Characterization and distribution of novel alleles of the vernalization gene Vrn-A1 in Chinese wheat(Triticum aestivum L.) cultivars

The ability of wheat to adapt to a wide range of environmental conditions is determined mostly by allelic diversity among genes regulating vernalization requirement.Vrn-1 is a major regulator of this requirement.In this study,two novel alleles of Vrn-A1 were discovered in Chinese cultivars:vrn-A1n was identified in two landraces,Jiunong 2 and Ganchun 16,and Vrn-A1o was detected in Duanhongmangmai.Both novel alleles showed a linked duplication in the promoter region.The common copy of these two alleles was identical to the recessive allele vrn-A1.Compared with the recessive allele vrn-A1,the other copy of vrn-A1n contained a 54-bp deletion in the promoter region and the distinct copy of Vrn-A1o contained an11-bp deletion in the promoter region.In segregating populations in the greenhouse under nonvernalizing(20–25°C)and long-day(16 h light)conditions,plants with the novel vrn-A1n allele did not head earlier than those with the recessive vrn-A1 allele.However,plants that were either homozygous or heterozygous for the novel Vrn-A1o allele headed earlier than those with the recessive vrn-A1 allele.To identify the novel allele with the small-sized product and facilitate screening,a DNA marker for the novel dominant allele Vrn-A1o was designed.Analysis of the novel-allele distribution showed that two cultivars carrying the vrn-A1n allele were dispersed in the northwestern spring wheat zone,and 12 cultivars carrying the dominant Vrn-A1o allele were widely distributed in the northwestern spring wheat zone,Xinjiang winter and spring wheat zone,Yellow and Huai River valley winter wheat zone,and QinghaiTibetan Plateau spring and winter wheat zone.Our study identifies useful germplasm and a DNA marker for wheat breeding.

Association of HLA-B Alleles With Human Immunodeficiency Virus Type 1 Infection in the Yi Ethnic Group in Sichuan Province

Objective To determine the distribution of HLA-B alleles in the Chinese Yi ethnic group and its association with HIV infection. Methods One hundred and six unrelated healthy HIV negative and 73 HIV positive Chinese Yi ethnic individuals were typed by PCR-SSP. Results The frequency of alleles B*07, B*35, and B*46 were increased in HTV-1 -positive subjects, whereas the alleles B*55, B*44 and B*78 were absent in the HIV-infected persons studied. The B*46 allele was present in a significantly higher gene frequency among HIV-1-positive individuals (P=0.02, OR=3.32, 95% CI=1.13-9.78) compared with control subjects. Conclusion HLA-B*46 may be associated with its susceptibility to HIV-1 infections.

Genome-wide association study identifies favorable SNP alleles and candidate genes for waterlogging tolerance in chrysanthemums

Chrysanthemums are sensitive to waterlogging stress,and the development of screening methods for tolerant germplasms or genes and the breeding of tolerant new varieties are of great importance in chrysanthemum breeding.To understand the genetic basis of waterlogging tolerance(WT)in chrysanthemums,we performed a genome-wide association study(GWAS)using 92,811 single nucleotide polymorphisms(SNPs)in a panel of 88 chrysanthemum accessions,including 64 spray cut and 24 disbud chrysanthemums.The results showed that the average MFVW(membership function value of waterlogging)of the disbud type(0.65)was significantly higher than that of the spray type(0.55)at P<0.05,and the MFVW of the Asian accessions(0.65)was significantly higher than that of the European accessions(0.48)at P<0.01.The GWAS performed using the general linear model(GLM)and mixed linear model(MLM)identified 137 and 14 SNP loci related to WT,respectively,and 11 associations were commonly predicted.By calculating the phenotypic effect values for 11 common SNP loci,six highly favorable SNP alleles that explained 12.85—21.85%of the phenotypic variations were identified.Furthermore,the dosage-pyramiding effects of the favorable alleles and the significant linear correlations between the numbers of highly favorable alleles and phenotypic values were identified(r2=0.45;P<0.01).A major SNP locus(Marker6619-75)was converted into a derived cleaved amplified polymorphic sequence(dCAPS)marker that cosegregated with WT with an average efficiency of 78.9%.Finally,four putative candidate genes in the WT were identified via quantitative real-time PCR(qRT-PCR).The results presented in this study provide insights for further research on WT mechanisms and the application of molecular marker-assisted selection(MAS)in chrysanthemum WT breeding programs.

HLA class Ⅱ alleles and risk for peripheral neuropathy in type 2 diabetes patients

The potential impact of human leukocyte antigen （HLA） genotype variations on development of diabetic peripheral neuropathy （DPN） is not well determined. This study aimed to identify the association of HLA class II alleles with DPN in type 2 diabetes （T2D） patients. Totally 106 T2D patients, 49 with DPN and 57 without DPN, and 100 ethnic-matched healthy controls were analyzed. Both groups of the patients were matched based on sex, age, body mass index （BMI） and duration of T2D. Polyneuropathy was diagnosed using electrodiagnostic methods. HLA-DRB1 and DQB1 genotyping was performed in all subjects by the polymerase chain reaction with sequence-specific primers （PCR-SSP） method. T2D patients with DPN showed higher frequencies of HLA-DRB1＊10 and DRB1＊12 alleles compared to control group （P = 0.04）. HLA-DQB1＊02 allele and HLA-DRB1＊07-DQB1＊02 haplotype were associated with a decreased risk for developing DPN in T2D patients （P = 0.02 and P = 0.05 respectively）. Also, patients with severe neuropathy showed higher frequencies of DRB1＊07 （P = 0.003） and DQB1＊02 （P = 0.02） alleles than those with mild-to-moderate form of neuropathy. The distribution of DRB 1 and DQB 1 alleles and haplotypes were not statistically different between all patients and healthy controls. Our findings implicate a possible protective role of HLA-DQB1＊02 allele and HLA-DRB1＊07-DQB1＊02 haplotype against development of peripheral neuropathy in T2D patients. Therefore, variations in HLA genotypes might be used as genetic markers for prediction and potentially management of neuropathy in T2D patients.

Two novel gene-specific markers at the Pik locus facilitate the application of rice blast resistant alleles in breeding

Blast,a disease caused by Magnaporthe oryzae,is a major constraint for rice production worldwide.Introgression of durable blast resistance genes into high-yielding rice cultivars has been considered a priority to control the disease.The blast resistance Pik locus,located on chromosome 11,contains at least six important resistance genes,but these genes have not been widely employed in resistance breeding since existing markers hardly satisfy current breeding needs due to their limited scope of application.In this study,two PCR-based markers,Pikp-Del and Pi1-In,were developed to target the specific In Del(insertion/deletion)of the Pik-p and Pi-1 genes,respectively.The two markers precisely distinguished Pik-p,Pi-1,and the K-type alleles at the Pik locus,which is a necessary element for functional genes from rice varieties.Results also revealed that only several old varieties contain the two genes,of which nearly half carry the K-type alleles.Therefore,these identified varieties can serve as new gene sources for developing blast resistant rice.The two newly developed markers will be highly useful for the use of Pik-p,Pi-1 and other resistance genes at the Pik locus in markerassisted selection(MAS)breeding programs.

Self-compatibility in peach[Prunus persica(L.)Batsch]:patterns of diversity surrounding the S-locus and analysis of SFB alleles

Self-incompatibility(SI)to self-compatibility(SC)transition is one of the most frequent and prevalent evolutionary shifts in flowering plants.Prunus L.(Rosaceae)is a genus of over 200 species most of which exhibit a Gametophytic SI system.Peach[Prunus persica(L.)Batsch;2n=16]is one of the few exceptions in the genus known to be a fully selfcompatible species.However,the evolutionary process of the complete and irreversible loss of SI in peach is not well understood and,in order to fill that gap,in this study 24 peach accessions were analyzed.Pollen tube growth was controlled in self-pollinated flowers to verify their self-compatible phenotypes.The linkage disequilibrium association between alleles at the S-locus and linked markers at the end of the sixth linkage group was not significant(P>0.05),except with the closest markers suggesting the absence of a signature of negative frequency dependent selection at the S-locus.Analysis of SFB1 and SFB2 protein sequences allowed identifying the absence of some variable and hypervariable domains and the presence of additionalα-helices at the C-termini.Molecular and evolutionary analysis of SFB nucleotide sequences showed a signature of purifying selection in SFB2,while the SFB1 seemed to evolve neutrally.Thus,our results show that the SFB2 allele diversified after P.persica and P.dulcis(almond)divergence,a period which is characterized by an important bottleneck,while SFB1 diversified at a transition time between the bottleneck and population expansion.

Determination of the Number of SSR Alleles Necessary for the Analysis of Genetic Relationships Between Maize Inbred Lines

The amount of molecular marker information has considerable impact on the results of studies of crop germplasm genetic relationships in crop. The number of alleles required to reveal genetic relationship in maize inbred lines is a theoretical issue that needs to be addressed. In this study, 112 pairs of SSR （simple sequence repeat） primers and 97 maize inbred lines were selected to study the relationship between the number of inbred lines and the number of SSR primers and alleles required for a stable cluster. The results showed that the number of SSR primers is not tightly associated with the stability of the cluster analysis results, while an increase in the number of alleles can significantly improve the stability of cluster analysis results. The number of inbred lines （X） is significantly associated with the number of alleles required for stable cluster analysis （Y）, and the regression equation is Y- 600.8xe（-15.9/x）. This equation can be used to calculate the number of SSR alleles required for a genetic relationship study of maize inbred lines. These results provide a reference for determining of SSR alleles number in genetic relationship analysis of maize inbred line and other crop germplasm.

Differential expressions among five Waxy alleles and their effects on the eating and cooking qualities in specialty rice cultivars

Eating and cooking qualities（ECQs） of rice are important attributes due to its major influence on consumer acceptability. To better understand the molecular mechanism of the variation in ECQs, we investigated and compared the expressions among different alleles of the Waxy（Wx） gene and its effect on ECQs in specialty rice cultivars. The results showed that the accumulation of amylose was positively and significantly correlated to the level of mature Wx m RNA and granule-bound starch synthase I（GBSS I） in developing rice grain at 12 days after flowering. The amount of GBSS I and its activity together are the main factors controlling amylose synthesis. Differences in ECQs among five Wx allele types were investigated in samples from 15 rice varieties. The apparent amylose content（AAC） and gel consistency（GC） were similar in each type of Wx allele. The AAC followed the order, Wx^a type〉Wx^in type〉Wx^b type〉Wx^mq type〉wx. Contrary to this, the GC showed an opposite trend compared to AAC. There was a wide variation in rapid visco analyzer（RVA） profile among five Wx allele types, while varieties sharing a specified Wx allele had basically the similar RVA profile, although there was a slight difference in some RVA parameters, peak, hot paste and cool paste viscosities.

Expression Analysis of Restorer Alleles-Induced Genes in Pepper

Fertility restoration of cytoplasmic male-sterility in pepper （Capsicum annuum L.） is useful for commercial production of hybrid seeds. However, the mechanism of fertility restoration has not been determined. We previously constructed a cDNA library and identified some genes related to fertility restoration in pepper using suppression subtractive hybridization technology. In this study, the expression patterns of 20 genes were investigated using semi-quantitative RT-PCR. Three genes expressed only in restorer lines, but not in sterility lines. Four genes expressed only in anther, but not in other organs. Among these 7 genes, the clone TG31 was observed to specifically express in anther of restorer lines. The work described here provides a comprehensive overview on the expression pattern of the genes that are induced by restorer alleles in pepper. It will also contribute to the current understanding of molecular networks for the regulation of fertility restoration.

Molecular characteristics of S-RNase alleles as the determ inant of self-i ncompatibility in the style of Fragaria viridi

Strawberry(Fragaria spp.)is a member of the Rosoideae subfamily in the family Rosaceae.The self-incompatibility(SI)of some diploid species is a key agronomic trait that acts as a basic pollination barrier;however,the genetic mechanism underlying SI control in strawberry remains unclear.Two candidate S-RNases(S a-and S^-RNase)identi fi ed in the transcriptome of the styles of the self-incompatible Fragaria viridis 42 were con fi rmed to be SI determinants at the S locus following genotype identi fi cation and intraspeci fi c hybridization using sel fi ng progenies.Whole-genome collinearity and RNase T2 family analysis revealed that only an S locus exists in Fragaria;however,none of the compatible species contained S-RNase.Although the results of interspeci fi c hybridization experiments showed that F.viridis(SI)styles could accept pollen from F.mandshurica(self-compatible),the reciprocal cross was incompatible.S a and S b-RNase contain large introns,and their noncoding sequences(promotors and introns)can be transcribed into long noncoding RNAs(lncRNAs).Overall,the genus Fragaria exhibits S-RNase-based gametophytic SI,and S-RNase loss occurs at the S locus of compatible germplasms.In addition,a type of SI-independent unilateral incompatibility exists between compatible and incompatible Fragaria species.Furthermore,the large introns and neighboring lncRNAs in S-RNase in Fragaria could offer clues about S-RNase expression strategies.

A catalog of gliadin alleles:Polymorphism of 20th-century common wheat germplasm

A new, improved version of the catalog of 182 alleles at the six Gli loci of common wheat(T.aestivum L.) shown in electrophoregrams of 128 standard genotypes was used for analysis of1060 cultivars and lines bred in the 20 th century. The most frequent alleles in the studied germplasm occurred with frequencies of 18%–40%, with 30 unique alleles, one in each cultivar. Extremely high genetic diversity was found(average H for the six main Gli loci was0.870 ± 0.046), nearly identical in winter(H = 0.831) and spring(H = 0.856) wheats but differing among 28 groups of cultivars released in 22 countries. Each country or region was characterized by its own specific set of the most frequent Gli alleles, and the 28 cultivar groups formed five main relationship clusters if polymorphism at the six Gli loci was considered. However, different levels of similarity between groups of cultivars were found if polymorphism of the A, B, or D genomes of common wheat was tested separately. In general, the 20 th century germplasm of common wheat was differentiated and structured by country or region and cultivar type(spring or winter). Each elemental genome(in particular, A and D) contributed to the structure of the polymorphism studied. We propose that the structure of the wheat germplasm was a result of natural selection under the ecoclimatic conditions of cultivation specific to each country or region. As many as 27.4% of cultivars studied violated the requirement of the DUS rules for uniformity, being represented by mixtures of two or more closely related genotypes. However, the composition of a cultivar as a set of related but different genotypes may contribute to its adaptivity, and thereby to the known high plasticity of common wheat.

Human leukocyte antigen class-Ⅱ DRB1 alleles and Giardia lamblia infection in children: A case-control study

Objective:To compare the genotype frequencies of HLA class-ⅡDRB1 alleles in Giardia(G.)lamblia-infected children.Methods:A total of 490 Egyptian children aged 2-16 years were subjected to microscopic stool examination to detect G.lamblia infection,and to exclude other intestinal pathogens.On the basis of their microscopic findings,a group of 80 children were chosen as giardiasis cases,another 80 children were confirmed as Giardia free control group by immunochromatographic test,and the remaining children were excluded.Both giardiasis and control groups were then subjected to blood examination to identify their genetic type of HLA-DRB1 alleles.Results:HLA class-ⅡDRB1*03:01 and DRB1*13:01 alleles were significantly associated with G.lamblia infection(P<0.001 for each variable).On the other hand,HLA class-ⅡDRB1*04:02,DRB1*10:01,DRB1*14:01 and DRB1*15:01 alleles were significantly demonstrated in Giardia free children.However,other HLA-DRB1 alleles did not show any significant association with giardiasis.Conclusions:HLA class-ⅡDRB1*03,DRB1*13,DRB1*04,DRB1*10,DRB1*14 and DRB1*15 alleles may be involved in the establishment of host immune response to G.lamblia infection.

Generation of conditional knockout alleles for PRL-3

Phosphatase of regenerating liver-3 （PRL-3） is a member of the protein tyrosine phosphatase （PTP） superfamily and is highly expressed in cancer metastases. For better understanding of the role of PRL-3 in tumor metastasis, we applied a rapid and efficient method for generating PRL-3 floxed mice and investigated its phenotypes. A BAC retrieval strategy was applied to construct the PRL-3 conditional gene-targeting vector. Exon 4 was selected for deletion to generate a nonfunctional prematurely terminated short peptide as it will cause a frame-shift mutation. Conditional knockout PRL-3 mice were generated by using the Cre-loxP system and were validated by Southern blot and RT-PCR analysis. Further analysis revealed the phenotype characteristics of PRL-3 knockout mice and wildtype mice. In this study, we successfully constructed the PRL-3 conditional knockout mice, which will be helpful to clarify the roles of PRL-3 and the mechanisms in tumor metastasis.

Identification of Multiple Alleles at the Wx Locus and Development of Single Segment Substitution Lines for the Alleles in Rice

The microsatellite markers 484/485 and 484/W2R were used to identify the multiple alleles at the Wx locus in rice germplasm. Fifteen alleles were identified in 278 accessions by using microsatellite class and G-T polymorphism. Among these alleles, （CT）12-G, （CT）15-G, （CT）16-G, （CT）17-G, （CT）18-G and （CT）21-G have not been reported. Seventy-two single-segment substitution lines （SSSLs） carrying different alleles at the Wx locus were developed by using Huajingxian 74 with the （CT）11-G allele as a recipient and 20 accessions containing 12 different alleles at the Wx locus as donors. The estimated length of the substituted segments ranged from 2.2 to 77.3 cM with an average of 17.4 cM.

The distribution of HLA-A,-B,and-DRB1 alleles and haplotypes in inhabitants of Guizhou Province of China

The present study was aimed to analyze the frequencies of human leukocyte antigen （HLA）-A, -B, and -DRB1 alleles and A-B-DRBI, A-B, A-DRB1 and B-DRB1 haplotypes in inhabitants of Guizhou province, China. All samples were typed in the HLA-A,-B, and -DRB1 loci using the polymerase chain reaction-reverse sequence spe- cific oligonucleotide probe （PCR-rSSOP） method and HLA polymorphisms were analyzed. A total of 18 HLA-A, 31 HLA-B, and 13 HLA-DRB1 alleles were found in the Guizhou population. The first two frequent alleles in the HLA-A, -B, and -DRB1 loci were A＊1 1（30.72%） and A＊02（30.65%）, B＊40（16.27%） and B＊46（16.27%）, and DRBl＊09（15.91%） and DRBl＊15（13.51%）, respectively. The most common haplotype was A＊02-B＊46- DRBl＊09（5.59%） in A-B-DRB1, A＊02-B＊46（I 1.73%） in A-B, B＊46-DRBl＊09（7.49%） in B-DRB1, and A＊02- DRBl＊09（8.08%） in A-DRB1. Some baplotypes with strong linkage disequilibrium （LD） were found not only in the common haplotypes, such as A＊33-B＊58, B＊30-DRB1＊07, and B＊33-DRB1＊03, but also in the rare haplotypes, such as A＊01-B＊37, B＊37-DRB1＊10, and A＊01-DRB1＊10. Guizhou inhabitants shared some characteristics of the Southern Chinese population but also had their own unique features. Overall, HLA polymorphism in Guizhou population was more consistent with that of Chengdu population than that of other populations in China.

Mining Elite Alleles of Growth Duration and Productive Panicle Number per Plant by Association Mapping with Conditional Phenotypic Value in Japonica Rice

To provide genetic information and materials for breeding hybrid japonica rice with wide adaptability and strong competitive advantage of yield, elite alleles and their carrier varieties of growth duration （GD） and productive panicle number per plant （PN） were detected. A natural population composed of 94 japonica varieties was phenotyped for the GD, PN and plant height （PH） in two environments. The conditional phenotypic data were transferred by the linear model method in software QGAStation 1.0, and association mapping based on the unconditional and conditional phenotype values of GD and PN was analyzed by using general linear model in software TASSEL. A total of 34 simple sequence repeat （SSR） marker loci associated with GD and PN were detected in the two environments. Among them, 15 were associated with GD, and 19 were associated with PN. Four elite alleles of RM8095-120bp, RM7102-176bp, RM72-170bp and RM72-178bp were associated with GD, and their carrier varieties were Hongmangshajing, Nipponbare, Hongmangshajing and Nannongjing 62401, respectively. These elite alleles from the carrier varieties can shorten GD by 2.03-9.93 d when they were introduced into improved materials. RM72-182bp associated with PN was an elite allele, and its carrier variety was Xiaoqingzhong. It can increase PN by three when introduced into improved materials. Moreover, these elite alleles can be used to improve target traits without influencing another two traits.

New Alleles of Rice <i>ebisu dwarf</i>(<i>d</i>2) Mutant Show both Brassinosteroid-Deficient and -Insensitive Phenotypes

ebisu dwarf (d2) is a mutant caused by mutation in a rice brassinosteroid biosynthetic enzyme gene, CYP90D2/D2, thereby conferring a brassinosteroid-deficient dwarf phenotype. Three newly isolated d2 alleles derived from a Nippon- bare mutant library (d2-3, d2-4, and d2-6) produced more severe dwarf phenotypes than the previously characterized null allele from a Taichung 65 mutant library, d2-1. Linkage analysis and a complementation test clearly indicated that the mutant phenotypes in d2-6 were caused by defects in CYP90D2/D2, and exogenous treatment with brassinolide, a bioactive brassinosteroid, rescued the dwarf phenotype of three Nipponbare-derived d2 mutants. However, the content of endogenous bioactive brassinosteroid, castasterone, and the expression of brassinosteroid-response genes indicated that partial suppression of the brassinosteroid response in addition to a brassinosteroid deficiency has occurred in the Nipponbare-derived d2 mutants. Based on these results, we discuss the possibility that wild-type Nipponbare has some defects in an unknown factor or factors related to the brassinosteroid response in rice.

Association of HLA Alleles(A, B, DRB1) and HIV-1 Infection in the Han Population of Hubei, China

The HIV susceptibility and resistance alleles in the HLA genes were determined by investigating the distribution characteristics of the HLA alleles（A, B, and DRB1） in HIV-infected individuals of the Han population in Hubei, and by comparing these alleles with HIV-negative individuals from the same area. A cohort of 424 HIV-1 infected individuals were chosen as study subjects, and 836 HIV-negative healthy subjects from the same area served as the control population. HLA-A, B, and DRB1 allele typing was performed using polymerase chain reaction-sequence-specific oligonucleotide probes（PCR-SSOP） and polymerase chain reaction-sequencing based typing（PCR-SBT） techniques. Arlequin ver3.0 was used to analyze the allele and haplotype frequencies of HLA-A, B, and DRB 1, whereas Epi Info 7 and SPSS18.0 was used to analyze the differences in the HLA alleles between the HIV-1 positive and HIV-1 negative groups. A＊02：03, DRB1＊01：01, and DRB1＊15：01 alleles and their haplotypes as well as the HLA_Bw4-Bw6 hybrid showed a protective effect on HIV-1 infection. After adjusting for confounding factors such as age and sex, multivariate logistic regression analysis revealed that B＊15：02G, DRB1＊01：01, and DRB1＊15：01 subtypes were the resistance genes of HIV-1 infection, while B＊13：01 might increase susceptibility to HIV-1 infection. The correlation between A＊02：06 and B＊15：01G subtypes and HIV-1 susceptibility was independent of the age and sex of the host. This study demonstrated the influence of genetic factors in humans such as HLA polymorphism on individuals to resist HIV-1 infection. Association studies of HLA polymorphism, susceptibility/resistance to HIV-1 infection, and hosts＇ genetic background are of significant importance for research on HIV-1 pathogenesis and vaccine design.

Elite sd1 alleles in japonica rice and their breeding applications in northeast China

The Green Revolution gene sd1 has been used extensively in modern rice breeding,especially in indica cultivars.However,elite sd1 alleles and related germplasm resources used for japonica rice breeding have not been identified,and extensive efforts are needed for japonica rice breeding to obtain new dwarfing sources.Data from MBKbase-Rice revealed seven sd1 haplotypes in indica and four in japonica rice.Two new sd1 alleles were identified in indica rice.In 295 japonica accessions from northeast Asia,except for the weak functional allele SD1-EQ,sd1-r was the major allele,reducing plant height in comparison with SD1-EQ.Japonica germplasm resources carrying reported sd1 alleles were identified by genotype searching and further verified by literature search,genealogical analysis,and d Caps markers.Pedigrees and geographic distribution showed that sd1-r is an excellent allele widely used in northern China and Tohoku in Japan,and sd1-j is commonly used in east China and Kyushu in Japan.Dongnong-and Xiushui-series cultivars carrying sd1-r and sd1-j,respectively,are essential branches of the backbone parents of Chinese japonica rice,Akihikari and Ce21,with the largest number of descendants and derived generations.In semi-dwarf japonica rice breeding,sd1-d was introgressed into Daohuaxiang 2(DHX2).Dwarf and semi-dwarf lines carrying sd1-d were selected and designated as 1279 and 1280,respectively,after withstanding typhoon-induced strong winds and heavy rains in 2020,and are anticipated to become useful intermediate materials for future genetic research and breeding.This work will facilitate the introduction,parental selection,and marker-assisted breeding,and provide a material basis for the next step in identifying favorable genes that selected together with the sd1 alleles in japonica backbone parents.