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1.
Recent studies revealed that DNA methylation plays an important role in plant growth and development. In this study, a water-saving and drought-resistant rice variety Huhan 3 was subjected to drought stress from tillering to grain-filling stages in six successive growth cycles. The variations in DNA methylation pattern between the original generation (Go) and the sixth generation (G6) were analyzed by using methylation sensitive amplification polymorphism method. The results revealed that the methylated loci accounted for 34.3% to 34.8% of the total loci. Among these methylated loci, 83.1% to 84.8% were full- and hyper-methylated and 15.2% to 16.9% were hemi-methylated. The DNA methylation level decreased from the three-leaf to four-leaf stages in Huhan 3. Differentially methylated loci (DML) between generations or/and between different developmental stages accounted for 4.0% of the total loci, most of which were only related to plant development (57.9%). Compared to Go, the DNA methylation pattern of G8 changed after drought domestication, at the three-leaf stage, de-methylation accounting for 59.1%, while at the four-leaf stage, re-methylation for 47.9%. Genome-wide alternations of DNA methylation were observed between the two seedling stages, and DML mainly occurred on the gene's promoter and exon region. The genes related to DML involved in a wide range of functional biology and participated in many important biological processes.  相似文献   

2.
Genetic Identification of a New Small Grain Dwarf Gene in Rice   总被引:1,自引:0,他引:1  
The plant material used in the study was rice line 162d, a new small grain dwarf mutant. Polymorphic analysis of 221 SSR loci demonstrated that 162d derived from a semidwarf variety Shuhui 162 through mutation, and 162d and Shuhui 162 were just a pair of near isogenic lines. Genetic analysis of Fl and F2 populations suggested that dwarfism in 162d was controlled by a single recessive gene. Phenotypic characteristics of the mutant gene were that plant height was about a quarter of normal height, grain size about a quarter of normal size, leaf was short and broad, and seed setting rate was very low,compared with the near isogenic line Shuhui 162. The mutant gene was sensitive to gibberellin (GA3) treatment and did not located on the region near the centromere of rice chromosome 5, where dl gene located. Therefore, it was concluded that the mutant gene of 162d was a new small grain dwarf gene in rice.  相似文献   

3.
A spontaneous mutation,tentatively named d63,was derived from the twin-seedling progenies of rice crossed by diploid SARIII and Minghui 63.Compared with wild-type plants,the d63 mutant showed multiple abnormal phenotypes,such as dwarfism,more tillers,smaller flag leaf and reduced seed-setting rate and 1000-grain weight.In this study,two F 2 populations were developed by crossing between d63 and Nipponbare,d63 and 93-11.Genetic analysis indicated that d63 was controlled by a single recessive gene,which was located on the short arm of chromosome 8,within the genetic distance of 0.40 cM from RM22195.Hence,D63 might be a new gene as there are no dwarf genes reported on the short arm of chromosome 8.  相似文献   

4.
By crossing homologuos triploid plants derivedfrom twin-seedlings with diploid plants,manykinds of aneuploid were produced as expectedbecause the abnormal chromosome pairing oc- curred in triploid itself and F_1.In the mean- time,we also obtained a few normal developeddiploid F_1 plants.The self progeny(F_2)showed agronomic stability,checked withSSLP and RFLP markers.It was found thatthe F_1 was non-segregated hybrid.In thisstudy,the triploid served as male parent andthe diploid indica rice variety R725 served as  相似文献   

5.
6.
Analysis on Factors Affecting Seedling Establishment in Rice   总被引:2,自引:0,他引:2  
Elongations of coleoptile and mesocotyl are related directly to rice seedling establishment in soil and height of plant is related to lodging in rice production.Twelve typical rice cultivars with different lengths of coleoptile and mesocotyl(long,medium and short)were selected by screening the lengths of coleoptile and mesocotyl in 1500 accessions.The seedling establishments of these typical cultivars were compared under the combinations of different sowing depths and flooding durations,and two semi-dwarf varieties(G140,Zhong 96-21)with good seedling establishments and optimum mesocotyl lengths were found.The length of mesocotyl was completely fitted negative binomial distribution and the length of coleoptile was nearly fitted lognormal distribution. Analysis of the relationships among mesocotyl,coleoptile,seeding depth,flooding duration,and their interactions to seedling establishment percentage showed that there existed significant relations among mesocotyl,coleoptile,mesocotyl×coleoptile, seeding depth,flooding duration and mesocotyl×sowing depth in the experiment for seedling establishment.  相似文献   

7.
An experiment was conducted to study the effects of different Pb concentrations on rice seed germination and seedling growth in three cultivars (Jiayu 293, Jiayu 948 and Xieyou 963). The method of qualitative traits combining with quantitative traits by orthogonal polynomials was applied to analyze rice seed vigor by regression model. The seeds from different rice cultivars had different sensitivity to Pb poison. In the Pb concentration of 100-700 mg/L, Pb significantly decreased root length and shoot height, and the degree of the restraint would aggravate with the increasing of Pb concentration. However, Pb did not reduce root dry weight and shoot dry weight, which indicated that different physiological characteristics had different sensitive reactions to Pb. The predicting equations of regression were developed, which could be used to predict the effects of different Pb concentrations on rice seed vigor.  相似文献   

8.
Anoxia germinability (AG) of 35 rice varieties was evaluated under different temperature and water submergence conditions. The shoot (including coleoptile) length of seedlings germinating under 30℃, 0.2 m water submergence for 5 days could be used as an optimal criterion for the AG evaluation of all the varieties. Differences were observed among the AGs of 359 varieties from different regions and subspecies with the optimized method. Moreover, 81 recombinant inbred lines derived from a cross of Kinmaze (japonica)/DV85 (indica) were used to detect quantitative trait loci (QTLs) conferring AG. A total of five QTLs for AG in the recombinant inbred population were detected on chromosomes 1, 2, 5 and 7, respectively. Phenotypic variations explained by each QTL ranged from 10.5% to 19.6%. Based on the directions of the additive effects, the alleles at three loci qAG-1, qAG-2 and qAG-7 from Kinmaze increased AG, while alleles at loci qAG-5a and qAG-5b from DV85 increased AG. Meanwhile, three pairs of epistatic loci were found to be located on chromosomes 2, 3, 5 and 11 with significant effects ranging from 16.7% to 48.8%, and the highest one 48.78%, was detected between C563–X182 on chromosome 3 and R830–X208 on chromosome 5.  相似文献   

9.
Four hundred and seventy-seven accessions of the second core collection of rice landrace from five rice cropping regions (16 prefectures) of Yunnan Province, China, were evaluated for cold tolerance at booting stage. The results showed as follows: 1) there was a significant positive correlation (0.588**) between anther length and seed setting rate under natural low temperature conditions but was not significant in greenhouse (0.080). 2) there were significant differences in cold tolerance among core collections from different cropping regions under natural low temperature conditions while a negligible cold damage in greenhouse (with a seed setting rate approaching or exceeding 70%) for cold tolerance evaluation. Cold tolerance of core collection from Northwest Yunnan cold highland japonica region was the strongest, and that from south marginal paddy-upland rice region was the most sensitive, suggesting that the breeding goals for cold tolerance should be different in various rice cropping regions. 3) there were remarkable differences in cold tolerance of core collections from different prefectures of Yunnan Province under natural low temperature conditions. Based on the reduction of seed setting rate and characteristics of natural climate, the 16 prefectures could be divided into three categories, i.e. serious cold damage , cold damage and slight cold damage regions. 4) Difference of cold tolerance between different rice cropping regions and prefectures revealed further that temperature change caused by elevation and latitude was not only a dominant factor for differentiation of japonica and indica but also the basic reason that the genetic diversity and six ecological group of indica and japonica were being developed and, even the critical factor leading to the formation of the cold tolerance gene as well. The cold tolerance at booting stage could be believed to be resulted from the long term co-evolution between Yunnan rice landrce and cold stress in rice cropping  相似文献   

10.
A doubled haploid(DH)population consisted of 120 lines,derived from a cross between an indica variety,TN1, and a japonica variety,Chunjiang 06,was used to identify QTLs controlling rice cold tolerance at the plumule and 3-leaf-seedling stages by using the QTLNetwork software.The percentages of normal plumules after 4°C treatments for 7 d, 9 d,11 d,and 14 d,as well as the cold stress tolerance index(CSTI)and the withering index(WI)of rice seedling were investigated.A total of five single-effect QTLs,each for percentages of normal plumules after 4°C treatments for 9 d,11 d and 14 d,and CSTI and WI,respectively were identified.The QTLs for the percentages of normal plumules after low temperature treatments for 9 d,11 d and 14 d were on chromosomes 4,2 and 11,accounting for 14.1%,17.3%and 21.5%of the phenotypic variation,respectively.QTLs for CSTI and WI were on chromosomes 10 and 1,respectively.Two pairs of epistatic loci were identified,but none of the epistatic loci involved the single-effect QTLs.The RM528-RM340 interval on chromosome 6 interacted with the RM278-RM3919B interval on chromosome 9 for CSTI,and the epistatic interaction accounted for 17.7%of the phenotypic variation.A pair of epistatic loci was identified for WI,the RM246-RM5461 interval on chromosome 1 interacted with the ISA-RM447 interval on chromosome 8,which accounted for 22.6%of the phenotypic variation.  相似文献   

11.
从4500对SARⅡ 628的双胚苗中筛选出5对二倍体 三倍体双胚苗。SSR分析显示它们在所检测的310个位点上没有差异。以AFLP为基础的MSAP(methylation sensitive AFLP)研究显示,5个二倍体在493个位点上甲基化状态没有差异。与二倍体比较,相应的三倍体虽然在甲基化总体水平上变化不大,但共有29个位点甲基化类型在不同单株上发生了变异,表明SARⅡ 628自然同源三倍化后甲基化变异在M0代就迅速发生。变异共有10种类型,包括甲基化程度上升、下降各3种类型以及不定类型4种。对其中22个位点测序检索显示:这些甲基化变异涉及整个水稻基因组的12对染色体且具有位点特异性,不同单株的变异位点各不相同,预示着SARⅡ 628不同单株在自然同源三倍化后将走向不同的命运。  相似文献   

12.
 利用经测验可区分籼粳品种的19对SSR特异引物对来自云南元江普通野生稻自然居群的56个个体进行了SSR分析。19对引物中,有17对(占89.47%)在所有参试个体中仅能扩增出一种带型,而RM18和RM251能扩增出多态带型。RM4等16对(84.21%)引物扩增出的带与籼稻或粳稻特征带相同,其中11个位点偏粳而4个位点偏籼;RM18、RM202、RM205等3对引物扩增出的带型不同于籼稻或粳稻带型。结果表明,云南元江普通野生稻基因组DNA在所检测的19个位点上,多数位点(89.47%)上个体间无差异,84.21%的位点已有籼粳分化,13.79%的位点仍具有原始性。说明云南元江普通野生稻主体比较纯而原始,但已开始了籼粳的分化。  相似文献   

13.
橡胶树不同倍性的气孔性状差异研究   总被引:2,自引:0,他引:2  
以通过流式细胞倍性检测鉴定出的橡胶树二倍体、三倍体、四倍体植株为研究对象,对不同倍性植株的气孔性状进行观察和统计。结果表明:不同倍性间的橡胶树叶片的气孔长度、气孔宽度、气孔密度均存在极显著差异。随着橡胶树倍性的提高,气孔的长度和宽度均增大,而气孔密度减小。二倍体、三倍体和四倍体的气孔长度范围分别为10.65~15.29、14.04~18.89、15.15~19.37μm,气孔宽度范围分别为7.13~10.65、8.58~11.83、10.38~13.83μm,气孔密度范围分别为520.62~867.69、402.53~764.80、381.79~555.32个/mm~2。以气孔长度15.15μm、气孔宽度10.38μm和气孔密度555.32个/mm~2为临界值,可以鉴定二、四倍体混合群体中的四倍体。三倍体和二倍体、四倍体在气孔长度值、宽度值和密度值在分布区间上均存在较大的重复,但以气孔长度14.04μm,气孔宽度8.58μm和气孔密度764.80个/mm~2为临界值,可以筛除二、三、四倍体混合群体中的部分二倍体,提高多倍体鉴定的效率。  相似文献   

14.
QTLs for drought tolerance at the rice seedling stage were analyzed using a doubled haploid (DH) population consisted of 251 lines from the cross between a japonica parent Maybelle and an indica parent Baiyeqiu. A genetic linkage map with 226 SSR marker loci was constructed. Single-locus analysis following composite interval mapping (CIM) detected a total of five QTLs located on five different chromosomes of rice. Four QTLs were also detected following two-locus analysis, resolving two pairs of epistatic QT...  相似文献   

15.
One of the most effective ways of enhancing rice yield is the utilization of the strong inter-subspecific hybrid heterosis between indica rice and japonica rice in replacement of inter-varietal hybrid heterosis being widely applied. Recently, great progress has been made to increase rice yield in several countries e.g. Japan, Korea, China etc [1]. For example, an indica-japonica hybrid rice combination ‘Xieyou 9308’, which was derived from an indica cytoplasmic male sterile line Xieqingzao…  相似文献   

16.
It was generally recognized that the common wild rice (Oryza rufipogon Griff.) was the ancestor of cultivated rice (O. sativa L.) and there was indica-japonica differentiation in common wild rice before it evolved into cultivated rice [1-10]. The analysis…  相似文献   

17.
The generation of banana triploids from tetraploid-diploid crosses requires knowledge on the influence of the parents on black Sigatoka resistance and agronomic traits to the triploid progenies. The objective of this investigation was to determine the influence of tetraploid and diploid parents on black Sigatoka resistance and agronomic traits in the triploid progenies generated from tetraploid-diploid crosses. The mating scheme was designed as a 4 × 5 North Carolina II mating design. Due to problems in seed set and germination, progenies from 2 male parents with 4 female parents were evaluated at two sites in Uganda. The results showed that the male-parent triploid progeny heritability estimate for the number of leaves at harvest was greater than the female parent estimate. The diploid parents had higher correlation coefficients for the total leaves at harvest with the triploid progenies than tetraploid parents with triploid progenies. Disease development over time took more days in diploid parents than in the tetraploid parents with the triploid progenies as intermediates. These results suggested that diploids transferred black Sigatoka resistance to the triploid progenies as measured by the number of standing leaves and disease development overtime. There was a positive correlation (P < 0.05) between tetraploid female parents and triploid progenies for plant height and bunch weight. The triploid progeny-tetraploid female parent heritability estimates for plant height (0.92) and bunch weight (0.72) were highly significant. These results indicated that the female synthetic tetraploids influenced plant height and bunch weight in the triploid progenies. Therefore, it is important to select the tetraploids with heavy bunches to effectively improve yield in triploid progenies generated by tetraploid-diploid crosses. The tetraploid-diploid progenies had a significant (P < 0.05) family-by-site interaction for bunch weight indicating that new banana genotypes need to be tested across different environments to select stable genotypes to promote to end-users.  相似文献   

18.
水稻耐光氧化特性的QTL定位   总被引:1,自引:0,他引:1  
利用由127个株系组成的来源于籼稻品种窄叶青8号和粳稻品种京系17的加倍单倍体群体,以耐性指数和敏感性指数为指标,采用QTL Mapper 1.6统计软件进行水稻耐光氧化反应特性的QTL定位和上位性分析,共检测到控制耐性指数的1个加性效应QTL,位于第3染色体上;控制敏感性指数的加性效应QTL 5个,分别位于第1、1、6、8和9染色体上。还检测到3对影响耐性指数的加性×加性上位性互作效应QTL和5对敏感性指数的上位性QTL。还对41个水稻材料进行了光氧化实验筛选。  相似文献   

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