, but ex- tremely significantly negatively relative to effective tiller number per plant; kernel number per spike is extremely significantly positively relative to kernel weight per spike, but extremely significantly negatively related to 1 000-grain weight; 1 000-grain weight is extremely significantly positively related to kernel weight per spike. Based on principal component analysis, these 9 traits could be included by 5 principal com- ponents （grain number, grain weight, spike length, tiller number and growth period）. According to the comprehensive evaluation values of these five principal components, 50 landraces including ZM019573, ZM019849, ZM019730, ZM018745, ZM019657, ZM019891, ZM020533, ZM018508, 7M019074 and ZM020026 have good performance.

Analysis on the Expression of TaMOR Gene in Two Different Spring Wheat Varieties at Different Years

[Objectives]The TaMOR gene is a gene that affects the initiation and growth of the secondary roots of wheat,but the expression patterns in different parts of the wheat root system and the differences in expression in different varieties are not clear.This study aimed to investigate the expression of the TaMOR gene in the seminal roots,secondary roots and root base.[Methods]Real-time fluorescence quantitative PCR technology was used to analyze the relative expression levels of the TaMOR gene in seminal roots,secondary roots and root base of seedlings of ancient variety Monkhead and modern variety Longchun 35.[Results]There was no significant difference in the number of seminal roots between Longchun 35 and Monkhead,and the numbers of seminal roots of the two varieties did not change significantly during the three sampling periods.The number of secondary roots and shoot dry weight of Longchun 35 were significantly higher than those of Monkhead,and the number of secondary roots and shoot dry weight of both varieties increased with the sampling time point.The root dry weight of Monkhead increased with the sampling time,while Longchun 35 showed the largest value at the second time.The fluorescence quantitative PCR results showed that for 13-day seedlings,the relative expression of the TaMOR gene in root base was significantly higher than that in the seminal roots and secondary roots.There was no significant difference in the relative expression of gene TaMOR in the root system of Monkhead and Longchun 35.[Conclusions]The root allocation of gramineous crops decreases with the breeding years,and the difference in gene TaMOR expression level needs further study.

Exploring the Potential Impacts of Climate Variability on Spring Wheat Yield with the APSIM Decision Support Tool

Assessing the impacts of climate variability on agricultural productivity at regional, national or global scale is essential for defining adaptation and mitigation strategies. We explore in this study the potential changes in spring wheat yields at Swift Current and Melfort, Canada, for different sowing windows under projected climate scenarios (i.e., the representative concentration pathways, RCP4.5 and RCP8.5). First, the APSIM model was calibrated and evaluated at the study sites using data from long term experimental field plots. Then, the impacts of change in sowing dates on final yield were assessed over the 2030-2099 period with a 1990-2009 baseline period of observed yield data, assuming that other crop management practices remained unchanged. Results showed that the performance of APSIM was quite satisfactory with an index of agreement of 0.80, R2 of 0.54, and mean absolute error (MAE) and root mean square error (RMSE) of 529 kg/ha and 1023 kg/ha, respectively (MAE = 476 kg/ha and RMSE = 684 kg/ha in calibration phase). Under the projected climate conditions, a general trend in yield loss was observed regardless of the sowing window, with a range from ?-24% to -94% depending on the site and the RCP, and noticeable losses during the 2060s and beyond (increasing CO2 effects being excluded). Smallest yield losses obtained through earlier possible sowing date (i.e., mid-April) under the projected future climate suggested that this option might be explored for mitigating possible adverse impacts of climate variability. Our findings could therefore serve as a basis for using APSIM as a decision support tool for adaptation/mitigation options under potential climate variability within Western Canada.

Impact of Climate Variability on Yield of Spring Wheat in North Dakota

Agricultural production is highly dependent on the climatic variability of the specific regions. Differential climatic and soil conditions bring about changes in yield, quality of crops thus affecting the economy. This study evaluated the impact of variability in different climatic factors keeping the other factors constant on spring wheat production in North Dakota from 2007 to 2011. The spring wheat yield mainly depends on the climatic changes during growing periods April to September. Average maximum air temperature was significantly different from April to September except June from 2007 to 2011. High average minimum and maximum air temperatures during planting time increase yield and planting area for 2010. In 2011, low mean soil temperature, excess rainfall in April caused low yield of spring wheat. The unmitigated climate variability will result in declines in yields. So, adoption of sustainable agriculture practices helps the farmers to develop the different practices for their farms.

Spring Wheat Response to Disease Control and Subsurface Drainage Management in the Red River of the North Valley, USA

Increased variability in rainfall events and high production input costs are driving agricultural producers to consider subsurface water management in the flat Red River of the North Valley in Eastern North Dakota and Northwestern Minnesota, USA. Subsurface tile incorporated with water table control structures was utilized from 2009 to 2011 to investigate the response of hard red spring wheat (HRSW) (Triticum aestivum L. emend. Thell.) for yield, disease, and other agronomic characteristics to soil water management. A factorial arrangement of four cultivars, two seed treatments, and two foliar fungicide treatments in a split-plot design with closed and open tile as whole-plots was used. Mean wheat yields averaged across years were not significantly different with closed or open tile treatments. There existed an optimum management practice where plant useable water was not freely drained and analyzing the data with the optimum water management for each year found the optimum water table managed treatment yielded higher with 3812 kg ha-1 compared with limited water table management with 3679 kg ha-1. In 2011, the cultivars Faller and Howard were taller, and Traverse had lower root disease severity. In 2010 and 2011, Howard and Traverse had more leaf disease with open tile compared with closed tile. Across years, there was no difference in root disease, stand, number of spikes, crop height, or yield response to appli-cation of seed treatments with open or closed tile. In 2010, there was a 3.7% yield advantage with application of seed treatment on open tile. Across years, there was no yield response to application of foliar fungicides;however, wheat yield with foliar fungicide was 5% higher than without application in 2010. Producers should be using water table control and disease management to maximize HRSW yield. Further research should investigate water table management throughout the season based on weather conditions.

西北春麦区APSIM-Wheat模型作物参数全局敏感性分析与比较

为提高西北春麦区APSIM-Wheat模型的适应性及校准的效率和精度,需要对作物参数进行重新率定,并对参数的取值范围进行标定,设定±10%、±20%、±30%、±40%和±50%五个参数取值范围,采用EFAST法和Morris法比较不同参数取值范围下模型的18个作物参数对春小麦产量和生物量的敏感性,并分析EFAST方法下最适宜的参数取值范围,同时对比两种敏感性分析方法的一致性。结果表明,对产量敏感的参数分别为每克茎籽粒数量(GPGS)、初花期积温(TFI)、灌浆期积温(TSGF)、出苗期到拔节期积温(TEOJ)、开花期积温(TF)、潜在灌浆速率(PGFR);对生物量敏感的参数分别为出苗期到拔节期积温(TEOJ)、灌浆期积温(TSGF)、初花期积温(TFI)、开花期积温(TF)。模型敏感参数和不敏感参数的适宜取值范围分别为±30%和±5%。不同参数取值范围下EFAST法和Morris法得到的敏感性结果一致性较好,在进行参数的敏感性分析时可以互相替代。

Impacts of Climate Change on Growth Period and Planting Boundaries of Spring Wheat in China under RCP4.5 Scenario

This article contributes to research on how climate change will impact crops in China by moving from ex-post empirical analysis to forecasting. We construct a multiple regression model, using agricultural observations and meteorological simulations by GCMs, to simulate the possible planting boundaries and suitable planting re- gions of spring wheat under RCP4.5 scenario for the base period 2040s and 2070s. We find that the south bound- ary of possible planting region for spring wheat spreads along the belt： south Shandong-north Jiangsu-north Anhui-central Henan-north Hubei-southeast Sichuan-north Yunnan provinces, and will likely move northward under RCP4.5 scenario in 2040s and 2070s, resulting in the decrease of possible planting area in China. Moreover, the sowing and harvest date of spring wheat in the base period shows a gradually delayed phenomenon from the belt： south Xinjiang - Gansu, to the Tibet Plateau. As a result, the growth period of spring wheat in China will shorten because of the impacts of climate change. These results imply that a variety of adaptations measures should be set up in response to changing climatic conditions, including developing the planting base for spring wheat, restricting the planting area of spring wheat in sub-suitable areas at risk while expanding the planting area of optimal crops.