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1.
Jorge Luis Fuentes Fernando José Correa-Victoria Fabio Escobar Gustavo Prado Girlena Aricapa Myriam Cristina Duque Joe Tohme 《Euphytica》2008,160(3):295-304
The present work was conducted to identify microsatellite markers linked to the rice blast resistance gene Pi-1(t) for a marker-assisted selection program. Twenty-four primer pairs corresponding to 19 microsatellite loci were selected from
the Gramene database (www. gramene.org) considering their relative proximity to Pi-1(t) gene in the current rice genetic map. Progenitors and DNA bulks of resistant and susceptible families from F3 segregating populations of a cross between the near-isogenic lines C101LAC (resistant) and C101A51 (susceptible) were used
to identify polymorphic microsatellite markers associated to this gene through bulked segregant analysis. Putative molecular
markers linked to the blast resistance gene Pi-1(t) were then used on the whole progeny for linkage analysis. Additionally, the diagnostic potential of the microsatellite markers
associated to the resistance gene was also evaluated on 17 rice varieties planted in Latin America by amplification of the
specific resistant alleles for the gene in each genotype. Comparing with greenhouse phenotypic evaluations for blast resistance,
the usefulness of the highly linked microsatellite markers to identify resistant rice genotypes was evaluated. As expected,
the phenotypic segregation in the F3 generation agreed to the expected segregation ratio for a single gene model. Of the 24 microsatellite sequences tested, six
resulted polymorphic and linked to the gene. Two markers (RM1233*I and RM224) mapped in the same position (0.0 cM) with the
Pi-1(t) gene. Other three markers corresponding to the same genetic locus were located at 18.5 cM above the resistance gene, while
another marker was positioned at 23.8 cM below the gene. Microsatellite analysis on elite rice varieties with different genetic
background showed that all known sources of blast resistance included in this study carry the specific Pi-1(t) allele. Results are discussed considering the potential utility of the microsatellite markers found, for MAS in rice breeding
programs aiming at developing rice varieties with durable blast resistance based on a combination of resistance genes.
Centro Internactional de Agricultura Tropical (CIAT) institute where the research was carried out 相似文献
2.
Kei Matsushita Nobuko Yasuda Thinlay Shinzo Koizumi Taketo Ashizawa Yoshihiro Sunohara Shuichi Iida Osamu Ideta Hideo Maeda Yoshikatsu Fujita 《Euphytica》2011,180(2):273-280
The rice cultivar ‘Chumroo’ is commonly cultivated in the mid- and high-altitude areas of Bhutan. This cultivar has shown
durable blast resistance in that area, without evidence of breakdown, for over 20 years. Chumroo was inoculated with 22 blast
isolates selected from the race differential standard set of Japan. The cultivar showed resistance to all the isolates. To
identify the resistance gene(s), Chumroo was crossed with a susceptible rice cultivar, Koshihikari. The F1 plants of the cross showed resistance. Segregation analyses of 300 F3 family lines fitted the segregation ratio of 1:2:1 and indicated that a single dominant gene controls the resistance to a
blast isolate Ao 92-06-2 (race 337.1). The Chumroo resistance locus (termed Pi46(t)) was mapped between two SSR markers, RM6748 and RM5473, on the terminal region of the long arm of chromosome 4, using linkage analysis with SSR markers. The nearest marker, RM5473, was linked to the putative resistance locus at a map distance of 3.2 cM. At the chromosomal region, no true resistance genes
were identified, whereas two field resistance genes were present. Therefore, we designated Pi46(t) as a novel blast resistance locus. 相似文献
3.
4.
Sang-Nag Ahn Yeon-Kyu Kim Ha-Cheol Hong Seong-Sook Han Soo-Jin Kwon Hae-Chune Choi Huhn-Pal Moon Susan R. McCouch 《Euphytica》2000,116(1):17-22
A single dominant blast resistance gene conferring resistance to a Korean rice blast isolate was identified in rice variety
`Suweon 365'. We report the chromosomal localization and molecular mapping of this blast resistance gene designated as Pi-18, which confers resistance to Korean isolate `KI-313' of the blast pathogen. To know whether there is a relationship among
genes conditioning resistance to location-specific isolates of the blast pathogen and thereby to identify linked markers to
resistance gene for isolate KI-313 collected in Korea, RFLP markers previously reported to be linked to major blast resistance
genes in different rice germplasm and other markers mapped to nearby regions were surveyed for polymorphism between a resistant
(`Suweon 365') and a susceptible (`Chucheongbyeo') parent. Linkage associations of the RFLP markers with the resistance gene
were verified using an F2 and F3 segregating population of known blast reaction. RFLP analysis showed that Pi-18 was located near the end of chromosome 11, linked to a single copy clone RZ536 at a distance of 5.4 centiMorgans (cM) and
that this gene was different from Pi-1(t). An allelism test revealed that this gene was also different from Pi-k. Currently, a combination of RAPD and microsatellite primers is being employed to find additional markers in this region.
Tightly linked DNA markers will facilitate selection for resistant genotypes in breeding programs and provide the basis for
map based cloning of this new blast resistance gene.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
Shu-Jun Wu Huan Zhong Yong Zhou Hui Zuo Li-Hui Zhou Jin-Yan Zhu Cao-Qiu Ji Shi-Liang Gu Ming-Hong Gu Guo-Hua Liang 《Euphytica》2009,165(3):557-565
The indica variety Dular has a high level of resistance to rice stripe virus (RSV). We performed quantitative trait locus (QTL) analysis
for RSV resistance using 226 F2 clonal lines at the seedling stage derived from a cross between the susceptible japonica variety Balilla and the resistant indica variety Dular with two evaluation criteria, infection rate (IR) and disease rating index (DRI). The experiments were performed
in both 2004 and 2005. Based on IR, three putative QTLs were detected and had consistent locations in the 2 years, one QTL
was detected in the RM7324–RM3586 interval on chromosome 3. The other two QTLs were linked and located in the RM287–RM209
and RM209–RM21 intervals on the long arm of chromosome 11, and accounted for 87.8–57.8% of the total phenotypic variation
in both years. Based on DRI, three putative QTLs were also detected and had consistent locations in both years. One of them
was located in the RM1124–SSR20 interval on the short arm of chromosome 11, while the other two linked QTLs had the same chromosomal
locations on chromosome 11 as those detected by IR, and accounted for 55.7–42.9% of total phenotypic variation in both years.
In comparison to the mapping results from previous studies, one of the two linked QTLs had a chromosomal location that was
similar to Stv-b
i
, an important RSV resistance gene, while the other appeared to be a newly reported one. 相似文献
6.
This paper describes the relative efficiency of three marker systems, RAPD, ISSR, and AFLP, in terms of fingerprinting 14
rice genotypes consisting of seven temperatejaponica rice cultivars, three indica near-isogenic lines, three indica introgression lines, and one breeding line of japonica type adapted to high-altitude areas of the tropics with cold tolerance genes. Fourteen RAPD, 21 ISSR, and 8 AFLP primers
could produce 970 loci, with the highest average number of loci (92.5) generated by AFLP. Although polymorphic bands in the
genotypes were detected by all marker assays, the AFLP assay discriminated the genotypes effectively with a robust discriminating
power (0.99), followed by ISSR (0.76) and RAPD (0.61). While significant polymorphism was detected among the genotypes of
japonica and indica through analysis of molecular variance (AMOVA), relatively low polymorphism was detected within the genotypes of japonica rice cultivars. The correlation coefficients of similarity were significant for the three marker systems used, but only the
AFLP assay effectively differentiated all tested rice lines. Fingerprinting of backcross-derived resistant progenies using
ISSR and AFLP markers easily detected progenies having a maximum rate of recovery for the recurrent parent genome and suggested
that our fingerprinting approach adopting the ‘undefined-element-amplifying’ DNA marker system is suitable for incorporating
useful alleles from the indica donor genome into the genome of temperate japonica rice cultivars with the least impact of deleterious linkage drag. 相似文献
7.
Molecular mapping of a novel blast resistance gene Pi38 in rice using SSLP and AFLP markers 总被引:2,自引:0,他引:2
Blast, caused by Magnaporthe grisea, is the most devastating disease of rice worldwide. In this study, the main objective was to identify and map a new gene for blast resistance, in an indica rice cultivar ‘Tadukan’ against blast fungal isolate B157, using molecular tools. F2 segregating population was derived from ‘CO39’ (susceptible) and ‘Tadukan’ (resistant), and molecular mapping of the blast resistance gene was carried out using simple sequence length polymorphism (SSLP) and amplified fragment length polymorphism (AFLP) methods. Two SSLP markers, RM206 and RM21 and three AFLP markers (AF1: E‐aca/M‐ctt; AF2: E‐aca/M‐cat and AF3: E‐acc/M‐cac2) were identified to be linked to the resistance gene. The co‐segregation analysis using SSLP markers implied that the blast resistance gene designated Pi38 resides on rice chromosome 11. 相似文献
8.
Molecular mapping of the fertility-restoration gene Rf4 for WA-cytoplasmic male sterility in rice 总被引:4,自引:0,他引:4
The wild abortive cytoplasmic male sterility (CMS‐WA) system, an ideal type of sporophytic CMS in indica rice, is used for the large‐scale commercial production of hybrid rice. Searching for restorer genes is a good approach when phenotyping is very time‐consuming and requires the determination of spikelet sterility in testcross progeny. To establish more precisely the genetical and physical maps of the Rf4 gene, high‐resolution mapping of this locus was carried out using simple sequence repeat (SSR) markers and newly designed markers in a F2 population. The genetic linkage analysis indicated that five SSR markers (RM6737, RM304, RM171, RM5841 and RM228) on the long arm of chromosome 10 were linked with the Rf4 gene. Rf4 was flanked by two SSR markers RM171 and RM6737 at distances of 3.2 and 1.6 cM, respectively. Also, within the region between Rf4 gene and RM171, a newly designed primer pair, AB443, produced two sterile‐specific markers, AB443‐400 and AB443‐500, 0.5 and 1.03 cM from the gene. The flanking markers identified give promise for their application in molecular marker‐assisted selection (MAS) and they are also suitable for starting chromosome walking to clone Rf4 gene in the near future. 相似文献
9.
N. K. Sheeba B. C. Viraktamath S. Sivaramakrishnan M. G. Gangashetti Pawan Khera R. M. Sundaram 《Euphytica》2009,167(2):217-227
The present study was carried out with the objective to validate the molecular markers, which have been previously reported
to be linked to fertility restorer (Rf) gene(s) for WA-CMS lines of rice. Two mapping populations involving fertility restorer lines for WA-cytoplasm, viz., (i)
an F2 population derived from the cross IR58025A/KMR3R consisting of 347 plants and (ii) a BC1F1 population derived from the cross IR62829A/IR10198R//IR62829A consisting of 130 plants were analyzed. Nine SSR and three
CAPS markers reported to be linked to Rf genes along with two previously unreported SSR markers were analyzed in the mapping populations. In both the populations
studied, the trait of fertility restoration was observed to be under digenic control. Eight SSR markers (RM6100, RM228, RM171,
RM216, RM474, RM311, MRG4456 and pRf1&2) showed polymorphism between the parents of the F2 population, while the SSR markers RM6100 and RM474 showed polymorphism between the parents of both the F2 and BC1F1 populations. Only one CAPS marker, RG146FL/RL was polymorphic between the parents of the BC1F1 population. RM6100 was observed to be closely segregating with fertility restoration in both the mapping populations and
was located at a distance of ~1.2 cM. The largest phenotypic variation was accounted for the region located between RM311
and RM6100. Using the marker-trait segregation data derived from analysis of both the mapping populations, a local linkage
map of the genomic region around Rf-4, a major fertility restoration locus on Chromosome 10 was constructed, and RM6100 was observed to be very close to the gene
at a distance of 1.2 cM. The accuracy of the marker RM6100 in predicting fertility restoration was validated in 21 restorers
and 18 maintainers. RM6100 amplified the Rf-4 linked allele in a majority of the restorers with a selection accuracy of 94.87%. Through the present study, we have established
the usefulness of the marker RM6100 in marker-assisted selection for fertility restoration in segregating populations and
identification of restorers while screening rice germplasm for their fertility restoration ability. 相似文献
10.
K. Selvaraju P. Shanmugasundaram S. Mohankumar M. Asaithambi R. Balasaraswathi 《Euphytica》2007,157(1-2):35-43
Rice leaffolder (RLF) (Cnaphalocrocis medinalis (Guenée) is a destructive and widespread insect pest throughout the rice growing regions in Asia. The genetics of resistance
to RLF in rice is very complex and not thoroughly explored. The present study was conducted to detect the quantitative trait
loci (QTL) associated with RLF resistance involving 176 recombinant inbred lines (RILs) of F8 generation derived from a cross between IR36, a leaffolder susceptible variety and TNAULFR831311, a moderately resistant
indica rice culture. Simple sequence repeat (SSR) markers were used to construct specific linkage groups of rice. All the RILs were
screened to assess their level of resistance to RLF by measuring the leaf area damaged. Besides this, the length and width
of the flag leaf of each RIL were measured since these two parameters were considered as correlated traits to the RLF resistance
in rice. All the above parameters observed across the RILs showed quantitative variation. Correlation analysis revealed that
damage score based on greenhouse screening was positively correlated with length and width of the flag leaf. Out of 364 SSR
markers analysed, 90 were polymorphic between the parents. Multi-point analysis carried out on segregating 69 SSR marker loci
linkage group wise resulted in construction of linkage map with eleven groups of 42 SSR markers. Through single marker analysis,
19 SSR markers were found to have putative association with the three phenotypic traits studied. Of these markers, RM472 was
identified as a locus having major effect on RLF resistance trait based on length of the flag leaf. Interval mapping detected
two QTLs on linkage group 1. Among these QTLs, the QTL flanked by RM576–RM3412 were found to be associated with width of the
flag leaf and RLF resistance. The putative SSR markers associated with leaffolder resistance identified in the present study
may be one of the loci contributing resistance to RLF in rice. 相似文献
11.
L. Bazrkar A. J. Ali N. A. Babaeian A. A. Ebadi M. Allahgholipour K. Kazemitabar G. Nematzadeh 《Euphytica》2008,164(3):669-677
Tagging of restorer genes for wild abortive (WA) CMS source by studying a 222 individual plants from a F2 population of a cross between IR58025A × IR42686R. The restorer line IR42686R that was used in this study had been previously
derived through random mating composite population (RMCP) involving 12 parents facilitated by IR36 genetic male sterility.
Four Rf genes were tagged to simple sequence repeats (SSR) markers on chromosomes 1, 7, 10, 12 by recessive class analysis. The recombination
frequency between a positive marker and Rf locus was calculated using maximum likelihood estimator assuming that all the 46 extremely sterile individual plants were
homozygous at the targeted Rf locus. The recombination frequency between the marker and the restorer trait were converted to genetic distances using Kosambi
function. A new Rf locus designated as Rf7 on chromosome 12 was found to be linked to RM7003 at a genetic distance of 13.3 cM (LOD 6.12). We report here first, a new
molecular marker (RM 6344) linked to Rf4 locus on chromosome 7 that was previously mapped by trisomic analysis. RM443 and RM315 were flanking the Rf3 gene at a genetic distance of 4.4 (LOD 10.29) and 20.7 cM (LOD 3.98) on chromosome 1, respectively. The Rf6 was flanked on both side with SSR markers RM258 and RM591 at a genetic distance of 4.4 (LOD 10.29) and 23.3 cM (LOD 3.39)
located on chromosome 10. The random mating composite population is an excellent breeding approach to develop superior restorer
lines and for pyramiding different Rf genes of different CMS systems. Rf genes tagged with closely linked SSR markers would be facilitating marker assisted selection
(MAS) in hybrid rice breeding program by reducing time and workload for identifying potential restorers.
L. Bazrkar and A. J. Ali equally contributed to this work. 相似文献
12.
Development of molecular markers linked to the <Emphasis Type="Italic">Fom-1</Emphasis> locus for resistance to Fusarium race 2 in melon 总被引:2,自引:2,他引:0
Ali Oumouloud Maria Soledad Arnedo-Andres Rafael Gonzalez-Torres Jose María Alvarez 《Euphytica》2008,164(2):347-356
Fusarium wilt, caused by Fusarium oxysporum f. sp. melonis (F.o.m), is a worldwide soil-borne disease of melon (Cucumis melo L.). The most effective control measure available is the use of resistant varieties. Resistance to races 0 and 2 of this
fungal pathogen is conditioned by the dominant gene Fom-1. An F2 population derived from the ‘Charentais-Fom1’ × ‘TRG-1551’ cross was used in combination with bulked segregant analysis utilizing
the random amplified polymorphic DNA (RAPD) markers, in order to develop molecular markers linked to the locus Fom-1. Four hundred decamer primers were screened to identify three RAPD markers (B17649, V01578, and V061092) linked to Fom-1 locus. Fragments amplified by primers B17649 and V01578 were linked in coupling phase to Fom1, at 3.5 and 4 cM respectively, whereas V061092 marker was linked in repulsion to the same dominant resistant allele at 15.1 cM from the Fom-1 locus. These RAPDs were cloned and sequenced in order to design primers that would amplify only the target fragment. The
derived sequence characterized amplified region (SCAR) markers SB17645 and SV01574 (645 and 574 bp, respectively) were present only in the resistant parent. The SV061092 marker amplified a band of 1092 bp only in the susceptible parent. These markers are more universal than the CAPS markers
developed by Brotman et al. (Theor Appl Genet 10:337–345, 2005). The analysis of 24 melon accessions, representing several melon types, with these markers revealed that different melon
types behaved differently with the developed markers supporting the theory of multiple, independent origins of resistance
to races 0 and 2 of F.o.m. 相似文献
13.
Recently a major gene determining non-specific adult plant disease resistance against stripe rust (Puccinia striiformis) designated Yrns-B1 was mapped in wheat Triticum aestivum L. by using a cross between ‘Lgst. 79-74’ (resistant) and ‘Winzi’ (susceptible). Linkage to five Gatersleben wheat microsatellite
(GWM) markers was discovered, previously mapped on chromosome arm 3BS. In the present study this map was improved by the incorporation
of four additional GWM markers. QTL-analysis revealed high LOD values for the resistance at all nine loci, whereas the largest
LOD (20.76) was found for the newly mapped marker Xgwm1329.
Microsatellite analysis and resistance tests of a collection of old German/UK wheat varieties, including probable ancestors
of ‘Lgst.79-74’ were carried out. A high coincidence of non-specific adult plant disease resistance against stripe rust and
the presence of ‘Lgst. 79-74’ allele (117 bp) of the marker Xgwm533 was observed among the varieties tested. Linkage during the inheritance of both the resistance and the 117 bp allele of Xgwm533 was demonstrated. The probable origin of Yrns-B1 is discussed. Carriers of this resistance gene were grown on large areas since more than 100 years. To estimate the capability
of Xgwm533 as a diagnostic marker for non-specific adult plant disease resistance against stripe rust, microsatellite analysis and resistance
tests of a collection of Russian spring wheat varieties were performed. The 117 bp allele of Xgwm533 was found in about 35% of the Russian cultivars analysed, however, none of them possessed the expected disease resistance.
Thus, the utilisation of Xgwm533 as diagnostic marker seems to be restricted to certain genepools. 相似文献
14.
In order to study the function of blast resistance gene and estimate resistance scale to Pyricularia grisea Sacc., the cause of Rice Blast Disease in rice, we evaluated 58 rice genotypes for phenotypic and molecular assessment. Phenotypic tests were conducted in a blast upland nursery and also in the greenhouse by using specific races of blast IA-82 and IA-90 in the greenhouse and local races for the nursery. The traits assessed consisted of infection type (IT), percent diseased leaf area (DLA) (in both nursery and greenhouse), and lesion number (LN), lesion size (LS, mm2) only in greenhouse conditions. Molecular assessment was done by using three STS, JJ80, JJ81, and JJ113, and four microsatellite markers, RM224, RM277, RM463, and RM179 which are linked to resistance genes on rice chromosomes. Genotypes had different reactions against blast races in the phenotypic part of experiment. Consequently, all genotypes were divided into three groups with high, intermediate, and susceptible resistance. Our results indicated that partial resistant genotypes are preferable for achieving durable control. Eventually, the association test between molecular data and phenotypic results showed that there is a significant level for some of the SSR markers. This means there is at least one race-specific resistance gene in the genetic sources of these genotypes that bring about resistance functions to the blast races. These results demonstrated the existence of functional resistance genes in Iranian rice genotypes. Thus, these functional genes are responsible for some parts of resistance that have been measured in phenotypic tests. Our results could be useful for breeding programs to make some modifications in the rice germplasm and would also be applicable for the marker-assisted selection process. 相似文献
15.
Moytri RoyChowdhury Yulin Jia Aaron Jackson Melissa H. Jia Robert Fjellstrom Richard D. Cartwright 《Euphytica》2012,184(1):35-46
The Pi-z gene in rice confers resistance to a wide range of races of the rice blast fungus, Magnaporthe oryzae. The objective of this study was to characterize Pi-z in 111 rice germplasm accessions using DNA markers and pathogenicity assays. The existence of Pi-z in rice germplasm was detected by using four simple sequence repeat (SSR) markers (RM527, AP4791, AP5659-1, AP5659-5) closely
linked to Pi-z, and was verified using pathogenicity assays with an avirulent strain (IE1k) and two virulent races (IB33 and IB49). Among
111 germplasm accessions evaluated, 73 were found to contain the Pi-z gene using both SSR markers and pathogenicity assays. The remaining 38 germplasm accessions were found to be inconsistent
in their responses to the blast races IB33, IEIk and IB49 with expected SSR marker alleles, suggesting the presence of unexpected
SSR alleles and additional R gene(s). These characterized germplasm can be used for genetic studies and marker-assisted breeding for improving blast resistance
in rice. 相似文献
16.
Epidemiological field controls in different Italian locations and seedling evaluations of the ‘Thatcher’ near-isogenic lines
(NILs) carrying the leaf rust resistance genes Lr1, Lr9, Lr24 and Lr47 were conducted during 5 years of testing. These genes confirmed their effectiveness in both field and greenhouse conditions.
Moreover a backcross program was carried out by using as recurrent parents the susceptible high-quality common wheat cvs ‘Bolero’,
‘Colfiorito’, ‘Serio’ and ‘Spada’ and the ‘Thatcher’ NILs carrying the above mentioned genes as donor parents. The progenies
of different cross combinations were selected by both resistance tests and marker assisted selection using molecular markers
(STS, SCAR, CAPS) closely linked to Lr genes: a complete cosegregation was observed between the resistance genes used and the corresponding molecular markers. 相似文献
17.
Seungho Cho Jagdish Kumar Jeff L. Shultz K. Anupama F. Tefera Fred J. Muehlbauer 《Euphytica》2002,128(2):285-292
Seed traits are important considerations for improving yield and product quality of chickpea (Cicer arietinum L.). The purpose of this study was to construct an intraspecific genetic linkage map and determine map positions of genes
that confer double podding and seed traits using a population of 76 F10 derived recombinant inbred lines (RILs) from the cross of ‘ICCV-2’ (large seeds and single pods) × ‘JG-62’ (small seeds and
double podded). We used 55 sequence-tagged microsatellite sites (STMS), 20 random amplified polymorphic DNAs (RAPDs), 3inter-simple
sequence repeats (ISSR) and 2 phenotypic markers to develop a genetic map that comprised 14 linkage groups covering297.5 cM.
The gene for double podding (s) was mapped to linkage group 6 and linked to Tr44 and Tr35 at a distance of7.8 cM and 11.5 cM, respectively. The major gene
for pigmentation, C, was mapped to linkage group 8 and was loosely linked to Tr33 at a distance of 13.5 cM. Four QTLs for 100 seed weight (located
on LG4 and LG9), seed number plant-1 (LG4), days to 50% flower (LG3) were identified. This intraspecific map of cultivated chickpea is the first that includes
genes for important morphological traits. Synteny relationships among STMS markers appeared to be conserved on six linkage
groups when our map was compared to the interspecific map presented by Winter et al. (2000).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
18.
With an objective to evaluate the Bhutan rice (Oryza sativa L.) landraces for genetic diversity in blast resistance, 402 accessions viz. 352 landraces, a differential set of 32 R gene
lines and 18 modern cultivars were field-evaluated in three blast ‘hotspot’ sites followed by genetic analysis of the 352
landraces with 27 microsatellite markers. Across the sites, 19 landraces (5.4%) exhibited complete resistance with zero disease
score and 203 (58%) and 163 (46%) landraces showed high partial resistance for early leaf and panicle blast, respectively,
with disease score of four to six. Field evaluation for leaf and panicle blast at three experimental sites in Bhutan showed
best cultivar discrimination in early leaf blast at the tillering stage (heritability, h2 = 0.32) and in the panicle blast at maturity (h2 = 0.44). Subdivision of the genetic variation into cultivar groups revealed the most variation for blast severity within
the 352 landraces with h2 of 0.31 and 0.46 for early leaf and panicle blast, respectively. Cluster analysis of the landraces revealed two distinct
rice cultivar groups, which separated at dissimilarity of 0.84 according to origin of the cultivars from low, mid and high
altitude zones in Bhutan. All microsatellites were polymorphic with two to 21 different alleles per marker and a high polymorphic
information content value of 0.61. The identified blast resistant landraces were genetically diverse originating from different
rice cultivation zones. Further investigation of the resistant and partial resistant material may reveal specific blast resistance
genes, which could be useful to mitigate blast incidence in rice-producing countries. 相似文献
19.
一个粳稻来源抗稻瘟病基因的鉴定、遗传分析和基因定位 总被引:1,自引:0,他引:1
7001S是一个广谱抗稻瘟病的粳稻两用核不育系,对来自全国不同稻区的22株稻瘟病菌系均表现为高度抗性。通过构建7001S/80-4B F2群体的遗传分析和初步定位表明,F2分离单株对稻瘟病菌的抗性呈明显的抗、感双峰分布,抗感分离符合3﹕1的理论比例,说明粳稻7001S对稻瘟病菌的抗性由1对显性核基因或一个显性QTL位点控制,并将该基因初步定位于第11染色体长臂末端。进一步通过扩大遗传群体和分子标记开发,利用基于BSA的隐性群体分析技术,将目的基因精细定位于P21-2415和RM27322之间约310 kb的范围内,并获得了可用于分子标记辅助选择的紧密连锁和共分离分子标记,同时对目标基因所在区域进行基因预测,初步确定了候选基因。为进一步开展该抗稻瘟病基因的克隆、功能验证和抗病机理研究,以及通过分子标记辅助选择技术培育抗稻瘟病水稻新品种等工作奠定了基础。 相似文献
20.
Kazunori Taguchi Kazuyuki Okazaki Hiroyuki Takahashi Tomohiko Kubo Tetsuo Mikami 《Euphytica》2010,173(3):409-418
Caused by Aphanomyces cochlioides Drechsler, Aphanomyces root rot is a serious disease of sugar beet (Beta vulgaris L.), for which sources of resistance are scarce. To identify the segregation pattern of the rare resistance trait found in
Japanese sugar beet line ‘NK-310mm-O’, F1 and BC1F2 seedings, drawn from a cross between ‘NK-310mm-O’ and susceptible line ‘NK-184mm-O’, were inoculated with zoospores and their
survival evaluated in the greenhouse. Resistance segregation followed was that of a single dominant gene, which was designated
Acr1 (Aphanomyces cochlioides resistance 1). Molecular markers tightly linked to Acr1 were identified by bulked segregant analysis of two BC1F2 populations. Fourteen AFLP markers linked to Acr1 were identified, the closest located within ±3.3 cM. Three F5 lines and two BC2F1 lines, selected on the basis of their Acr1-AFLP markers, were tested for their resistance to Aphanomyces root rot in a highly infested field. Results indicated that
Acr1 conferred significant resistance to Aphanomyces root rot at the field level. Based on its linkage with CAPS marker tk, a
representative marker for chromosome III, Acr1 was located on this chromosome. The clear linkage between tk and Rhizomania resistance trait Rz1, suggests the clustering of major disease resistance genes on chromosome III. 相似文献