The paper is related to the norm estimate of Mercer kernel matrices. The lower and upper bound estimates of Rayleigh entropy numbers for some Mercer kernel matrices on [0, 1] × [0, 1] based on the Bernstein-Durrm...The paper is related to the norm estimate of Mercer kernel matrices. The lower and upper bound estimates of Rayleigh entropy numbers for some Mercer kernel matrices on [0, 1] × [0, 1] based on the Bernstein-Durrmeyer operator kernel are obtained, with which and the approximation property of the Bernstein-Durrmeyer operator the lower and upper bounds of the Rayleigh entropy number and the l2 -norm for general Mercer kernel matrices on [0, 1] x [0, 1] are provided.展开更多
The paper deals with estimates of the covering number for some Mercer kernel Hilbert space with Bernstein-Durrmeyer operators. We first give estimates of l2- norm of Mercer kernel matrices reproducing by the kernelsK...The paper deals with estimates of the covering number for some Mercer kernel Hilbert space with Bernstein-Durrmeyer operators. We first give estimates of l2- norm of Mercer kernel matrices reproducing by the kernelsK(α,β)(x,y):=∑∞k=0 Ck(α,β)(x)Qk(α,β)(y),where Qk(α,β) (x) are the Jacobi polynomials of order k on (0, 1 ), Ck(α,β) 〉 0 are real numbers, and from which give the lower and upper bounds of the covering number for some particular reproducing kernel Hilbert space reproduced by Kα,β (x, y).展开更多
A chromosome segment substitution line (CSSL) is a powerful tool for combining quantitative trait locus (QTL) mapping with the pyramiding of desirable alleles. The rice CSSL Z1364 with increased kernel number was iden...A chromosome segment substitution line (CSSL) is a powerful tool for combining quantitative trait locus (QTL) mapping with the pyramiding of desirable alleles. The rice CSSL Z1364 with increased kernel number was identified in a BC3F8 population derived from a cross of Nipponbare as the recipient with Xihui 18 as the donor parent. Z1364 carried three substitution segments distributed on chromosomes 1, 6, and 8. The mean substitution length was 1.19 Mb. Of 17 QTL identified on the substitution segments, qSP1 for spikelets per panicle, qSSD1 for seed-set density, and qNSB1 for number of secondary branches explained respectively 57.34%, 87.7%, and 49.44% of the corresponding phenotypic variance and were all linked to RM6777. Chi-square analysis showed that the increased kernel number in Z1364 was inherited recessively by a single gene. By fine mapping, qSP1 was delimited to a 50-kb region on the short arm of chromosome 1. Based on DNA sequence, a previously uncharacterized rice homolog of Arabidopsis thaliana AT4G32551 was identified as a candidate gene for qSP1 in which mutation increases the number of spikelets and kernels in Z1364. qSP1 was expressed in all tissues, but particularly in 1-cm panicles. The expression levels of OsMADS22, GN1A, and DST were upregulated and those of LAX2, GNP1, and GHD7 were downregulated in Nipponbare. These results provide a foundation for functional research on qSP1.展开更多
Under a very general condition (TNC condition) we show that the spectral radius of the kernel of a general branching process is a threshold parameter and hence plays a role as the basic reproduction number in usual ...Under a very general condition (TNC condition) we show that the spectral radius of the kernel of a general branching process is a threshold parameter and hence plays a role as the basic reproduction number in usual CMJ processes. We discuss also some properties of the extinction probability and the generating operator of general branching processes. As an application in epidemics, in the final section we suggest a generalization of SIR model which can describe infectious diseases transmission in an inhomogeneous population.展开更多
Ear morphological traits such as volume and shape are important features of maize and the quantitative associations among them can help understand kernel yield determination. 150 mature ears each of 4 maize cultivars ...Ear morphological traits such as volume and shape are important features of maize and the quantitative associations among them can help understand kernel yield determination. 150 mature ears each of 4 maize cultivars were collected from field experiments, and ear length(L), diameter(D), area(S) and volume(V) were recorded for individual ears, kernel weight per ear also recorded for a portion of the examined ears. Following principles of dimensional analysis, 8 theoretical equations of 3 sets,which relate ear higher dimensions to its length and diameter, were developed and parameterized and validated with the field observations. The 3 optimized equations showed that the shape of ears in maize can be featured with 3 dimensionless form factors, namely diameter-to-length ratio(c=D/L), areal form factor(b=S/L/D), and volumetric form factor(a=V/L/D/D). Statistically,all of them were significantly different among cultivars, and a's values varied from 0.582 to 0.612, and b's 0.839-0.868, and c's 0.242-0.308. Volumetric form factor and areal form factor could estimate precisely ear volume and area respectively, but diameter-to-length ratio was not suitable to estimate ear diameter by its length. Ear volume explained almost all variation of ear kernel weight and product L*D*D did the same substantially. Dimensional analysis proved to be promising in understanding relationship among morphological traits of ears in maize. Its application in crop researches should improve our knowledge of the physical properties of crop plants.展开更多
The kernel of interval grey number is most likely the real number,which can be used to represent whitenization value of interval grey number.A novel method for calculating kernel of interval grey number is constructed...The kernel of interval grey number is most likely the real number,which can be used to represent whitenization value of interval grey number.A novel method for calculating kernel of interval grey number is constructed based on the geometric barycenter of whitenization weight function in the two-dimensional coordinate plane,and the calculation of kernel is converted to the calculation of barycenter in geometric figures.The method fully considers the effect of all information contained in whitenization weight function on the calculation result of kernel,and is the extension and perfection of the existing methods in the scope of application.展开更多
Asparagus officinalis L.is favored by its high health function,but its hybrid seeds are expensive.The amount of seed,seed plumpness and germination rate are related to the production costs of breeding enterprises and ...Asparagus officinalis L.is favored by its high health function,but its hybrid seeds are expensive.The amount of seed,seed plumpness and germination rate are related to the production costs of breeding enterprises and large growers.Therefore,it is necessary to investigate the seed number and thousand kernel weight of A.officinalis L.This study developed a quick and accurate method to measure the seed number and thousand kernel weight of A.officinalis L.using image processing technology.Seed sample of A.officinalis L.was scanned with 200 dpi resolution,and the seed number was then obtained using Image-ProPlus software.After weighing the seeds,thousand kernel weight was finally calculated.By recording‘macro’,the batch processing of the samples can also be realized.This method is simple and accurate,and can greatly save the time of investigation.展开更多
Plant tissue sap analysis is becoming an established tool for crop fertilization recommendation. Few research was conducted to use it as screening tools in crop breeding. With introduction of hhand-held sap analysis m...Plant tissue sap analysis is becoming an established tool for crop fertilization recommendation. Few research was conducted to use it as screening tools in crop breeding. With introduction of hhand-held sap analysis meters, sap analysis is becoming a promising tool for genotype screening. In this study, we measured Brix and pH of flag leaf juice of 10 winter wheat genotypes after heading stage. Brix value tended to increase during the measurement period. Brix value of flag leaf sap was negatively correlated with kernel number per spike and grain yield per spike, positively correlated with kernel weight. The pH values of flag leaf sap were negatively correlated with kernel number per spike and grain yield per spike, positively correlated with kernel weight.展开更多
Corn (maize, Zea mays L.) hybrids expressing the flexibility trait in ear size (number of kernels per ear) are marketed for ability to give higher yields under adverse conditions. Altered kernel number is associated w...Corn (maize, Zea mays L.) hybrids expressing the flexibility trait in ear size (number of kernels per ear) are marketed for ability to give higher yields under adverse conditions. Altered kernel number is associated with altered number of silk, a major route for infection of kernels by aflatoxin-producing fungi such as Aspergillus flavus. The effect of plant density and irrigation level on yield and accumulation of aflatoxins and fumonisins in harvested grain was compared in a fixed-ear hybrid (Pioneer 33K81), a semi-flexible ear hybrid (Pioneer 3223) and a flexible ear hybrid (Golden Acres 8460) over a range of seeding densities (49,400, 61,750, 74,700, 86,450, and 98,800 seeds·ha–1) in non-irrigated, moderately-irrigated (6.4 cm soil water deficit) and well-irrigated plots (3.8 cm soil water deficit), during three years with variable rainfall. Irrigation increased yields in all hybrids, but in the absence of irrigation, yields were highest with the semi-flexible ear trait hybrid. In general, the hybrid with the flexible ear trait had lower optimal seeding densities than the other hybrids for each soil water regime. In general, kernel number was least affected by seeding density in the hybrid with fixed-ear trait compared to the semi- and flexible ear hybrids. The lowest levels of aflatoxin and of fumonisin contamination in harvested grain were associated with the flexible ear trait at all rainfall and irrigation levels, but there was no evidence that reducing stress by lowering seeding density reduced mycotoxin contamination. Inoculation with A. flavus resulted in much higher levels of aflatoxin and significantly higher levels of fumonisin contamination in grain of all hybrids under most conditions of rainfall and irrigation, suggesting that factors that promote A. flavus infection can affect production of both mycotoxins.展开更多
Grain number,one of the major determinants of yield in Triticeae crops,is largely determined by spikelet number and spike rachis node number(SRN).Here,we identified three quantitative trait loci(QTLs)for SRN using 145...Grain number,one of the major determinants of yield in Triticeae crops,is largely determined by spikelet number and spike rachis node number(SRN).Here,we identified three quantitative trait loci(QTLs)for SRN using 145 recombinant inbred lines derived from a barley R90/1815D cross.qSRN1,the major-effect QTL,was mapped to chromosome 2H and explained up to 38.77%of SRN variation.Map-based cloning revealed that qSRN1 encodes the RAWUL domain-containing protein HvSRN1.Further analysis revealed that two key SNPs in the HvSRN1 promoter region(-2 kb upstream of the transcription start site)affect the transcript level of HvSRN1 and contribute to variation in SRN.Similar to its orthologous proteins OsLAX2 and ZmBA2,HvSRN1 showed protein–protein interactions with HvLAX1,suggesting that the LAX2–LAX1 model for spike morphology regulation may be conserved in Poaceae crops.CRISPR-Cas9-induced HvSRN1 mutants showed reduced SRN but increased grain size and weight,demonstrating a trade-off effect.Our results shed light on the role of HvSRN1 variation in regulating the balance between grain number and weight in barley.展开更多
Spike number per m^2(SN),kernel number per spike(KNPS) and thousand-kernel weight(TKW)are the three main components determining wheat(Triticum aestivum L.) yield.To evaluate the relationships among them a doubled hapl...Spike number per m^2(SN),kernel number per spike(KNPS) and thousand-kernel weight(TKW)are the three main components determining wheat(Triticum aestivum L.) yield.To evaluate the relationships among them a doubled haploid(DH) population consisting of 168 lines grown at three locations for three years was analyzed by unconditional and conditional QTL mapping.Thirty-three unconditional QTL and fifty-nine conditional QTL were detected.Among them,two QTL(QSN-DH-2B and QSN-DH-3A-1.1) improved SN,with no effect on KNPS.QKNPS-DH-2B-2.1 improved KNPS,with no effect on SN.QKNPS-DH-1A-1.1,QKNPS-DH-2D-1.1and QKNPS-DH-6A improved KNPS,with no effect on SN or TKW.QKNPS-DH-6B was associated with increased SN and TKW.In addition,QTKW-DH-4B,QTKW-DH-5B and QTKW-DH-7B increased TKW without decreasing KNPS.These results provide useful information for marker assisted selection(MAS) and improvement in wheat yield.展开更多
Doubled haploid(DH) technology is important in modern maize breeding. Haploid inducers determine the efficiency of both haploid induction and identification. It has taken decades to improve the efficiency,haploid indu...Doubled haploid(DH) technology is important in modern maize breeding. Haploid inducers determine the efficiency of both haploid induction and identification. It has taken decades to improve the efficiency,haploid induction rate(HIR), from the ~2% of the ancestor haploid inducer, stock6, to the ~10% of modern haploid inducers. Improvement of kernel oil content(KOC) would further enhance haploid identification efficiency. Using molecular marker-assisted selection, in combine with the number of haploids per ear as phenotypic criterion, we developed a new high-oil haploid inducer line, CHOI4, with a mean HIR of 15.8%and mean KOC of 11%. High KOC of CHOI4 can achieve a mean accuracy greater than 90% in identification of haploids of different backgrounds, with reduced false discovery rates and false negative rates in comparison with the previous high-oil haploid inducer line, CHOI3. Comparison of phenotypic selection strategies suggested that the number of haploids per ear can be used as a phenotyping criterion during haploid inducer line development. CHOI4 could further increase the efficiency of large-scale DH breeding programs with lower cost.展开更多
This study was carried out to evaluate the changes in silk activity of two corn cultivars Xundan 518 and Yongyou 618 after silk emergence. Artificial pollination was conducted at different days after silk emergence, a...This study was carried out to evaluate the changes in silk activity of two corn cultivars Xundan 518 and Yongyou 618 after silk emergence. Artificial pollination was conducted at different days after silk emergence, and the ear length, ear diameter,barren tip length, 100-grain weight, grain number per ear and grain weight per ear were measured at harvest. The results showed that with the delay of pollination, the number and weight of grains per ear increased at first, peaked at D2 to D4, and decreased subsequently; ear diameter and 100-grain weight showed a downward trend. Correlation analysis revealed that grain number per ear and grain weight per ear were most closely correlated. Rapid silk extrusion and long-lasting silk activity proved that the two corn cultivars Xundan 518 and Yongyou 618 are tolerant to high temperature.展开更多
Investigation of genetic diversity of geographically distant wheat genotypes is </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">useful ...Investigation of genetic diversity of geographically distant wheat genotypes is </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">useful approach in wheat breeding providing efficient crop varieties. This article presents multivariate cluster and principal component analyses (PCA) of some yield traits of wheat, such as thousand-kernel weight (TKW), grain number, grain yield and plant height. Based on the results, an evaluation of economically valuable attributes by eigenvalues made it possible to determine the components that significantly contribute to the yield of common wheat genotypes. Twenty-five genotypes were grouped into four clusters on the basis of average linkage. The PCA showed four principal components (PC) with eigenvalues ></span><span style="font-family:""> </span><span style="font-family:Verdana;">1, explaining approximately 90.8% of the total variability. According to PC analysis, the variance in the eigenvalues was </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">greatest (4.33) for PC-1, PC-2 (1.86) and PC-3 (1.01). The cluster analysis revealed the classification of 25 accessions into four diverse groups. Averages, standard deviations and variances for clusters based on morpho-physiological traits showed that the maximum average values for grain yield (742.2), biomass (1756.7), grains square meter (18</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">373.7), and grains per spike (45.3) were higher in cluster C compared to other clusters. Cluster D exhibited the maximum thousand-kernel weight (TKW) (46.6).展开更多
基金Supported by the Science Foundation of Zhejiang Province(Y604003)
文摘The paper is related to the norm estimate of Mercer kernel matrices. The lower and upper bound estimates of Rayleigh entropy numbers for some Mercer kernel matrices on [0, 1] × [0, 1] based on the Bernstein-Durrmeyer operator kernel are obtained, with which and the approximation property of the Bernstein-Durrmeyer operator the lower and upper bounds of the Rayleigh entropy number and the l2 -norm for general Mercer kernel matrices on [0, 1] x [0, 1] are provided.
基金Supported by the National Natural Science Foundation of China (Grant No. 10871226)
文摘The paper deals with estimates of the covering number for some Mercer kernel Hilbert space with Bernstein-Durrmeyer operators. We first give estimates of l2- norm of Mercer kernel matrices reproducing by the kernelsK(α,β)(x,y):=∑∞k=0 Ck(α,β)(x)Qk(α,β)(y),where Qk(α,β) (x) are the Jacobi polynomials of order k on (0, 1 ), Ck(α,β) 〉 0 are real numbers, and from which give the lower and upper bounds of the covering number for some particular reproducing kernel Hilbert space reproduced by Kα,β (x, y).
基金supported by the National Key Research Plan Project (2017YFD0101107)the Chongqing Science and Technology Commission Special Project (cstc2016shmsztzx0032)the Southwest University Innovation Team Project (XDJK2017A004)
文摘A chromosome segment substitution line (CSSL) is a powerful tool for combining quantitative trait locus (QTL) mapping with the pyramiding of desirable alleles. The rice CSSL Z1364 with increased kernel number was identified in a BC3F8 population derived from a cross of Nipponbare as the recipient with Xihui 18 as the donor parent. Z1364 carried three substitution segments distributed on chromosomes 1, 6, and 8. The mean substitution length was 1.19 Mb. Of 17 QTL identified on the substitution segments, qSP1 for spikelets per panicle, qSSD1 for seed-set density, and qNSB1 for number of secondary branches explained respectively 57.34%, 87.7%, and 49.44% of the corresponding phenotypic variance and were all linked to RM6777. Chi-square analysis showed that the increased kernel number in Z1364 was inherited recessively by a single gene. By fine mapping, qSP1 was delimited to a 50-kb region on the short arm of chromosome 1. Based on DNA sequence, a previously uncharacterized rice homolog of Arabidopsis thaliana AT4G32551 was identified as a candidate gene for qSP1 in which mutation increases the number of spikelets and kernels in Z1364. qSP1 was expressed in all tissues, but particularly in 1-cm panicles. The expression levels of OsMADS22, GN1A, and DST were upregulated and those of LAX2, GNP1, and GHD7 were downregulated in Nipponbare. These results provide a foundation for functional research on qSP1.
文摘Under a very general condition (TNC condition) we show that the spectral radius of the kernel of a general branching process is a threshold parameter and hence plays a role as the basic reproduction number in usual CMJ processes. We discuss also some properties of the extinction probability and the generating operator of general branching processes. As an application in epidemics, in the final section we suggest a generalization of SIR model which can describe infectious diseases transmission in an inhomogeneous population.
基金Supported by the National Natural Science Foundation of China(31271658)National Key Research and Development Program of China(2016YFD0300306)
文摘Ear morphological traits such as volume and shape are important features of maize and the quantitative associations among them can help understand kernel yield determination. 150 mature ears each of 4 maize cultivars were collected from field experiments, and ear length(L), diameter(D), area(S) and volume(V) were recorded for individual ears, kernel weight per ear also recorded for a portion of the examined ears. Following principles of dimensional analysis, 8 theoretical equations of 3 sets,which relate ear higher dimensions to its length and diameter, were developed and parameterized and validated with the field observations. The 3 optimized equations showed that the shape of ears in maize can be featured with 3 dimensionless form factors, namely diameter-to-length ratio(c=D/L), areal form factor(b=S/L/D), and volumetric form factor(a=V/L/D/D). Statistically,all of them were significantly different among cultivars, and a's values varied from 0.582 to 0.612, and b's 0.839-0.868, and c's 0.242-0.308. Volumetric form factor and areal form factor could estimate precisely ear volume and area respectively, but diameter-to-length ratio was not suitable to estimate ear diameter by its length. Ear volume explained almost all variation of ear kernel weight and product L*D*D did the same substantially. Dimensional analysis proved to be promising in understanding relationship among morphological traits of ears in maize. Its application in crop researches should improve our knowledge of the physical properties of crop plants.
基金Supported by the National Natural Science Foundation of China(71271226,70971064,71101159)the Humanities and Social Science Foundation of Ministry of Education(11YJC630273,12YJC630140)+4 种基金the Program for Chongqing Innovation Team in University(KJTD201313)the Science and Technology Research Projects of Chongqing Education Commission(KJ120706)the Open Foundation of Chongqing Key Laboratory of Electronic Commerce and Supply Chain System(2012ECSC0101)the Special Fund of Chongqing Key Laboratory of Electronic Commerce and Supply Chain System(2012ECSC0217)the Chongqing City Board of Education Science and Technology Research Projects(1202010)
文摘The kernel of interval grey number is most likely the real number,which can be used to represent whitenization value of interval grey number.A novel method for calculating kernel of interval grey number is constructed based on the geometric barycenter of whitenization weight function in the two-dimensional coordinate plane,and the calculation of kernel is converted to the calculation of barycenter in geometric figures.The method fully considers the effect of all information contained in whitenization weight function on the calculation result of kernel,and is the extension and perfection of the existing methods in the scope of application.
基金Modern Agricultural Industry Technology System Project(CARS-23-G-05)Modern Agricultural Science and Technology Innovation Project of Hebei Academy of Agriculture and Forestry Sciences(2019-3-2-1)the Third Batch of"Giant Plan"Vegetable Scientific Research and Innovation Team Project in Hebei Province.
文摘Asparagus officinalis L.is favored by its high health function,but its hybrid seeds are expensive.The amount of seed,seed plumpness and germination rate are related to the production costs of breeding enterprises and large growers.Therefore,it is necessary to investigate the seed number and thousand kernel weight of A.officinalis L.This study developed a quick and accurate method to measure the seed number and thousand kernel weight of A.officinalis L.using image processing technology.Seed sample of A.officinalis L.was scanned with 200 dpi resolution,and the seed number was then obtained using Image-ProPlus software.After weighing the seeds,thousand kernel weight was finally calculated.By recording‘macro’,the batch processing of the samples can also be realized.This method is simple and accurate,and can greatly save the time of investigation.
基金Item supported by national natural sciencefoundation (No.20337010)
文摘Plant tissue sap analysis is becoming an established tool for crop fertilization recommendation. Few research was conducted to use it as screening tools in crop breeding. With introduction of hhand-held sap analysis meters, sap analysis is becoming a promising tool for genotype screening. In this study, we measured Brix and pH of flag leaf juice of 10 winter wheat genotypes after heading stage. Brix value tended to increase during the measurement period. Brix value of flag leaf sap was negatively correlated with kernel number per spike and grain yield per spike, positively correlated with kernel weight. The pH values of flag leaf sap were negatively correlated with kernel number per spike and grain yield per spike, positively correlated with kernel weight.
文摘Corn (maize, Zea mays L.) hybrids expressing the flexibility trait in ear size (number of kernels per ear) are marketed for ability to give higher yields under adverse conditions. Altered kernel number is associated with altered number of silk, a major route for infection of kernels by aflatoxin-producing fungi such as Aspergillus flavus. The effect of plant density and irrigation level on yield and accumulation of aflatoxins and fumonisins in harvested grain was compared in a fixed-ear hybrid (Pioneer 33K81), a semi-flexible ear hybrid (Pioneer 3223) and a flexible ear hybrid (Golden Acres 8460) over a range of seeding densities (49,400, 61,750, 74,700, 86,450, and 98,800 seeds·ha–1) in non-irrigated, moderately-irrigated (6.4 cm soil water deficit) and well-irrigated plots (3.8 cm soil water deficit), during three years with variable rainfall. Irrigation increased yields in all hybrids, but in the absence of irrigation, yields were highest with the semi-flexible ear trait hybrid. In general, the hybrid with the flexible ear trait had lower optimal seeding densities than the other hybrids for each soil water regime. In general, kernel number was least affected by seeding density in the hybrid with fixed-ear trait compared to the semi- and flexible ear hybrids. The lowest levels of aflatoxin and of fumonisin contamination in harvested grain were associated with the flexible ear trait at all rainfall and irrigation levels, but there was no evidence that reducing stress by lowering seeding density reduced mycotoxin contamination. Inoculation with A. flavus resulted in much higher levels of aflatoxin and significantly higher levels of fumonisin contamination in grain of all hybrids under most conditions of rainfall and irrigation, suggesting that factors that promote A. flavus infection can affect production of both mycotoxins.
基金supported by the National Key R&D Program of China (2018YFD1000706)Hainan Yazhou Bay Seed Laboratory (B21Y10214)+1 种基金the National Natural Science Foundation of China (no.31771774)the Agricultural Science and Technology Innovation Program,and the China Agricultural Research System (CARS-05).
文摘Grain number,one of the major determinants of yield in Triticeae crops,is largely determined by spikelet number and spike rachis node number(SRN).Here,we identified three quantitative trait loci(QTLs)for SRN using 145 recombinant inbred lines derived from a barley R90/1815D cross.qSRN1,the major-effect QTL,was mapped to chromosome 2H and explained up to 38.77%of SRN variation.Map-based cloning revealed that qSRN1 encodes the RAWUL domain-containing protein HvSRN1.Further analysis revealed that two key SNPs in the HvSRN1 promoter region(-2 kb upstream of the transcription start site)affect the transcript level of HvSRN1 and contribute to variation in SRN.Similar to its orthologous proteins OsLAX2 and ZmBA2,HvSRN1 showed protein–protein interactions with HvLAX1,suggesting that the LAX2–LAX1 model for spike morphology regulation may be conserved in Poaceae crops.CRISPR-Cas9-induced HvSRN1 mutants showed reduced SRN but increased grain size and weight,demonstrating a trade-off effect.Our results shed light on the role of HvSRN1 variation in regulating the balance between grain number and weight in barley.
基金funded by the National Natural Science Foundation of China(No.31171554)Major Projects for Development of New Genetically Modified Crops(No.2011ZX08002-003)+1 种基金Fund for the Doctoral Program of Higher Education of China(No.20123702110016)the Natural Science Foundation of Shandong(No.ZR2015CM036)
文摘Spike number per m^2(SN),kernel number per spike(KNPS) and thousand-kernel weight(TKW)are the three main components determining wheat(Triticum aestivum L.) yield.To evaluate the relationships among them a doubled haploid(DH) population consisting of 168 lines grown at three locations for three years was analyzed by unconditional and conditional QTL mapping.Thirty-three unconditional QTL and fifty-nine conditional QTL were detected.Among them,two QTL(QSN-DH-2B and QSN-DH-3A-1.1) improved SN,with no effect on KNPS.QKNPS-DH-2B-2.1 improved KNPS,with no effect on SN.QKNPS-DH-1A-1.1,QKNPS-DH-2D-1.1and QKNPS-DH-6A improved KNPS,with no effect on SN or TKW.QKNPS-DH-6B was associated with increased SN and TKW.In addition,QTKW-DH-4B,QTKW-DH-5B and QTKW-DH-7B increased TKW without decreasing KNPS.These results provide useful information for marker assisted selection(MAS) and improvement in wheat yield.
基金supported by the National Key Research and Development Program of China(2016YFD0101200)the China Agriculture Research System(CARS-02)+1 种基金2020 Research Program of Sanya Yazhou Bay Science and Technology City(SKJC-2020-02-03)the National Natural Science Foundation of China(91935303,32001554)。
文摘Doubled haploid(DH) technology is important in modern maize breeding. Haploid inducers determine the efficiency of both haploid induction and identification. It has taken decades to improve the efficiency,haploid induction rate(HIR), from the ~2% of the ancestor haploid inducer, stock6, to the ~10% of modern haploid inducers. Improvement of kernel oil content(KOC) would further enhance haploid identification efficiency. Using molecular marker-assisted selection, in combine with the number of haploids per ear as phenotypic criterion, we developed a new high-oil haploid inducer line, CHOI4, with a mean HIR of 15.8%and mean KOC of 11%. High KOC of CHOI4 can achieve a mean accuracy greater than 90% in identification of haploids of different backgrounds, with reduced false discovery rates and false negative rates in comparison with the previous high-oil haploid inducer line, CHOI3. Comparison of phenotypic selection strategies suggested that the number of haploids per ear can be used as a phenotyping criterion during haploid inducer line development. CHOI4 could further increase the efficiency of large-scale DH breeding programs with lower cost.
基金Supported by Major Science and Technology Project of Henan Province(161100110500-0104)Special Fund for Meteorologicalscientific Research in the Public Interest(GYHY201406026)
文摘This study was carried out to evaluate the changes in silk activity of two corn cultivars Xundan 518 and Yongyou 618 after silk emergence. Artificial pollination was conducted at different days after silk emergence, and the ear length, ear diameter,barren tip length, 100-grain weight, grain number per ear and grain weight per ear were measured at harvest. The results showed that with the delay of pollination, the number and weight of grains per ear increased at first, peaked at D2 to D4, and decreased subsequently; ear diameter and 100-grain weight showed a downward trend. Correlation analysis revealed that grain number per ear and grain weight per ear were most closely correlated. Rapid silk extrusion and long-lasting silk activity proved that the two corn cultivars Xundan 518 and Yongyou 618 are tolerant to high temperature.
文摘Investigation of genetic diversity of geographically distant wheat genotypes is </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">useful approach in wheat breeding providing efficient crop varieties. This article presents multivariate cluster and principal component analyses (PCA) of some yield traits of wheat, such as thousand-kernel weight (TKW), grain number, grain yield and plant height. Based on the results, an evaluation of economically valuable attributes by eigenvalues made it possible to determine the components that significantly contribute to the yield of common wheat genotypes. Twenty-five genotypes were grouped into four clusters on the basis of average linkage. The PCA showed four principal components (PC) with eigenvalues ></span><span style="font-family:""> </span><span style="font-family:Verdana;">1, explaining approximately 90.8% of the total variability. According to PC analysis, the variance in the eigenvalues was </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">greatest (4.33) for PC-1, PC-2 (1.86) and PC-3 (1.01). The cluster analysis revealed the classification of 25 accessions into four diverse groups. Averages, standard deviations and variances for clusters based on morpho-physiological traits showed that the maximum average values for grain yield (742.2), biomass (1756.7), grains square meter (18</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">373.7), and grains per spike (45.3) were higher in cluster C compared to other clusters. Cluster D exhibited the maximum thousand-kernel weight (TKW) (46.6).