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1.
Waraluk Kasettranan Prakit Somta Peerasak Srinives 《Journal of Crop Science and Biotechnology》2009,12(1):37-42
Powdery mildew disease caused by the fungus Erysiphe polygoni D.C. is an important disease of mungbean. Loss can be more serious if the disease attacks at seedling stage. In this paper,
we report genetics of the resistance to powdery mildew disease in mungbean using a recombinant inbred line (RIL) population
derived from a cross between the susceptible parent “KPS1” and the resistant parent “VC6468-11-1A”. Five hundred and ninety-two
RILs were developed by random descending from 200 F2 plants. The population was evaluated against the fungus in field and greenhouse conditions. The data were analyzed following
a nested design for selfpollinating plants to determine genetic heritability of powdery mildew resistance. The severity of
the infestation was measured by using disease index (DI) and area under disease progress curve (AUDPC). Both values showed
continuous distribution in the RILs. Under field conditions, the narrow-sense heritability of DI and AUDPC were 0.67 and 0.48,
respectively. While under greenhouse conditions, the values were 0.68 and 0.62, respectively. The results suggested that the
resistance is quantitatively inherited with high heritability and predominantly additive gene action. To develop powdery mildew-resistant
mungbean varieties, the plant breeder can select for resistant lines by using standard selection procedures for self-pollinating
crops, viz. pedigree selection, bulk selection, early generation testing, and single-seed descent. 相似文献
2.
John A. Henning M. Shaun Townsend David H. Gent Nahla Bassil Paul Matthews Emily Buck Ron Beatson 《Euphytica》2011,180(3):411-420
Hop powdery mildew [Podosphaera macularis (Wallr.) U. Braun & S. Takam.] is best controlled via the production of resistant varieties. Recent evidence supports selection
against plant susceptibility genes to fungal pathogens as a more durable resistance mechanism than selection for resistance
genes. The objective of this study was to identify molecular-based QTLs, their genetic effects and epistasis among QTLs associated
with susceptibility to powdery mildew. Parents and offspring from the cross, ‘Perle’ × ‘USDA 19058M’, were clonally replicated
and inoculated in a greenhouse using a CRD experimental design in Corvallis, OR. DNA was extracted, purified and analyzed
via three different marker systems. Analysis of the resulting markers was based upon the “two-way pseudo-testcross” procedure.
QTL mapping using multiple interval mapping and Bayesian interval mapping analyses were performed using WinQTL Cartographer
2.5_003. Comparison amongst mapping analyses identified three persistent QTLs on three linkage groups without significant
epistatic effect upon expression. The persistent QTL on linkage group C7 had both additive and dominant effects controlling
phenotype expression. The presence or absence of the two AFLP markers bordering the QTL on C7 defined susceptibility in offspring.
This is the first report in hop identifying molecular markers linked to QTLs associated with disease susceptibility. 相似文献
3.
Powdery mildew (PM) can cause significant yield loss in mungbean and several loci conferring resistance to this disease have been identified. A restriction fragment length polymorphism (RFLP) marker (VrCS65) linked closely to one of these loci was used to screen a mungbean bacterial artificial chromosome (BAC) library and positive BAC clones identified were used to develop simple sequence repeat (SSR or microsatellite) and sequence tagged site (STS) markers. Four of the new PCR markers (including two SSRs and two STSs) co-segregated with the original RFLP marker VrCS65, and another SSR marker (VrCS SSR2) was located 0.5 cM away from it. These PCR-based and locus-specific markers could be useful in breeding cultivars with enhanced resistance to PM and in the further characterization of the locus including the isolation of gene(s) responsible for the resistance. 相似文献
4.
Hossein Hosseini Moghaddam Leen Leus Jan De Riek Johan Van Huylenbroeck Erik Van Bockstaele 《Euphytica》2012,184(3):413-427
Disease resistance is a sought-after trait in plant breeding programmes. One strategy to make resistance more durable is to
increase the number of resistance genes, thereby increasing the number of pathotypes withstood. One of the most important
diseases on roses is powdery mildew (PM) (Podosphaera pannosa). Recent studies show that pathotypes of PM and different types of resistances in roses exist. The results of this study
aim to contribute to PM resistance in roses by the development of pathotype-specific markers on a genetic map. A diploid rose
population (90 genotypes) derived from a cross between Rosa wichurana and Rosa ‘Yesterday’ was used to construct a genetic linkage map encompassing 20 AFLP primer combinations, 43 SSR, and 2 morphological
markers. By applying the F1 pseudo test cross population strategy, two parental linkage maps were constructed (parent ‘Yesterday’
536 cM; parent R. wichurana 526 cM). Both parental maps consisted of seven linkage groups with an average length of 70 cM (Kosambi) corresponding to
the seven haploid rose chromosomes. These new maps were used to identify QTLs controlling disease resistance. The offspring
population was screened for resistance to two PM pathotypes, R–E and R–P. QTLs for controlling pathotype-specific disease
resistance were mapped by applying Kruskal–Wallis rank-sum tests and simple interval mapping. With two pathotypes analysed,
nine QTL loci were detected on linkage groups 2, 3, 5 and 6, explaining 15–73% of the phenotypic variance for pathotype-specific
disease response. The genetic maps developed here will be useful for future rose breeding, pathotype-specific resistance research
and development of a consensus map for roses. 相似文献
5.
Ratanakorn Kitsanachandee Prakit Somta Orawan Chatchawankanphanich Khalid P. Akhtar Tariq Mahmud Shah Ramakrishnan M. Nair Tejinderjit S. Bains Asmita Sirari Livinder Kaur Peerasak Srinives 《Breeding Science》2013,63(4):367-373
Yellow mosaic disease (YMD) is one of the major diseases affecting mungbean (Vigna radiata (L.) Wilczek). In this study, we report the mapping of the quantitative trait locus (QTL) for mungbean yellow mosaic India virus (MYMIV) resistance in mungbean. An F8 recombinant inbred line (RIL) mapping population was generated in Thailand from a cross between NM10-12-1 (MYMIV resistance) and KPS2 (MYMIV susceptible). One hundred and twenty-two RILs and their parents were evaluated for MYMIV resistance in infested fields in India and Pakistan. A genetic linkage map was developed for the RIL population using simple sequence repeat (SSR) markers. Composite interval mapping identified five QTLs for MYMIV resistance: three QTLs for India (qYMIV1, qYMIV2 and qYMIV3) and two QTLs for Pakistan (qYMIV4 and qYMIV5). qYMIV1, qYMIV2, qYMIV3, qYMIV4 and qYMIV5 explained 9.33%, 10.61%, 12.55%, 21.93% and 6.24% of variation in disease responses, respectively. qYMIV1 and qYMIV4 appeared to be the same locus and were common to a major QTL for MYMIV resistance in India identified previously using a different resistant mungbean. 相似文献
6.
Bacterial leaf pustule (BLP) caused by Xanthomonas axonopodis pv. glycines (Xag) is a serious soybean disease. A BLP resistant genotype ‘TS-3’ was crossed with a BLP susceptible genotype ‘PK472’, and a segregating F2 mapping population was developed for genetic analysis and mapping. The F2 population segregation pattern in 15:1 susceptible/resistance ratio against Xag inoculum indicated that the resistance to BLP in ‘TS-3’ was governed by two recessive genes. A total of 12 SSR markers, five SSR markers located on chromosome 2 and seven SSR markers located on chromosome 6 were identified as linked to BLP resistance. One of the resistance loci (r1) was mapped with flanking SSR markers Sat_183 and BARCSOYSSR_02_1613 at a distance of 0.9 and 2.1 cM, respectively. Similarly, SSR markers BARCSOYSSR_06_0024 and BARCSOYSSR_06_0013 flanked the second locus (r2) at distances of 1.5 and 2.1 cM, respectively. The identified two recessive genes imparting resistance to BLP disease and the SSR markers tightly linked to these loci would serve as important genetic and molecular resources to develop BLP resistant genotypes in soybean. 相似文献
7.
Jundae Lee Jee-Hwa Hong Jae Wahng Do Jae Bok Yoon 《Journal of Crop Science and Biotechnology》2010,13(4):227-233
Pepper (Capsicum spp.) anthracnose caused by Colletotrichum spp. is a serious disease damaging pepper production in Asian monsoon regions. For QTL mapping analyses of anthracnose resistance,
an introgression BC1F2 population was made by interspecific crosses between Capsicum annuum ‘SP26’ (susceptible recurrent parent) and Capsicum baccatum ‘PBC81’ (resistant donor). Both green and red fruits were inoculated with C. acutatum ‘KSCa-1’ and C. capsici ‘ThSCc-1’ isolates and the disease reactions were evaluated by disease incidence, true lesion diameter, and overall lesion
diameter. On the whole, distribution of anthracnose resistance was skewed toward the resistant parent. It might indicate that
one or two major QTLs are present. The introgression map consisting of 13 linkage groups with a total of 218 markers (197
AFLP and 21 SSR), covering a total length of 325 cM was constructed. Composite interval mapping analysis revealed four QTLs
for resistance to ‘KSCa-1’ and three QTLs for ‘ThSCc-1’ isolate, respectively. Interestingly, the major QTLs (CaR12.2 and CcR9) for resistance to C. acutatum and C. capsici, respectively, were differently positioned but there were close links between the minor QTL CcR12.2 for C. capsici and major QTL CaR12.2 as well as the minor QTL CaR9 for C. acutatum and major QTL CcR9. These results will be helpful for marker-assisted selection and pyramiding two different anthracnose-resistant genes in
commercial pepper breeding. 相似文献
8.
Mahmoud W. F. Yaish Daynet Sosa Francisco Javier Vences Francisca Vaquero 《Euphytica》2006,152(3):397-404
Halo-blight is an important worldwide bacterial disease of common bean (Phaseolus vulgaris L.) caused by Pseudomonas syringae pv. phaseolicola. Nine races of the pathogen and five race-specific resistance genes have been previously described. However, a quantitative response to this pathogen has also been described. The objective of this study was to identify halo-blight resistance loci linked to molecular markers that could be used in resistance breeding. Chromosomal regions related to race 5 halo-blight resistance were localized on a genetic map of RAPD and AFLP molecular markers and constructed by the analysis of a “Jules” × “Canela” F2 progeny. “Jules” shows quantitative resistance to halo-blight and “Canela” is a very appreciated but susceptible Spanish bean landrace. Two QTL for resistance to halo-blight were mapped in two linkage groups. There were four large groups, with 14–22 molecular markers each, five with 4–8 markers each, and three with 2 or 3 markers each. 相似文献
9.
Mapping and validation of QTLs for resistance to an Indian isolate of Ascochyta blight pathogen in chickpea 总被引:1,自引:0,他引:1
Pratibha Kottapalli Pooran M. Gaur Sanjay K. Katiyar Jonathan H. Crouch Hutokshi K. Buhariwalla Suresh Pande Kishore K. Gali 《Euphytica》2009,165(1):79-88
Ascochyta blight (AB) caused by Ascochyta rabiei, is globally the most important foliar disease that limits the productivity of chickpea (Cicer arietinum L.). An intraspecific linkage map of cultivated chickpea was constructed using an F2 population derived from a cross between an AB susceptible parent ICC 4991 (Pb 7) and an AB resistant parent ICCV 04516. The
resultant map consisted of 82 simple sequence repeat (SSR) markers and 2 expressed sequence tag (EST) markers covering 10
linkage groups, spanning a distance of 724.4 cM with an average marker density of 1 marker per 8.6 cM. Three quantitative
trait loci (QTLs) were identified that contributed to resistance to an Indian isolate of AB, based on the seedling and adult
plant reaction. QTL1 was mapped to LG3 linked to marker TR58 and explained 18.6% of the phenotypic variance (R
2) for AB resistance at the adult plant stage. QTL2 and QTL3 were both mapped to LG4 close to four SSR markers and accounted
for 7.7% and 9.3%, respectively, of the total phenotypic variance for AB resistance at seedling stage. The SSR markers which
flanked the AB QTLs were validated in a half-sib population derived from the same resistant parent ICCV 04516. Markers TA146
and TR20, linked to QTL2 were shown to be significantly associated with AB resistance at the seedling stage in this half-sib
population. The markers linked to these QTLs can be utilized in marker-assisted breeding for AB resistance in chickpea. 相似文献
10.
Stripe (yellow) rust, caused by Puccinia striiformis Westend. f. sp. tritici Eriks. (Pst), is an important disease of wheat (Triticum aestivum L.) globally. Use of host resistance is an important strategy to manage the disease. The cultivar Flinor has temperature-sensitive
resistance to stripe rust. To map quantitative trait loci (QTLs) for these temperature-sensitive resistances, Flinor was crossed
with susceptible cultivar Ming Xian 169. The seedlings of the parents, and F1, F3 progeny were screened against Chinese yellow rust race CYR32 in controlled-temperature growth chambers under different temperature
regimes. Genetic analysis confirmed two genes for temperature-sensitive stripe rust resistance. A linkage map of SSR markers
was constructed using 130 F3 families derived from the cross. Two temperature-sensitive resistance QTLs were detected on chromosome 5B, designated QYr-tem-5B.1 and QYr-tem-5B.2, respectively, and are separated by a genetic distance of over 50 cM. The loci contributed 33.12 and 37.33% of the total
phenotypic variation for infection type, respectively, and up to 70.45% collectively. Favorable alleles of these two QTLs
came from Flinor. These two QTLs are temperature-sensitive resistance loci and different from previously reported QTLs for
resistance to stripe rust. 相似文献
11.
Huei-Mei Chen Hsin-Mei Ku Roland Schafleitner Tejinderjit S. Bains C. George Kuo Chien-An Liu Ramakrishnan M. Nair 《Euphytica》2013,191(2):205-216
Mungbean yellow mosaic Indian virus (MYMIV) and bruchid infestation are severe production constraints of mungbean in South Asia, a major global mungbean production area. Marker-assisted selection for resistance against these disorders while maintaining or even improving agronomic traits is an important step toward breeding elite mungbean varieties. This study employed recombinant inbred lines (F12) derived from a cross between MYMIV-tolerant Vigna radiata NM92 and bruchid-resistant V. radiata ssp. sublobata TC1966 to identify chromosomal locations associated with disease and insect pest resistance and seed traits. A linkage map comprising 11 linkage groups was constructed with random amplified polymorphic DNA (RAPD), sequence characterized amplified regions (SCAR), cleaved amplified polymorphic DNA (CAP), amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. Quantitative trait loci (QTLs) for MYMIV and bruchid resistance, 100 seed weight and seed germination rate were identified. Three major QTLs for MYMIV and one major bruchid resistance locus were mapped on LG 9. The resistance alleles were contributed by the MYMIV tolerant parent NM92 and the bruchid resistant parent TC1966 respectively. One of the MYMIV QTLs was tightly linked in repulsion phase to the bruchid resistance locus. In addition, three minor QTLs for MYMIV resistance were found, where the resistance alleles were contributed by TC1966. Lines combining MYMV resistance alleles from both parents have greater resistance to MYMIV than the tolerant parent. Two minor bruchid resistance QTLs were identified in TC1966. Furthermore, three QTLs each for 100 seed weight and germination rate were detected. The markers defining the QTLs identified in this study will be useful in marker-assisted breeding of improved mungbean varieties in the future. 相似文献
12.
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
13.
Xiaoling Ji Chaojie Xie Zhongfu Ni Tsomin Yang Eviatar Nevo Tzion Fahima Zhiyong Liu Qixin Sun 《Euphytica》2008,159(3):385-390
Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a devastating disease of wheat (Triticum aestivum) in China and worldwide, causing severe yield losses annually. Wild emmer (T. dicoccoides) accession IW72 collected from Israel is resistant to powdery mildew at the seedling and adult stages. Genetic analysis indicated
that the resistance was controlled by a single dominant gene, temporarily designated MlIW72. The F2 population and F3 families derived from a hybrid between IW72 and susceptible durum wheat line Mo75 were used for molecular mapping of the
resistance gene. MlIW72 was linked with SSR loci Xgwm344, Xcfa2040, Xcfa2240, Xcfa2257 and Xwmc525 on the long arm of chromosome 7A. In addition, two STS markers, MAG2185 (derived from RFLP marker PSR680) and MAG1759 (developed
from EST CD452874), were mapped close to MlIW72. All these markers were physically located in the terminal bin 0.86–1.00 of 7AL. The chromosome location and genetic mapping
results suggested that the powdery mildew resistance gene identified in wild emmer accession IW72 might be a new allele at
the Pm1 locus or a new locus closely linked to Pm1. 相似文献
14.
A. Badea F. Eudes R. J. Graf A. Laroche D. A. Gaudet R. S. Sadasivaiah 《Euphytica》2008,164(3):803-819
Fusarium head blight (FHB) caused by Fusarium species, is among the most devastating wheat diseases, causing losses in numerous sectors of the grain industry through yield
and quality reduction, and the accumulation of poisonous mycotoxins. A germplasm collection of spring and winter wheat, including
nine reference cultivars, was tested for Type II FHB resistance and deoxynivalenol (DON) content. Genetic diversity was evaluated
on the basis of Simple Sequence Repeat (SSR) markers linked to FHB resistance quantitative trait loci (QTLs) and Diversity
Arrays Technology (DArT) markers. The allele size of the SSR markers linked to FHB resistance QTLs from known resistance sources
was compared to a germplasm collection to determine the presence of these QTLs and to identify potentially novel sources of
resistance. Forty-two accessions were identified as resistant or moderately resistant to Fusarium spread, and two also had very low DON concentrations. Genetic relationships among wheat accessions were generally consistent
with their geographic distribution and pedigree. SSR analysis revealed that several resistant accessions carried up to four
of the tested QTLs. Resistant and moderately resistant lines without any known QTLs are considered to be novel sources of
resistance that could be used for further genetic studies. 相似文献
15.
The frequency of soybean white mold (Sclerotinia sclerotiorum, SWM) outbreaks has increased since 1978, and this disease is currently considered to be the second most important cause
of soybean yield loss worldwide. We have studied SWM in stems of soybean cultivar Maple Arrow, which shows partial resistance
to SWM, in an attempt to identify the quantitative trait loci (QTLs) underlying soluble pigment(s) content, which is associated
with SWM resistance. A SWM-susceptible cultivar, Hefeng 25, was crossed with Maple Arrow, and 149 F5:6 recombinant inbred lines were subsequently advanced through single-seed-descent. A total of 109 simple sequence repeat (SSR)
markers were used to construct a genetic linkage map. Three QTLs for soluble pigment content in soybean stems associated with
the resistance to SWM, namely, Qsp-1 (Satt502-Sat_159), Qsp-2 (Sat_156-Satt251), and Qsp-3 (Satt525-Satt233), were identified
in 2007 and 2008 and located onto linkage groups D1a+q, B1 and A2, respectively. The phenotypic variation (R
2) explained by these QTLs ranged from 6.29 to 15.37%. These three QTLs were not significantly related to known QTLs associated
with escape resistant mechanisms. The use of these QTLs in marker-assisted selection may contribute to improved soybean resistance
to SWM. 相似文献
16.
In several autogamous and vegetatively propagated crops, DNA markers have been used for cultivar identification. However,
allogamous crops such as bunching onion (Allium fistulosum L.) are recalcitrant to marker-aided cultivar identification, as well as hybrid seed purity tests, due to the high degree
of genetic heterogeneity within each cultivar. To aid cultivar identification and ensure its accuracy in bunching onion, we
proposed the “SSR-tagged breeding” scheme in our previous study. The feasibility of this scheme was investigated here using
a landrace of bunching onion with two populations tagged with two or four selected SSR markers. Compared with a control population,
no significant differences were detected in the agronomic traits of the SSR-tagged populations. The targeted SSR loci were
genetically uniform within each population whereas other loci maintained high heterogeneity. These results demonstrate that
the SSR-tagged breeding scheme, even with a very small number of markers, is efficient for the identification of newly bred
cultivars, and consequently for F1 purity tests, in allogamous crops in which inbreeding depression is as severe as in bunching onion. 相似文献
17.
B. Chaitieng A. Kaga O. K. Han X. W. Wang S. Wongkaew P. Laosuwan N. Tomooka D. A. Vaughan 《Plant Breeding》2002,121(6):521-525
Both restriction fragment length polymorphism (RFLP) and amplified fragment length polymorphism (AFLP) analyses were employed to map a new source of resistance to powdery mildew in mungbean. Disease scores of an F2 population derived from the cross between a moderately resistant breeding line VC1210A and a susceptible wild relative (Vigna radiata var. sublobata, accession TC1966) showed a continuous distribution and was treated as a quantitative trait. Although no significant quantitative trait loci (QTL) that can explain the variation was detected by QTL analysis based on the reconstructed RFLP linkage map, new marker loci associated with resistance were discovered by AFLP analysis. The RFLP loci detected by two of the cloned AFLP bands are associated with resistance and constitute a new linkage group. A major resistance quantitative trait locus was found on this linkage group that accounted for 64.9% of the variation in resistance to powdery mildew. One of the probes developed in this study has the potential to assist in breeding for powdery mildew resistance in mungbean. 相似文献
18.
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
19.
In this study, a F2 population derived from the cross between deep-rooted variety “Moroberekan” with shallow-rooted variety “IR20” were used
to identify and validate of SSR markers associated with root morphological traits. The F2 lines were divided into two groups. In the first group, 152 seedling having minimum of four tillers were chosen and separated
into four plantlets to plant them in polyvinyl chloride pipes for root study under well-watered (WW) condition at maturity
stage. The lines were genotyped using SSR markers. QTLs for maximum root length (MRL) and root dry weight showed co-segregation
with RM472, RM7 and RM201. The same material was forwarded to next generation (F3) to validate the linked markers under both WW and low-moisture stress (LMS) conditions. These three markers were associated
consistently with MRL across generations. In the second group, 1240 F2 plants were forwarded to F5 using SSD breeding method to test the effectiveness of the marker-assisted selection (MAS) method for drought resistant.
The high performing genotypic group was significantly superior to low performing genotypic group for MRL, grain yield, root
volume, root dry weight and root number, indicating the efficiency of MAS for root-related traits under LMS. Comparing MAS
with farmer selection in F6, the results showed that MAS group means were significantly different from farmer group means for MRL, root volume, root
dry weight and root number. Thus, MAS was combined with participatory selection to select five high-yielding and deep rooted
promising lines. Identification of stable QTL for root morphological traits under WW and LMS conditions can aid in MAS and
to introduce them into varieties with good yield potential and accepted by farmer. 相似文献
20.
Xuefei Ning Xianlei Wang Xingwang Gao Ziqiang Zhang Lihu Zhang Weili Yan Guan Li 《Euphytica》2014,195(3):345-353
Powdery mildew caused by Podosphaera xanthii is a major disease in melon. Here we report two Px race 1 strains named Px1A and Px1B in Xinjiang, which have different pathogenicities. The more pathogenic Px1B made some powdery mildew resistant genes on linkage group V (LGV) lose their resistant traits. The inheritances of resistance to Px1A and Px1B in melon Edisto47 were studied using a BC1 population derived from a cross between the resistant genotype Edisto47 and the susceptible cultivar Queen. The resistance/susceptibility segregation ratios observed in the Px1A-inoculated BC1 population and the loci of polymorphic markers indicated that resistance to Px1A was controlled by two dominant genes. Quantitative trait locus analysis identified two loci mapped on LGII and LGV, respectively, for powdery mildew resistance. However, for resistance to Px1B, Edisto47 was found to bear one dominant gene. A genetic linkage map was constructed using the Px1B-inoculated BC1 population to map the resistant gene. Comparative genomic analyses revealed that the linkage map of Pm-Edisto47-1 was collinear with the corresponding genomic region of the melon chromosome 2. Genetic analysis showed that Pm-Edisto47-1 was located between simple sequence repeat (SSR) markers CMGA36 and SSR252089, at a genetic distance of 2.1 cM to both markers. Synteny analysis showed that two genes named MELO3C015353 and MELO3C015354 were predicted as candidates for Edisto47-1 in this region. 相似文献