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1.
Kazi S Shultz J Afzal J Johnson J Njiti VN Lightfoot DA 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,116(7):967-977
Soybean [Glycine max (L.) Merr.] cultivars show differences in their resistance to both the leaf scorch and root rot of sudden death syndrome
(SDS). The syndrome is caused by root colonization by Fusarium virguliforme (ex. F. solani f. sp. glycines). Root susceptibility combined with reduced leaf scorch resistance has been associated with resistance to Heterodera glycines HG Type 1.3.6.7 (race 14) of the soybean cyst nematode (SCN). In contrast, the rhg1 locus underlying resistance to Hg Type 0 was found clustered with three loci for resistance to SDS leaf scorch and one for
root infection. The aims of this study were to compare the inheritance of resistance to leaf scorch and root infection in
a population that segregated for resistance to SCN and to identify the underlying quantitative trait loci (QTL). “Hartwig”,
a cultivar partially resistant to SDS leaf scorch, F. virguliforme root infection and SCN HG Type 1.3.6.7 was crossed with the partially susceptible cultivar “Flyer”. Ninety-two F5-derived
recombinant inbred lines and 144 markers were used for map development. Four QTL found in earlier studies were confirmed.
One contributed resistance to leaf scorch on linkage group (LG) C2 (Satt277; P = 0.004, R
2 = 15%). Two on LG G underlay root infection at R8 (Satt038; P = 0.0001 R
2 = 28.1%; Satt115; P = 0.003, R
2 = 12.9%). The marker Satt038 was linked to rhg1 underlying resistance to SCN Hg Type 0. The fourth QTL was on LG D2 underlying resistance to root infection at R6 (Satt574;
P = 0.001, R
2 = 10%). That QTL was in an interval previously associated with resistance to both SDS leaf scorch and SCN Hg Type 1.3.6.7.
The QTL showed repulsion linkage with resistance to SCN that may explain the relative susceptibility to SDS of some SCN resistant
cultivars. One additional QTL was discovered on LG G underlying resistance to SDS leaf scorch measured by disease index (Satt130;
P = 0.003, R
2 = 13%). The loci and markers will provide tagged alleles with which to improve the breeding of cultivars combining resistances
to SDS leaf scorch, root infection and SCN HG Type 1.3.6.7.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
2.
Common loci underlie field resistance to soybean sudden death syndrome in Forrest,Pyramid, Essex,and Douglas 总被引:8,自引:0,他引:8
Njiti VN Meksem K Iqbal MJ Johnson JE Kassem MA Zobrist KF Kilo VY Lightfoot DA 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(2-3):294-300
Soybean [Glycine max (L.) Merr.] sudden death syndrome (SDS) caused by Fusarium solani f. sp. glycines results in severe yield losses. Resistant cultivars offer the most-effective protection against yield losses but resistant
cultivars such as ’Forrest’ and ’Pyramid’ vary in the nature of their response to SDS. Loci underlying SDS resistance in ’Essex’ × Forrest
are well defined. Our objectives were to identify and characterize loci and alleles that underlie field resistance to SDS
in Pyramid×’Douglas’. SDS disease incidence and disease severity were determined in replicated field trials in six environments
over 4 years. One hundred and twelve polymorphic DNA markers were compared with SDS disease response among 90 recombinant
inbred lines from the cross Pyramid×Douglas. Two quantitative trait loci (QTLs) for resistance to SDS derived their beneficial
alleles from Pyramid, identified on linkage group G by BARC-Satt163 (261-bp allele, P=0.0005, R2=16.0%) and linkage group N by BARC-Satt080 (230-bp allele, P=0.0009, R2=15.6%). Beneficial alleles of both QTLs were previously identified in Forrest. A QTL for re- sistance to SDS on linkage group
C2 identified by BARC-Satt307 (292-bp allele, P=0.0008, R2=13.6%) derived the beneficial allele from Douglas. A beneficial allele of this QTL was previously identified in Essex. Recombinant
inbred lines that carry the beneficial alleles for all three QTLs for resistance to SDS were significantly (P≤0.05) more resistant than other recombinant inbred lines . Among these recombinant inbred lines resistance to SDS was environmentally
stable. Therefore, gene pyramiding will be an effective method for developing cultivars with stable resistance to SDS.
Received: 20 October 1999 / Accepted: 22 May 2001 相似文献
3.
Samreen Kazi J. Shultz J. Afzal Rizwan Hashmi Mohammed Jasim Jason Bond Prakash R. Arelli David A. Lightfoot 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,120(3):633-644
Soybean [Glycine max (L.) Merr.] cultivars varied in their resistance to different populations of the soybean cyst nematode (SCN), Heterodera glycines, called HG Types. The rhg1 locus on linkage group G was necessary for resistance to all HG types. However, the loci for resistance to H. glycines HG Type 1.3- (race 14) and HG Type 1.2.5- (race 2) of the soybean cyst nematode have varied in their reported locations.
The aims were to compare the inheritance of resistance to three nematode HG Types in a population segregating for resistance
to SCN and to identify the underlying quantitative trait loci (QTL). ‘Hartwig’, a soybean cultivar resistant to most SCN HG
Types, was crossed with the susceptible cultivar ‘Flyer’. A total of 92 F5-derived recombinant inbred lines (RILs; or inbred
lines) and 144 molecular markers were used for map development. The rhg1 associated QTL found in earlier studies were confirmed and shown to underlie resistance to all three HG Types in RILs (Satt309;
HG Type 0, P = 0.0001 R
2 = 22%; Satt275; HG Type 1.3, P = 0.001, R
2 = 14%) and near isogeneic lines (NILs; or iso-lines; Satt309; HG Type 1.2.5-, P = 0.001 R
2 = 24%). A new QTL underlying resistance to HG Type 1.2.5- was detected on LG D2 (Satt574; P = 0.001, R
2 = 11%) among 14 RILs resistant to the other HG types. The locus was confirmed in a small NIL population consisting of 60
plants of ten genotypes (P = 0.04). This QTL (cqSCN-005) is located in an interval previously associated with resistance to both SDS leaf scorch from
‘Pyramid’ and ‘Ripley’ (cqSDS-001) and SCN HG Type 1.3- from Hartwig and Pyramid. The QTL detected will allow marker assisted
selection for multigenic resistance to complex nematode populations in combination with sudden death syndrome resistance (SDS)
and other agronomic traits. 相似文献
4.
Ming Pei You Brandon Lancaster Krishnapillai Sivasithamparam Martin John Barbetti 《Plant and Soil》2008,302(1-2):203-211
In Australia, in the past, pasture legumes were rotated mainly with cereals, but increasingly these rotations now involve
pasture legumes with a wider range of crops, including legumes. This increasing frequency of the leguminous host in the rotation
system may be associated with increased root rots in legumes in the current pasture-crop rotations. The primary aim of this
study was to see whether the pathogenicity on pasture legumes of strains of Rhizoctonia solani sourced from lupins and cereals (common crops in rotation with pastures) is associated with increased incidence of root rots
in pasture legumes in the disease conducive sandy soils of the Mediterranean regions of southern Australia. The second aim
was to determine sources of resistance among newly introduced pasture legumes to R. solani strains originating from rotational crops as this would reduce the impact of disease in the pasture phase. Fifteen pasture
legume genotypes were assessed for their resistance/susceptibility to five different zymogram groups (ZG) of the root rot
pathogen R. solani under glasshouse conditions. Of the R. solani groups tested, ZG1–5 and ZG1–4 (both known to be pathogenic on cereals and legumes) overall, caused the most severe root
disease across the genotypes tested, significantly more than ZG6 (known to be pathogenic on legumes), in turn significantly
>ZG4 (known to be pathogenic on legumes) which in turn was >ZG11 (known to be pathogenic on legumes including tropical species).
Overall, Ornithopus sativus Brot. cvs Cadiz and Margurita, Trifolium michelianum Savi. cvs Paradana and Frontier and T. purpureum Loisel. cv. Electro showed a significant level of resistance to root rot caused by R. solani ZG11 (root disease scores ≤1.2 on a 1–3 scale where 3 = maximum disease severity) while O. sativus cvs Cadiz and Erica showed a significant level of resistance to root rot caused by R. solani ZG4 (scores ≤1.2). O. compressus L. cvs Charano and Frontier, O. sativus cv. Erica, and T. purpureum cv. Electro showed some useful resistance to root rot caused by R. solani ZG6 (scores ≤1.8). This is the first time that cvs Cadiz, Electro, Frontier, Margurita and Paradana have been recognised
for their levels of resistance to root rot caused by R. solani ZG11; and similarly for cvs Cadiz and Erica against ZG4; and for cvs Charano, Erica, and Electro against ZG6. These genotypes
with resistance may also serve as useful sources of resistance in pasture legume breeding programs and also could potentially
be exploited directly into areas where other rotation crops are affected by these R. solani strains. None of the tested genotypes showed useful resistance to R. solani ZG1–4 (scores ≥2.0) or ZG1–5 (scores ≥2.5). This study demonstrates the relative potential of the various R. solani ZG strains, and particularly ZG1–4, ZG1–5, ZG4 and ZG6 to attack legume pastures and pose a significant threat to non-pasture
crop species susceptible to these strains grown in rotation with these pasture legumes. Significantly, the cross-pathogenicity
of these strains could result in the continuous build-up of inoculum of these strains that may seriously affect the productivity
eventually of legumes in all rotations. In particular, when choosing pasture legumes as rotation crops, caution needs to be
exercised so that the cultivars deployed are those with the best resistance to the R. solani ZGs most likely to be prevalent at the location. 相似文献
5.
’Forrest’ resistance to the soybean cyst nematode is bigenic: saturation mapping of the Rhg1and Rhg4 loci 总被引:1,自引:0,他引:1
K. Meksem P. Pantazopoulos V.N. Njiti L.D. Hyten P. R. Arelli D. A. Lightfoot 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(5):710-717
Field resistance to cyst nematode (SCN) race 3 (Heterodera glycines I.) in soybean [Glycine max (L.) Merr.] cv ’Forrest’ is conditioned by two QTLs: the underlying genes are presumed to include Rhg1 on linkage group G and Rhg4 on linkage group A2. A population of recombinant inbred lines (RILs) and two populations of near-isogenic lines (NILs) derived
from a cross of Forrest×Essex were used to map the loci affecting resistance to SCN. Bulked segregant analysis, with 512 AFLP
primer combinations and microsatellite markers, produced a high-density genetic map for the intervals carrying Rhg1 and Rhg4. The two QTLs involved in resistance to SCN were strongly associated with the AFLP marker EATGMCGA87 (P=0.0001, R2=24.5%) on linkage group G, and the AFLP marker ECCGMAAC405 (P=0.0001, R2 =26.2%) on linkage group A2. Two- way analysis of variance showed epistasic interaction (P=0.0001, R2 =16%) between the two loci controlling SCN resistance in Essex×Forrest recombinant inbred lines. Considering the two loci
as qualitative genes and the resistance as female index FI <5%, jointly the two loci explained over 98% of the resistance.
The locations of the two QTLs were confirmed in the NILs populations. Therefore SCN resistance in Forrest×Essex is bigenic.
High-efficiency marker-assisted selection can be performed using the markers to develop cultivars with stable resistance to
SCN.
Received: 5 November 2000 / Accepted: 23 January 2001 相似文献
6.
Ying-Hui Li Chen Zhang Zhong-Shan Gao Marinus Johannes Maria Smulders Zulu Ma Zhang-Xiong Liu Hai-Yang Nan Ru-Zhen Chang Li-Juan Qiu 《Molecular breeding : new strategies in plant improvement》2009,24(1):63-76
Soybean cyst nematode (SCN; Heterodera glycines Ichinohe) is one of the most destructive pests in the cultivation of soybean (Glycine max (L.) Merr.) worldwide. Markers based on the SCN resistance gene will enable efficient marker-assisted selection (MAS). We
sequenced the candidate gene rhg1 in six resistant and two susceptible soybean genotypes and identified 37 SNPs (single nucleotide polymorphisms) among the
sequences, of which 11 were in the coding region. Seven of these 11 SNPs led to changes in the amino acid sequence of the
gene. The amino acid sequence we obtained differs from the previously published one by a stretch of 26–27 amino acids. Six
codominant allele-specific SNP markers based on agarose gel detection were developed and tested in 70 genotypes, among which
occurred only nine different haplotypes. Two neutrality tests (Tajima’s D and Fu and Li’s F) were significant for the six SNP loci in the 70 genotypes, which is consistent with intensive directional selection. A strong
LD pattern was detected among five SNPs except 2868T > C. Two SNPs (689C > A and 757C > T) formed one haplotype (689C-757C)
that was perfectly associated with SCN resistance. The new allele-specific PCR markers located in the alleged sequence of
the rhg1 candidate gene, combined with the microsatellite marker BACR-Satt309, will significantly improve the efficiency of MAS during
the development of SCN-resistant cultivars. 相似文献
7.
Haddish Melakeberhan 《Plant and Soil》2007,301(1-2):111-121
The soybean cyst nematode (SCN, Heterodera glycines) continues to spread in soils receiving many forms of soil nutrient amendments, including small amounts of N although applied
with no particular reference to SCN and/or other stress inducing factors. The objective of this 2-year study was to test if
standard at-planting application of 112.09 kg−1 ha−1 of 06–15–40 (N–P–K) containing urea (+N), or 0–15–40 (N–P–K) (−N) or a no fertiliser check (0) affect yield of SCN resistant
(‘Jack’) and two susceptible (‘CX 252’ and ‘Kenwood-94’) soybean cultivars under high and low SCN and other soil abiotic stresses.
Yield was higher under low compared to high stress during both years, with Jack producing the highest yield and Kenwood-94
the lowest. While not statistically significant, +N tended to decrease nodulation and increase yield under low stress in all
cultivars. Nodulation was correlated positively with yield and negatively with daily nematode population density (DNPD), suggesting
potential problems for N supply under nematode infestation. The susceptible cultivars accumulated significantly more leaf
Ca and Mg than Jack, which was more pronounced in the presence of high rather than low stress, confirming known responses
to stress. At high stress, only CX 252 showed a yield increase in response to N treatment, suggesting possible physiological
adaptation mechanisms. Future research that account for the relationships amongst DNPD, frequency of sampling, and host response
to better understand confounding factors and to conclusively prove or disprove any benefits from supplementary N under SCN
infestation are discussed. 相似文献
8.
The phytotoxicity of culture filtrates of Fusarium solani f. sp. glycines, the fungus causing sudden death syndrome (SDS) of soybean (Glycine max), was tested with a viability stain of soybean suspension-cultured cells and a stem cutting assay of soybean seedlings. Suspension-cultured
cells from a SDS-susceptible soybean cultivar were exposed to cell-free culture filtrates of F. solani f. sp. glycines or other F. solani isolates for 2, 4, 6, and 8 days and then stained with 0.1% phenosafranin. The percentage of dead soybean suspension-cultured
cells was greater (P<0.001) with filtrates prepared from F. solani f. sp. glycines than from other F. solani isolates, and dead cells increased over time and with higher concentrations of culture filtrate. Cuttings of soybean seedlings
with their stems immersed in culture filtrates of F. solani f. sp. glycines isolates developed SDS-like foliar symptoms, but not when immersed in filtrates of other isolates. There was a positive correlation
(r=0.94, P<0.001) between soybean foliar symptom severity and percentage of stained soybean suspension-cultured cells. Both methods
were used to determine the phytotoxicity of fungal culture filtrates.
Received: 9 December 1997 / Revision received: 10 August 1998 / Accepted: 28 August 1998 相似文献
9.
The biodiversity and spatial distribution of macrofauna biomass are studied for 12 sites of stonesand littoral in the Neva
Estuary in 2002–2005. The highest biodiversity has been observed for chironomids and oligochaetes in the Neva Bay (36% and
24% of total species number) and in the eastern Gulf of Finland (33% and 23%). Amphipods (≤89%), molluscs (≤61%), and chironomids
(≤37%) dominate by biomass. The biomass spatial distribution vary dramatically from 9 to 37 g m−2 in the freshwater Neva Bay and from 1 to 68 g m−2 for the other Neva Estuary areas. The bottom fauna biomass in the Neva Bay is significantly lower than in the 1980–1990’s
and constitutes 20–50% of the biomass previously observed. We explain such a significant decrease by a reduction of the insects
and aborigine crustaceans Gammarus lacustris Sars and Asellus aquaticus L. The invasive amphipod species Gmelinoides fasciatus (Stebbing) dominated by biomass for the study period (3.8–15.6 g m−2, or >30% of total macrozoobenthos biomass). 相似文献
10.
M. J. Iqbal K. Meksem V. N. Njiti My. A. Kassem D. A. Lightfoot 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(2-3):187-192
Resistance to the sudden-death syndrome (SDS) of soybean (Glycine max L. Merr.), caused by Fusarium solani f. sp. glycines, is controlled by a number of quantitatively inherited loci (QTLs). Forrest showed a strong field resistance to SDS while
Essex is susceptible to SDS. A population of 100 recombinant inbred lines (RILs) derived from a cross of Essex × Forrest was
used to map the loci effecting resistance to SDS using phenotypic data obtained from six environments. Six loci involved in
resistance to SDS were identified in this population. Four of the QTLs identified by BARC-Satt214 (P = 0.0001, R2= 24.1%), BARC-Satt309 (P = 0.0001, R2 = 16.3), BARC-Satt570 (P = 0.0001, R2 = 19.2%) and a random amplified polymorphic DNA (RAPD) marker OEO21000 (P = 0.0031, R2=12.6) were located on linkage group (LG) G (Satt309 and OEO21000 were previously reported). Jointly the four QTLs on LG G explained 50% of the variation in SDS disease incidence (DI). All
the QTLs on LG G derived the beneficial allele from Forrest. Two QTLs, BARC-Satt371 (P = 0.0019, R2 = 12%) on LG C2 (previously reported) and BARC-Satt354 (P = 0.0015, R2 = 11.5%) on LG I, derived their beneficial allele from Essex and jointly explained about 40% of the variation in SDS DI.
Two-way and multi-way interactions indicated that gene action was additive among the loci underlying resistance to SDS. These
results suggest that cultivars with durable resistance to SDS can be developed via gene pyramiding.
Received: 19 January 2000 / Accepted: 30 April 2000 相似文献
11.
The effects of the blue form of Fusarium solani, the causal agent of sudden death syndrome (SDS), on Heterodera glycines were examined in the greenhouse. Roots of soybean cv. Coker 156 were inoculated with either H. glycines alone or F. solani + H. glycines in combination. Population levels of H. glycines were reduced 47% in the presence of F. solani. Life-stage development of H. glycines increased 3% in 30 days in the presence of F. solani. Fusarium solani colonized epidermal and cortical cells adjacent to developing juveniles of H. glycines and the nematode-induced syncytia within the soybean root tissue. At 40 days after inoculation, F. solani was isolated from 37% of the cysts in soil recovered from the F. solani + H. glycines combination treatment. Fusarium solani significantly affected H. glycines population density, life-stage development, and succeeding populations. 相似文献
12.
M. T. McCarville M. O’Neal G. L. Tylka C. Kanobe G. C. MacIntosh 《Entomologia Experimentalis et Applicata》2012,143(1):55-66
Soybean, Glycine max (L.) Merrill (Fabaceae), is an introduced crop to America and initially benefited from a small number of pests threatening its production. Since its rapid expansion in production beginning in the 1930s, several pests have been introduced from the native range of soybean. Our knowledge of how these pests interact and the implications for management is limited. We examined how three common economic soybean pests, the nematode Heterodera glycines Ichinohe (Nematoda: Heteroderidae), the fungus Cadophora gregata Harrington & McNew (Incertae sedis), and the aphid Aphis glycines Matsumura (Hemiptera: Aphididae), interact on soybean cyst nematode‐susceptible (SCN‐S) and soybean cyst nematode‐resistant cultivars carrying the PI 88788 resistance source (SCN‐R). From 2008 to 2010, six soybean cultivars were infested with either a single pest or all three pests in combination in a micro‐plot field experiment. Pest performance was measured in a ‘single pest’ treatment and compared with pest performance in the ‘multiple pest’ treatment, allowing us to measure the impact of SCN resistance and the presence of other soybean pests on each pest’s performance. Performance of H. glycines (80% reduction in reproduction) and A. glycines (19.8% reduction in plant exposure) was reduced on SCN‐R cultivars. Regardless of cultivar, the presence of multiple pests significantly decreased the performance of A. glycines, but significantly increased H. glycines performance. The presence of multiple pests decreased the performance of C. gregata on SCN‐S soybean cultivars (20.6% reduction in disease rating). 相似文献
13.
To investigate the biocontrol effectiveness of the antibiotic producing bacterium, Pseudomonas aureofaciens 63–28 against the phytopathogen Rhizoctonia solani AG-4 on Petri plates and in soybean roots, growth response and induction of PR-proteins were estimated after inoculation
with P. aureofaciens 63–28 (P), with R. solani AG-4 (R), or with P. aureofaciens 63–28 + R. solani AG-4 (P + R). P. aureofaciens 63–28 showed strong antifungal activity against R. solani AG-4 pathogens in Petri plates. Treatment with P. aureofaciens 63–28 alone increased the emergence rate, shoot fresh weight, shoot dry weight and root fresh weight at 7 days after inoculation,
when compared to R. solani AG-4; P + R treatment showed similar effects. Peroxidase (POD) and β-1,3-glucanase activity of P. aureofaciens 63–28 treated roots increased by 41.1 and 49.9%, respectively, compared to control roots. POD was 26% greater in P + R treated
roots than R. solani treated roots. Two POD isozymes (59 and 27 kDa) were strongly induced in P + R treated roots. The apparent molecular weight
of chitinase from treated roots, as determined through SDS-PAGE separation and comparison with standards, was about 29 kDa.
Five β-1,3-glucanase isozymes (80, 70, 50, 46 and 19 kDa) were observed in all treatments. These results suggest that inoculation
of soybean plants with P. aureofaciens 63–28 elevates plant growth inhibition by R. solani AG-4 and activates PR-proteins, potentially through induction of systemic resistance mechanisms. 相似文献
14.
QTL associated with horizontal resistance to soybean cyst nematode in Glycine soja PI464925B 总被引:1,自引:0,他引:1
Winter SM Shelp BJ Anderson TR Welacky TW Rajcan I 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(3):461-472
Soybean cyst nematode (Heterodera glycines Ichinohe; SCN) is the primary disease responsible for yield loss of soybean [Glycine max (L.) Merr.]. Resistant cultivars are an effective management tool; however, the sources currently available have common resistant
genes. Glycine soja Sieb. and Zucc., the wild ancestor of domesticated soybean, represents a diverse germplasm pool with known SCN resistance.
The objectives of this research were to: (1) determine the genetic variation and inheritance of SCN resistance in a G. max (‘S08-80’) × G. soja (PI464925B) F
4:5 recombinant inbred line (RIL) population; and (2) identify and evaluate quantitative trait loci (QTL) associated with SCN
resistance. Transgressive segregation for resistance was observed, although neither parent was resistant to the Chatham and
Ruthven SCN isolates. Broad sense heritability was 0.81 for the Ruthven and 0.91 for the Chatham isolate. Root dry weight
was a significant covariate that influenced cyst counts. One RIL [female index (FI) = 5.2 ± 1.11] was identified as resistant
to the Chatham isolate (FI < 10). Seventeen and three RILs infected with Chatham and Ruthven isolates, respectively, had mean
adjusted cyst counts of zero. Unique and novel QTL, which derived resistance from G. soja, were identified on linkage groups I, K, and O, and individually explained 8, 7 and 5% (LOD = 2.1–2.7) of the total phenotypic
variation, respectively. Significant epistatic interactions were found between pairs of SSR markers that individually may
or may not have been associated with SCN resistance, which explained between 10 and 15% of the total phenotypic variation.
Best-fit regression models explained 21 and 31% of the total phenotypic variation in the RIL population to the Chatham and
Ruthven isolates, respectively. The results of this study help to improve the understanding of the genetic control of SCN
resistance in soybean caused by minor genes resulting in horizontal resistance. The incorporation of the novel resistance
QTL from G. soja could increase the durability of SCN-resistance in soybean cultivars, especially if major gene resistance breaks down. 相似文献
15.
Experiments were established in field microplots to examine the association between Heterodera glycines and the blue form of Fusarium solani in sudden death syndrome of soybean (SDS). Foliar disease symptoms occurred on more plants per plot, appeared 3 to 7 days earlier, and were more severe on plants grown in plots infested with F. solani + H. glycines than on those inoculated with F. solani only. Yields were suppressed only in treatments that included the nematode. Numbers of H. glycines cysts and second-stage juveniles were significantly lower in plots infested with F. solani + H. glycines than with the nematode alone. Fusarium solani was able to infect cysts and eggs. 相似文献
16.
Novel quantitative trait loci for broad-based resistance to soybean cyst nematode (Heterodera glycines Ichinohe) in soybean PI 567516C 总被引:1,自引:0,他引:1
Tri D. Vuong David A. Sleper James G. Shannon Henry T. Nguyen 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,121(7):1253-1266
Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) is the most destructive pest of soybean worldwide. Host plant resistance is an effective approach to control this
pest. Plant introduction PI 567516C has been reported to be highly resistant to multiple-HG types of SCN. The objectives of
this study were to identify and map novel quantitative trait loci (QTL) for SCN resistance to six HG types (also known as
races 1, 2, 3, 5, 14, and LY1). Mapping was conducted using 250 F2:3 progeny derived from a Magellan (susceptible) × PI 567516C (resistant) cross. F6:7 recombinant inbred lines (RILs) developed from the F2:3 progeny were employed to confirm the putative QTL identified. A total of 927 polymorphic simple sequence repeats (SSR) and
single nucleotide polymorphism (SNP) markers were genotyped. Following the genetic linkage analysis, permutation tests and
composite interval mapping were performed to identify and map QTL. Four QTL were associated with resistance to either multiple-
or single-SCN HG types. Two QTL for resistance to multiple-SCN HG types were mapped to Chromosomes 10 and 18 and have not
been reported in other SCN resistance sources. New QTL were confirmed by analysis of 250 F6:7 RILs from the same population. SSR and SNP markers closely associated with these QTL can be useful for the development of
near-isogenic lines for fine-mapping and positional cloning of candidate genes for SCN resistance. 相似文献
17.
M. Ramirez J. M. Gómez D. Cantero J. Páca M. Halecký E. I. Kozliak M. Sobotka 《Folia microbiologica》2009,54(5):409-414
A strain of Acidithiobacillus thiooxidans immobilized in polyurethane foam was utilized for H2S removal in a bench-scale trickle-bed reactor, testing the limits of acidity and SO4
2− accumulation. The use of this acidophilic strain resulted in remarkable stability in the performance of the system. The reactor
maintained a >98–99 % H2S removal efficiency for c of up to 66 ppmv and empty bed residence time ≤12–15 s. Removal of >98 % H2S was achieved under steady-state conditions, over the pH range of 0.44–7.30. Despite the accumulation of acidity and SO4
2− (up to 97 g/L), the system operated without inhibition. 相似文献
18.
Analysis of Root Growth by Impedance Spectroscopy (EIS) 总被引:1,自引:0,他引:1
Electrical impedance spectroscopy (EIS) is investigated as a non-destructive method for monitoring root growth of tomato.
This paper aims to (i) review the basic principles of EIS applied to the characterisation of the different parts of the soil–root–stem-electrode
continuum, (ii) experiment the validity of the relationship between root weight and root capacitance taking into account the
influence of the soil and plant electrodes position, (iii) describe an EIS analysis of the root growth of tomato plants. All
experiments were carried out in 50 dm3 containers either in hydroponics at 930 μS for the test of root fresh or dry weight and root capacitance relationships, or
in a potting mix (oxisol) for electrode placement tests and EIS estimation of root growth. Electrical measurements of the
soil–root–stem-electrode continuum were done with a two-electrode measuring system using unpolarisable Ag–AgCl electrodes.
A ‘root cutting’ and a ‘progressively immersed root system’ experiments were carried out in order to validate the relationship
between root capacitance and root mass at 1 kHz. The effects of soil electrode and plant electrode placement were also tested,
pointing out the sensitivity of the method to the insertion height of the “plant electrode” into the stem. For the root growth
experiment, Impedance Spectra (IS) measurements were made just before harvesting the roots for dry weight and length determination.
Measurements were made 14, 22, 26 and 39 days after planting, until flowering. The IS of the soil–root–stem-electrode continuum
was modelled by a lumped electric circuit consisting of a series resistor R
0 for the soil and of four parallel resistance (R
i
)-capacitance (C
i
) circuits for the other components of the circuit. The model had nine parameters whose values were estimated by Complex Nonlinear
Least Squares curve fitting. A stepwise ascendant regression was used to identify the electrical parameters that better correlated
with root dry mass or length increment: C
3 and C
4 were well correlated with root dry mass with a r
2 of 0.975, whereas root length was explained by the combination of 1/R
3, C
3, 1/R
2 and 1/R
1 with a r
2 of 0.986. This work may be considered as a new methodological contribution to the understanding of root electrical properties
in the non-destructive diagnosis of root systems. 相似文献
19.
The biosorption equilibrium isotherms of Ni(II) onto marine brown algae Lobophora variegata, which was chemically-modified by CaCl2 were studied and modeled. To predict the biosorption isotherms and to determine the characteristic parameters for process
design, twenty-three one-, two-, three-, four- and five-parameter isotherm models were applied to experimental data. The interaction
among biosorbed molecules is attractive and biosorption is carried out on energetically different sites and is an endothermic
process. The five-parameter Fritz–Schluender model gives the most accurate fit with high regression coefficient, R
2 (0.9911–0.9975) and F-ratio (118.03–179.96), and low standard error, SE (0.0902–0.0.1556) and the residual or sum of square error, SSE (0.0012–0.1789)
values to all experimental data in comparison to other models. The biosorption isotherm models fitted the experimental data
in the order: Fritz–Schluender (five-parameter) > Freundlich (two-parameter) > Langmuir (two-parameter) > Khan (three-parameter) > Fritz–Schluender
(four-parameter). The thermodynamic parameters such as ΔG
0, ΔH
0 and ΔS
0 have been determined, which indicates the sorption of Ni(II) onto L. variegata was spontaneous and endothermic in nature. 相似文献
20.
Cuiping Yuan Guoan Zhou Yinghui Li Kejing Wang Zhi Wang Xianghua Li Ruzhen Chang Lijuan Qiu 《Molecular breeding : new strategies in plant improvement》2008,22(4):593-602
Soybean cyst nematode (SCN) (Heterodera glycines Ichinohe) is the most important pathogen in soybean production worldwide and causes substantial yield losses. An apparent
narrow genetic base of SCN resistance was observed in current elite soybean cultivars, and searching for novel SCN resistance
genes as well as novel resistance sources rather than focusing on the two important genes rhg1 and Rhg4 has become another major objective in soybean research. In the present paper we report a 1,477 bp Hs1
pro-1
homolog, named GmHs1
pro-1
. This gene was cloned from soybean variety Wenfeng 7 based on information for Hs1
pro-1
, a beet cyst nematode resistance gene in sugar beet. It has two domains, Hs1pro-1_N and Hs1pro-1_C, both of which are believed
to confer resistance to nematodes. Of the 1,477 bp sequence in GmHs1
pro-1
, an open reading frame of 1,314 bp, encoding a protein with 437 amino acids, was flanked by a 5′-untranslated region of 27 bp
and a 3′-untranslated region of 135 bp. Fourteen single-nucleotide polymorphisms (SNPs) were observed in 44 soybean accessions
including 23 wild soybeans, 8 landraces, and 13 soybean varieties (or lines), among which 5 in wild soybeans and 3 in landrace
accessions were unique. Sequence diversity analysis on the 44 soybean accessions showed π = 0.00168 and θ = 0.00218 for GmHs1
pro-1
; landraces had the highest diversity, followed by wild soybeans, with varieties (or lines) having the lowest. Although we
did not detect a significant effect of selection on GmHs1
pro-1
in the three populations, sequence diversity, unique SNPs, and phylogenetic analysis indicated a slight domestication bottleneck
and an intensive selection bottleneck. High sequence diversity, more unique SNPs, and broader representation across the phylogenetic
tree in wild soybeans and landraces indicated that wild collections and landrace accessions are invaluable germplasm for broadening
the genetic base of elite soybean varieties resistant to SCN.
C. Yuan and G. Zhou contributed to this paper equally. 相似文献