Abstract:Anthocyanins and betalains are both natural water-soluble pigments with similar distribution and functions in plants. Anthocyanins is a type of phenylalanine-derived pigment， and the betalains is a tyrosine-derived pigment that contains the chromophore betalamic acid. Anthocyanins are widely distributed in plants， but in Caryophyllaceae plants， betalains present instead of anthocyanins. It is worth attention that anthocyanins and betalains have never been found in the same plant at the same time. This mutual exclusion may be raised by accident in evolution， or the co-existence of both pigments would bring troubles in plant survival. This article reviewed and discussed the general characters of anthocyanins and betalains， the biosynthetic pathways and their regulations， the cases of induced co-existence of the two pigments， and the possible reasons for the mutual exclusion between the two pigments. In addition， the possible mechanism of the mutual repulsion of the two pigments， the research focuses for the future， and the possible application value in molecular breeding are also prospected. The purpose of this article is to better understand the relationship between anthocyanins and betalains through the review and prospect of previous studies， reveal the mechanisms for their mutual exclusion， as well as provide new ideas and methods for research and application in related fields.

Abstract:Chinese woad （Isatis indigotica Fort.， 2n=14； Radix Isatidis） is the traditional Chinese medicinal plant widely used in China， and serves as the germplasm resources in crop genetic improvement. This article reviews the progresses in the genomic structure， bioactive compounds and their biosynthesis， as well as distant hybridization with other crop species. The genome size of Chinese woad is about 300 Mb with the tPCK karyotype and 30，000 protein coding genes， and the high quality reference genome reveals the candidate genes and synthesis pathways for main bioactive compounds， indole alkaloids， phenylpropanoids and terpenoids. Through making crosses （male parent） with Brassica rapa and B. napus， the non-classical hybrids containing few chromosomes and fragments of Chinese woad are produced. The somatic hybrids with radish were found with chromosomes of both parents， while they failed to produce seeds by either selfing or backcrossing. The somatic hybrids with B. rapa ssp. chinensis （L.） P. Hanelt show its duplicated chromosomes but male fertile. The somatic hybrids with B. napus derive the whole set of rapeseed-woad additional lines， after successive backcrossing with B. napus. Several lines， if compared to the woad， showed improved resistance against many viruses. The recombinant mitochondria DNA molecule produced during the somatic fusion causes the new cytoplasmic male sterility， and the fertility restoration is realized by the introgression of the gene（s） from one particular chromosome of woad. Finally， we discuss the future genetic study and their utilization based on their novel additional lines.

Abstract:The Northeast Inner Mongolia Autonomous Region is an important soybean production area of in China, and is also an experimental area of genetically modified soybeans. In order to understand the local wild soybean resources? situation and provide reference for safe cultivation of the genetically modified soybeans，we investigated the distribution of wild soybean populations in 61 discontinuous field plots in Zhalantun and Arun of Hulunbuir，as well as Keyouqian of Xingan League. Fifty-four plots（88.52%）were found to have soybeans，including three types： the wild populations，mixed populations of both wild and semi-wild soybeans，and a population of entirely semi-wild soybeans which was discovered for the first time. The sizes of most populations in this region were relatively small，showing ca. 72.2% of the populations being ≤ 1000 m²，and ca. 59.3% being ≤500 m². The frequencies of wild soybean quadrats were above 80%，40%-60% and below 20% for ca. 46%, 41% and 13% of the plots. From the seeds of 836 single plants collected from 54 wild soybean populations，six seed-coat color types（black，bicolor，brown，brown-green，green and yellow-green）and three leaf-shape types （long oval， oval and lanceolate）were observed. The 100-seed weight of wild soybeans was relatively small，accounting for 84.57% for the type of ≤1.5 g in the total sample，with an average of 1.19±0.49 g. It was estimated that approximately 17.92%，29.48%，and 40.10% of the remaining idle lands may have potential distribution of wild soybeans. We found that the advanced agricultural ecosystem would reduce the density of wild soybeans in populations. The semi-wild soybean was found with higher probability in the long-term soybean growing area. This article also discussed the measures on safe cultivation of genetically modified soybeans in the Northeast Inner Mongolia in the future，as well as the protection of wild soybean resources.

Abstract:The genus Hordeum belongs to the Triticeae tribe of the Poaceae family. The Hordeum species are distributed in wide geographical regions showing diversified local climates， making them as important adapted germplasm resources facing climatic changes. However， the morphological similarity among Hordeum species often complicated their classification on efficiency and accuracy in the survey and germplasm collection. The construction of the retrieving key of Hordeum species and a unique electronic ‘identity card’ for each species will provide an reference for species classification and rapid identification of Hordeum species， valuable in the survey， collection， evaluation and utilization of Hordeum germplasm resources. In this study， 38 accessions of 32 Hordeum species were grown under greenhouse conditions in 2020 and 2021， in order to investigate 45 qualitative and 15 quantitative traits. Based on photographing important phenotypes such as whole plant， spike， and triple spikelets， as well as analyzing the subtle differences， each Hordeum species was classified. As a result， a taxonomic key table for the Hordeum species and the electronic identity card for each species were achieved.

Abstract:Landraces are important parent sources in wheat breeding， and play vital roles in the breeding progress via introgressing elite traits. Using allele-specific markers of wheat vernalization genes Vrn-A1， Vrn-B1， Vrn-D1， Vrn-B3 and photoperiod gene Ppd-D1， this study detected their dominant allelic variations in 445 Gansu landraces， and analyzed the relationship with winter-spring growth habits. The results showed： （1） The frequencies of the dominant alleles at the four vernalization genes were 2.5% （Vrn-A1a）， 11.0% （Vrn-B1a）， 1.6% （Vrn-B1b）， 0.5% （Vrn-B1c）， 67.4% （Vrn-D1） and 0.5% （Vrn-B3）， respectively， and the frequency of the photoperiod-insensitive Ppd-D1a allele was 17.8%. （2） Except for Vrn-B1a + Vrn-D1， different combinations of dominant alleles were detected in landraces collected from spring wheat regions. The frequency distribution of dominant vernalization alleles decreased gradually from spring wheat to winter wheat regions， whereas all recessive allele composition at Vrn1 and Vrn-B3 loci increased constantly. The Ppd-D1a was detected in Gansu landrace germplasm from different wheat regions， and its frequency in winter wheat region was much higher than that in spring wheat region. The highest frequency （35.6%） was observed in Longdong dry land winter wheat area， and the lowest （5.1%） was detected in Taomin high and cold spring wheat region. （3） Through comparing the genotyping results with the historic phenotype recorded from wheat resource catalogue of Gansu Landrace， a lower coincidence was observed in winter/strong winter landraces than that in spring/mild winter wheat， and the coincidence decreased gradually for the landraces from the spring wheat to winter wheat regions. （4） Eighty-three spring wheat， 119 mild winter wheat and 82 winter wheat were identified， which can be applied in spring wheat region （Central and western Gansu province， high and cold Taomin spring wheat area） and autumn-planting winter wheat regions with warmer （Longnan Jialing River Upstream and Upper Wei River in Southern Tianshui） and colder winter region （Pingliang， Qingyang Jing River basin， North of Dingxi and Tianshui）， respectively. In conclusion， this study provided a reference for mining excellent traits of landrace varieties in modern wheat breeding.

Abstract:Based on 220 maize inbred lines， 6 bract related traits were evaluated in field experiments at two locations in two years. The genetic diversity analysis， principal component analysis， clustering analysis and stepwise regression analysis were applied for statistical analysis and identifying the evaluation indicators. The results showed that the genetic variations at bract related traits were abundant， with the coefficient of variation ranged from 13.41% to 51.79% as well as the genetic diversity index ranged from 1.71 to 2.08. Principal component analysis simplified the six traits into three principal components， showing the cumulative contribution rate of 86.674%. The first principal component was mainly related to the bract mass and the bract length. The second principal component and the third principal component were mainly related to the bract wrapping degree and the bract number， respectively. The comprehensive evaluation D value ranged from 0.161 to 0.728， of which 101314 and 7026B showed the highest and lowest D value， respectively. 220 inbred lines were divided into three groups by cluster analysis， among which 62 inbred lines were in group I， with few bract numbers， shorter and narrower bracts， lower bract mass and wrapping degree. Stepwise regression analysis showed that bract length， bract width and wrapping degree could be used as the important indicators for the comprehensive evaluation of bract traits in maize. Collectively， these results provided a theoretical reference for the accurate identification of bract traits in maize germplasm resources suitable for mechanical harvest.

Abstract:In order to uncover elite local germplasm resources and improve the efficiency of maize breeding in Guangxi of China， 169 maize landraces from Guangxi were genotyped using 10K SNPs in the present study， followed by their genetic diversities and population structure analysis. The results showed that the average genetic diversity and polymorphic information content （PIC） of 5877 screened SNP markers were 0.37 and 0.30， respectively， exhibiting relatively higher diversity in maize landraces from Guangxi. The landraces from Northeastern Guangxi exhibited the highest diversity level （gene diversity=0.39， observed heterozygosity=0.27， minimum allele frequency=0.30， PIC=0.31）. Gained from the population structure and principal component analysis， 169 landraces were divided into two major populations. The genetic relationship and structured assignment among populations were not observed correlating with their geographical originations. Besides， all landraces exhibited relatively higher heterozygosity but relatively lower genetic similarity coefficients. Analysis of molecular variance （AMOVA） showed that 2% of genetic variation was contributed by inter-population diversity， while 98% was contributed by intra-population diversity. The genetic differentiation coefficient （F_ST） between populations was 0.049， indicating a relatively low level of genetic differentiation among populations. In summary， the present study uncovered the polymorphism and genetic relationship of maize landraces from different geographical regions of Guangxi， providing a theoretical reference for the improvement of maize germplasm and practical guidance of new variety development in these regions.

Abstract:The beany flavor and potential allergenicity of soybean caused by Lox and 7S globulin limit human consumption. Breeding for soybean varieties with Lox and 7S globulin deficiency or high 11S/7S ratio is， therefore， of interest to improve the nutritional value and process different soybean products. In this study， the protein subunit composition of 2713 soybean germplasms was determined by the optimized soybean protein SDS-PAGE extraction method. The soybean germplasm resources with different protein subunit composition types were excavated， and the genetic and environmental factors affecting the protein subunit content were analyzed. The results identified a significant negative correlation between 7S globulin and 11S globulin. The 11S/7S ratio of local varieties was higher than that of modern varieties. A significant difference on the content and ratio of 7S and 11S globulin were observed in samples harvested from years. There was no significant correlation between 7S and 11S globulin and their subunits and protein and oil content. A total of 15 soybean germplasm resources with specific composition of soybean protein subunits were screened， including four showing 11S/7S ratio greater than 3.0 without subunit structural variation， five with Lox deletion， one with α' subunit deletion， two with α subunit deletion， one with β subunit deletion， one with 11S/7S ratio greater than 3.0 and Lox deletion， and one with complete deletion of 7S subunit. The identification of these germplasms laid a material foundation in breeding of high-quality soybean varieties applicable for different soybean products.

Abstract:Faba bean （Vicia faba L.） is an important legume crop in China. Southern China is the autumn planting area of faba bean， where mainly produces large-grained fresh faba bean. The correlation analysis of the seed size-related traits of the faba bean resources from this area was carried out to explore the associated molecular markers applicable for molecular marker-assisted breeding. In this study， phenotype of seed size-related traits in 90 faba bean resources were collected in 2019 and 2020. Sixty-seven pairs of polymorphic SSR markers were used for genotyping， producing a total of 278 alleles with the average alleles of 4.1. The resources were divided into 3 groups by cluster analysis， in which accessions with higher values of seed length， seed width and 100-seed weight are mainly found in the A group. In addition to the population structure analysis， the MLM models （Q+K） of TASSEL software were used to conduct associate studies of seed size-related traits and 67 SSR markers. A total of 50 significantly associated markers （P<0.001） were detected by mixed linear model （MLM） of TASSEL， of which 29 markers had a P-value less than 0.0001. In multiple environments analysis， ICS48 and ICS455 were significantly associated with both grain width and grain weight. According to the association stability and contribution rate， three dominant alleles （ICS48-H1， ICS51-H1 and ICS455-H3） related to seed size were obtained （P<0.0001； r²>18%）. This study will contribute to the molecular marker-assisted selection and molecular design breeding of faba bean in autumn planting areas in China.

Abstract:The macadamia nut fruits have rich diversity on their single fruit weight， seed yield， and kernel yield. In order to indentify the Macadamia germplasms with the best performance applicable for breeding programs， 100 macadamia germplasms were investigated in this study， and a comprehensive evaluation analysis was conducted on 12 fruit quantitative traits through statistics methods such as correlation， cluster analysis， and principal component analysis， etc. The results showed that the coefficient of variation of the 12 quantitative traits ranged from 9.66% to 23.62%， with a significant degree of variation on the traits of single fruit weight （23.62%） and kernel weight （21.20%）， respectively. There was a highly significant positive correlation between single fruit weight and kernel weight， which is the important reference for selecting large fruits. Cluster analysis separated the 100 germplasms into two groups， with group Ⅰ having poor appearance of the fruits quality， such as small fruit size， relatively low seed rate and kernel yield rate； while group Ⅱ have good appearance of the fruits quality， such as large fruit size， high seed rate and kernel yield rate， which meets the market demands. Principal component analysis divided the 12 quantitative traits into 4 principal components， with a cumulative contribution rate of 79.902%. The initial eigenvalues and the cumulative contribution of the first principal component were 4.280 and 35.667%， respectively， and the components were mainly associated with the size of the fruit traits； the cumulative contribution of the second principal component was 20.177% and they were mainly associated with the kernel traits； the cumulative contribution of the third and the fourth principal component was 13.026% 11.032%， respectively， and they were mainly associated with the seed and kernel yield of the fruit， respectively. The comprehensive evaluation score of the fruit traits ranged from -2.333 to 0.983， and the top 10 excellent germplasms were identified as the following sequence， Pattern， SS14， Zhuangyuan 1， Lincang 47， Guire No. 1， Nanya 2， A4， B2， Lincang 1， and Gui 3. Notably， the FS3 was identified with the largest single fruit weight， the Guire No. 1 was identified with the heaviest kernel， the Breeding 8 was identified with the highest seed yield， and the A4 was identified with the highest kernel yield， respectively. These comprehensive evaluation data and identified exellent germplasms provide important references for future conventional or hybrid breeding in Macadamia.

Abstract:Fragrance volatile organic compounds play key role on exploitation and utilization in ornamental plants. In this study， headspace solid phase microextraction combined with gas chromatography mass spectrometry （HS-SPME-GC-MS） was used to determine and quantify the volatile organic compounds （VOCs） in five rose petals. Ninety-one VOCs were identified and classified into nine types： terpenes， alcohols， esters， aldehydes， alkanes， phenols， ketones， ethers， acids. Forty-five components were detected in R. centifolia； 52 components including five exclusive compositions were detected in R. ‘Morocco’； 40 compounds including two exclusive compositions were detected in R. ‘de Grasse’； 57 compounds including eight exclusive compositions were detected in R. ‘Duc de Fitzjames’； 63 compounds including 11 exclusive compositions were detected in R. × damascena. The compounds 2-Phenylethanol， Geraniol， β-Citronellol， and Geranyl acetate were predominant in five rose petals. R. × damascena had the highest content of VOCs， reaching 3622.68 ng/g， and the contents of VOCs in R. ‘Morocco’， R. ‘Duc de Fitzjames’， R. ‘de Grasse’， R. centifolia were 2507.07 ng/g， 2445.9 ng/g， 1394.54 ng/g， 883.38 ng/g， respectively. Heatmap cluster analysis and cluster analysis showed that R. × damascena was closely related to R.‘Duc de Fitzjames’， and the content of terpenes were significantly different in petals of five rose. Collectively， this study provided reference for future exploitation and utilization of Rosa genus resources.

Abstract:Improving the fragrance characteristics through hybridization is an important way of fragrant flower breeding. In this study， Headspace-Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry （HS-SPME-GC-MS） was employed to determine the volatile organic compounds （VOCs） in blooming petals of the rose variety Mantingfanghua and its parents. Comparison analysis of VOCs showed that 25， 36 and 22 VOCs were identified in the blooming petals of Mantingfanghua， its paternal species Rosa beggeriana Schrenk and maternal variety Queen Elizabeth， respectively. The totally identified 59 components can be sorted to 8 major compounds based on their chemical structures， including alcohols， terpenes， esters， hydrocarbons， ethers， aldehydes， ketones and acids. Mantingfanghua has 10 components in common with Rosa beggeriana Schrenk， while 13 in common with Queen Elizabeth； Mantingfanghua has the VOCs composition in higher similarity to its maternal variety. The total VOCs content in Mantingfanghua was 579.70 ng/g， which was lower than that in its paternal species （13939.42 ng/g） and its maternal variety （1157.10 ng/g）. The contents of terpenoids and benzenoids/phenylpropanoids were lower in Mantingfanghua than those in its parents； in opposite， the contents of sesquiterpenoids in Mantingfanghua were higher than those in its parents. Meanwhile， the content of fatty acid derivatives in Mantingfanghua fell in between those in their parents. Principal component analysis showed that the β-Cubebene， β-Cadinene， β-Caryophyllene were the main VOCs that may affect the fragrance from Mantingfanghua. This study provides insights for the genetic improvement of rose floral fragrance metabolism， which has important value for both theoretical and practical purpose.

Abstract:The study aimed to analyze the degree of variation， heterosis and genetic tendency of floral traits in hybrid progenies of Camellia oleifera. 322 hybrid progenies and their parents （DY2×HS） were analyzed at eight characters， including flower transverse diameter， flower longitudinal diameter， petal number， anthers number， style dehiscence number， stamens group length， style length and pistils length， followed by the genetic variation analysis， test of normality and probability grading， heterosis analysis and cluster analysis. The results showed that： （1） The coefficient of variation ranged from 11.74% to 22.10%， with an average of 16.26%. （2） The normal distribution was observed at the flower transverse diameter， flower longitudinal diameter， anthers number and stamens group length， the bi-modal distribution was detected at the number of petals and style length， and the skewness distribution was detected at style dehiscence number and pistils length. The class III showed highest proportion of frequency distribution with an average of 43.05%， while grade V accounted for the lowest proportion， with an average of 8.07%. （3） The mid-parent heterosis of floral organs ranged from –28.48% to 5.65%， the ultra-high parent heterosis ranged from –49.29% to –9.12%， and the ultra-low parent heterosis ranged from –18.06% to 29.12%. Except for the ultra-high parent heterosis was all negative which suggested a certain degree of heterosis decline， the other two indicators showed a trend of positive and negative bidirectional distribution， among which the style dehiscence number and anthers number were positive in the mid-parent heterosis and the ultra-low parent heterosis， and the advantages were obvious and stable； the style length and the pistils length are positive in the ultra-low parent heterosis. The results of relative heritability showed that the male parent was superior than the female parent in number of anthers and style dehiscence， and the progenies had a paternal tendency. For the remaining 6 quantitative traits， female parent was more dominant and the progenies had a maternal characteristics. （4） The test materials were divided into three groups by cluster analysis， among which the group II had the best comprehensive performance and heterosis utilization value. These results demonstrate that hybrid progeny populations have a high degree of genetic variation and the heterosis of significance， which can provide a reference basis for enriching the comprehensive evaluation system of C. oleifera and screening of excellent individuals early.

Abstract:The growth， leaf morphology， chlorophyll synthesis and photosynthetic parameters in diploid and triploid Passiflora edulis Mantianxing were measured. The results showed that： （1） Compared with triploid plants， the triploid plants showed shorter stalk and petiole， narrower leaves and shorter distance between than that of diploid leaves， and the content of carotenoid was no significant difference. （2） The total content of chlorophyll， chlorophyll a and chlorophyll b synthesized by triploid leaves was higher in triploid. （3） During the diurnal process of photosynthesis， both diploid and triploid had a lunch break and the net photosynthetic rate （Pn）， transpiration rate （Tr）， stomatal conductance （Gs） and intercellular CO₂ concentration （Ci） of triploid plant were higher than those of diploid plant， which were increased by 9.5%， 6.9%， 4.5% and 3.9%， respectively. （4） The variation trend of monthly photosynthesis in diploid and triploid was similar， both reaching the highest value in August and falling to the lowest value in December， both of which are single-peak curves. The Pn， Tr and Gs of triploid Mantianxing are superior to diploid. （5） There was correlation between the indexes of the two ploidy plants， which indicated that the traits influenced and promoted each other to make the plant grow normally. The size， opening and closing of stomata significantly affected the Pn and Tr of plant leaves. These results showed that the photosynthetic capacity and light energy utilization capacity of triploid Mantianxing were enhanced with the increase of gene dose， and the accumulation of chlorophyll synthesis content of triploid Mantianxing was increased.

Abstract:In order to distinguish different species of wild yellow type Medicago ruthenica， the pollen morphology of wild yellow type M. ruthenica， M. ruthenica and M.falcata were characterized and compared via microscopic observations. It showed that the pollens in wild yellow type M. ruthenic， M. ruthenica and M. falcata were all N₃P₄C₅ type single granules. The pollen size of the two species of M. ruthenica were similar， which were smaller than M. falcate. There are significant differences on the pollen exine pattern among these three forage species. There are waxes covered on the pollen surface of yellow-flowered M. ruthenica and M. ruthenica， while it lacks of wax on the pollen surface of M. falcate. The pollen exine of yellow type M. ruthenica is mainly foveolate with slightly cerebroid-like pattern. The pollen exine of M. ruthenica is generally foveolate patterned， while that of M.falcata is generally cerebroid-like patterned. These results showed that the pollen exine pattern of yellow type M. ruthenica was most similar to M. ruthenica， but significantly different with M. falcata. Thus， the pollen exine pattern could be used as a morphological index for taxonomy of the germplams belonging to different species of M. ruthenica.

Abstract:According to the national guidelines of the “Conduct of tests for the distinctness， uniformity and stability of new varieties—Capsicum”， forty-seven morphological markers were included in characterizing of 457 new pepper varieties， including traits quantification， traits correlation analysis， cluster analysis and cultivation stability analysis across years， in order to reveal the characteristics and genetic diversity of current pepper varieties in China. The evaluation of 11 quantitative traits revealed considerable polymorphisms amongst the tested varieties. The coefficient of variation between varieties ranged from 23% to 93%. However， the average coefficient of variation within a variety was below 20%. It indicated that the tested varieties have relatively consistent performance within variety while abundant variations across varieties. The traits correlation analysis showed a significant correlation among 4 groups of quantitative traits. Cluster analysis separated the 457 varieties into 10 major groups at the genetic similarity coefficient of 0.52， and most of the varieties were assigned into three major clusters. Stability of their phenotypic performance was analyzed based on two-year cultivation experiments. The results showed that the performance of the varieties was relatively stable across two years， and the average correlation coefficient was 88.0%. The stability of single measurement traits was higher than that of group visual traits， and the group measurement traits has the lowest stability across years. This study provides the basis for the objective and rigorous evaluation of pepper varieties and valuable references for the pepper breeding in the future.

Abstract:qPh-3D is a major quantitative trait locus （QTL） regulating plant height （PH） in wheat. This locus could be repeatedly identified in datasets at 14 different environments in the recombinant inbred line （RIL） population derived from the cross between Kenong 9204 and Jing 411 （denoted as KJ-RILs）. qPh-3D was mapped to the chromosomal region of KN3D：515.08-539.08 Mb， and the allele from parent Jing 411 could reduce PH. In this study， we aimed to further characterize the genetic mechanism of PH reduction caused by qPh-3D and clarify its genetic effects on yield-related traits， using the KJ-RILs population containing 187 lines as well as a natural mapping population consisting of 316 breeding varieties （advanced lines）. In KJ-RILs， the qPh-3D allele from Jing 411 can significantly reduce PH via reducing all internode lengths without significant effect on spike length （SL）， whereas it can reduce kernel yield per plant （KYPP） at certain level. Two markers AX-110160363 and AX-111109273， which closely link with qPh-3D， were used for genotyping in the natural mapping population with the yield-related phenotypic datasets. The qPh-3D allele with decreased PH was found with a positive effect on SL， but a significant negative effect on KYPP. Based on the breeding selection effect analysis at the qPh-3D locus， the qPh-3D allele with decreased PH was present in a higher proportion in wheat varieties released from Beijing and Shanxi in China， but lower in Shandong， Qinghai， Sichuan and the foreign countries. This allele was detected in a lower proportion in earlier varieties， while its presence in modern varieties was detected increasingly. In addition， a closely linked PCR-based InDel marker targeting the qPh-3D locus was developed. Collectively， the findings of this study will provide theoretical guidance for future applications of qPh-3D in molecular breeding programs in wheat.

Abstract:Dry direct seeding method can effectively reduce human/resource consumption. Mesocotyl length （ML） affects the emergence and seedling vigor of dry direct seeding rice. Cultivating long ML varieties is the most economical and effective way to promote the popularization of the dry direct seeding method. Dry direct seeding has been popularized in Indica rice areas in South Asia and Southeast Asia， but less in Japonica rice areas. A number of candidate genes related to mesocotyl elongation have been found， but their reliability and applicability remain yet to be verified. Based on 97 identified candidate genes that modulate the mesocotyl elongation， we carried out candidate genes association analysis in two natural populations of Japonica rice， TROP and TEMP. Four significant candidate genes were identified， and each explained 4.7%-6.3% and 5.4%-6.7% phenotypic genetic variation in TROP and TEMP， respectively. Of these， three genes LOC_Os01g44130， LOC_Os03g50560 and LOC_Os05g27790 were identified in both populations， while LOC_Os11g10990 and LOC_Os10g20860 were detected in the TROP and TEMP populations， respectively. The deduced proteins are annotated mainly involving in plant hormone synthesis and metabolism， signal transduction and plant growth process. Six and three superior haplotypes with potential used for molecular marker assisted breeding were further identified in TROP （LOC_Os05g27790-Hap3 and LOC_Os05g27790-Hap6， LOC_Os03g50560-Hap1， LOC_Os01g44130-Hap1 and LOC_Os11g10990-Hap1 and LOC_Os11g10990-Hap3） and TEMP （LOC_ Os05g27790-Hap6， LOC_Os01g44130-Hap1 and LOC_Os10g20860-Hap5） populations. Collectively， these genes and their corresponding superior haplotypes identified in this study can be applied to the molecular breeding of rice varieties with long mesocotyl.

Abstract:Panicle apical abortion is often observed in rice production， which impairs the number of grains per panicle， the seed setting rate and the yield of single plant， and should be avoided in breeding practice. The dense and erect panicle is a plant type adaptable to dense planting. It is of importance to isolate the genes related to these two traits in molecular design breeding. Here， we present the research result of a rice panicle mutant zhao1， which displays the dense panicle and panicle apical abortion. Either dense panicle or panicle apical abortion was segregated independently in the F₂ population derived from zhao1 crossed with IRAT129. Genetic analysis showed that the dense and erect panicle trait is controlled by a single dominant gene， while the panicle apical abortion trait may involve no more than two pairs of genes. Based on the linkage analysis and map-based cloning at both traits respectively， the gene DEP1 was found to be the candidate for the dense panicle trait in zhao1 which carries the identity mutation as the dep1. The linkage mapping and map-based cloning to the trait of panicle apical abortion finally delimited the candidate gene to the physical interval of 6.85-6.93 Mb on chromosome 3， where 8 putative genes are annotated. The gene LOC_Os03g12790 was observed with the most significant decrease on transcriptional profile， and served as the best candidate for the panicle apical abortion phenotype. Collectively， our results laid the foundation for the future cloning of the functional gene in rice.

Abstract:Awn is a specialized extension at the tip of lemma or glume of floret in cereal species， consisting of chlorenchyma cells and vascular bundles which support photosynthesis and nutrients transport， respectively. The awn plays important roles in plant defense， photosynthesis and grain filling， as well as facilitate the threshed grains embedding in soil and the geminated seedlings come up. Cultivated barley （Hordeum vulgare L.） has awn remained post domestication， and various morphological diversifications of the awns have been observed within natural population. Studies on genetical regulation and distribution of the barley awn variants have both theoretical and practical significance. In this study， a barley mutant with hooded awn was identified and genetically attributes to a single dominant mutation. By taking use of bulked-segregants-analysis （BSA） the mutation was mapped towards the end of short arm of the barley chromosome 4H， where the barley gene HvKNOX3 resides in the interval. A local duplication of 305 bp fragments in the fourth intron of HvKNOX3 was found to co-segregate with the hooded phenotype. HvKNOX3， which encodes a homeobox protein with function in transcriptional regulation， expressed specifically in young spikelets 1~1.5 cm long at early development and the rachis of 35 days after planting. By analyzing the sequence diversity of the HvKNOX3 among 20 representative landraces/cultivars of the barley pan-genome， the coding sequences were highly conserved while the exons or untranslated regions were detected with rich amount of variations， others are located in non-coding regions. With a co-dominant marker that captures the 305 bp fragmental duplication in genotyping of 238 Chinese barley landraces， a significant high ratio of the hooded genotype was observed amongst germplasms that collected from Tibet， providing evidence for the presumption that the hooded awn variant was originated from Himalayan area.

Abstract:Dwarf cotton has the advantage in lodging resistance and suitable for dense planting， which is conducive to shaping ideotype of cotton plant architecture， optimizing population performance， improving photosynthetic productivity and increasing yield per unit area. A plant architecture mutant was found in the distant hybrid line N31. Following continuous self-crossing for multiple generations， a stable homozygous mutant was obtained and named as df31. Phenotypic investigation showed that df31 decreased in plant height， branch angle， internode length， while elongated the growth period than N31. Genetic analysis showed that the segregation of mutant phenotype and normal phenotype present in a ratio of 1∶3 in an F₂ population， which indicated that the short stature mutation was controlled by a single recessive gene. The cytological observation showed that compared with N31， the number of parenchyma cells in a unit area in petiole， hypocotyl and stem of df31 increased， accompanying with more vascular bundles and less developed cambium. Along the vegetative growth， the content of endogenous GA₃ and BR in df31 showed an obvious decreasing， the content of IAA was not affected， and its growth rate was slow. Through this study， the comprehensive phenotypic identification of the dwarf mutant df31 and the genetic basis of dwarf gene underneath were analyzed， furthermore the dwarf mutations were analyzed at the cellular and physiological levels， which laid the foundation for further studies on gene mapping and cloning.

Abstract:Double haploid techniques have been widely used to accelerate plant breeding， and in recent years， maize （Zea mays L.） lines containing mutations in the membrane protein （DMP） of the functionally unknown domain DUF679 have been used as haploidy-induced lines. In this study， soybean DMP genes with more than 60% homology with maize DMP gene were searched and bioinformatic analysis was performed. The molecular mechanism and biodiversity of GmDMP gene in soybean were investigated by using 2214 resequencing databases. The analysis results show that： GmDMP1 （Glyma.18G097400） and GmDMP2 （Glyma.18G098300） have high evolutionary affinity with maize DMP gene. The full length of genes is 645 bp， the homology rate of amino acid sequence is over 95%， and the number of encoded amino acids is completely consistent with the isoelectric point. The phosphorylation distribution differs at only one site. Both GmDMP1 and GmDMP2 genes have the same domain DUF679， which is more likely to locate in the ER， and both are transmembrane non-secreting hydrophilic proteins. There were 3 and 1 non-synonymous mutations of GmDMP1 and GmDMP2 genes in 2214 germplasm resources， respectively， consisting of 3 and 2 haplotypes. GmDMP1^H3 has been strongly selected during domestication， and the mutation site of the GmDMP1^H1 and GmDMP1^H2 haplotypes is located in the DUF679 domain. It is possible to obtain a haploid inducible line by mutating two DMP genes in soybean， thus shortening the breeding life of soybean.

Abstract:Haynaldia villosa is an important genetic resource for wheat genetic improvement. The 2V chromosome in H. villosa ， which hosts many important genes， such as powdery mildew resistance， glume ridge bristles， photoperiod response， longer spikes and more grains， are valuable in common wheat improvement. However， the lack of molecular markers to the 2V chromatin impairs the introgression into wheat. In order to develop specific molecular markers on chromosome 2V， we designed two sets of primers， including： （1） 30 pairs of sequence-tagged site primers based on the expressed sequence tag sequences of different segments of the 2nd chromosome of common wheat， and （2） 296 pairs of intron targeting primers designed based on the homologous comparison between wheat 2D and rye 2R. Two and 33 specific molecular markers on chromosome 2V were validated and successfully developed， accounted for 6.7% and 11.1% of the total primers tested， respectively. This result suggests that marker development based on next generation sequencing technology is an efficient method. Most of the genes on the 2D chromosome of wheat were collinear to those of the 2V chromosome， while few exceptions were also observed， indicating a complex collinearity on the 2V chromosome of H. villosa to the 2D chromosome of common wheat. A total of 35 markers were finally qualified， including lfz8187_-1100 that was located at 2VS FL0.68-1.00， and lfz8387_-280， lfz8462_-760 and lfz8470_-200 that were located at 2VS FL0.00-0.26， as well as 31 markers that were located on the long arm of 2V chromosome. Collectively， these markers provided an effective tool for identifying structural variation of H. villosa 2V chromosome， as well as the beneficial genes introgressed into common wheat.

Abstract:Sweet potato stem nematode disease （SPSND）， caused by the Ditylenchus destructor Thorne， is a quarantine disease that seriously affects the yield and quality of sweet potato. Identifying resistance genes and breeding resistant varieties through molecular design is an effective way to control SPSND. In this study， the resistant sweet potato variety 'American Red' （male parent） was pollinated with the susceptible variety 'Xuzishu8' （female parent） to generate a segregating population of 274 F₁ progenies. The F₁ progenies were evaluated for their resistance to SPSND using an artificial inoculation method. The resistance to SPSND was observed showing continuously distribution a skewed peak. The relative incidence volume ratio of SPSND was significantly positively correlated with the expansion diameter and expansion length， but not correlated with the tuber diameter， tuber length， and length-width ratio. That indicated that the size and shape of the tuber were un-correlated with the resistance severity. The heritability of the relative incidence volume ratio of SPSND resistance was 75.7%， indicating that resistance was mainly controlled by genetic factors. Based on the previously-published genetic map， QTL mapping for resistance was performed， identifying 10 tightly linked QTLs， each of which might explain 6.6%-10.7% of the phenotypic variation. The candidate gene functional annotation revealed that pathways such as phenylpropanoid biosynthesis， plant hormone signal transduction， and plant-pathogen interactions were likely involved in disease resistance stress. Out of five key candidate genes that were analyzed for quantitative expression analysis， the expression level of the candidate gene itf13g19570 was significantly increased after inoculation with stem nematode. Collectively， this study provided a basis for future identification of SPSND resistance genes and the analysis of their resistance mechanisms.

Abstract:To obtain the sequence information of salt-tolerant genes in castor bean， we conducted a study to explore differentially expressed genes and related metabolic pathways under salt stress. We used seedling leaves of castor bean （cultivar Tongbi No. 5） treated with salt stress （300 mmol/L NaCl） for 0， 12， and 24 hours as experimental materials. Transcriptome sequencing analysis was performed using high-throughput sequencing technology. The results showed that there were 4822 and 3103 differentially expressed genes at 12 and 24 hours of salt stress， respectively. Co-expression pattern clustering analysis was conducted on the shared 1872 differentially expressed genes， and three expression patterns were identified. KEGG pathway analysis revealed significant enrichment of three pathways， namely valine， leucine， and isoleucine degradation （ko00280）， plant circadian rhythm regulation （ko04712）， and starch and sucrose metabolism （ko00500）， in the adaptation process to salt stress. GO functional enrichment analysis showed that most differentially expressed genes were enriched in biological processes， with the highest enrichment in cellular processes （GO：0009987） and response to non-biological stress （GO：0009628）. In addition， a total of 19 transcription factors were found to be involved in the salt stress response of castor bean. In the plant hormone signal transduction pathway， 42 differentially expressed genes were identified， with 97.6% of genes showing upregulated expression at 12 and 24 hours. Furthermore， we identified differentially expressed genes involved in photosynthesis， antioxidant regulation， and Na⁺， K⁺， and Ca²⁺ transport related to salt stress in castor bean seedlings. qRT-PCR results confirmed the reliability of the above experimental results. In conclusion， this study provides a theoretical basis for the exploration of salt-tolerant genes and the analysis of salt stress adaptation mechanisms in castor bean.

Abstract:Cannabis is an annual herb and a versatile， sustainable crop， while uncovering the population diversity remain poorly investigated. In this study， the EST-SSR molecular markers were used to analyze the genetic diversity and population structure of cannabis. The results showed that a total of 113 score bands were amplified using 20 pairs of primers， of which all （100%） were polymorphic. A total of 232 alleles were detected， with an average of 4.0176 alleles per primer pair. The average observed heterozygosity （Ho） was 0.7102， and the average expected heterozygosity （He） was 0.6935. The Shannon information index of 200 individuals ranged from 0.7204 - 2.4625， with an average value of 1.5368. Polymorphism information content （PIC） ranged from 0.3519 to 0.8801， with an average of 0.6558. The mean gene flow （Nm） was 13.6525.Based on population genetic structure， principal component analysis and unweighted group analysis （UPGMA） with arithmetic mean， cannabis materials were grouped into 3 groups.. The results were similar between the clustering methods， but the distribution of minority individual plants was different among the three models. The results of clustering， genetic diversity and genetic similarity coefficient showed that cannabis individuals were closely related to each other. In addition， five pairs of core primers， which were able to distinguish the test germplasm， were deployed for the fingerprint construction. Collectively， these results provided a reference for the future breeding， genetic improvement and collection of core germplasm resources of cannabis.

Abstract:Fusarium head blight （FHB） is a devastating disease of wheat， which seriously reduces grain yield and quality. It is an effective way to prevent the damage of FHB by introducing resistant genes into wheat varieties. In this study， the wheat line L06486 that carries the FHB resistance genes Fhb1， Fhb2， Fhb4 and Fhb5， was used as the donor and crossed with the variety Jimai 24， which was high-yield and widely adaptive across the Huanghuai area of wheat planting， but highly susceptible to FHB. Then the acquired plants were crossed with the dwarf wheat line 206A. A large spray facility was used to carry out the fog-way inoculation of spore-fluid through scab on the ears of wheat， across F₃ to F₆ multiple generations and populations. The resistance of the selected F₇ stable lines was validated by floret-inoculation and their resistant genes composition was identified with specific markers for Fhb1， Fhb2， Fhb4 and Fhb5. It showed that 106 F₇ lines had improved resistance to FHB in comparing with the recipient parent Jimai 24. Out of these 106 lines， 98 lines showed a range of moderate susceptible to high resistance， and 105 lines carried 1 to 4 FHB resistance genes each. The frequencies of Fhb1， Fhb2， Fhb4 and Fhb5 presence were 96.23%， 41.51%， 18.87% and 87.74%， respectively. Lines with single or multiple Fhb genes showed higher resistance to FHB than those with none of Fhb gene； the more Fhb genes it carried， the higher resistance to FHB. Altogether， these selected lines will be valuable in improving the FHB resistance in Huanghuai wheat planting region in the future.