Genetic Structure of Malus sieversii Population from Xinjiang,China,Revealed by SSR Markers

One hundred and nine Malus sieversii accessions from four geographical populations located at Kuerdening in Mohe town, Gongliu County, Jiaowutuohai, in Xinyuan County, Daxigou in Houcheng County of Ily State, and Baerluke Mountain in Yumin County of Tacheng State, Xinjiang Uygur Autonomous Region of China were studied by SSR markers. The purpose of the study was to determine the genetic structure and diversity in these eco-geographical populations with eight pair SSR primers of apple. The results indicated that： an average of 16 bands was detected in the four populations. The percentage of polymorphic bands in Gongliu population （89.06%） was the highest in the four populations. The average Nei＇s gene diversity index was 0.257 for all the loci. Totally, 128 polymorphic loci were detected and the percentage of polymorphic loci （P） was 100%, 88.28%, 84.83%, 87.50%, and 87.12%, respectively, at the species level and Gongliu, Xinyuan, Huocheng, and Yumin population levels. The Nei＇s gene diversity index （H = 0.2619） and Shannon＇s information index （1 = 0.4082） in the species level were higher than in the population level. The Nei＇s gene diversity index and Shannon＇s information index in the four populations were Gongliu 〉 Huocheng 〉 Xinyuan 〉 Yumin. Gongliu population and Xinyuan population were the highest in genetic identity and the closest in genetic distance. Gene flow between the populations was 7.265 based on genetic differentiation coefficient （GST = 0.064）. The UPGMA cluster analysis indicated that the genetic relationships between the Gongliu and Xinyuan population were the closest, and the Yumin population were the farthest with the other three populations. The UPGMA cluster analysis indicated that the four geographical populations located in Gongliu, Xinyuan, Huocheng, and Yumin were relatively independent populations. Concurrently, there was also mild gene exchange between the populations. On the basis of the study of population genetic structure and the highest genetic diversity, Gongliu population should be given a high priority consideration in Malus sieversii population＇s in situ germplasm conservation.

Genetic Structure of Three Populations of Oxya chinensis in Shanxi,China

Starch gel electrophoresis was used to analyze genetic structure of three populations of Oxya chinensis from Shanxi Province,China.Four allozyme polymorphic loci (MDH-1,MDH-2,LDH,ME) were found.The data suggest that two populations of O.chinensis about 41 kilometers apart are genetically similar,but differentiated from the third population with a geographic distance of 357 kilometers.However,the heterozygosity levels of those two genetically similar populations were much different.The Nei's genetic distance between two geographically close populations is 0.068,which is much smaller than those of geographically distant populations (0.23 in average).The observed overlap of geographical distance and genetic distance implies that for O.chinensis population divergence may correlate with geographic isolation.

Dynamic Study on Soil Fungi Population in Artificial Vegetation Areas of Shapotou in Ningxia

[Objective] The changes of fungi in different soil layers and sand dunes of artificial vegetation areas in Ningxia Shapotou during different times were studied. [Method]The number of soil fungi in different soil layers at same plot and in same soil layer at different plots were changed significantly.The quantitative distribution of fungi was the most in Cuiliugou but the fewest in quicksand among all soil types.[Result] The quantity of soil fungi in grasslands was varied in different soil layers at the same sample and in the same soil layer at different sample plots. The quantity of fungi from different soil types distributed mostly in Cuiliugou, a natural desert steppe, but little in quicksand. The species and quantity of fungi in CuiLiugou was the most in different types of sand-fixing lands. [Conclusion] The quantity of soil fungi in artificial vegetation areas raises with the increase of sand-fixing ages, The enhancement of vegetation construction and artificial management measures in inland is helpful for improving present situation of desertification.

Population Distribution and Dynamics of Quercus liaotungensis, Fraxinus rhynchophylla and Acer mono in Dongling Mountain, Beijing

The spatial distribution and population dynamics of Quercus liaotungensis Koidz., Fraxinus rhynchophylla Hance and Acer mono Maxim. were studied in three warm temperate deciduous forests in Dongling Mountain, Beijing. Clumped distributions appeared in most seedlings (≤0.4 m), short saplings (0.4-1 m) and tall saplings (1-2 m). Random distributions appeared in adults of Q. liaotungensis in Plot 1, F. rhynchophylla in Plot 3. The LSD method was used to discern the differences of different aged population. The class distribution of Q. liaotungensis was nearly a reverse-J shape for Plot 1 and Plot 3, suggesting that the population regenerates continuously. The age-structures of F. rhynchophylla and A. mono in Plot 1 and the test results indicated that they would increase continuously. In Plot 2, the class distribution and the test results showed that all populations would not regenerate continuously.

Population Genetic Structure in Apricot (Prunus armeniaca L.) Cultivars Revealed by Fluorescent-AFLP Markers in Southern Xinjiang,China

Population-wide genetic structure was studied using fluorescent-AFLP markers on 85 apricot （Prunus armeniaca L.） cultivars collected from Kuche, Kashi, Hetian in the Tarim Basin, southern Xinjiang Uygur Autonomous Region of China. The purpose of this study was to determine the genetic structure and genotypic diversity among the different eco-geographical populations. Based on the results from this study, 8 pairs of fluorescent-AFLP primers showed clear electrophoregram and high polymorphism amongst the 64 pairs of EcoR Ⅰ/Mse Ⅰ （Mse Ⅰ - a FAM fluorescent marked primer） primers screened. There was a significant polymorphic difference for the same primer pair in different populations and for the same population with different primer pairs. The percentage of polymorphic loci （P） at species level was higher than Kuche, Hetian, Kashi population levels, respectively. The Nei＇s gene diversity index （H） and Shannon＇s information index （I） at species level were higher than those of Kuche, Hetian, and Kashi at population level, respectively. H and I of Kuche population were the highest amongst the three populations. Apricot population genetic diversity was found mainly within the population, Genetic differentiation coefficient between populations （GST） was 0.0882. Gene flow Nm between the populations was 5.1689. Population genetic identity was between 0.9772-0.9811 and genetic distance was between 0.0191-0.0232. These results further indicated that the similarity between populations was higher and the genetic distance between populations was smaller. The UPGMA cluster analysis indicates that the geographical populations at Kuche, Kashi, Hetian were relatively independent Mendelian populations. Concurrently, there was also partial gene exchange between the populations. All the evidences indicated that the genetic diversity in Kuche population was the highest, suggesting that it could be a transition population from wild apricot to cultivated apricot. There were abundant genetic diversities in apricot cultivar populations in southern Xinjiang, China, which provide promising germplasm for further breeding and theoretical basis for biodiversity conservation and utilization for apricot population in this area.

Population Density and Habitat Utilization of Ibex(Capra ibex)in Tomur National Nature Reserve,Xinjiang,China

Surveys was conducted to study the population density and habitat utilization of the ibex （Capra ibex） in Tomur National Nature Reserve during October- December 2005. The results are as follows： ① The mean group size of the ibex in Tomur Nature Reserve is 8.43 and the population density is 269.76/100 km^2; ② The ibex prefer areas with steep slope （between 30° -45°）, broken substrates and cliffs nearby （ 〈 100 m）. They avoid grasslands and fiat hillsides; ③The probable reason for this habitat selection is serf-protection.

Population pharmacokinetics of paeoniflorin in guanxin Ⅱ prescription

To evaluate the effect of components in Guanxin Ⅱ prescription on the pharmacokinetic profiles of paeoniflorin. Plasma concentration of Paeoniflorin in rats after intravenous injection of Paronia Pall Extract （PPE） and oral administration of PPE and three types of decoctions in Guanxin Ⅱ prescription, respectively, were determined by HPLC analyses. NONMEM （nonlinear mixed-effect modeling） method was used to analyze full set of pharmacokinetic data directly. A two-compartment model with first-order degradation in absorption compartment was employed for the data analysis. The mean of population parameters, CL1, V1, CL2, V2, Ka0, and Kal, were measured to be 0.509 L/h, 0.104 L, 0.113 L/h, 0.123 L, 0.135/h, and 0.0135/h, respectively. Inter-individual variabilities were estimated and dose formulation （DF） was identified as a significant covariate of Ka 1, Ka0, and V1. It is concluded that the pharmacokinetic behaviors of paeoniflorin in rats can alter with different dose formulations.

Effects of Nitrogen Fertilizer on Rhizosphere Microbial Populations under Cotton Intercropped with Red Date in Arid Desert Oasis of Southern Xinjiang

[Objective]This study aimed to determine the number of microorganisms of cotton rhizosphere in a soil at various amounts of applied nitrogen fertilizer in a red date-cotton intercropping system. [Method] In the field experiment, nitrogen fer-tilizer was applied at 0, 150, 300, 450, 600, and 750 kg/hm2, respectively. The dy-namic changes of the populations of bacteria, fungi and actinomycetes at the rhizo-sphere of cotton intercropped with red date were investigated. [Result] Microbial populations significantly increased at nitrogen fertilizer of 300 and 450 kg/hm2 during bud, flowering and bol opening periods. The numbers of bacteria and actinomycetes were higher during flowering and bol opening stages than at bud stage. The num-ber of fungi slightly changed during the entire growth period. Appropriate amount of nitrogen fertilizer （300 to 600 kg/hm2） was favorable to the survival of the microor-ganisms in the soil under the intercropping system. [Conclusion] The study provides a guideline for screening and determining the optimum amount of applied nitrogen fertilizer.

Status of the Xinjiang Ground Jay:population,breeding ecology and conservation

The Xinjiang Ground Jay (Podoces biddulphi) is a bird species endemic to China. It has a restricted range, living only in the Taklimakan Desert, southern part of Xinjiang. So far, little information has been known of the status and ecology of the bird in the world. Since 1988, I have been taking field investigations on the distribution, population size and breeding ecology of the Xinjiang Ground Jay in the desert.In this thesis, the desertification in relation to the eastward expansion of the ground jays was discussed.

A new pathotype characterization of Daxing and Huangyuan populations of cereal cyst nematode(Heterodera avenae) in China

The cereal cyst nematode（CCN, Heteroder aavenae） causes serious yield loss on cereal crops, especially wheat, worldwide. Daxing population in Beijing City and Huangyuan population in Qinghai Province, China, are two CCN populations. In this study, the CCN pathotypes of Daxing and Huangyuan populations were characterized by tests on 23 standard ＂International Test Assortment＂ with the local species Wenmai 19 as the susceptible control. Tested materials were grouped by three nematode populations＇ virulence on resistant genes（Rha1, Rha2, Rha3, Cre1） and nonresistant genes, varieties and lines. Both Daxing and Huangyuan populations were avirulent to Ortolan（Ha1）. Barley cvs. Ortolan, Siri, Morocco, Bajo Aragon 1-1, and Martin 403-2 were all resistant to both populations. Cultivars Herta, Harlan 43 and wheat Iskamish-K-2-light were all susceptible to Huangyuan population, all of them, however, were resistant to Daxing population. The other five oats were all resistant to the two tested CCN populations. Except Iskamisch K-2-light, all the other wheat cultivars（Capa, Loros×Koga, AUS 10894, and Psathias） were susceptible to Daxing population. Because the pathotypes of the two tested CCN populations in Beijing and Qinghai were not identical to any of the 13 pathotypes previously characterized by the test assortment, we classified Daxing and Huangyuan populations as the new pathotypes, named Ha91.

KCNQ1 rs2237895 gene polymorphism increases susceptibility to type 2 diabetes mellitus in Asian populations

BACKGROUND The association of single nucleotide polymorphism of KCNQ1 gene rs2237895 with type 2 diabetes mellitus(T2DM)is currently controversial.It is unknown whether this association can be gene realized across different populations.AIM To determine the association of KCNQ1 rs2237895 with T2DM and provide reliable evidence for genetic susceptibility to T2DM.METHODS We searched PubMed,Embase,Web of Science,Cochrane Library,Medline,Baidu Academic,China National Knowledge Infrastructure,China Biomedical Literature Database,and Wanfang to investigate the association between KCNQ1 gene rs2237895 and the risk of T2DM up to January 12,2022.Review Manager 5.4 was used to analyze the association of the KCNQ1 gene rs2237895 polymorphism with T2DM and to evaluate the publication bias of the selected literature.RESULTS Twelve case–control studies(including 11273 cases and 11654 controls)met our inclusion criteria.In the full population,allelic model[odds ratio(OR):1.19;95%confidence interval(95%CI):1.09–1.29;P<0.0001],recessive model(OR:1.20;95%CI:1.11–1.29;P<0.0001),dominant model(OR:1.27.95%CI:1.14–1.42;P<0.0001),and codominant model(OR:1.36;95%CI:1.15–1.60;P=0.0003)(OR:1.22;95%CI:1.10–1.36;P=0.0002)indicated that the KCNQ1 gene rs2237895 polymorphism was significantly correlated with susceptibility to T2DM.In stratified analysis,this association was confirmed in Asian populations:allelic model(OR:1.25;95%CI:1.13–1.37;P<0.0001),recessive model(OR:1.29;95%CI:1.11–1.49;P=0.0007),dominant model(OR:1.35;95%CI:1.20–1.52;P<0.0001),codominant model(OR:1.49;95%CI:1.22–1.81;P<0.0001)(OR:1.26;95%CI:1.16–1.36;P<0.0001).In non-Asian populations,this association was not significant:Allelic model(OR:1.06,95%CI:0.98–1.14;P=0.12),recessive model(OR:1.04;95%CI:0.75–1.42;P=0.83),dominant model(OR:1.06;95%CI:0.98–1.15;P=0.15),codominant model(OR:1.08;95%CI:0.82–1.42;P=0.60.OR:1.15;95%CI:0.95–1.39;P=0.14).CONCLUSION KCNQ1 gene rs2237895 was significantly associated with susceptibility to T2DM in an Asian population.Carriers of the C allele had a higher risk of T2DM.This association was not significant in non-Asian populations.

Genetic Diversity of Natural Myrica rubra Sieb.et Zucc Populations in Guangxi Revealed by ISSR Markers

The present study was conducted to assess the molecular characterization and genetic diversity amongst natural populations of Myrica rubra in Guangxi Zhuang Autonomous Region, China, thus to provide scientific evidence for germplasm conservation and exploitation. Using ISSR （inter-simple sequence repeats） markers, the level of genetic variation and the molecular characterization of 10 natural populations of M. rubra, originated from Guangxi Zhuang Autonomous Region in China, were performed. Based on 11 primers, 123 clear and reproducible DNA fragments were generated, of which 95 （77.24%） were polymorphic. The average value of Nei＇s gene diversity （He） was 0.268. The coefficient of genetic differentiation （Gst） was 0.341, revealing that 34.1% of the total molecular variance existed among populations. The Mantel statistical testing showed that the genetic distance was correlated to the geographic distance, but the correlation was not significant. Ten populations were divided into two big clusters according to unweighted pair group method with arithmetic mean （UPGMA） analysis. One consisted of populations of Rongxian （RX）, Hepu （HP）, Liangqing （LQ）, Marshan （MS）, Lingshan （LS） and Shansi （SS）, which originated from the southern Guangxi, while the other was composed of Guanyang （GY） and Lingui （LG） populations of northern Guangxi, Huanjiang （HJ） populations of northwestern Guangxi and Shanglin （SL） populations of southern Guangxi. The level of genetic variation in wild M. rubra population distributed in Guangxi is high. Gene drift within the population was responsible for genetic variation in wild M. rubra in Guangxi, and the effect of the genetic flow among inter-populations was not significant. Classification of wild M. rubra populations was correlated to climate and environment. The molecular characterization and diversity assessment of M. rubra is of immense value for planning conservation of its genetic resources and their exploitation for further studies.

Evaluating the performance of genomic selection on purebred population by incorporating crossbred data in pigs

Genomic selection(GS)has been widely used in livestock,which greatly accelerated the genetic progress of complex traits.The population size was one of the significant factors affecting the prediction accuracy,while it was limited by the purebred population.Compared to directly combining two uncorrelated purebred populations to extend the reference population size,it might be more meaningful to incorporate the correlated crossbreds into reference population for genomic prediction.In this study,we simulated purebred offspring(PAS and PBS)and crossbred offspring(CAB)base on real genotype data of two base purebred populations(PA and PB),to evaluate the performance of genomic selection on purebred while incorporating crossbred information.The results showed that selecting key crossbred individuals via maximizing the expected genetic relationship(REL)was better than the other methods(individuals closet or farthest to the purebred population,CP/FP)in term of the prediction accuracy.Furthermore,the prediction accuracy of reference populations combining PA and CAB was significantly better only based on PA,which was similar to combine PA and PAS.Moreover,the rank correlation between the multiple of the increased relationship(MIR)and reliability improvement was 0.60-0.70.But for individuals with low correlation(Cor(Pi,PA or B),the reliability improvement was significantly lower than other individuals.Our findings suggested that incorporating crossbred into purebred population could improve the performance of genetic prediction compared with using the purebred population only.The genetic relationship between purebred and crossbred population is a key factor determining the increased reliability while incorporating crossbred population in the genomic prediction on pure bred individuals.

Changes in the adult sex ratio of six duck species breeding populations over two decades

Despite all efforts,long-term changes in the adult sex ratios of breeding duck populations are still unclear;this uncertainty is especially true for male-bias populations,which are often under the scrutiny of researchers lacking convenient results for the active protection of endangered species.Species with male-bias populations are usually strongly affected by a decline in population size that leads to a higher extinction risk.In this study,we examined our long-term data of the abundance of breeding populations in six duck species(Mallard Anas platyrhynchos,Gadwall Mareca strepera,Red-crested Pochard Netta rufina,Common Pochard Aythya ferina,Tufted Duck Aythya fuligula,and Common Goldeneye Bucephala clangula)from fishponds in South Bohemia,Czechia,between 2004 and 2022.This evidence was used to assess long-term changes in the adult sex ratio in these breeding populations and investigate the possible effects of the NAO index(North Atlantic Oscillation index)on them,indicating climate conditions in winter.We determined a long-term decrease of the proportion of females in the breeding season in two of the six examined species:Common Pochard and Red-crested Pochard,which is driven by the long-term increase in the number of males in contrast to the decreasing or stable number of females likely caused by different migration behaviours between females and males.In the case of Common Pochard,in breeding populations,we estimated 60-65%of males in the early 2000s rising to 75-80%in the early 2020s.However,we establish no significant effects linked to climate conditions of the previous winter in these species as a crucial cause of the changes of the proportion of females in the breeding population.

Multi Location Field Evaluation of BC1F2 Sorghum Populations for Striga Resistance in Niger

In Niger, a landlocked country, sorghum is the second staple food cultivated over the country by smallholder farmer. The crop is important for human and animal consumption. Despite its importance, the crop is affected by biotic and abiotic constraints. Among those constraints, striga has a high impact on yield. In fact, to survive, farmers are growing their local preferred sorghum varieties wish is highly sensible to the weed. Striga management is a challenge that requires a permanent solution. In addition, the development of high-yielding Striga resistant genotypes will be appreciated by farmers. The development of striga resistance will be based on the breeding population performances under farmer’s diverse environmental conditions adaptation. The main objective of this study is to evaluate two breeding populations for striga resistance in two different environments at Boulke and Dibissou in Tahoua region, to identify the early and high-yielding striga tolerant genotypes under natural infestation.

Evolution and Determinants of Population Agglomeration in Less Developed Metropolitan Areas:A Case Study of the Taiyuan Metropolitan Area,China

It is of importance to enhance the urban areas'capacity for population aggregation in underdeveloped regions,aiming to rectify the imbalanced and insufficient pattern of economic development in China.Taking the Taiyuan Metropolitan Area(TMA)in central China as a case study,this paper examines the evolutionary process and characteristics of population agglomeration from 2000 to 2020,and identifies factors associated with agglomeration and their spatial effects.The findings indicated that:1)against the background of sustained population shrinkage in the provincial area,the TMA showed a demographic trend of steady increase,albeit with a decelerated growth rate.In the metropolitan area,urban population size continued to grow rapidly,whereas the rural areas endured sustained losses.Disparities in city size continued to widen,and the polarization of concentrated population in the core cities kept increasing.2)Agglomerations in both secondary and service industries had significant positive effects on local population agglomeration,with the former effect being stronger.Regional economic development,government fiscal expenditure,and financial advancement all contributed to facilitating local population clustering.From a spatial spillover perspective,service agglomeration and financial development promoted population agglomeration in surrounding areas.Conversely,fiscal expenditure inhibited such agglomeration.As for industrial agglomeration and regional economic development,their spatial spillover effects were non-significant.The results obtained reveal several policy implications aimed at enhancing the population agglomeration capacity of the metropolitan area in underdeveloped regions during the new era.

Mercury Levels Assessment in the Population of Aby and Frambo Villages in the Vinicity of Aby Lagoon in Côte d’Ivoire (West Africa)

The Minamata Convention in the aim to protect human life and the environment, seeks to reduce mercury (Hg) by monitoring it concentrations in the environment. Artisanal and Small-scale Gold Mining (ASGM) has been identified as the most important anthropogenic source of human exposure to Hg. In this context, the main goal of this study was to assess the level of mercury in hair of two (2) populations living along two lagoons respectively Aby and Tendo, in Ivory Coast. To reach this goal, hair samples of 138 residents were collected and analyzed by using Cold Vapor Atomic Fluorescence Spectrophotometry (CV-AFS) technique for mercury concentration. Results showed that for the entire population the Hg mean was 2.34 μg/g. Also, they were ranged between 0.15 to 8.53 μg/g and presented substantial differences amongst the villages. In Aby village, we observed the highest Hg concentrations (Mean = 2.62 μg/g). Our findings showed that almost the entire sample group (82%) exceed the USEPA recommended limit, furthermore 56% of them exceed the normal level of WHO and 2% of the respondent has the unhealthy levels of mercury (≥6 μg Hg/g) of hair by WHO standards. Gender differences in hair mercury varies greatly among reports. Lower levels in women’s hair compared to men were reported in the both village. Considering age, the lowest concentrations were observed with children. However, when we take in account the age groups, data suggested that the most exposed sub-population of [18-29] years old is from Aby village in opposite at Frambo village, the same case those who were ≥ 40 years old. It’s convenient to note that, the proportion of Mercury levels would not to be neglected among studied population especially with the resident from Aby village. So, some measures need to be taken at the political level to control mercury contamination.

Status of Impoverished Population and Contradiction of Economic Development in Qinling-Bashan Mountainous Area——A Case Study of Hanzhong City,Shaanxi Province

The status of impoverished population and economic development in Qinling-Bashan Mountainous area,Shaanxi is introduced based on the brief account of its general situation.Firstly,there are a large proportion of rural people and great outflow of population;a considerable proportion of the weak,the disabled,the sick and the dementia and low population quality;weak capacity of the economy to generate profit on its own and declining trend of financial self-sufficiency rate.taking into account that Qinling-Bashan Mountainous area is the poorest area with the largest impoverished population and the most complex structure of poverty,the impact of the status of the poor population in Qinling-Bashan Mountainous area on its economy is discussed:the first one is backward ecological concept and serious damage to ecological environment;outflow of excellent talents and a serious shortage of labor;the industrial structure is irrational and the resources advantage can not be transformed into economic advantage.Some corresponding measures and suggestions are proposed:the first one to build new small town so as to lessen the loss of population;the second one is to provide preferential policies so as to attract and retain qualified person;the third one to develop education and establish the concept of ecological civilization;the fourth one is to unblock the channels of information transmission and restructure the industry.

Comparative Study of Genetic Structure and Genetic Diversity betweenWild and Cultivated Populations of Taxus cuspidata,Northeast China

Taxus cuspidata is a rare plant with important medicinal and ornamental value.Aiming at the obvious differences between wild and cultivated populations of T.cuspidata from Northeast China,a total of 61 samples,that is,33 wild yews and 28 cultivated yews were used to analyze the differences and correlations of the kinship,genetic diversity,and genetic structure between them by specific length amplified fragment sequencing(SLAF-seq).Finally,470725 polymorphic SLAF tags and 58622 valid SNP markers were obtained.Phylogenetic analysis showed that 61 samples were classified into 2 clusters:wild populations and cultivated populations,and some wild yews were categorized into the cultivated populations;the genetic diversity analysis showed that the Nei diversity index of wild populations(0.4068)was smaller than that of cultivated populations(0.4414),and the polymorphic information content(PIC)of wild populations(0.2861)was smaller than that of cultivated populations(0.3309).The genetic differentiation analysis showed that the total populations of gene diversity(H_(t))of cultivated and wild populations were respectively 0.8159 and 0.5685,the coefficient of gene differentiation(G_(st))of cultivated and wild populations was respectively 0.3021 and 0.1068,and the gene flow(N_(m))(2.4967)of wild populations was larger than cultivated populations(0.8199).The molecular variance(AMOVA)revealed that inter-population variation accounted for 29.57%of the total genetic variation,while intra-population variation accounted for 70.42% of the total genetic variation(p<0.001),this suggested that the genetic variation in the T.cuspidata is mainly attributed to within-population factors.In conclusion,the genetic distance between geographical ecological groups of wild populations was generally smaller than that of cultivated populations,and the degree of genetic diversity and genetic differentiation was smaller than that of cultivated populations.As evident,the utilization of SLAF-seq technology enables efficient and accurate development of SNP markers suitable for genetic analysis of T.cuspidata species.These developed SNP markers can provide a molecular foundation for T.cuspidata breeding,construction of genetic maps,variety identification,and association analysis of agronomic traits.

QTL Mapping for Dough Mixing Characteristics in a Recombinant Inbred Population Derived from a Waxy×Strong Gluten Wheat (Triticum aestivum L.)

Protein and starch are the most important traits in determining processing quality in wheat. In order to understand the genetic basis of the influence of Waxy protein （Wx） and high molecular weight gluten subunit （HMW-GS） on processing quality, 256 recombinant inbred lines （RILs） derived from the cross of waxy wheat Nuomai 1 and Gaocheng 8901 were used as mapping population. DArT （diversity arrays technology）, SSR （simple sequence repeat）, HMW-GS, and Wx markers were used to construct the molecular genetic linkage map. QTLs for mixing peak time （MPT）, mixing peak value （MPV）, mixing peak width （MPW）, and mixing peak integral （MPI） of Mixograph parameters were evaluated in three different environments. The genetic map comprised 498 markers, including 479 DArT, 14 SSR, 2 HMW-GS, and 3 Wx protein markers, covering 4 229.7 cM with an average distance of 9.77 cM. These markers were identified on 21 chromosomes. Eighteen additive QTLs were detected in three different environments, which were distributed on chromosomes 1A, 1B, 1D, 4A, 6A, and 7D. QMPT-1D.1 and QMPT-1D.2 were close to the Glu-D1 marker accounting for 35.2, 22.22 and 36.57% of the phenotypic variance in three environments, respectively. QMPV-1D and QMPV-4A were detected in all environments, and QMPV-4A was the nearest to Wx-B1. One minor QTL, QMPI-1A, was detected under three environments with the genetic distances of 0.9 cM from the nearest marker Glu-A1, explaining from 5.31 to 6.67% of the phenotypic variance. Three pairs of epistatic QTLs were identified on chromosomes 2D and 4A. Therefore, this genetic map is very important and useful for quality trait related QTL mapping in wheat. In addition, the finding of several major QTLs, based on the genetic analyses, further suggested the importance of Glu-1 loci on dough mixing characteristics.