2019, 20(2):239-248. DOI: 10.13430/j.cnki.jpgr.20180720002
Abstract:Pepper is one of the globally cultivated vegetable crops, the mature fruits of which contains different carotenoids, such as α-carotene, β-carotene, zeaxanthin, lutein, cryptoxanthin, capsanthin and capsanthin. Since the different regulation mechanisms of carotenoid biosynthesis are present, carotenoids with different components and contents are accumulated, thus resulting in the diversity of fruit colors. This article systematically summarizes the research progress of color and carotenoid components, the biosynthesis pathway of carotenoids, the function of key enzyme genes and related transcriptional regulatory mechanisms in pepper fruits. Moreover, we suggest the problems in current research and proposes corresponding research prospects. It is of great significance to breed high carotenoid pepper varieties, purposeful regulate the biosynthesis of carotenoids and improve the quality of capsicum fruit in the future.
2019, 20(2):249-257. DOI: 10.13430/j.cnki.jpgr.20181102001
Abstract:Strawberry is one of the most important berry crops worldwide, and is always ranking first in cultivation area and yield harvest among the small berries. Nowadays the strawberry planting has become one of profiling agricultural industries in China. The breeding of cultivated strawberries began in England in the early 19th century, while it began in the 1950s in China. According to the timeline, the breeding history and representative varieties of strawberry at home and abroad were described in this paper. So far a relatively complete reference genome has not been assembled, due to the high degree of homology between subgenomes in the octoploid strawberry genome. The diploid strawberry (Fragaria vesca) genome has high integrity and precision after revision. With the development of sequencing technology, a large number of molecular markers related to strawberry quality and resistance have been developed. These markers have also been used in strawberry breeding program and greatly improved the breeding efficiency. There are some problems in strawberry breeding in China, such as narrow parental genetic background and single breeding method. In view of these problems, the future direction and development trend of strawberry breeding in China were reviewed.
2019, 20(2):258-266. DOI: 10.13430/j.cnki.jpgr.20180712001
Abstract:Keeping consistent with the current cropping pattern of rice-rice-rape and the requirement of rapeseed mechanized cultivation, early maturity has become increasingly important in rapeseed theoretical and breeding research. Here we reviewed the current progress based on the aspects of academic research, variety breeding and application of early-maturing rapeseed varieties. First, we introduced the early maturity, the growth phenotype and the selection reference of early maturity. Second, the theoretical research of early maturity, including the genetic analysis and gene mapping were summarized. Third, the breeding necessity, breeding approaches, breeding process, and variety application and prospect were introduced. Finally, we suggested the bottlenecks and countermeasures of early maturity in rapeseed. This report will provide insight for the innovation of germplasm and breeding of early-maturity rapeseed.
2019, 20(2):267-275. DOI: 10.13430/j.cnki.jpgr.20180815003
Abstract:Soil salinization serves as one of the important abiotic stresses, which might result in reduction of rice production. Breeding for salinity tolerance of rice is an effective way to prevent yield loss, and a comprehensive and precise evaluation of salt-toleranceduring the whole growth stage therefore becomes of interest. In this study, 19 rice varieties with levels of saline tolerance were tested under different salt concentration conditions, and 11 agronomic-related traits were investigated. Furthermore, the optimum concentration of salt tolerance was determined by using interquartile range method between varieties. The saline with maximum showed that the salt tolerance coefficient of 11 agronomic traits can be reduced to 3 principal components. By using the principal interquartile range between varieties was supposed to be the optimum stress environment. Because under this saline, the rice varieties shown the maximum genetic variation which measure by interquartile range between varieties. A series of comprehensive multivariate statistical analysis method, included principal component analysis, membership function analysis, stepwise regression analysis and cluster analysis, was used to explore the rational evaluation method of salt tolerance of rice during the whole growth stage. The results showed that under 0.3% salinity, between varieties，the salt tolerance coefficient of most traits shown the highest interquartile range. The0.3% salinity was the optimum concentration for identification saline tolerance in rice. The results of principal component analysis component contribution rate and membership function analysis, the three principal component values can be further simplified into the comprehensive evaluation index of rice saline tolerance: D value. D value can be used to evaluate the salt tolerance of rice germplasm simply and accurately. It can realize the comprehensive evaluation of salt tolerance of rice germplasm. In this study, we also used stepwise regression analysis to establish the optimal linear regression equation for the salt tolerance coefficient of 11 agronomic traits and D value: D=-0.365+0.647PL+0.152PN+0.274TW. Through stepwise regression analysis, the saline tolerance coefficient of spike length, spike grain number and total weight was the key indicator of D value. The saline tolerance of 19 rice germplasm can be divided into 5 grades by cluster analysis, corresponding to 5 salt tolerance grades of rice. It can be regarded as an important reference for salt tolerance evaluation of other rice germplasm. This study provides a comprehensive, objective and accurate method for the identification and evaluation of saline tolerance in rice during the whole growth stage, which can be used as an important basis for the identification and evaluation of saline tolerance in rice during the whole growth stage.
2019, 20(2):276-283. DOI: 10.13430/j.cnki.jpgr.20180814001
Abstract:Forty-four maize inbred lines, which were from different heterotic groups with known levels of ear rot resistance, were tested for resistance to ear rot by artificial inoculation using Fusarium verticilloides or Fusarium graminearum in 2016 and 2017. As observed, the inbreds lines from Tangsipingtou group showed overall susceptible, while the inbred lines from Lvdahonggu group showed overall resistant to ear rot. Within the Raid group, different inbred lines represented the variation of resistance. The inbred lines Ji V203, Cheng 351 and Dan 598 showed simultaneously highly resistant against infections of Fusarium verticilloides and Fusarium graminearum, while PHTD5 and Ye 81162 were highly susceptible. We also observed the differences on levels of resistance of 44 inbred lines in two calendar years, suggesting that the incidence of corn ear rot was greatly affected by environmental factors. That also provided an explanation on the complexity of resistance to ear rot. Notably, the resistant phenotype in highly-resistant and highly-susceptible inbred lines were reproducible over years, while inbred lines with moderate resistance were largely influenced , likely associated to the environmental factors. Taken together, these results provided insight in genetic improvement of resistance to ear rot in maize.
2019, 20(2):284-296. DOI: 10.13430/j.cnki.jpgr.20180719001
Abstract:Winter freezing seriously threatens the yield stability of common wheat in the north area of China. Test for freezing resistance under the field condition largely depended on the environmental climate. By taking use of artificial freezing, we investigated the relative conductivity and freezing survival rate of the plants under different freezing treatments in 209 wheat varieties, with a purpose of obtaining excellent variety resources for cold resistance breeding of wheat. Furthermore, we analyzed the correlation of relative conductivity, freezing survival rate and lethal temperature with field frost damage grade. The results showed a significant negative correlation between the freezing survival rate and freezing injury level after treatment for 3h at -14°C (correlation coefficient = -0.427). By cold treatment under different temperatures, we found the optimal temperature condition that could be used to identify the cold resistance at seedling stage. As a result, several cold resistance varieties such as Henong 05 (9) 7-11-4-15, Jimai 585, Le 639, Shimai 15, Bao 5108, Shixin 828, Zhongmai 1 and Henong 7069 were obtained.
2019, 20(2):297-308. DOI: 10.13430/j.cnki.jpgr.20180717001
Abstract:Poplar is an important timber and shelterbelt tree species. The soil drought severely limits its growth, development and quality. Deciphering the theory and production for drought resistance is of interest on the poplar varieties cultivation, arid land use, and ecological environment construction to evaluate poplar full sib family drought resistance and select drought index. In this study, 123 progenies derived from a cross of Populus deltoides. ‘Danhong’ × P. simonii. ‘Tongliao1’ were subjected for moderate pot water control experiment via determining 12 growth parameters such as photosynthesis, leaf and water indexes. In addition, we established field experimental forest and measured one year growth increment. The results showed that all tested traits represented significant changes under the drought conditions in relative to the control. The drought stress severely modified stomatal conductance (Ga) than other traits (P<0.01). Correlation analysis indicated that responsive traits exhibited different degrees of correlation. Drought resistances of the progenies at seedling stage were evaluated with principle component analysis and subordinate function. The hybrid population were classified into three types as drought sensitive type、moderate drought resistance type and high drought resistance type with each contained 30、72、and 21 individuals. DX-27、DX-4、DX-3 and other seven lines adopt to drought better than male parent P. simonii. ‘Tongliao1’. Line DX-55 and DX-81 got the maximum drought resistance D value (all 0.60), and showed the strongest drought resistance. Stepwise linear regression and correlation analysis indicated diameter (D), net photosynthesis (Pn), stomatal conductance (Ga) and transpiration rate (Tr) could be used as drought resistance index of which Ga has the most large direct effect on drought resistance. The comprehensive evaluation was used to analyze field growth characters, and classified progenies into 4 types. Populus deltoides. ‘Danhong’ and P. simonii. ‘Tongliao1’ belong to the first and fourth class, respectively. Six lines（DX-76、DX-78、DX-53、DX-55、DX-3、DX-20）possess better drought resistance ability than male parent P. simonii. ‘Tongliao1’ belong to the first and second class, and regarded as drought resistance and fast growth material, preliminarily. Thus, this research provided theoretical basis in breeding for drought resistance in poplar and tests for drought resistance at the seedling stage.
2019, 20(2):309-320. DOI: 10.13430/j.cnki.jpgr.20180726001
Abstract:The objective of this study aimed to evaluate salt tolerance of vegetable jute, via under different salt stress conditions on and comprehensively evaluate the salt tolerance. In this study, 13 vegetable jute germplasms and 2 jute which used as control were treatmented with NaCl and Na2SO4 at different concentrations of 0, 50, 100, 150, 200 mmol/L, respectively. Then germination potential, germination rate, sprout length and radical length were measured after salt treatment. The 13 vegetable jute germplasms were evaluated and classified using subordination function method and hierarchical cluster analysis. The result showed the different kinds and concentrations salt stress have different effects on germination potential, germination rate, sprout length and radical length of vegetable jute w.With the increase of salt concentration, all indexes were significantly lower than the control 200 mmol/L.According to the degree of inhibit of NaCl stress, the indexes of jute germination were from large to small radical length , germination potential, sprout length, germination rate.According to the degree of inhibit of Na2SO4 stress, the indexes of jute germination were from large to small radical length, sprout length, germination potential, germination rate. Na2SO4 stress on the germination of vegetable jute was higher than NaCl. Based on the results, 13 vegetable jute germplasms and 2 control lines could be classified into groups, including high salt tolerance, moderate salt tolerance, salt sensitivity. Finally, 14MCB-1,yueyin No.2, Egyptmacai, funong NO.1 were highly NaCl tolerant, guimacai2 was highly Na2SO4 tolerant, the ping guo ma cai showed salt sensitive to both salt.
2019, 20(2):321-334. DOI: 10.13430/j.cnki.jpgr.20180731001
Abstract:In this study, ninety-six rice core germplasm resources and these 47 hybrid progeny in Ningxia province were tested for rice blast resistance in the fields, by using artificial inoculation and natural infection with physiological races of rice blast pathogen. Moreover, eight functional markers, which associated to the respective rice blast resistance genes, were used for marker-assisted detection of the resistance genes in mentioned materials as well as additional 28 different Genotypes. As observed, the resistance of genotypes containing Pita, Pib, Pikm, Pikh, P9 and Pi5 represented significantly high level of resistance than that of other genotypes. The Pita gene, pyramiding with either of Pikm, Pikh, Pi2 and Pi5 genes, showed increased resistance to rice blast, and notably, stacking of Pita and Pikh genes showed highest resistance. However, Pib and Pita+Pikh in a genotype showed reduced rice blast resistance. Thus, this work provides an important reference in breeding for new rice varieties with broad-spectrum resistance, by pyramiding of rice blast resistance genes in Ningxia region.
2019, 20(2):335-346. DOI: 10.13430/j.cnki.jpgr.20180624001
Abstract:High temperature, which can reduce crop seed vigor, slow down or completely inhibit germination, is one of the important abiotic stresses that restrict cucumber production. A set of core germplasm including 96 cucumber accessions were used to identify thermotolerance at high temperature 42℃ during the seed germination stage. The thermotolerance was evaluated using a comprehensive index, which include the relative germination percentage, relative germination vigor, relative germination index and relative radicle length. The re-sequencing data of the core germplasm were used to perform the Genome-wide association study (GWAS). We identified two accessions, CG109 and CG110, which have a pretty strong thermotolerance, with the comprehensive index of over 0.9. We detected 5 loci for relative germination percentage: GGP4.1, GGP4.2, GGP5.1, GGP5.2 and GGP6.1; 2 for relative germination vigor: GGV4.1 and GGV5.1; 2 for relative germination index: GGI4.1 and GGI5.1; 2 for relative radicle length: GRL6.1 and GRL7.1. Among them, GGI4.1, GGV4.1 and GGP4.1 are located to the same physical region of Chr.4, and GGI5.1, GGV5.1 and GGP5.2 are located to the same region of Chr.5. The loci located in these two regions can be detected simultaneously by relative germination percentage, relative germination vigor and relative germination index three different indicators, which suggested that the two regions could include genes related to thermotolerance.
2019, 20(2):347-358. DOI: 10.13430/j.cnki.jpgr.20180630002
Abstract:Due to the diversity on anthocyanin content, the sweetpotato germplasm served as natural raw material and offered obvious advantages in high-quality special varieties breeding. In this study, we analyzed the anthocyanin accumulation of 66 sweetpotato accessions and the nucleotide polymorphisms of anthocyanin synthesis genes using molecular markers such as TRAP. The anthocyanins accumulation in storage roots and leaves was independent and not directly related to those in other tissues. The skin color of storage root and the fibrous root is identical, closely associated to the color of fibrous root primordium. Moreover, the analysis by TRAP molecular markers revealed IbCHS, IbDFR and other genes associated with anthocyanin accumulation, which existed multiple copies in the genome, showed higher polymorphism within this collection. The transcriptional factor IbMYB1-2a/b showed a relevance to the accumulation of anthocyanin in storage roots, but not in other tissues. Notably, IbMYB1-2a/b gene was not existed in all purple-fleshed sweetpotatoes. Thirdly, the CHSRV1/ AN4 primer combination was an ideal TRAP marker, which could clarify these 66 germplasm accessions. In relative to these morphological markers, the molecular markers showed advantage in reflection of the genetic relationship between sweetpotato germplasm resources. Thus, this study provided insights on anthocyanin accumulation and also genetic resources that might be valuable in breeding for vegetables and purple-fleshed sweetpotato varieties.
2019, 20(2):359-369. DOI: 10.13430/j.cnki.jpgr.20180812001
Abstract:Litsea populifolia (Hemsl.) Gamble, a deciduous arbor of Lauraceae, has potential and extensive application in Traditional Chinese Medicine (TCM), cosmetics and edible essence. However, this species distributes in a narrow geographical region (restricted in Sichuan province, China), which seriously prohibits the exploitation and utilization of L. populifolia. Understanding the genetic diversity of populations among L. populifolia is urgently necessary and helpful for the future breeding and diversity conservation. In this study, the genetic diversity of 84 leaf samples, which were collected from 7 different regions in Mount emei area, was analyzed by genotyping-by-sequencing (GBS) technique. After the construction of GBS library using standard pipeline, we identified 48,795 SNP sites globally, 47.69% and 30.71% of which were located in intronic regions and intergenic regions, respectively. According to the phylogenetic tree, principal components and population structure analysis, seven subgroups of samples were clustered into three clusters. The average of Ho and He was 0.27218and 0.20635, respectively. As a result of ANOVA, the percentage of intra-group variation reached 96.28%, while inter-group variation was only 3.72%. These results indicated that regional divergence issued the main factor of genetic diversity among L. populifolia in Emei Mountain, and the different altitudes in high altitude area also affected the genetic diversity of intra-population. The high nucleotide diversity in the populations and the high percentage of intra-group variation illustrated that genetic variation of L. populifolia in Emei Mountain mainly exists in intra-population. The characteristics of dioecism and cross-pollination in L. populifolia caused higher gene flow. However, due to the fragmentation of its habitat and the complex vertical climate, there was a low gene flow between the groups, causing obvious population differentiation and the variation mainly within the populations. Our data provided a fundamental basis for the genetic breeding and diversity conservation of Litsea populifolia. In terms of family line selection, a large number of samples should be included in the population, and the preservation of germplasm resources should be at a lower altitude as far as possible.
2019, 20(2):370-376. DOI: 10.13430/j.cnki.jpgr.20180810001
Abstract:Broomcorn millet (Panicum miliaceum L.) is one of the minor crops in China, which represented resistant and tolerant against drought, lower-fertilizer and abiotic stresses as well as short life-cycle. Within this study, by generating an EMS-triggered mutant population by using broomcorn millet variety Yi-Xuan-Da-Hong-Mi, we analyzed the mutation frequency and phenotypic variation of 2333 M2 plants. Out of that, a total of 103 plants with visible phenotype differing with the parental line were identified, yielding 4.4% of mutation rate. These mutants showed modifications on any of leaf color, leaf shape, plant height, mature period, fertility, spike shape, seed-coat color and so on. Thus, these mutants would become a genetic resource being useful in deciphering the gene function and breeding for new varieties in Broomcorn millet.
2019, 20(2):377-386. DOI: 10.13430/j.cnki.jpgr.20180605001
Abstract:To explore candidate genes of tobacco important traits and provide insights of space mutagenesis, we conducted the whole genome re-sequencing (30x coverage) in tobacco mutant NC89-M that was generated by space mutagenesis, and wild-type NC89. In comparison to the reference genome, 1880413 single nucleotide polymorphisms (SNPs), 398922 Indels and 4969 structure variations (SVs) were observed in NC89, while 1876219 SNPs, 120 Indels and 42 SVs were detected in NC89-M. A total of 271655 SNPs and 23450 Indels differed between NC89-M and NC89, which resulted in sequence modifications on 8378 and 2156 genes, respectively. SNPs were often observed in mutant, suggesting that single nucleotide mutation is predominant using spare mutagenesis. The ratio of conversion type to transversion type is 2.053. It is proved that the single-base mutations are the main mutation type in the tobacco genome induced by space and conversion type is the main mutation type among the single base mutation. The number of insertion was significantly more than that of the deletion. It is proved that the insertion is the main mutation type in Indel caused by space mutagenesis. Among the SV, space mutagenesis mainly results in five types of structural variation including insertion, deletion, inversion, intra-chromosomal translocation and inter-chromosomal translocation. KEGG annotation of mutant genes indicated that the number of mutant genes in the metabolic pathway and biosynthesis of secondary metabolites are the highest. Gene function annotation indicated that several functional genes were modified in mutant, including MADS-box genes that control flowering time, KNOX1 gene that regulates development of lateral organ and leaf edge shape and also the genes that associate to the synthesis of terpenoids.
2019, 20(2):387-395. DOI: 10.13430/j.cnki.jpgr.20180802001
Abstract:This study attempted to identify SSR markers that can be used to validate the authenticity of F1 hybrids between buckwheat species and for the future research on hybrid breeding of buckwheat. By employment of 235 pairs of SSR primers, we performed PCR amplification using five parental lines of buckwheat to identify these polymorphic markers. We applied these polymorphic markers and morphological analysis to validate if the interspecific plants were hybrids. As a result, 2 pairs of polymorphic primers (SSR2159/58 and SSR6790/89) were identified, and three true hybrids were identified, including F.tataricum var. Daku No.1 × F. cymosum, F. tataricum × F. cymosum, F. giganteum × F. cymosum. Thus, SSR markers can be used for identifying interspecific hybrids of buckwheat.
2019, 20(2):396-405. DOI: 10.13430/j.cnki.jpgr.20180808001
Abstract:To evaluate the application of SSR markers in pepper DUS testing, here we employed thirty pairs of SSR primers in fingerprinting analysis of 130 varieties. A total of 163 alleles were detected in 130 accessions, which ranged from 2 to 15 with a mean value of 5.4. The polymorphism information content (PIC) ranged from 0.17 to 0.76, with the average of 0.43. These genotypes can be clarified using the polymorphic information. These pepper cultivars with close genetic background were clustered. The genetic distance of the 130 cultivars ranged from 0.01 to 0.91.There were 20 pairs of cultivars whose genetic distance was less than 0.10, among which 3 pairs had one locus difference. It was more suitable to judge the distinctness of pepper varieties by using the number of difference locus. Ten pairs of primers were used to detect the uniformity of the variety 0313963-4 and the comprehensive uniformity ratio R value was 96.5, which was lower than the requirement of phenotypic trait in DUS test. Therefore, SSR markers directly used in pepper DUS determination still need further study, but it can be used in the selection of Similar varieties.
2019, 20(2):406-411. DOI: 10.13430/j.cnki.jpgr.20180720001
Abstract:The dehydration rate plays a central role in determining moisture content of grain at harvest. In this study, we investigated the grain dehydrate rate (GDR) from 35-55 d after pollination and other correlative traits in 428 maize inbred lines at three locations (Yuanyang, Yucheng, Handan) of Henan province. The results presents GDR shows abundant genetic diversity in three locations, which correlates with the moisture content of cob, bract and significantly relates with grain at 35-55 d after pollination,un-relates with plant height, ear height, tasseling branch, tasseling stage, silking stage. However, the correlation between GDR and physiological mature period and bract number is not clear. In 428 maize inbred lines, GDR at 35-55 d after pollination only significantly correlates with that at 35-40 d after pollination (before physiological maturing period), but, no correlates to GDR at 50-55 d after pollination. This indicates that GDR before physiology maturing period influenced remarkably GDR 35-55 d after pollination as comparison with in other stage. By growth period, grain dehydration rate (>1%) and grain moisture content (<25%) at 55 d after pollination, 42 elite inbred lines with different growth period, low grain moisture content and high grain dehydration rate were identified.
2019, 20(2):412-425. DOI: 10.13430/j.cnki.jpgr.20180801002
Abstract:Guizhou has the largest tea planting area in China, which also has the abundant tea plant germplasm resources. Accurate identification of the authenticity and genetic structure of the cultivars is the pivotal to germplasms identification and parents selection in hybridized breeding. In this study, 54 tea plant germplasms including the cultivars or improved cultivars in Guizhou province were used as materials, the genetic identification of them was conducted using 35 SSR markers, firstly. A total of 317 alleles were detected, yielding the polymorphic information content (PIC) ranged from 0.22 to 0.92, with a mean value of 0.73. The genetic differentiation of each SSR marker was evaluated by PI and PIsibs, which showed that any two pairs of primers could distinguish the tea plant germplasms in this study. Five core SSR markers were selected to generate the fingerprinting of these tea plant resources, which provided the resolution sufficient for identification of the individuals in larger groups. Additionally, by using the genotyping-by-sequencing (GBS) approach, the genome-wide SNPs were identified with the 54 cultivars or improved cultivars, and a total of 698117 high quality SNPs were identified. The phylogenetic analysis, principle component analysis (PCA) and genetic structure analysis of the 54 tea plant samples were performed. The 54 tea plant germplasms were divided into 4 sub-populations, and the genetic backgrounds of the cultivars and the improved cultivars were highly overlapped. According to the results, the general breeding model of tea plants in Guizhou in the previous was speculated, which revealed that the germplasms utilization of early tea plants breeding in Guizhou depended too much on Fudingdabaicha and the local tea plant germplasm resources of Yunnan province, and it was also shown that increasing the hybrid utilization of the excellent tea plant cultivars in other provinces and the ancient tea plant resources in Guizhou would contribute to the germplasm innovation and the breeding of new tea plants in the subsequent breeding practice.
2019, 20(2):426-435. DOI: 10.13430/j.cnki.jpgr.20180814002
Abstract:Lobed-leaf is widely known as an ideal morphological marker in rapeseed breeding. Genetic variation of lobed-leaf plays an important role in enriching the leaf shape diversity and improving genetic breeding of rapeseed. In this study, fifty plants with normal leaf and 50 plants with lobed-leaf were selected from the F2 population respectively, which was derived from a cross of the normal leaf line Zhongshuang No.11 and the leaf-lobed new line Y176. Two bulked DNA pools were generated, which were subjected for SLAF-seq-BSA (specific-locus amplified fragment sequencing and bulked segregant analysis). A total of 177,941 labels were obtained and 150,168 SNPs were identified, including 128,200 SNPs that were polymorphic between both parents. A physical interval expanding ~2.83 Mb on chrA10 (14,528,149~17,353,693 bp) was tightly associated with lobed-leaf trait. Within that, 666 candidate genes was found. Since the genetic confidence interval of this locus differed to the physical positions of previously reported genes, there might be a new gene controlling leaf margin cleavage. Furthermore, 666, 517, 587, 151 and 258 genes in this region were annotated by NR, Swiss-Prot, GO, KEGG and COG databases, respectively. Thus, this information might be helpful in future map-based gene isolation of lobed-leaf in Brassica napus L.
2019, 20(2):436-443. DOI: 10.13430/j.cnki.jpgr.20180807001
Abstract:Seed hairs in carrot negatively affect the germination of carrot seeds, and they were necessary to be removed by mechanical or manual approaches before sowing. The development of seed hairs has been shown to be relevant to the regulation mechanism of transcription factor DcTTG1. In this study, we analyzed the genomic and transcriptional variation of DcTTG1 in a seed-hairless carrot genotype (named: ‘Wuye-hairless’), which was identified from the wild carrot germplasm ‘Wuye’ in Hongshan district of Wuhan city. In both genotypes ‘Wuye’ and ‘Wuye-hairless’, DcTTG1 contained an open reading frame with a length of 1011 bp, encoding for 336 amino acid residues. Three amino acid substitutions caused by three nucleotide mutations were observed between two genotypes. By bioinformatic analysis, the deduced DcTTG1 protein sequence contained four WD-40 motifs in both genotypes.The cluster analysis showed that the DcTTG1 of carrot and other TTG1 of Apiaceae plant were clustered in same branch. The transcriptional level of DcTTG1 in ‘Wuye’ was significantly higher than ‘Wuye-hairless’ in the stem, leaf and 5 d after pollination of flowers, while no significant difference was observed at the stages of un-pollinated flowers and seeds formation (20 d after pollination).
2019, 20(2):444-450. DOI: 10.13430/j.cnki.jpgr.20180711001
Abstract:Vacuolar H+‐pyrophosphatase plays an important role in plant growth and stress response. By taking use of in-silico cloning and RT-PCR, here we isolated a vacuolar H+‐PPase cDNA (named LbVP1) from Lycium barbarum and analyzed the spatiotemporal expression pattern and its sequence structure. The open reading frame of LbVP1 expanded 2301 bp which encodes for 766 amino acid residues. Sequence alignment suggested a 87.9% identity of the putative LbVP1 protein in relation to Arabidopsis thaliana VP1. This deduced protein contained conserved domains and amino acid residues with the H+‐PPase proteins from other plants. By transient expression in Arabidopsis thaliana protoplast, LbVP1 was found mainly in the vacuolar membrane. The quantitative real-time PCR reflected variations on expression of LbVP1 varied in flower, leaves and fruit of different development stages. Under drought stress, its transcriptional level of this gene in leaves and fruits was significantly different in relative to the controls. Thus, these results will provide insights for elucidating the molecular mechanism of LbVP1 in response to the drought stress.
2019, 20(2):451-458. DOI: 10.13430/j.cnki.jpgr.20180508002
Abstract:Water stress proteins play an important role in the process of drought tolerance in many plants. Nostoc flagelliforme showed strong tolerance to drought, salt and radiation stresses. In this study, using the genomic DNA of Nostoc flagelliforme as a template, the open reading frame (ORF) of a water stress protein gene was cloned by PCR amplification, and this gene was named NfwspA3 according to the online annotation via blastP in NCBI (https://www.ncbi.nlm.nih.gov/). Bioinformatic analysis showed that NfwspA3 gene contained 1017 base pair that encodes a putative protein consisted of 338 amino acid residues. The predicted isoelectric point was 4.31 and the theoretical molecular weight was 34.67 kDa. The encoded protein was predicted being a hydrophilic stable protein, and distributed in the cytoplasm. By analyzing the recombinant expression vector of pET32a-NfwspA3 under the condition of PEG-6000 simulating drought stress, it showed strong drought tolerance. Meanwhile, the recombinant expression strain showed higher activity of galactosidase. Thus, this work will provide a theoretical basis for detecting the molecular mechanism of water stress protein and a gene element that might be used for genetically modified breeding in Nostoc flagelliforme.
2019, 20(2):459-465. DOI: 10.13430/j.cnki.jpgr.20180709003
Abstract:Germplasm resource management is a basic work. It is heavy , complex and the workflow is long. It also contains large amount of relevant information to be dealed with. With more and more state's attention to germplasm resources ,and the development of the third national census and collection of crop germplasm resources, collection and preservation of germplasm resources in the future will further increase. At the same time, with the further improvement of breeding level and breeding technology in China, the demand for germplasm resources is increasing. As a result, the quantity of germplasm resources in and out of the germplasm resource bank increased exponentially. So we need modern management system to manage germplasm resources. It will make the management of crop germplsm resources be efficient and standardized. Shanghai crop germplasm resources management information system was established by Shanghai Agribiological Gene Center .It based on more than 10 years of operating experience. In this paper, the construction principle, overall design framework and main function modules of the management information system are introduced in detail. And emphatically introduces the aspects of storehouse management, seed information management, seed import and export management, seed early warning, summary statistics, user management, feedback management and so on. It could provide the reference for other germplasm resource bank to establish the similar management system.
2019, 20(2):466-475. DOI: 10.13430/j.cnki.jpgr.20180816002
Abstract:TALE (three-amino acid-loop-extension) are essential transcription factors that regulate the differentiation of meristem in the plant growth and development. In this study, a total of 40 TALE family genes on six chromosomes were identified by bioinformatical analysis of the whole genome of the Leguminosae model plant Lotus japonicus. Their conserved domain, gene structure, family evolution, chromosome distribution, physicochemical properties and expression differences were examined. As a result of the domain differences revealed that two major groups were divided into BELL and KNOX. Phylogenetic analysis found that the Lotus japonicus TALE family gene sequences was conservative in evolution, while Soybean TALE gene was distinctly different with Lotus japonicus in differentiation. The results of physicochemical properties showed their mainly possessed 4-6 exons encoding weak acid proteins of 290-792. The Real-time PCR result showed that TALE genes are diverse and exhibited different expression patterns in different tissues of Lotus japonicus, related to the number of motif elements. BELL subfamily is highly expressed in the terminal bud, while KNOX subfamily is Prominent in the root. This study lays a foundation for further study on the complicated biological functions of Lotus japonicus TALE．
2019, 20(2):476-483. DOI: 10.13430/j.cnki.jpgr.20180731002
Abstract:Caffeoyl-CoA O-methyltransferase (CCoAOMT) is one of the key enzymes in lignin biosynthesis. By reversible transcription PCR (RT-PCR) technique, a CCoAOMT gene (DsCCoAOMT) was cloned from the bamboo shoot of Dendrocalamus sinicus. The full-length cDNA of DsCCoAOMT was 777 base pairs that encoded a protein of 238 amino acids with predicted molecular mass of 28.85kDa and a basic isoelectric point of 5.35. The deduced protein was rich in helix and coin. The phylogenetic analysis revealed the highest sequence homology of DsCCoAOMT in relative to CCoAOMT from the poaceous plants, followed by the monocotyledon of non-graminaceae and gymnosperms and then some dicotyledons. That suggested a differentiation of CCoAOMT between monocotyledons and dicotyledons before angiosperms evolution. According to the analysis of codon bias, the DsCCoAOMT had high bias toward the synonymous codons with G and C at third codon position. The results of codon usage frequency showed that heterologous expression of DsCCoAOMT might be applicable in the microorganism yeast expression system and in plants Nicotiana tabacum and Solanum lycopersicum. By real-time quantitative PCR, the DsCCoAOMT gene was highly expressed in the shoots, followed by the culms and the leaves at last. As the shoots developed, DsCCoAOMT is up-regulated at the higher level, suggesting that the gene might play an important regulation role in fast-growing D. sinicus. Thus, this study might be helpful for further understanding the function and molecular mechanism of the DsCCoAOMT gene.