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1.
Zhang X Colleoni C Ratushna V Sirghie-Colleoni M James MG Myers AM 《Plant molecular biology》2004,54(6):865-879
Mutations in the maize gene sugary2 (su2) affect starch structure and its resultant physiochemical properties in useful ways, although the gene has not been characterized previously at the molecular level. This study tested the hypothesis that su2 codes for starch synthase IIa (SSIIa). Two independent mutations of the su2 locus, su2-2279 and su2-5178, were identified in a Mutator-active maize population. The nucleotide sequence of the genomic locus that codes for SSIIa was compared between wild type plants and those homozygous for either novel mutation. Plants bearing su2-2279 invariably contained a Mutator transposon in exon 3 of the SSIIa gene, and su2-5178 mutants always contained a small retrotransposon-like insertion in exon 10. Six allelic su2
– mutations conditioned loss or reduction in abundance of the SSIIa protein detected by immunoblot. These data indicate that su2 codes for SSIIa and that deficiency in this isoform is ultimately responsible for the altered physiochemical properties of su2
– mutant starches. A specific starch synthase isoform among several identified in soluble endosperm extracts was absent in su2-2279 or su2-5178 mutants, indicating that SSIIa is active in the soluble phase during kernel development. The immediate structural effect of the su2
– mutations was shown to be increased abundance of short glucan chains in amylopectin and a proportional decrease in intermediate length chains, similar to the effects of SSII deficiency in other species. 相似文献
2.
Pyramiding transgenes for multiple resistance in rice against bacterial blight,yellow stem borer and sheath blight 总被引:11,自引:0,他引:11
Datta K Baisakh N Thet KM Tu J Datta SK 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(1):1-8
The present investigation revealed that the alk and gel(t) genes, which cause the differences between a japonica rice variety Nipponbare and an indica rice variety Kasalath in terms of the disintegration of endosperm starch granules in alkali solution and their gelatinisation
in a 4 M urea solution, respectively, cosegregated in backcross inbred lines derived from a cross between the two varieties.
The segregation pattern of the profile for amylopectin chain-length, which was distinguished by enrichment in short chains
of DP≦11 and depletion in intermediate-size chains of 12≦DP≦24 in japonica as compared with indica, was exactly the same as those of the above physico-chemical properties of starch granules, and the gene was designated as
acl(t). Gene-mapping analysis showed that the starch synthase IIa (SSIIa) gene is located at the alk locus on chromosome 6 in the rice genome. These results lead us to the possibility that different alleles of the SSIIa gene are responsible for differences in amylopectin structure between the two varieties, in that SSIIa plays a distinct role
in the elongation of short chains within clusters (A+B1 chains) of amylopectin. It is proposed that the activity of SSIIa in japonica rice is reduced in amount or functional capacity relative to the activity of this enzyme in indica rice. This, in turn, would explain why starch from japonica rice has a lower gelatinisation temperature than starch from indica rice and is more susceptible to disintegration in alkali or urea. The evidence for this hypothesis is that the alk(t), gel(t), acl(t) and SSIIa genes all map to the same locus.
Received: 29 January 2001 / Accepted: 12 April 2001 相似文献
3.
Liangming Chen Zhigang Zhao Xi Liu Linglong Liu Ling Jiang Shijia Liu Wenwei Zhang Yihua Wang Yuqiang Liu Jianmin Wan 《Molecular breeding : new strategies in plant improvement》2011,27(2):247-258
The incomplete fertility of japonica × indica rice hybrids has inhibited breeders’ access to the substantial heterotic potential of these hybrids. As hybrid sterility
is caused by an allelic interaction at a small number of loci, it is possible to overcome it by simple introgression at the
major sterility loci. Here we report the use of marker-assisted backcrossing to transfer into the elite japonica cv. Zhendao88 a photoperiod-sensitive male sterility gene from cv. Lunhui422S (indica) and the yellow leaf gene from line Yellow249 (indica). The microsatellite markers RM276, RM455, RM141 and RM185 were used to tag the fertility genes S5, S8, S7 and S9, respectively. Line 509S is a true-breeding photoperiod-sensitive male sterile plant, which morphologically closely resembles
the japonica type. Genotypic analysis showed that the genome of line 509S comprises about 92% japonica DNA. Nevertheless, hybrids between line 509S and japonica varieties suffer from a level of hybrid sterility, although the line is highly cross-compatible with indica types, with the resulting hybrids expressing a significant degree of heterosis. Together, these results suggest that segment
substitution on fertility loci based on known information and marker-assisted selection are an effective approach for utilizing
the heterosis of rice inter-subspecies. 相似文献
4.
Jianzhong Lin Bo Zhou Yuanzhu Yang Jin Mei Xiaoying Zhao Xinhong Guo Xingqun Huang Dongying Tang Xuanming Liu 《Plant cell reports》2009,28(7):1065-1074
Traditional transformation methods are complex and time consuming. It is generally difficult to transform indica rice varieties using traditional transformation methods due to their poor regeneration. In this contribution, a simple method
was developed for the transformation of indica rice. In this method, the mature embryos of soaked seeds were pierced by a needle, and then soaked in the Agrobacterium inoculum under vacuum infiltration. The inoculated seeds germinated and grew to maturation (T
0) under nonsterile conditions. The herbicide or antibiotic analysis and molecular analysis were conducted on T
0 plants. The results showed that although the efficiency of transformation was about 6.0%, it was easier to transform indica rice using the proposed method, and the transformation process was significantly shortened. The success of transformation
was further confirmed by the genetic and molecular analyses of T
1 transformants. 相似文献
5.
Qiu Y Guo J Jing S Zhu L He G 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(3):485-494
The brown planthopper (Nilaparvata lugens Stål; BPH) has become a severe constraint on rice production. Identification and pyramiding BPH-resistance genes is an economical and effective solution to increase the resistance level of rice varieties. All the BPH-resistance genes identified to date have been from indica rice or wild species. The BPH12 gene in the indica rice accession B14 is derived from the wild species Oryza latifolia. Using an F2 population from a cross between the indica cultivar 93-11 and B14, we mapped the BPH12 gene to a 1.9-cM region on chromosome 4, flanked by the markers RM16459 and RM1305. In this population, BPH12 appeared to be partially dominant and explained 73.8% of the phenotypic variance in BPH resistance. A near-isogenic line (NIL) containing the BPH12 locus in the background of the susceptible japonica variety Nipponbare was developed and crossed with a NIL carrying BPH6 to generate a pyramid line (PYL) with both genes. BPH insects showed significant differences in non-preference in comparisons between the lines harboring resistance genes (NILs and PYL) and Nipponbare. BPH growth and development were inhibited and survival rates were lower on the NIL-BPH12 and NIL-BPH6 plants compared to the recurrent parent Nipponbare. PYL-BPH6 + BPH12 exhibited 46.4, 26.8 and 72.1% reductions in population growth rates (PGR) compared to NIL-BPH12, NIL-BPH6 and Nipponbare, respectively. Furthermore, insect survival rates were the lowest on the PYL-BPH6 + BPH12 plants. These results demonstrated that pyramiding different BPH-resistance genes resulted in stronger antixenotic and antibiotic effects on the BPH insects. This gene pyramiding strategy should be of great benefit for the breeding of BPH-resistant japonica rice varieties. 相似文献
6.
Ryoo N Yu C Park CS Baik MY Park IM Cho MH Bhoo SH An G Hahn TR Jeon JS 《Plant cell reports》2007,26(7):1083-1095
To elucidate the role of SSIIIa during starch synthesis in rice (Oryza sativa L.) endosperm, we characterized null mutants of this gene, generated by T-DNA insertions. Scanning electron microscope (SEM)
analysis revealed that the starch granules in these mutants are smaller and rounder compared with the wild type controls,
and that the mutant endosperm is characterized by a loosely packed central portion exhibiting a floury-like phenotype. Hence,
the OsSSIIIa (Oryza sativa SSIIIa) mutations are referred to as white-core floury endosperm 5-1 (flo5-1) and flo5-2. Based upon their X-ray diffraction patterns, the crystallinity of the starch in the flo5 mutant endosperm is decreased compared with wild type. Through determination of the chain-length distribution of the mutant
endosperm starch, we found that flo5-1 and flo5-2 mutants have reduced the content of long chains with degree of polymerization (DP) 30 or greater compared with the controls.
This suggests that OsSSIIIa/Flo5 plays an important role in generating relatively long chains in rice endosperm. In addition,
DP 6 to 8 and DP 16 to 20 appeared to be reduced in endosperm starch of flo5-1 and flo5-2, whereas DP 9 to 15 and DP 22 to 29 were increased in these mutants. By the use of differential scanning calorimetry (DSC),
the gelatinization temperatures of endosperm starch were found to be 1–5°C lower than those of the control. We propose a distinct
role for OsSSIIIa/Flo5 and the coordinated action of other SS isoforms during starch synthesis in the seed endosperm of rice. 相似文献
7.
8.
Genetic and physical mapping of <Emphasis Type="Italic">Pi36</Emphasis>(t), a novel rice blast resistance gene located on rice chromosome 8 总被引:12,自引:0,他引:12
Blast resistance in the indica cultivar (cv.) Q61 was inherited as a single dominant gene in two F2 populations, F2-1 and F2-2, derived from crosses between the donor cv. and two susceptible japonica cvs. Aichi Asahi and Lijiangxintuanheigu (LTH), respectively. To rapidly determine the chromosomal location of the resistance
(R) gene detected in Q61, random amplified polymorphic DNA (RAPD) analysis was performed in the F2-1 population using bulked-segregant analysis (BSA) in combination with recessive-class analysis (RCA). One of the three linked
markers identified, BA1126550, was cloned and sequenced. The R gene locus was roughly mapped on rice chromosome 8 by comparison of the BA1126550 sequence with rice sequences in the databases (chromosome landing). To confirm this finding, seven known markers, including
four sequence-tagged-site (STS) markers and three simple-sequence repeat (SSR) markers flanking BA1126550 on chromosome 8, were subjected to linkage analysis in the two F2 populations. The locus was mapped to a 5.8 cM interval bounded by RM5647 and RM8018 on the short arm of chromosome 8. This
novel R gene is therefore tentatively designated as Pi36(t). For fine mapping of the Pi36(t) locus, five additional markers including one STS marker and four candidate resistance gene (CRG) markers were developed
in the target region, based on the genomic sequence of the corresponding region of the reference japonica cv. Nipponbare. The Pi36(t) locus was finally localized to an interval of about 0.6 cM flanked by the markers RM5647 and CRG2, and co-segregated with
the markers CRG3 and CRG4. To physically map this locus, the Pi36(t)-linked markers were mapped by electronic hybridization to bacterial artificial chromosome (BAC) or P1 artificial chromosome
(PAC) clones of Nipponbare, and a contig map was constructed in silico through Pairwise BLAST analysis. The Pi36(t) locus was physically delimited to an interval of about 17.0 kb, based on the genomic sequence of Nipponbare. 相似文献
9.
Xin Xu N. Hayashi C. T. Wang H. Kato T. Fujimura S. Kawasaki 《Molecular breeding : new strategies in plant improvement》2008,22(2):289-299
The Pik-h gene in rice confers resistance to several races of rice blast fungus (Magnaporthe oryzae), and has been classified as a member of the Pik cluster, one of the most resistance (R) gene-dense regions in the rice genome. However, the loss of a key mutant isolate has long made it difficult to differentiate
Pik-h from other Pik group genes especially from Pik-m. We identified new natural isolates enabling the differentiation between Pik-h and Pik-m genes, and first confirmed the authenticity of the International Rice Research Institute (IRRI) “monogenic” line IRBLkh-K3,
and then fine-mapped the Pik-h gene in the Pik cluster. Using 701 susceptible individuals among 3,060 siblings from a cross of IRBLkh-K3×CO39, the Pik-h region was delimited to 270 kb, the narrowest interval among the Pik group genes reported to date, in the cv. Nipponbare genome. Annotation of this genome region first revealed 6 NBS-LRR type
R-gene analogs (RGAs), clustered within the central 120 kb, as possible counterparts of Pik-h and 6 other Pik group R genes. Interestingly, the Pik-h region and the cluster of RGAs were shown to be located 130 kb and 230 kb apart from Xa4 and Xa2 bacterial blight resistance genes, respectively, once classified as belonging to the Pik cluster. The closest recombination events were limited to the margins of the Pik-h region, and recombination was suppressed in the core interval with the RGA cluster. This fine-mapping, performed in a short
time using an HEGS system, will facilitate utilization of the cluster’s genetic resources and help to elucidate the mechanism
of evolution of R-genes. The presence of natural isolates also confirmed that evolution of Pik-h corresponds to pathogen evolution. 相似文献
10.
Chang-Jie Yan Zhi-Xi Tian Yu-Wei Fang Ya-Chun Yang Jian Li Sheng-Yuan Zeng Shi-Liang Gu Chen-Wu Xu Shu-Zhu Tang Ming-Hong Gu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,122(1):63-76
Starch paste viscosity plays an important role in estimating the cooking, eating, and processing quality of rice. The inheritance
of starch paste viscosity in glutinous rice remains undefined. In the present study, 118 glutinous rice accessions were collected,
and the genotypes of 17 starch synthesis-related genes (SSRG) were analyzed by using 43 gene-specific molecular markers. Association
analysis indicated that 10 of 17 SSRGs were involved in controlling the rapid visco analyzer (RVA) profile parameters. Among
these, the PUL gene was identified to play an important role in control of peak viscosity (PKV), hot paste viscosity (HPV), cool paste viscosity
(CPV), breakdown viscosity (BDV), peak time (PeT), and paste temperature (PaT) in glutinous rice. Other SSRGs involved only
a few RVA profile parameters. Furthermore, interactions between SSRGs were found being responsible for PeT, PaT, and BDV.
Some of the RVA parameters, including PKV, HPV, CPV, CSV, and PaT, were mainly governed by single SSRG, whereas other parameters,
such as BDV, SBV, and PeT, were controlled by a few SSRGs, functioning cooperatively. Further, three near-isogenic lines (NIL)
of a japonica glutinous cv. Suyunuo as genetic background, with PUL, SSIII-1, and SSIII-2 alleles replaced with those of indica cv. Guichao 2, were employed to verify the genetic effects of the various genes, and the results were consistent with those
obtained from the association analysis. These findings indicated that starch paste viscosity in glutinous rice had a complex
genetic system, and the PUL gene played an important role in determining the RVA profile parameters in glutinous rice. These results provide important
information for potentially improving the quality of glutinous rice. 相似文献
11.
Shigeru Kaneko 《Mycoscience》2003,44(4):335-338
Two new species of Lirula (L. japonica and L. exigua) on Abies mariesii collected in subalpine areas of northern Japan are described as members of Rhytismatales, Discomycetes. Lirula japonica causes needle cast in fir, but L. exigua seems to occur on the needles of physically damaged twigs. Morphological characteristics of both species are discussed. 相似文献
12.
Liu X Yang Q Lin F Hua L Wang C Wang L Pan Q 《Molecular genetics and genomics : MGG》2007,278(4):403-410
Blast, caused by the ascomycete fungus Magnaporthe oryzae, is one of the most devastating diseases of rice worldwide. The Chinese native cultivar (cv.) Q15 expresses the broad-spectrum
resistance to most of the isolates collected from China. To effectively utilize the resistance, three rounds of linkage analysis
were performed in an F2 population derived from a cross of Q15 and a susceptible cv. Tsuyuake, which segregated into 3:1 (resistant/susceptible)
ratio. The first round of linkage analysis employing simple sequence repeat (SSR) markers was carried out in the F2 population through bulked-segregant assay. A total of 180 SSR markers selected from each chromosome equally were surveyed.
The results revealed that only two polymorphic markers, RM247 and RM463, located on chromosome 12, were linked to the resistance
(R) gene. To further define the chromosomal location of the R gene locus, the second round of linkage analysis was performed using additional five SSR markers, which located in the region
anchored by markers RM247 and RM463. The locus was further mapped to a 0.27 cM region bounded by markers RM27933 and RM27940
in the pericentromeric region towards the short arm. For fine mapping of the R locus, seven new markers were developed in the smaller region for the third round of linkage analysis, based on the reference
sequences. The R locus was further mapped to a 0.18 cM region flanked by marker clusters 39M11 and 39M22, which is closest to, but away from
the Pita/Pita
2 locus by 0.09 cM. To physically map the locus, all the linked markers were landed on the respective bacterial artificial
chromosome clones of the reference cv. Nipponbare. Sequence information of these clones was used to construct a physical map
of the locus, in silico, by bioinformatics analysis. The locus was physically defined to an interval of ≈37 kb. To further
characterize the R gene, five R genes mapped near the locus, as well as 10 main R genes those might be exploited in the resistance breeding programs, were selected for differential tests with 475 Chinese
isolates. The R gene carrier Q15 conveys resistances distinct from those conditioned by the carriers of the 15 R genes. Together, this valuable R gene was, therefore, designated as Pi39(t). The sequence information of the R gene locus could be used for further marker-based selection and cloning.
Xinqiong Liu and Qinzhong Yang contributed equally to this work. 相似文献
13.
Selvaraj Michael Gomez N. Manikanda Boopathi S. Satheesh Kumar T. Ramasubramanian Zhu Chengsong P. Jeyaprakash A. Senthil R. Chandra Babu 《Acta Physiologiae Plantarum》2010,32(2):355-364
Drought is a major limitation for rice production in rainfed ecosystems. Identifying quantitative trait loci (QTLs) linked
to drought resistance provides opportunity to breed high yielding rice varieties suitable for drought-prone areas. Although
considerable efforts were made in mapping QTLs associated with drought-resistance traits in rice, most of the studies involved
indica × japonica crosses and hence, the drought-resistance alleles were contributed mostly by japonica ecotypes. It is desirable to look for genetic variation within indica ecotypes adapted to target environment (TE) as the alleles from japonica ecotype may not be expressed under lowland conditions. A subset of 250 recombinant inbred lines (RILs) of F8 generation derived from two indica rice lines (IR20 and Nootripathu) with contrasting drought-resistance traits were used to map the QTLs for morpho-physiological
and plant production traits under drought stress in the field in TE. A genetic linkage map was constructed using 101 polymorphic
PCR-based markers distributed over the 12 chromosomes covering a total length of 1,529 cM in 17 linkage groups with an average
distance of 15.1 cM. Composite interval mapping analysis identified 22 QTLs, which individually explained 4.8–32.2% of the
phenotypic variation. Consistent QTLs for drought-resistance traits were detected using locally adapted indica ecotypes, which may be useful for rainfed rice improvement. 相似文献
14.
Honggen Zhang Lijia Zhang Hua Si Yongshen Ge Guohua Liang Minghong Gu Shuzhu Tang 《Molecular breeding : new strategies in plant improvement》2016,36(7):102
Three-line japonica hybrids have been developed mainly on Chinsurah Boro II (BT)-type cytoplasmic male sterile (CMS) lines of Oryza sativa L., but the unstable sterility of some BT-type CMS lines, and the threat of genetic vulnerability when using a single cytoplasm source, have inhibited their use in rice cultivation. Previously, the sterility of Honglian (HL)-type japonica CMS lines derived from common red-awned wild rice (Oryza rufipogon) has been proven to be more stable than that of BT-type japonica CMS lines. Here, we genetically characterized HL-type japonica CMS lines and the restorer-of-fertility (Rf) gene for breeding HL-type japonica hybrids. HL-type japonica CMS lines displayed stained abortive pollen grains, unlike HL-type indica CMS lines. The BT-type japonica restorer lines, which contain Rf, had different capabilities to restore HL-LiuqianxinA (HL-LqxA), an HL-type japonica CMS line, and the restorers for the HL-type japonica CMS lines could be selected from the preexisting BT-type japonica restorers in rice production. A genetic analysis showed that the restoration of normal fertility to HL-LqxA was controlled by a major gene and was affected by minor effector genes and/or modifiers. The major Rf in SiR2982, a BT-type japonica restorer, was mapped to a ~100-kb physical region on chromosome 10, and was demonstrated to be Rf5 (Rf1a) by sequencing. Furthermore, Rf5 partially restored fertility and had a dosage effect on HL-type japonica CMS lines. These results will be helpful for the development of HL-type japonica hybrids. 相似文献
15.
This paper discusses a number of experiments performed, involving the fusion by an electric field of mesophyll protoplasts
from Solanum tuberosum cv. Bintje, S. tuberosum dihaploid clones 243, 299 and the wild tuberous disease-resistant species S. bulbocastanum and S. pinnatisectum. Three fusion experiments (S. bulbocastanum + S. tuberosum dihaploid 243, S. pinnatisectum + S. tuberosum cv. Bintje and S. pinnatisectum + S. tuberosum dihaploid 299) yielded 542 calli, the 52 ones of which produced shoots. Obtained regenerants were estimated by the flow-cytometry (FC)
and RAPD analysis to determine hybrid plants.The utilisation of the FC as a useful method for detecting somatic hybrids is
also discussed in this paper. The combination S. bulbocastanum + S. tuberosum dihaploid 243 led to the creation of eight somatic hybrids, the combination S. pinnatisectum + S. tuberosum cv. Bintje yielded four somatic hybrids and the combination S. pinnatisectum + S. tuberosum dihaploid 299 resulted in no hybrid regenerants. Morphology in vitro, growth vigour and production of tuber-like structures
were evaluated in hybrid plants. Plants were transferred in vivo for further estimation (acclimatization, habitus evaluation
and tuberization ability). 相似文献
16.
Mapping of quantitative trait loci associated with ultraviolet-B resistance in rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) 总被引:2,自引:0,他引:2
Sato T Ueda T Fukuta Y Kumagai T Yano M 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,107(6):1003-1008
The detection of quantitative trait loci (QTLs) associated with UV-B resistance in rice should allow their practical application in breeding for such a complex trait, and may lead to the identification of gene characteristics and functions. Considerable variation in UV-B resistance exists within cultivated rice (Oryza sativa L.), but its detailed genetic control mechanism has not been well elucidated. We detected putative QTLs associated with the resistance to enhanced UV-B radiation in rice, using 98 BC1F5 (backcross inbred lines; BILs) derived from a cross between Nipponbare (a resistant japonica rice variety) and Kasalath (a sensitive indica rice variety). We used 245 RFLP markers to construct a framework linkage map. BILs and both parents were grown under visible light with or without supplemental UV-B radiation in a growth chamber. In order to evaluate UV-B resistance, we used the relative fresh weight of aerial parts (RFW) and the relative chlorophyll content of leaf blades (RCC). The BIL population exhibited a wide range of variation in RFW and RCC. Using composite interval mapping with a LOD threshold of 2.9, three putative QTLs associated with both RFW and RCC were detected on chromosomes 1, 3 and 10. Nipponbare alleles at the QTLs on chromosome 1 and 10 increased the RFW and RCC, while the Kasalath allele at the QTL on chromosome 3 increased both traits. Furthermore, the existence of both QTLs on chromosomes 1 and 10 for UV-B resistance was confirmed using chromosome segment substitution lines. Plants with Kasalath alleles at the QTL on chromosome 10 were more sensitive to UV-B radiation than plants with them on chromosome 1. These results also provide the information not only for the improvement of UV-B resistance in rice though marker-associated selection, but also for the identification of UV-B resistance mechanisms by using near-isogenic lines.Communicated by D.J. Mackill 相似文献
17.
Rakshit S Rakshit A Matsumura H Takahashi Y Hasegawa Y Ito A Ishii T Miyashita NT Terauchi R 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(4):731-743
Polymorphism over ∼26 kb of DNA sequence spanning 22 loci and one region distributed on chromosomes 1, 2, 3 and 4 was studied
in 30 accessions of cultivated rice, Oryza sativa, and its wild relatives. Phylogenetic analysis using all the DNA sequences suggested that O. sativa ssp. indica and ssp. japonica were independently domesticated from a wild species O. rufipogon. O. sativa ssp. indica contained substantial genetic diversity (π = 0.0024), whereas ssp. japonica exhibited extremely low nucleotide diversity (π = 0.0001) suggesting the origin of the latter from a small number of founders. O. sativa ssp. japonica contained a larger number of derived and fixed non-synonymous substitutions as compared to ssp. indica. Nucleotide diversity and genealogical history substantially varied across the 22 loci. A locus, RLD15 on chromosome 2, showed
a distinct genealogy with ssp. japonica sequences distantly separated from those of O. rufipogon and O. sativa ssp. indica. Linkage disequilibrium (LD) was analyzed in two different regions. LD in O. rufipogon decays within 5 kb, whereas it extends to ∼50 kb in O. sativa ssp. indica.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
18.
Chiharu Nakashima Tadashi Akashi Yukiko Takahashi Toshihiro Yamada Mitsuteru Akiba Takao Kobayashi 《Mycoscience》2007,48(4):250-254
Scolecostigmina chibaensis on Pinus parviflora is described as a new species. Cercospora cryptomeriicola Sawada on Cryptomeria japonica is transferred to the genus Pseudocercospora, based on the morphological characteristics of the type specimen and newly collected specimens. 相似文献
19.
Rice (Oryza sativa ssp. indica) is an important economic crop in many countries. Although a variety of conventional methods have been developed to improve
this plant, manipulation by genetic engineering is still complicated. We have established a system of multiple shoot regeneration
from rice shoot apical meristem. By use of MS medium containing 4 mg L−1 thidiazuron (TDZ) multiple shoots were successfully developed directly from the meristem without an intervening callus stage.
All rice cultivars tested responded well on the medium and regenerated to plantlets that were readily transferred to soil
within 5–8 weeks. The tissue culture system was suitable for Agrobacterium-mediated transformation and different factors affecting transformation efficiency were investigated. Agrobacterium strain EHA105 containing the plasmid pCAMBIA1301 was used. The lowest concentration of hygromycin B in combined with either
250 mg L−1 carbenicillin or 250 mg L−1 cefotaxime to kill the rice shoot apical meristem was 50 mg L−1 and carbenicillin was more effective than cefotaxime. Two-hundred micromolar acetosyringone had no effect on the efficiency
of transient expression. Sonication of rice shoot apical meristem for 10 s during bacterial immersion increased transient
GUS expression in three-day co-cultivated seedlings. The gus gene was found to be integrated into the genome of the T0 transformant plantlets. 相似文献
20.
Xifeng Chen Jianwei Pan Jing Cheng Guanghuai Jiang Yang Jin Zhimin Gu Qian Qian Wenxue Zhai Bojun Ma 《Molecular breeding : new strategies in plant improvement》2009,24(4):387-395
Spotted leaf 5 (spl5), a lesion mimic mutant, was first identified in rice (Oryza sativa L.) japonica cv. Norin8 in 1978. This mutant exhibits spontaneous disease-like lesions in the absence of any pathogens and resistance
to rice blast and bacterial blight; however, the target gene has not yet been isolated. In the present study, we employed
a map-based cloning strategy to finely map the spl5 gene. In an initial mapping with 100 F2 individuals (spl5/spl5) derived from a cross between the spl5 mutant and indica cv. 93-11, the spl5 gene was located in a 3.3-cM region on chromosome 7 using six simple sequence repeat (SSR) markers. In a high-resolution
genetic mapping, two F2 populations with 3,149 individuals (spl5/spl5) were derived from two crosses between spl5 mutant and two indica cvs. 93-11 and Zhefu802 and six sequence-tagged site (STS) markers were newly developed. Finally, the spl5 gene was mapped to a region of 0.048 cM between two markers SSR7 and RM7121. One BAC/PAC contig map covering these markers’
loci and the spl5 gene was constructed through Pairwise BLAST analysis. Our bioinformatics analysis shows that the spl5 gene is located in the 80-kb region between two markers SSR7 and RM7121 with a high average ratio of physical to genetic
distance (1.67 Mb/cM) and eighteen candidate genes. The analysis of these candidate genes indicates that the spl5 gene represents a novel class of regulators controlling cell death and resistance response in plants. 相似文献