Abstract:To study the distribution of radiation sensitivity and expression patterns of TaKu70 and TaKu80 genes that are core factors in DNA repair process, 259 wheat mini core collection genotypes were irradiated by γ-rays with 0, 100, 150 and 250 Gy doses. Through germination test, the damage rate of seedling height showed 3 types of function relationships with the doses of γ-rays irradiation: logarithmic, linear and power function. Using HD50 as the measurement of radiation sensitivity, the 259 mini core collection genotypes could be divided into four categories: sensitive (contained 10 genotypes), medium sensitive (contained 96 genotypes), medium insensitive (contained 101 genotypes), and insensitive (contained 52 genotypes). There were more sensitive and medium sensitive genotypes in the logarithmic function relationship. And the expression levels of TaKu70 and TaKu80 genes were up-regulated by increasing of γ-rays doses compared with 0 Gy, but not affected significantly. There were more medium sensitive and medium insensitive genotypes in the linear function relationship. And the expression levels of TaKu70 and TaKu80 genes were gradually up-regulated by increasing of γ-rays doses compared with 0 Gy. There were more medium insensitive and insensitive genotypes in the power function relationship. And the expression levels of TaKu70 and TaKu80 were up-regulated compared with 0 Gy, but up-regulated firstly and then down-regulated with the increasing of γ-rays doses, and the general expression peaked at 150 Gy.
Abstract:It is very important to studying the genetic diversity of sea island cotton based on genetic and phenotypic characteristics, which can provide a theoretical basis for sea island cotton hybrid breeding in selecting parents, introduce new germplasm resources for broadening the range of genetics and breed new varieties. This study analyzed the genetic diversity of Sea Island cotton in 94 germplasm based on the identification of 125 SSR molecular markers and investigation of 13 phenotypic traits in the field in two years, and classified into different groups and comparied them according to their differences in genetic traits and phenotypic traits. The results were as following: (1) there were 420 loci being detected using molecular markers, of which 249 loci were polymorphism, and Nei-Li similarity coefficient method were applied to estimate the genetic similarity coefficient between 94 sea island cotton varieties. It was showed that the genetic similarity coefficient was between 0.46~ 0.95. Meanwhile these 94 sea island cotton varieties were divided into four groups using SSR molecular markers and the classification results were in agreement with the results of pedigree analysis. (2) The results of phenotypictraits showed that the range of the quality traits were wide while the range of yield traits were narrow. According to the diversity cluster analysis, the diversity index of micronaire value was the highest among these traits, on the contrary, the diversity index of single boll weight was the lowest. It was also found that type Ⅰ had wider range in yield and the quality in the middle of these types; type II was with low value both in yield and quality; type III had higher mean value in yield than others; and type IV was not good at yield trait, but it’s fiber trait was better than others. (3) Combination of SSR markers and agronomic traits analysis showed that the genetic diversity of 94 sea island cotton germplams was rich. These two methods had the same results in classification and the results of clasification had been related with geographic distribution.
Abstract:The cultivars of herbaceous peony are variable, and the study of morphological characters has a great significant in scientific classification. At the same time, it also can provide scientific guidance on how to choose hybrid breeding parent.According to the DUS guidelines (2012) for the conduct of tests of herbaceous peony,33 major morphological characters (9 qualitative binary characters,3 quantitative characters and 21 qualitative polymorphic characters) such as height, branching ability and stem color had measured from 47 cultivars peonies. Besides, the author also made analysis of those databases with the methods of Q type cluster, R type cluster and principal component. The result showed the systemic cluster of 33 morphological characters can distinguish different herbaceous peony of different groups well. At the same time, Chinese cultivars of herbaceous peony have a distance with foreign cultivars in phylogenetic relationship. The cluster result of hybrid group is sporadic, there are two resons:1)cultivars that belong to hybrid group have a complex origin;2)multiple parents were participated in the breeding progress. The results were consistent with those in previous studies with the methods of traditional classification system and the methods of molecular markers, it can reflect the phylogenetic relationship between cultivars and cultivars group accurately.
Abstract:Genetic diversity and genetic structure of wild banana resources from watershed in Fujian province were examined by ISSR. The results showed that: 117 bands were amplified with 12 ISSR primers, polymorphic bands of which were 105, and their polymorphism percentage was 89.7%. The Nei’s genetic distance was 0.244, the Shannon’s information index was 0.381, the genetic diversity in different natural populations has significant difference and the Sanming wild banana was higher. The coefficient of gene differentiation was 0.589, gene flow was 0.349, the genetic differentiation among the populations was higher than that within the population. The clustering result based on Nei’s genetic distance was the same as model-cluster-method, the banana resources were clustered into 3 groups, including Sanming wild banana group in Shaxi tributary, Nanping wild banana group in Minjiang upstream and nearby tributary, and Fuzhou wild banana group in Minjiang downstream group. The results indicated that the rich genetic diversity comes from the high frequency of heritable variation among national populations that resulted from heterogeneous habitats in Minjiang watershed. The genetic diversity and genetic divergence of Sanming wild banana group was the highest, and it may be the original center of Fujian wild banana resources, which was also the most important community to utilize and protect. In addition, water was a key factor of genetic transfer in Minjiang watershed.
Abstract:In this paper, a total of 24 SSR markers distributed on 12 chromosomes were used to construct Ningxia rice microsatellite markers database with 47 varieties which identified carefully. 144 alleles were revealed，and 3 to 11 alleles were identified among different loci．The mean number of alleles per locus was 5.14. The average Nie genetic diversity index was 0.6187. The 28 loci were differences between the tested material. There is only one locus has difference between Ningjing 28 and Ningjing 23, Ningjing 23 and Ningjing 35. Two or more loci have differences between remaining varieties, accounting for 93.6% of the tested material. 10 pairs of core primers were selected from 28 pairs of primers which at least one pair of primers has difference between varieties, and varieties can be distinguished one by one. Using 10 core markers, in the same position on the migration to 1 and 0 mark represent yes and no, Ningxia rice DNA fingerprinting database was established.
Abstract:In this paper, drought tolerance at the germination stage of 15 peanut varieties (lines) was identified by PEG6000 treatment. The index took into account 8 indicators including relative germination energy, germination rate, germination index, radicle length, hypocotyl length, buds length and seedling fresh/dry weight. The results indicated that seed germination was promoted by low level of PEG6000 at early stage of stress treatment, but restrained with the extension of processing time and higher concentration. Except for the relative buds length, all other indicators were significantly positively correlated with the comprehensive drought tolerance of each variety. Based on subordination function method and the standard classification of tolerant ability in peanut, we screened 4 drought tolerant varieties (JS2, 6, 14, 15) and 3 mediate tolerant varieties (JS3, 11, 13), indicating the method as a quick and convenient technique in identification of drought tolerance of peanut germination.
Abstract:This experiment analyzed the genetic diversity of wild walnut in xinjiang by using SRAP molecular markers.Through the screening of 15 polymorphic SRAP primer combinations for PCR amplification,get the xinjiang wild walnut genetic differentiation corfficient(Gst) is 0.1152, this suggested that the most part to show that the genetic variation of wild walnut exist within the region and accounts for 88.48% of total variance; percentage of polymorphic loci was 94.07%, shannon’s information index I=0.4954,average allele Na=1.9454,showed that xinjiang wild walnut with high genetic diversity; genetic similarity coefficient among various regions between 0.8981 to 0.9496,genetic distance between 0.0553 to 0.1075,which show that there are abundant rich genetic variation between wild walnut resources. Cluster analysis results can be grouped into two categories,these fuether clarify the genetic relationship between the various.
Abstract:Abstract: Quality characters of 64 yam germplasm resources were analyzed. Results indicated that the variation coefficient of iron, amino acid , total saponins and zinc content respectively were 66.2%, 59.9%, 44.09% and 42.77%. Starch content had big difference, D.persimilis (23.52%) > D.alata (20.48%) > D.opposita (12.93%). Factor analysis results showed that the cumulative variance contribution rate of starch and amino acid content was 66.786%, which can be better to evaluate and judge the yam quality .Correlation analysis showed that it was positive correlation between the starch content and total saponins content, it was significantly positive correlation between protein content and total saponin content, which meant that starch and protein content were mutual promoting. Cluster analysis showed that the yam resources can be divided into three categories, which was respectively high starch, low starch and high iron. Analysis on quality characters of yam germplasm resources , can provide reliable basis for yam germplasm innov ation and breeding in the future.
Abstract:Abstract： In order to enhance the collection，conservation and utilization of yellow sun-cured tobacco resource, 32 yellow sun-cured tobacco resource were analyzed by 106 pairs of microsatellite(SSR) markers screened. On the base of the different origin, these tobacco resource were clustered into three populations (Z was from tobacco mid-genebank. G was from Hezhou of Guangxi province, M was from Baise of Guangxi province).The results were as follows:1) Totally 110 loci were produced with 85 polymorphic loci (77.27%) using106 pairs of SSR selected from 740 primer combinations. The range of variant coefficient was 0.49-0.95 based on molecular cluster. The results showed that the genetic basis of yellow sun-cured tobacco resource was narrow.2) The order of three populations’ diversity was Z>M>G. The genetic coefficient was 0.7762 between Z and M, in addition, the genetic coefficient was 0.8963 between G and M.3) 32 tobacco resource were divided into 2 groups at coefficient 0.49. The first group included Cunsanpi and Daninghanyanzi germplasm. The second group included 3 sub-groups. Gonghuishaiyan from Z population was clustered with the new collections, and other tobacco resource from Z population wasn’t clustered with the new collections.4) The genetic distance of the homonymic resource named Daningyan from different origins was far, and the coefficient was 0.788. The genetic distance between Gonghuibaogaiyan and Fenghuanghuangyan was nearest, and the coefficient was 0.939.
Abstract:Primula maximowicizii is a typical heterostyly species in genus Primula, which mainly distributed in northern China. To elucidate the diversity of pollen morphology, micromorphological characteristics of pollens in seven natural P. maximowicizii populations were investigated using SEM method. The polar view of most pollens were triangular, and the type of germinal aperture was trisyncolpate. Pollens of short-styled flowers were signi?cantly larger than those of long-styled flowers. Ornamentation of the pollens of short-styled flowers were reticulate with lumina of up to 0.4μm wide, and the pollens of long-styled flowers were microreticulate or verrucate with lumina of up to 0.23μm wide. The pollens’ characters were significantly different among populations with coefficient variation (CV) from 4.88% to 35.48%., and the average CV of short-styled flowers was 16.18%, the average CV of long-styled flowers was 14.89%. Acccording to the morphological characteristics of pollens, the seven P. maximowicizii populations were classified into two groups by UPGMA cluster analysis. The results provided theoretical data for genetic diversity research on P. maximowicizii.
Abstract:Three groups of Iris dichotoma with different flower colors were investigated by morphological comparison and Karyotype analysis. The results indicated that there were obvious differences among the three groups with violet, yellow and white flowers, respectively. Their flowering time were 15:00, 14:00 and 16:00, and closing time were was 19:30, 19:00 and 20:00, respectively. The respective average variation coefficients of I. dichotoma with different flower colors were 10.47%~65.16%, 4.46%~45.95% and 3.95%~55.43%. The variation of 13 characters of three groups such as flower diameter, outer perianth, inner perianth and fruit length had significant difference, while there was no significant difference in the tillering number and the number of seeds. The analysis of karyotype demonstrated that the karyotype formula for I. dichotoma (Violet) was 2n=2x=32=12sm 20m, and the karyotype was 1B. The chromosome number and karyotype of I. dichotoma(Yellow) were reported here for the first time and its karyotype formula was 2n=2x=32=6sm 26m, belonging to "1A" type. The karyotype of I. dichotoma(White) was 2B, whose karyotype formula was 2n=2x=32=8sm 24m. By the analysis of karyotype and variation of morphological characters, the genetic relationships among the three different flower color groups of I. dichotoma were discussed, which showed that their phylogenetic relationships were relatively close and I. dichotoma(Yellow) as well as I. dichotoma(White) should be the intraspecific variation of I. dichotoma (Violet).
Abstract:Based on the significant difference of morphology, chromosome karyotype analysis were carried out in Medicago sativa L.,Medicago falcata L. and alfalfa with cream flower. The results showed: three genotypes of materials had unambiguous difference in chromosome karyotype due to the satellite chromosomes in alfalfa with cream flower and Medicago falcata L.which included 2 terminal point chromosomes. The karyotype formula of Medicago sativa L.,Medicago falcata L. and alfalfa with cream flower respectively were: 2n=4x=24m+8sm，2n = 4x = 24m + 6sm +2T(SAT) and 2n=4x=24m+8sm (SAT). The chromosome similarity in Medicago sativa L. and alfalfa with cream flower was 89% and the dissimilarity was owing to the satellite condition in No.7 of Medicago sativa L. and No.15 of alfalfa with cream flower. The chromosome of Medicago falcata L. was very unique which constructed of Medicago sativa L. and alfalfa with cream flower from chromosome No.19. No.15 chromosome in alfalfa with cream flower had the higher similarity with No.25 chromosome in Medicago falcata L. and No.7 chromosome in Medicago sativa L.,but there were still difference in satellite condition.
Abstract:In this work, pot experiment was conducted in Beijing to study the differences in biomass and its allocation of 14 switchgrass. The results showed that the low-land switchgrass Kanlow produced the most biomass with dry weights of stems, aboveground parts and the whole plant reaching to 175.48 g/plant, 299.18 g/plant and 447.66 g/plant, respectively. While, the up-land switchgrass Nebraska produced the least biomass with dry weights of stems, aboveground parts and the whole plant being 20.53 g/plant, 58.08 g/plant and 140.51 g/plant, respectively. Taking the whole plant into consideration, Kanlow allocated the highest proportion (63.13%) of biomass into aboveground parts compared to the other switchgrass cultivars, while the lowest (40.55%) was found in Canada. Moreover, Kanlow allocated the highest proportion (48.67%) of biomass into aboveground vegetative organs and the lowest proportion (31.88%) was found in Nebraska. Taking aboveground parts of switchgrass as a whole, Alamo, Kanlow and Trailblazer allocated higher proportion of biomass (35.91%, 37.09% and 34.39%, respectively) into stalks and higher stems/leaves ratio (2.75, 2.56 and 2.48, respectively) was found compared with other switchgrass cultivars. The origin latitude significantly influenced the switchgrass biomass and its allocation. Considering the whole switchgrass plant, there was significant negative correlation between the origin latitude and switchgrass biomass. Significant positive correlations between the origin latitude and biomass proportion of belowground parts and the significant negative correlations between origin latitude and the biomass proportion of aboveground parts, seeds as well as stems were also found. When talking about aboveground parts of switchgrass, a significant negative correlations between origin latitude and stems biomass proportion as well as the stems/leaves ratio were found, while significant positive correlations exhibited between origin latitude and leaves and sheaths biomass proportion. The differences of biomas and its allocation reflected a reproductive and growth strategy long-term adaptive to the ecological environment in switchgrass. This work provides the basis for introduction of genetic resources and the variety breeding of switchgrass.
Abstract:This paper studied the development of female flowers and embryo in Dioscorea fordii Prain et Burk., and laid the foundation for it on the study of embryology and hybridization breeding. The results showed that: most of D. fordii Prain et Burk. was dioecious, and female flowering period was about 3 months in Hainan, from early September to the end of November. There were three rooms in its ovary, and two anatropous ovules in each room; The ovule was crassinucellate and bitegminous. The archesporial cell under the micropyle epidermis gradually developed into megasporocyte mother cell. Then the megaspore mother cell underwent meiosis and formed 4 megaspore in line, and only one of megaspore developed into functional megaspore. The mature embryo sac was Polygonum type with 7 cells and 8 nuclei. The fertilization of egg cell was premitotic type. The development of embryo was onagrad type, and went through 5 development stages, including two cell proembryo, inverted T type proembryo, globular embryo clavate embryo and pear shaped embryo. The development of endosperm was karyotype.
Abstract:The cut flowers of Paeonia suffruticosa ‘ Luoyang Hong ’ were used as materials. Effects of different temperature treatments (22℃,15℃ and 4℃) on flower color and anthocyanin biosynthesis were researched. The results showed that : compeared with 22℃, flowers under 15℃ and 4℃ treatments showed lower lightness, higher redness, higher chroma and increased anthocyanin accumulation. Color quality is obviously better than that of 22℃ treatment. qRT-PCR was used to analyze the relative expression levels of anthocyanin biosynthetic genes and results showed that 15℃ and 4℃ treatments promoted anthocyanin biosynthesis in the cut flowers via the promotion of related genes transcription (PsCHS1, PsCHI1, PsF3’H1, PsANS1, PsDFR1, PsMYB2, PsbHLH1 and PsbHLH3). Low-temperature mainly regulated and controled anthocyanin biosynthesis by upstream gene PsCHS1 and PsCHI1. Downstream genes PsDFR1, PsANS1 and PsF3’H1 were sensitive to low-temperature, which have the biggest increase transcription by 4℃ treatment. The above mentioned structural and regulatory genes were the important key of the anthocyanin biosynthesis.
Abstract:AT-hook proteins play an important role in regulation of eukaryotic gene expression, and implicated in plant development, organ formation, stress response, and hormonal signaling. In this study, our analysis revealed the presence of 32 genes encoding AT-hook proteins in the tomato genome, the distribution on the chromosome, the structure and function of proteins were analyzed. AT-hook proteins could be classified into 3 type based on phylogenetic analysis. , 13 of them belong to Type I, and other members have the similar classification with Arabidopsis thaliana, which was supported with organization of predicted conserved putative motifs in AT-hook proteins. Real-time fluorescence quantitative PCR were used to gain insights into the function of AT-hook gene family members during various stages of development and in response to abiotic stress and phytohormones. Some of the AHL genes were expressed in specific organs such as roots and flowers; 32 SlAHL genes showed distinct expression patterns in response to stresses of salt, SA, ABA, high temperature and cold, the expressions of several genes were significantly up/down regulated, implying that these members might participate in regulating the defense response against abiotic stresses. The results will provide a very useful reference for cloning and functional analysis of each member of AT-hook gene family in Solanaceae crops.
Abstract:LBD gene with LOB (lateral organ boundaries) domain structure, which plays very important role in plant development. Base on bioinformatic method, the LBD genes of Nicotiana Tabacum were screened with the LBD gene sequences of Arabidopsis. The sequence structure, phylogenetic relationship and expression pattern of the identified gene sequences were analyzed. The result show: a total of 98 LBD genes were identified from tobacco with simple genetic structures contained 1-3 exons generally. Tobacco LBD gene family be divided into two types (I and II). All LBD members had conserved domain CX2CX6CX3C, however, the type II genes had secondary structure of coiled coil made of LX6LX3LX6L. Furthermore, LBD genes can be divided into 5 sub families (Ia, Ib, Ic, Id and II) by their phylogenetic relationship with Arabidopsis. 36 members have EST evidenc; the analysis of EST, array data and transcriptome show that the LBD genes had different expression patterns and tissue specificity. These results provide abundant information for the LBD genes family further functional analysis.
Abstract:Aquaporins (AQPs) are the members of the major intrinsic proteins (MIPs) family with extraordinary ability to transport water, and play important roles in modulation of water relationships in plants. In this study, based on the genome database of Pyrus communis L. ‘Bartlett’ (http://www.rosaceae.org/species/pyrus/pyrus_communis/genome_v1.0), the AQPs gene family of Pyrus communis were identified and the sequences characteristic, phylogenetic trees, gene structure, GO function and expression profiles were analyzed. The phylogenetic tree was constructed using MEGA 6.0.5 software with neighbor-joining method. The structure of the genes were analyzed by GSDS 2.0 software, the motif was analyzed by MEME program, and GO analysis was carried by AgBase v2.00 software. Their expression patterns in different tissues were studied with semi RT-PCR. The results showed that there were 54 PcAQPs genes which containing AQP feature domains and conserved motifs were identified systematically in Pyrus communis. According to the gene structure, conserved domains and phylogeny relationship, the PcAQPs proteins were classified into 4 subfamilies (PIP, TIP, NIP and SIP) and the structure difference was larger between different subfamily genes, however, the genes with close relationship cluster had similar structure. GO analysis showed that the majority of PcAQPs gene had transporter activity, involved in substance transportation, stress response, growth, metabolism and other biological processes, but there were obvious differences in cellular components and biological processes between different subfamily members. Semi RT-PCR results showed that most of PcAQPs genes were expressed in roots, stems, leaves, and fruits, and the expression patterns of different genes and different subfamilies were different. These results laid foundation for cloning and functional analysis of PcAQPs gene in Pyrus communis.
Abstract:Abstract：RING(Really Interesting New Gene) ubiquitin ligases play significant roles in rice, such as growth, development，resistance to biotic and abiotic stresses. In this study，we cloned the RING finger gene (OsRING6) from the Japonica cultivar Nipponbare (Oryza sativa) based on the sequence analysis of the rice genome and the RT-PCR method. The OsRING6 full cDNA consists of 1355 bp nucleotides and contains a CDS of 918 bp nucleotides，and encoding a protein of 315 amino acids with the deduced molecular weight of 32.96 kD and a pI value of 3.49. The similarity comparison revealed that the CDS sequence of OsRING6 shared 97% and 83% homology with Oryza sativa Indica (CT832014) and Oryza brachyantha (XM_006659599)，respectively. The relative molecular weight of the MBP-OsRING6 recombinant protein induced by IPTG was about 100 kD，which was much bigger than deduced value of 76 kD. Promoter analysis indicated that it contains several regulatory elements related to drought stress, light response，ABA and GA signal transduction. Real-time PCR experiments showed that OsRING6 was expressed mainly in root，stem，leaves，leaf sheath，flowers and seed，and its expression level was the highest in germinated seeds and the lowest in flowers among these detected tissues. We also found that OsRING6 could be induced when treated with salt and ABA，respectively，and inhibited by PEG. These data suggest that OsRING6 might be involved in abiotic stresses such as slat and drought, and could be used for further functional study and breeding in rice.
Abstract:Silk is the main sexual organs of maize, and the normal development and morphogenesis of silk is crucial for the reproduction and yield of seed. We found a natural mutant sk-A7110 that showed an exhaustive deletion of silk, which makes itself suffer the abortion of seed on account of no pollination. Genetic analysis indicates that the mutation is controlled by a single recessive nucleus gene SKA7110. The SKA7110 is localized in a 255kp physical distance between the markers SAG21 and IDP1453 on chromosome 2 according to the gene mapping result by using bulked segregation analysis. The work of this study provides a basis for cloning and functional analysis of SKA7110.
Abstract:GluTR encoded by HEMA1 is the key enzyme in regulating chlorophyll biosynthesis. In this study, the encoding gene was cloned from apple leaves by RACE technology and designated as MdHEMA1. Bioinformatics analysis revealed that MdHEMA1 locates on chromosome 8 of apple genome, with a CDS length of 1638 bp and encodes 545 amino acid residues. The calculated molecular mass is 59279.4 Da with an isoelectric point of 8.45. Sequence analysis showed that MdHEMA1 protein contains 3 conserved domains. MdHEMA1 possesses the closest phylogenetic relationship with PbHEMA1 from Pyrus×bretschneideri. qRT-PCR results revealed that MdHEMA1 exhibited a highexpression level in photosynthetic tissues compared with that in other tissues. Besides, the expression level of MdHEMA1 varied in leaves and fruits at different developmental stages, which was positively correlated with the level of chlorophyll accumulation. The gene expression could also be induced by drought stress. Promoter analysis revealed that MdHEMA1 promoter possessed multiple putative cis-acting elements involved in abiotic stress.
Abstract:The study of MybA genotypes in different grape cultivars can provide the basis for identification and classification of grape cultivars as well as selection of parents in grape breeding. The result of MybA genotyping in 118 primary core collection of grape genetic resources shows that most Vitis vinifera cultivars and their hybrids have VvmybA1a which is an allele of VvmybA1 gene, with the exception of 10 Vitis vinifera cultivars and their hybrids. VvmybA1, VvmybA2 and VvmybA3 genes were all detected in most Vitis vinifera, hybrids of V. labrusca and V. Vinifera, and hybrid wine grapes, except for a few grape cultivars with VvmybA2 or VvmybA3 undetected. Hybrids of V. amurensis and V. vinifera, Beimei, Xiongyuebai and Gongniangyihao have all VvmybA1, VvmybA2 and VvmybA3, while Beichun and Beihong have only VvmybA1 and VvmybA3. VlmybA2 gene were only detected in some hybrids of V. labrusca and V. vinifera, and hybrid wine grapes. It is noteworthy that in five Vitis labrusca cultivars VvmybA1a (typical genotype of V. vinifera) but not VlmybA2 was detected. We speculate that they are the hybrids of V. labrusca and V. vinifera, with more V. labrusca parentage, and they are not the pure Vitis labrusca.
Abstract:The waxy gene sequences including microsatellite sequence (CT)n and the part of first intron were amplificated and sequenced using the PCR pecific primers Wx-F / AG-2 for 252 rice landraces from 16 areas 64 counties of Yunnan. The results showed that Four variable sites were detected in the waxy gene sequences incuding 260 bases. The (CT)n variation duplicate number 10, 11, 12, 14, 16, 17, 18, 19, 20, 21 was tested at site 56 of the first intron upstream; The variation G / T was present in the first intron 1 site and T only was present in the cultivars with (CT)n length greater than 16 breeds; There were three variations include ATA / GTA /A at 86-88 site; There were two (AATT) n variations (5 and 6) duplicate number at 128 site. According to these four polymorphic sites, the 252 Yunnan rice landraces were classified into 16 genotypes, which Wx4 (32.54%), Wx9 (13.89%), Wx12 (12.7%), Wx5 (12.3%), Wx1 (8.33%), Wx11 (7.94%) were the main type, other types of frequency were lower. There were differentiation in genotype types and genotype frequencies between Indica / japonica subspecies, water / upland rice and sticky / glutinous rice. The indica / japonica, water / upland rice and no-glutinous / glutinous rice subspecies or ecotypes had exclusive genotype, shared genotype frequency also had differences. This indicated that genetic differentiation were occurred between subspecies or ecotypes. Geographical distribution of genotypes showed that Lincang, Puer genotype species were the most abundant, and expansion outward as it the center, genotype species were decreasing trend, the T at the first intron 1 site were mainly distributed in Lincang, Pu'er, Banna, Dehong and other southern regions. This study revealed the waxy gene the variability and distribution of Yunnan rice landraces groups.
Abstract:Oryza minuta have abundant genetic diversity, containing a large number of elite genes, is the valuable resource for cultivated rice genetic improvement and rice genome research. This paper summarized the research progress obtained in the use of Oryza minuta germplasm at home and abroad, mainly including: identification of excellent traits, construction of genetic populations；mapping, cloning and breeding utilization of favorable genes；and discussed the difficulties and coping strategies on the utilization of elite genes from Oryza minuta. These results will be conducive to further tap and exploit the favorable genes from Oryza minuta.
Abstract:To screen the new wheat germplasm resistant to crown rot in Huang huai wheat area and establish the new identified method for the resistance which can distinguish the other disease in the basal straw of wheat, the resistance to crown rot of one hundred and eight varieties coming from Huang huai wheat area was evaluated by seedling survey method in the house and the DNA contents of Fusarium graminearum in the basal straw of forty-five wheat varieties were detected simultaneously by Real-time PCR so as to analyze the relationship between the DNA content of Fusarium graminearum and the resistance to crown rot of wheat. Twenty-two varieties with moderate resistance to crown rot were screened out, but no more resistant or immune varieties were found. The correlation analysis showed that, between the Fusarium graminearum DNA content in the basal straw of wheat and the average disease grade, there was significant correlation with the correlation coefficient 0.73, indicating that the Fusarium graminearum DNA content in the basal straw of wheat could be used as the important reference to determine the resistance to crown rot of wheat. The new wheat gerplasm and the Real-time PCR method used for the resistance evaluation will be helpful to breeding of wheat cultivar resistant to crown rot in Huang huai wheat area.
Abstract:mmature haploid embryos (n=21, ABD) were obtained by crossing durum wheat (Triticum durum, 2n=28, AABB) as the female parent and Aegilops tauschii (2n=28, DD) as the male parent. The haploid embryos were rescued by tissue culture. The plantlets regenerated were treated with colchicine to double their chromosomes and the synthetic wheat with winter growth habit were produced. The regeneration percentage of haploid plantlets was 75.81% using 1/2 MS medium only, but 92.44% haploid plantlets were obtained when the immature embryos were cultured on 1/2 MS medium and 1/2 MS medium supplemented with 2 mg/L 2,4-D alternately. The medium alternation was based on the development of immature embryos. If immature embryo developed well, 1/2 MS medium would be used; otherwise 1/2 MS medium containing 2 mg/L 2,4-D would be used. The poorly developed immature embryos grew well on the medium containing 2 mg/L 2,4-D, and then they were moved to 1/2 MS medium to produce more plantlets. double haploid plantlets (AABBDD) were gained by using 0.05% colchicine with method of half-root in plastic shed in winter. To doubling chromosomes in this season has an important reason that temperature is very beneficial for plantlets growing more strongly and having more tillers, all these made it easy to get more seeds of synthetic wheat.
Abstract:Abstract: Identification of the resistance to TuMV of 127 Brassica campestris L. ssp. chinensis germplasm was conducted with the method of artificial inoculation identification and ELISA test respectively. The result showed that the DI value ranged between 3.55 and 95.68, which expressed significant difference of resistance to TuMV among accessions. Distribution plot for different resistance level to TuMV basically corresponds to normal distribution and the peak was slightly partial to susceptible region. The result of cluster analysis based on DI value was similar to that of the grading levels. 6 accessions highly resistant to TuMV and 13 accessions resistant to TuMV were screened by seedlings inoculation identification. Their main agronomic characters demonstrate abundant diversity. The number of resistance accessions with the characters of having wrinkling or pubescence on leaf surface takes a relatively higher ratio, which demonstrates that the leaf character might have a certain correlation with TuMV resistance. The result of ELISA test showed that the amount of virus in 117 materials was significantly different with P/N value ranging between 3.10 and 25.37, but it had no significant correlation with DI value. ELISA test could be used as a supplementary identification method in screening resistance materials.