Huang-Huai River Research Articles

Population Genetic Analysis of a Bread Wheat Panel from Northern and Huang-Huai Agro-Ecological Regions in China

Bread wheat (Triticum aestivum L.) is one of the most extensively cultivated cereal crops around the world. Here, we investigated the population structure and genetic diversity of a panel mainly originated from two wheat agro-ecological regions (northern winter wheat region, NW; and the Huang-Huai River Valley’s facultative wheat region, HH) in China based on a 15K SNP array. Population genetic analysis revealed that the optimal population number (K) was three, and the three groups were roughly related to ecological regions, including NW (mainly Hebei), HH1 (Henan-Shaanxi), and HH2 (Shandong). Within HH, HH1 had a higher nucleotide diversity (π = 0.31167), minor allele frequency (MAF = 0.2663), polymorphism information content (PIC = 0.2668), and expected heterozygosity (Hexp = 0.3346) than HH2. Furthermore, our results demonstrated that genetic diversity decreases with the advancement of wheat breeding. Finally, inference of ancestry informative markers indicated that the genomes of the three pure groups from the three provinces (Hebei, Henan, and Shandong) of the two regions have genomic regions with different mosaic patterns derived from the two landrace groups. These findings may facilitate the development of wheat breeding strategies to target novel desired alleles in the future.

Interdecadal Variation in Rossby Wave Source over the Tibetan Plateau and Its Impact on the East Asia Circulation Pattern during Boreal Summer

The wave activity flux representing the energy propagation direction of planetary Rossby wave generally originates from a large wave source area. This study investigates the interdecadal variability and formation mechanism of Rossby wave source over the Tibetan Plateau (TP-RWS) and its impact on the atmospheric circulation and precipitation pattern in East Asia based on the ERA-20C reanalysis dataset in summer (June–July–August) during 1900 to 2010. Results show that the region with the maximum variabilities of Rossby wave source (RWS) in the past 110 years appears over the Tibetan Plateau (TP) during boreal summer, and the TP-RWS shows prominent characteristics of interdecadal oscillation. Secondly, the TP-RWS is mainly composed of the vortex stretching term (RWS-S1) and the absolute vorticity advection term (RWS-S2). The interdecadal TP-RWS is a synergistic result of the snow cover over northwestern TP associated with the RWS-S1, and the deep convection over southeastern TP associated with the RWS-S2. Furthermore, the interdecadal TP-RWS can lead to an alternatively positive and negative pattern of geopotential height anomalies from the northwestern TP to the North Pacific, which has a great climate effect on the precipitation in Huang-huai River Basin, South Korea and Japan Island. Under the guidance of the anomalous cyclonic circulation in East Asia, the prevailing southerly and easterly winds occur over the West Pacific and the Huang-huai River Basin, which lead to the water vapor convergence and upward movement at middle and lower troposphere.

Identification and validation of stable quantitative trait loci for yield component traits in wheat

Grain weight and grain number are important yield component traits in wheat and identification of underlying genetic loci is helpful for improving yield. Here, we identified eight stable quantitative trait loci (QTL) for yield component traits, including five loci for thousand grain weight (TGW) and three for grain number per spike (GNS) in a recombinant inbred line population derived from cross Yangxiaomai/Zhongyou 9507 across four environments. Since grain size is a major determinant of grain weight, we also mapped QTL for grain length (GL) and grain width (GW). QTGW.caas-2D, QTGW.caas-3B, QTGW.caas-5A and QTGW.caas-7A.2 for TGW co-located with those for grain size. QTGW.caas-2D also had a consistent genetic position with QGNS.caas-2D, suggesting that the pleiotropic locus is a modulator of trade-off effect between TGW and GNS. Sequencing and linkage mapping showed that TaGL3-5A and WAPO-A1 were candidate genes of QTGW.caas-5A and QTGW.caas-7A.2, respectively. We developed Kompetitive allele specific PCR (KASP) markers linked with the stable QTL for yield component traits and validated their genetic effects in a diverse panel of wheat cultivars from the Huang-Huai River Valley region. KASP-based genotyping analysis further revealed that the superior alleles of all stable QTL for TGW but not GNS were subject to positive selection, indicating that yield improvement in the region largely depends on increased TGW. Comparative analyses with previous studies showed that most of the QTL could be detected in different genetic backgrounds, and QTGW.caas-7A.1 is likely a new QTL. These findings provide not only valuable genetic information for yield improvement but also useful tools for marker-assisted selection.

Interdecadal Variability of Spring Eurasian Snowmelt and Its Impact on Eastern China Summer Precipitation

In this study, the interdecadal variability of Eurasian spring snowmelt and its relationship with Eastern China summer precipitation (ECSP) are investigated based on observations and reanalysis data. Results show that the second mode of the empirical orthogonal function (EOF) analysis of the spring snowmelt, featured as a west-east dipole pattern, displays two interdecadal changes near the late-1970s and in the mid-2000s. The increased spring snowmelt over the Western Siberia (WSI) and the opposite situation over the Eastern Europe (EEU) are significantly linked to a meridional quadrupole summertime rainfall pattern on interdecadal time scales, with excessive rainfall over the regions of southern China (SC) and the Huang-Huai River (HHR) and deficient rainfall over the middle and lower reaches of Yangtze River Valley (YRV) and Inner Mongolia-northeastern China (IMNC). Besides, the possible mechanisms are discussed from the perspective of the hydrological effect related to snowmelt-induced soil moisture. Increased spring snowmelt can produce more water inflowing into the soil, leading to anomalous soil moisture, which can persist into summer. Excessive (deficient) snowmelt-related soil moisture anomalies over the WSI (EEU) in summer will change local land thermal conditions and thus generate cyclonic (anticyclonic) circulations with a quasi-barotropic structure. Therefore, the eastward-propagating wave-activity flux (WAF) could be strengthened over the WSI and EEU in the mid- and upper-troposphere and further propagate downstream. Combining the local response of atmospheric circulations to summer surface heating induced by local snowmelt-related SM anomalies over Mongolia, an anomalous anticyclonic (cyclonic) circulation near the Lake Baikal (SC) and the related strong descending (ascending) motion over the IMNC (SC) are founded. Besides, strong positive (negative) upper-level divergence appears over the YRV (HHR), which is the right (left) side of the exit region of upper-level jet. The upper-level divergence could be attributed to the convergence (divergence) of meridional winds on the right side of the anticyclonic circulation, thus the uniform descending (ascending) motion also appears over the YRV (HHR) through the collocation of upper-level convergence (divergence) and the compensatory lower-level circulations. Consequently, a quadrupole pattern of secondary circulation over Eastern China is founded, thereby causing the anomalously distributed ECSP under favorable water vapor conditions.

Patterns and driving forces of the agricultural water footprint of Chinese cities

The patterns and determinants of different types of agricultural water footprints in China are poorly understood at the prefecture-city level. In this paper, we evaluate Chinese agricultural water footprints from 2000 to 2017 and analyzed their spatio-temporal characteristics. Our estimation results show that the annual average agricultural water footprint in China was 5.038 × 109 m3, and the proportions of green water, blue water, and gray water were 70%, 9%, and 21%, respectively. In addition, high agricultural water-footprint cities with obvious urban agglomeration effects are mainly located in the Northeast, the Huanghuai River, the Yangtze River Basin, and Northwestern of Xinjiang, while low agricultural water-footprint cities are concentrated in high coastal urbanization-level areas or less developed agricultural areas of the west. We also investigate their determinants using a spatio-temporal fixed-effect model and find that GDP per capita, total investment in fixed assets, the income level of rural residents, the proportion of food grown, spray and drip irrigation technology, low-pressure pipe irrigation technology and seepage control irrigation technology have significant positive impacts on the agricultural water footprint. In contrast, the proportion of secondary and tertiary industries, social retail consumption, urbanization, technology expenditure, and the effective irrigation area proportion have a significant inhibitory effect. The primary determinants of the agricultural water footprint also vary substantially across water footprint categories (green, blue, and gray water footprints) and regions. Our findings imply that the agricultural water footprint should be incorporated into city water resource management and monitoring system.

An Empirical Study on the Growth of Agricultural Green Total Factor Productivity in the Huanghuai River Economic Zone by Big Data Computing

Facing the new form and situation of the Huaihe Economic Zone, it is of great significance to analyze the sources of growth and the intrinsic mechanism of the green total factor productivity of its economic-ecological system, to grasp the spatial and temporal characteristics of green total factor productivity, and to study the influence of each factor on green total factor productivity to achieve sustainable economic development in the Huaihe Economic Zone. Based on the clarification of economic growth theory, green economy theory, carbon cycle theory, and green total factor productivity theory, this paper identifies and discusses the limitation that the existing research literature often ignores the endogenous role of carbon sinks when measuring green total factor productivity. Then, the green total factor productivity of Huaihe Economic Zone based on carbon cycle from 2004 to 2017 is measured using the superefficient nonradial SBM model. Combined with the GML productivity index, it is decomposed into technical progress and technical efficiency and analyzed in comparison with the green total factor productivity without considering ecological purification capacity (carbon sink) from the perspective of time and space. Finally, the spatial Durbin model is used to analyze the effects of seven variables, including the level of economic development, environmental regulation, R&D level, and openness to the outside world, on green total factor productivity in the Huaihe Economic Zone, and to analyze the direct and indirect effects of each variable on green total factor productivity. TFP based on expected output carbon sink and GDP overall outperforms TFP based on expected output GDP only, mainly because the growth of technical efficiency is underestimated when carbon sink is not considered. Technical efficiency and technological progress are equally important for the growth of TFP in an eco-economic perspective. It is of great practical significance for both the comprehensive understanding of the green total factor productivity level and the improvement path of the ecosystem and the coordinated and sustainable development of the Huaihe Economic Zone.

Inconsistent variation of return periods of temperature extremum in China and its projection based on CMIP6 results

Increasingly extreme temperature events under global warming can have considerable impacts on sectors such as industrial activities, health, and transportation, suggesting that risk for these kinds of events under climate change and its regional sensitivity should be reassessed. In this study, the observation and multi-model simulations from CMIP6 are comprehensively used to explore the regional differences of the extreme temperature response to climate change from the perspective of return period (RP). The Gumbel model of generalized extremum distribution is applied to estimate the RP for the annual extremum of temperature based on Gaussian distribution of daily temperature. The analysis on the observation in selected three sites indicates that the regional inconsistency of RP variation is not only existed in extreme high temperature (HTx) but also in low temperature (LTn) during the past several decades. The annual amplitude of temperature extremum in the Northeast China is enlarged with summer becoming hotter and winter becoming colder while the opposite situation is detected in Huang-Huai River Basin with cooler summer and relatively stable winter, and South China is characterized by hotter summer and slight warmer winter. From the spatial distribution of the HTx and LTn variations of fix RP, it is found that the Northeast China and Jiang-Huai River Basin is the most sensitive areas, respectively, in the response of extreme low temperature and high temperature to global warming. However, the regional inconsistency of the extreme temperature change is only observed under SSP1-2.6 scenario in the CMIP6 simulation but gradually disappeared from SSP2-4.5 to SSP5-8.5.

Lag impacts of the anomalous July soil moisture over Southern China on the August rainfall over the Huang\u2013Huai River Basin

The effect of soil moisture (SM) on precipitation is an important issue in the land–atmosphere interaction and shows largely regional differences. In this study, the SM of the ERA-Interim reanalysis and precipitation data of the weather stations were used to investigate their relationship over eastern China during July and August. Moreover, the WRF model was applied to further validate the effect of SM on rainfall. In the observations, a significantly negative relationship was found that, when the soil over southern China is wet (dry) in July, the rainfall decreases (increases) over the Huang–Huai–River basin (hereafter HHR) in August. In the model results, the soil can “memorize” its wet anomaly over southern China from July to August. In August, the wet soil increases the latent heat flux at surface and the air moisture at lower levels of the atmosphere, which is generally unstable due to the summer monsoon. Thus, upward motion is prevailing over southern China in August, and the increased surface air moisture is transported upwards. After that, the condensation of water vapor is enhanced at the middle and upper levels, increasing the release of latent heat in the atmosphere. The heat release forms a cyclonic circulation at the lower levels over eastern China, and induces the transport and convergence of water vapor increased over southern China in August. This further strengthens the upward motion over southern China and the cyclonic circulation at the lower levels. Therefore, positive feedback appears between water vapor transport and atmospheric circulation. Meanwhile, the cyclonic circulation over southern China results in a response of water vapor divergence and a downward motion over HHR. Consequently, the negative anomalies of precipitation occur over HHR in August. When the July soil is dry over southern China, the opposite results can be found through the similar mechanism.

Ancient Starch Remains Reveal the Vegetal Diet of the Neolithic Late Dawenkou Culture in Jiangsu, East China

The Liangwangcheng site, located in Pizhou County, Xuzhou City, northern Jiangsu Province, is one of the most important Neolithic Dawenkou Culture archeological sites in the Haidai area of China’s eastern seaboard. In recent years, archaeobotanical studies in the Haidai area, mainly focusing on Shandong Province, have yielded fruitful results, while relatively few such studies have been undertaken in northern Jiangsu Province. Here, we report the results of dental residue analysis conducted on 31 individual human skulls unearthed from the Late Dawenkou Culture Liangwangcheng site. The starch granules extracted from these residue samples indicate that foxtail and broomcorn millet, rice, roots and tubers, and legumes comprised the vegetal diet of Liangwangcheng’s occupants. Evidence suggests that mixed rice–millet agriculture played a definite role, with the coexistence of gathering as an economic element. According to archaeobotanical evidence from surrounding cotemporaneous sites, the Late Neolithic human groups that lived in the lower Huang-Huai River drainage shared similar subsistence patterns. Our results provide new evidence for a more comprehensive understanding of plant resource utilization and agricultural development in northern Jiangsu during the Dawenkou period.

The genetic diversity and heterotic groups of 169 Chinese semi-winter rapeseed (Brassica napus) cultivars and inbred lines

Until now, no distinct heterotic groups have been established in many rapeseed-growing countries. Numerous modern breeding lines with desirable seed quality have been developed but the loss of genetic diversity would be problematic. Simple sequence repeat markers covering all 19 B. napus linkage groups were used to evaluate the genetic diversity and to classify the heterotic groups of 169 Chinese semi-winter cultivars or inbred lines. The results indicate moderate genetic differentiation among the 169 accessions, which distributed in 10 major groups according to their pedigrees or origins. The Chinese accessions could be divided into two genotypes: northern restorers and southern maintainers for Polima cytoplasm male sterility. The maintainers consisted of nine clades originating from 10 major rapeseed-growing provinces in the upper, middle and lower reaches of the Yangtze River. The mid-parent heterosis on plant height and yield ability of the intragroup crosses was inferior to that of the intergroup hybrids. When the intragroup parental combinations with short genetic distances (GD) were included in all regressing data, GD is significantly correlated to heterosis level. Three major heterotic patterns were identified: (1) northern restorer × southern maintainer, (2) maintainer from the upper reaches of the Yangtze River × maintainer from the lower reaches of the Yangtze River and (3) maintainer from the middle Yangtze River × maintainer from the lower reaches of the Yangtze River. For the first time, the results showed the outline of heterotic groups in Chinese rapeseed under the conditions of the Huang-Huai River region.

Variation in Summer Rainfall over the Yangtze River Region during Warming and Hiatus Periods

Variation in summer precipitation over the Yangtze River region during a global warming period (1976−1997) and a hiatus period (1998−2013) are investigated in this study. The results show that during the warming period, precipitation over both the Yangtze River region and South China shows an increasing trend, attributable to increasing ascending motion, a decreasing East Asian westerly jet (EAWJ), and a decreasing temperature gradient. During the hiatus period, the rainfall belt moves from the Yangtze River region to the Huang-Huai River region in association with the northward displacement of the EAWJ, attributable to the increasing trend in the temperature gradient at high latitudes. Empirical orthogonal function (EOF) analysis is one of the widely used methods in atmospheric science. It is also known as principal component analysis (PCA). The second EOF mode of summer precipitation can represent the variation in rainfall over the Yangtze River region. During the warming period, rainfall over the Yangtze River region is controlled by a dipole mode of water vapor transport, induced by SST cooling in the Maritime Continent, which can lead to a strong Pacific–Japan teleconnection; warming SST in the east-central tropical Pacific can also strengthen this pattern. During the hiatus period, the Pacific–Japan pattern is weak, and the water vapor transport pattern over the western subtropical Pacific changes from a dipole structure to a weak monopole structure.

A new mean-extreme vector for the trends of temperature and precipitation over China during 1960–2013

A mean–extreme (M-E) vector is defined to combine the changes of climate means and extremes. The direction of the vertical axis represents changes in means, whereas the direction of the horizontal axis represents changes in extremes. Therefore, the M-E vector can clearly reflect both the amplitude and direction of changes in climate means and extremes. Nine types of M-E vectors are defined. They are named as MuEu, MuEd, MuEz, MdEu, MdEd, MdEz, MzEu, MzEd, and MzEz. Here M and E stand for climate means and extremes, respectively, whereas u, d, and z indicate an upward, downward trend and no trend, respectively. Both temperature mean and extremely high temperature days are consistently increased (MuEu) in nearly whole China throughout four seasons. However, the MuEd-type vector dominates in some regions. The MuEd-type vector appears over the Huang Huai river basin in spring, summer and winter. For the M-E vector of temperature mean and extremely low temperature days, the MuEd-type spreads the entire China for all seasons. The M-E vector for precipitation mean and the extreme precipitation days possesses identical trends (MuEu or MdEd) despite of seasons. The MuEu-type dominates in northeastern China and west of 105°E in spring, northwestern and central/southern China in summer, west of 100°E and northeastern China in autumn, and nearly whole China in winter. Precipitation mean and extreme precipitation days are all decreased (MdEd) in the rest of China for all reasons. The trends relationship in means and extremes over China presented herein could provide a scientific foundation to predict change of extremes using change of mean as the predictor.

Recent Change of the South Asian High

AbstractThis paper investigates the variability of the summer (May–September) South Asian High (SAH) for the period 1979–2012. Results show that the intensity and the area of the summer SAH decreased around 2002 at the decadal scale; and the East Asian westerly jet suppressed at the north edge of the SAH, which is consistent with the SAH variation. The precipitation pattern over eastern China also shifted during the same periods, with increased rainfall in the Huang-Huai River region and South China and decreased rainfall in the Yangtze River region. The relationship between the two variations is evidently strengthened via changes in moisture flux.

Pollen flow of wheat under natural conditions in the Huanghuai River Wheat Region, China

abstractThe transgenic pollen spread is the main pathway of transgenic plant gene flow. The maximum distance of pollen dispersal (horizontal), the spatial dynamics of pollen movement (vertical), and the patterns of pollen dispersal are important considerations in biosafety assessments of genetically modified crops. To evaluate wheat (Triticum aestivum) pollen dispersal, we measured the pollen suspension velocity and analyzed pollen dispersal patterns under natural conditions in the Huanghuai River wheat-growing region in 2009. The pollen suspension velocity was 0.3–0.4 m/s. The highest pollen densities were detected in the north, northwest, and south of the pollen source. Pollen was dispersed over distances greater than 245 m in the northwest and northeast directions. At the pollen source center, pollen density decreased with increasing vertical height. In the north of the pollen source, the pollen density from 65 m to 225 m showed a wave-mode decrease with increasing height. The horizontal transport of pollen over longer distances fitted polynomial equations. In the north, the pollen density was highest at 45 m from the pollen source, and decreased with increasing distance. In the northwest, the pollen density showed a double-peak trend. In the northeast, pollen density was highest from 45 m to 125 m from the source. Wind speeds greater than the pollen suspension velocity and the duration of continuous gusts were the main factors affecting pollen dispersal. This information will be useful for determining the spatial isolation distances for hybrid seed production and for the commercial production of transgenic wheat.

Improvement of aerosol optical depth retrieval using visibility data in China during the past 50 years

AbstractHorizontal visibility and water vapor pressure data from 483 stations in China from 1960 to 2009 were used to inverse aerosol optical depth (AOD) using a new series of parameters, which were revised for each station using the polybasic nonlinear regression method based on monthly Multiangle Imaging Spectroradiometer (MISR) AOD data during 2001–2005. Monthly AOD retrievals from 2006 to 2009 using the new parameters were compared with MISR AOD in the same period. AOD retrieved with the new parameters can capture the extreme values better than the inversion result with the original parameters, and the root‐mean‐square error between retrieval and MISR AOD reached the minimum of 0.047 in northwest China and the maximum of 0.102 in the Huang–Huai River Basin, respectively. The spatial distribution and seasonal features of monthly AOD from 1960 to 2009 in China were also analyzed. The monthly AOD in China for past 50 years, from 1960 to 2009, exhibited an increasing trend, especially during 1960–1985, with a linear rate of increase of 0.004/year. No distinct trend can be found for AOD from 1985 to 1995; then it increased obviously from 1996 to 2009 with an annual rate of 0.002. Seasonal change in AOD showed that it reached a maximum value in summer with the average value between 0.34 and 0.36 for the whole China, while a minimum value was reached in winter with a mean value between 0.2 and 0.22. It is noted that the aerosol vertical profile was a sensitive factor to the inversion result. The root‐mean‐square error using Goddard Chemistry Aerosol Radiation and Transport aerosol profiles was increased 1.9 to 5.7 times than using the traditional three‐segment profile in northwest, southwest, northeast, and northern China, which meant that the retrieval AOD was sensitive to aerosol vertical profile in these regions; at the same time, the root‐mean‐square error was decreased 1.13 to 1.37 times in other regions.

Possible contribution of heavy pollution to the decadal change of rainfall over eastern China during the summer monsoon season

A regional climate model (RegCM4.1) is used to conduct two sets of sensitivity experiments. There are 20-year runs in each set of experiments. The experiments in each set include the variation of anthropogenic SO2 emissions during 1989–2008 but exclude natural variations of the atmosphere and sea surface temperature. The model results suggest that the high-speed emission of SO2 and its uneven distribution over eastern China can contribute to the change in May–August rainfall over eastern China between the two decades of 1999–2008 and 1989–1998, especially to the decrease (increase) of rainfall in the Yangtze River valley (Huang-Huai River region). Furthermore, the areas of decreasing (increasing) rainfall correspond to the downward (upward) currents of the anomalous atmospheric circulation, which is caused by the two humps of the difference in sulfate concentration between the two decades.

Characteristics and Evaluation Parameters Associated with Cooking Quality of Chinese Fresh Noodle

Noodle cooking quality plays an important role in assessing processing quality of Chinese fresh noodle. Forty-six Chinese wheat cultivars and advanced lines from the Northern Plain and the Huang-Huai River Valleys Winter Wheat Regions were used to determine the relationship between wheat quality characters and evaluation parameters of Chinese fresh noodle cooking quality including total organic matter (TOM), cooking losses, water sorption, and noodle stickiness. The results indicated that large variations were observed in milling quality, dough rheology characteristics, starch properties, and noodle cooking quality parameters including TOM value, cooking losses, and noodle stickiness. Extensogram energy and maximum resistance contributed negatively to TOM value, with correlation coefficients of 0.66 (P0.01) and 0.56 (P0.01), respectively. Correlation coefficients between Farinogram stability, Extensogram energy and maximum resistance and cooked noodle weights with optimal cooking (6 min) and overcooking (10 min) ranged from 0.55 to 0.63 (P0.01). Farinogram mixing tolerance index was significantly and positively correlated with cooked noodle weights for 6 min and 10 min, with correlation coefficients of 0.67 (P0.01)and 0.69 (P0.01), respectively. Starch pasting temperature was significantly and positively correlated with cooked noodle weights for 10 min (r = 0.60, P0.01). This suggested that increased flour protein content and dough gluten strength contributed positively to noodle cooking quality, flour protein property was the major factor in determining noodle cooking quality, and noodle cooking quality was also affected slightly by starch pasting parameters. TOM value was significantly and positively correlated with cooked noodle weights for 6 min and 10 min, with correlation coefficients of 0.66 (P0.01) and 0.69 (P0.01), respectively.Correlation coefficient between cooked noodle weight with 6 min and 10 min cooking time was 0.86 (P0.01). Therefore, it was recommended that cooked noodle weight for 10 min could be an important parameter for evaluation of noodle cooking quality.The cooked noodle weight for 10 min (10 g fresh noodle) should be no more than 21.0 g for good noodle cooking quality in Chinese wheat samples.

Genetic Analysis and Molecular Mapping of Stripe Rust Resistance Gene in Wheat Cultivar Xiaoyan 9323

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most widespread and destructive wheat diseases worldwide. Resistance breeding is constantly pursued for decades to tackle the variations of prevalent Pst races. Xiaoyan 9323, the homology material of Xiaoyan 6, has early maturity, strong resistance to abiotic stresses, wide adaptability, higher resistance to stripe rust, excellent biological characteristics. To identify the resistance gene(s) against stripe rust, we crossed Xiaoyan 9323 with the susceptible genotype Mingxian 169, and tested F1, F2, F3, and BC1 progenies with Chinese race CYR32 at seedling stage in greenhouse. Then, SSR techniques were used to screen molecular markers linked to the gene conferring resistance to CYR32 in Xiaoyan 9323. The genetic analysis results showed that Xiaoyan 9323 displayed resistance to epidemic yellow rust races in China when tested with five races of stripe rust and one recessive gene conferring resistance to races CYR32. The mapping population of F2 generation was inoculated with CYR32. Six SSR markers, Xwmc807, Xbarc3, Xwmc684, Xwmc201, Xwmc553, and Xwmc179 were linked to the resistance gene, which were all located on chromosome arm 6AL. The closest flanking makers were Xwmc201 and Xwmc553 with genetic distances of 2.6 cM and 3.7 cM, respectively. According to SSR markers’ chromosome location, the gene was located at chromosome 6AL. Based on chromosomal location, reactions to various pathotypes and pedigree analysis, the gene may be a new one different from the known stripe rust resistance genes, designated as YrXY9323 temporarily. Two flanking SSR markers, Xwmc201 and Xwmc553, were used to test 42 wheat cultivars from Huang-Huai River Valleys wheat region. The results showed that 19% cultivars had the same polymorphic bands as YrXY9323, indicating that the polymorphic SSR markers can be useful in wheat molecular marker selection and breeding.

Association Analysis of Yield Traits with Molecular Markers in Huang-Huai River Valley Winter Wheat Region, China

为了获得与小麦产量性状关联的分子标记，筛选相关标记的等位变异，以128份黄淮麦区小麦品种（系）为材料，在4个环境下鉴定产量性状，并选用在小麦全基因组21条染色体上的64个SSR、27个EST-SSR和47个功能标记检测所有材料的基因型。91个SSR和EST-SSR标记共检测到315个等位变异，单个引物检测到2-7个等位变异，平均3．5个：47个功能标记共检测到107个等位变异，单个引物检测到2-5个等位变异，平均2.3个。关联分析表明，49个位点与4个环境的产量性状及其均值显著关联（P≤0．005），其中38个位点在2个或以上环境或均值下被重复验证，16个位点与2个或以上性状相关联。对相对稳定的等位变异作进一步分析，发掘了一批与产量性状相关的优异等位变异，如降低株高的等位变异Ax2＊-null和UMNl9＊-A362，增加穗长的等位变异barc21-A220，增加可育小穗数的等位变异gpw2111-A156，增加总小穗数的等位变异swes65-A120，增加穗数的等位变异VRN-Al＊-41068，增加穗粒数的等位变异cfd5-A215和增加千粒重的等位变异wmc626-A170。研究结果对利用分子标记辅助选择进行小麦产量性状的遗传改良具有一定的指导意义。

Random repeated cross sectional study on breeding site characterization of Anopheles sinensis larvae in distinct villages of Yongcheng City, People's Republic of China

BackgroundCharacterizing the breeding site of Anopheles sinensis is of major importance for the transition from malaria control to elimination in China. However, little information is available especially regarding the characteristics and influencing factors of breeding sites of An. sinensis in Yongcheng City, a representative region of unstable malaria transmission in the Huang-Huai River region of central China. The aims of this study were to determine the breeding site characteristics of An. sinensis and related environmental and physicochemical parameters, to find out which breeding site characteristics could best explain the presence of An. sinensis larvae, and to determine whether the breeding habit of An. sinensis has changed or not.MethodsRandom repeated cross sectional study was undertaken in six villages of the Yongcheng city characterized by different levels of the historical incidence of P. vivax malaria. The potential breeding sites of An. sinensis larvae in each village were examined twice per month both in the household courtyards and the village surroundings. The larval sampling was done by the standard dipping method. Some important breeding site characterizations were recorded and characterized. The anopheline mosquito larvae and emerged adults were identified to the species level morphologically and to sub-species by the ribosomal DNA PCR technique. Chi-square analysis and logistic regression analysis were applied to determine the importance of factors for explaining the presence or absence of An. sinensis larvae.ResultsAccording to the ribosomal DNA PCR assay, all sampled anopheline mosquito larvae and emerged adults belonged to An. sinensis. Only 3 containers that were sampled from the household courtyards were found to contain An. sinensis larvae. There were no differences in the species composition of mosquito larvae among containers that contained water in the household courtyards (P > 0.05). An. sinensis larvae were shown to be present in a total of 60 breeding sites in the village surroundings, this included 8 (13.3%) river fringes, 26 (43.3%) ponds, 23 (38.3%) puddles, and 3 (5.0%) irrigation/drainage ditches. Logistic regression analysis revealed that the breeding site type, water depth, chemical oxygen demand (COD), ammonia nitrogen, and sulphate were found to be the key factors determining the presence of An. sinensis larvae. Approximately 94.9% of An. sinensis larvae inhabited relatively large and medium-sized water bodies, with depths between 0.5 m and 1.0 m (73.3%), COD lower than 2 mg/L (75%), ammonia nitrogen lower than 0.4 mg/L (86.7%), and sulphate lower than 150 mg/L (58.3%), respectively.ConclusionThese results indicate that the majority of An. sinensis larval breeding sites were relatively large and medium-sized water bodies with depths between 0.5 m and 1.0 m, and containing low levels of COD, ammonia nitrogen, and sulphate, respectively. For effective An. sinensis larval control, the type of breeding site, water depth, COD, ammonia nitrogen, and sulphate should be given higher priority over other factors in areas where it is the primary vector.