Pyramided QTL underlying tolerance to Phytophthora root rot in mega-environments from soybean cultivars ‘Conrad’ and ‘Hefeng 25’

2010 ◽  
Vol 121 (4) ◽  
pp. 651-658 ◽  
Author(s):  
Xiuping Li ◽  
Yingpeng Han ◽  
Weili Teng ◽  
Shuzheng Zhang ◽  
Kangfu Yu ◽  
...  
Keyword(s):  
Root Rot ◽  
Phytophthora Root Rot ◽  
Soybean Cultivars

Detached-petiole inoculation method to evaluate Phytophthora root rot resistance in soybean plants

2017 ◽  
Vol 68 (6) ◽  
pp. 555
Author(s):  
Yinping Li ◽  
Suli Sun ◽  
Chao Zhong ◽  
Zhendong Zhu
Keyword(s):  
Root Rot ◽  
Dominant Gene ◽  
Phytophthora Sojae ◽  
Single Dominant Gene ◽  
Phytophthora Root Rot ◽  
Inoculation Methods ◽  
Inoculation Technique ◽  
Soybean Cultivars ◽  
F2 Population ◽  
Soybean Resistance

Phytophthora root rot (PRR) caused by Phytophthora sojae, is one of the most destructive soybean diseases. The deployment of resistant cultivars is an important disease management strategy. To this aim, the development of a fast and effective method to evaluate soybean resistance to P. sojae is strategic. In this study, a detached-petiole inoculation technique was developed and its reliability was verified in soybean cultivars and segregant populations for PRR resistance. The detached-petiole and hypocotyl inoculation methods were used to assess the resistance of soybean cultivars, the F2 population of a Zhonghuang47 × Xiu94-11 cross, and the derived F2:3 population. The reactions of 13 analysed cultivars to three P. sojae isolates were consistent between the two inoculation techniques. The reactions of the F2 and F2:3 populations to isolate PsMC1 were 95.20% similar between the two inoculation methods. The segregation of the resistance and susceptibility fit a 3 : 1 ratio. Our results suggest that the detached-petiole technique is a reliable method, and reveal that the PRR resistance in Xiu94-11 is controlled by a single dominant gene. The phenotypic ratios of the tested Jikedou2 × Qichadou1 F2 population using the detached-petiole inoculation technique fit a 3 : 1 ratio (Resistance : Susceptibility). This demonstrated that Qichadou1 contains a single dominant gene conferring resistance to P. sojae. Our new detached-petiole inoculation technique is effective, reliable, non-destructive to the plant, and does not require an excessive amount of seeds. It may be suitable for the largescale screening of soybean resistance to multiple P. sojae isolates.

scholarly journals Multi-Year Evaluation of Commercial Soybean Cultivars for Resistance to Phytophthora sojae

Plant Disease ◽  
2010 ◽  
Vol 94 (3) ◽  
pp. 368-371 ◽  
Author(s):  
T. L. Slaminko ◽  
C. R. Bowen ◽  
G. L. Hartman
Keyword(s):  
Resistance Genes ◽  
Root Rot ◽  
Rapid Development ◽  
Soybean Seed ◽  
Phytophthora Sojae ◽  
Primary Methods ◽  
Phytophthora Root Rot ◽  
Soybean Cultivars ◽  
Information Program ◽  
Poorly Drained Soils

Phytophthora sojae causes damping-off, root rot, and stem rot of soybean, particularly in poorly drained soils. Soybean cultivar resistance is one of the primary methods to control this disease, with Rps1c, Rps1k, and Rps1a being the most commonly used genes. The Varietal Information Program for Soybeans (VIPS) at the University of Illinois evaluates soybean cultivars for resistance to a number of diseases including Phytophthora root rot (PRR). The objectives of this research were to evaluate PRR resistance among commercial cultivars or advanced lines, and to compare these results with the information on PRR resistance provided by the company that entered the cultivar in VIPS. Each year from 2004 to 2008, between 600 and 900 cultivars were evaluated for resistance to either race 17 or 26 of P. sojae using the hypocotyl inoculation method. P. sojae single resistance genes were reported in 1,808 or 51% of the entries based on company information. Of these, the most commonly reported resistance genes were Rps1c (50%), Rps1k (40%), and Rps1a (10%). To a much smaller degree, companies reported using Rps3a (0.3%), Rps1b (0.2%), and Rps7 (0.2%). For the duration of the 5-year testing period, almost half of the cultivars (46%) were entered in VIPS with no reported resistance genes, and only nine out of a total of 3,533 entries (less than 0.3%) reported a stacked combination of resistance genes. Agreement between company-reported genes and any resistance found in the VIPS PRR evaluation was highest for those cultivars claiming to have Rps1c (90%) and Rps1k (83%), followed by Rps1a (70%). On average, 54% of the cultivars submitted to VIPS each year were new, reflecting the rapid development and turnover of soybean cultivars provided by the soybean seed companies.

scholarly journals Cellulase Activity as a Mechanism for Suppression of Phytophthora Root Rot in Mulches

2011 ◽  
Vol 101 (2) ◽  
pp. 223-230 ◽  
Author(s):  
Brantlee Spakes Richter ◽  
Kelly Ivors ◽  
Wei Shi ◽  
D. M. Benson
Keyword(s):  
Root Rot ◽  
Phytophthora Cinnamomi ◽  
Cellulase Activity ◽  
Enzyme Concentration ◽  
Disease Suppression ◽  
In Vitro Assays ◽  
Infested Soil ◽  
Phytophthora Root Rot ◽  
Standard Curve

Wood-based mulches are used in avocado production and are being tested on Fraser fir for reduction of Phytophthora root rot, caused by Phytophthora cinnamomi. Research with avocado has suggested a role of microbial cellulase enzymes in pathogen suppression through effects on the cellulosic cell walls of Phytophthora. This work was conducted to determine whether cellulase activity could account for disease suppression in mulch systems. A standard curve was developed to correlate cellulase activity in mulches with concentrations of a cellulase product. Based on this curve, cellulase activity in mulch samples was equivalent to a cellulase enzyme concentration of 25 U ml–1 or greater of product. Sustained exposure of P. cinnamomi to cellulase at 10 to 50 U ml–1 significantly reduced sporangia production, but biomass was only reduced with concentrations over 100 U ml–1. In a lupine bioassay, cellulase was applied to infested soil at 100 or 1,000 U ml–1 with three timings. Cellulase activity diminished by 47% between 1 and 15 days after application. Cellulase applied at 100 U ml–1 2 weeks before planting yielded activity of 20.08 μmol glucose equivalents per gram of soil water (GE g–1 aq) at planting, a level equivalent to mulch samples. Cellulase activity at planting ranged from 3.35 to 48.67 μmol GE g–1 aq, but no treatment significantly affected disease progress. Based on in vitro assays, cellulase activity in mulch was sufficient to impair sporangia production of P. cinnamomi, but not always sufficient to impact vegetative biomass.

scholarly journals Phytophthora Root Rot Resistance in Soybean E00003

Crop Science ◽  
2014 ◽  
Vol 54 (2) ◽  
pp. 492-499 ◽  
Author(s):  
Zhongnan Zhang ◽  
Jianjun Hao ◽  
Jiazheng Yuan ◽  
Qijian Song ◽  
David L. Hyten ◽  
...  
Keyword(s):  
Root Rot ◽  
Phytophthora Root Rot

scholarly journals Influence of Pure Mulches on Suppressing Phytophthora Root Rot Pathogens

2013 ◽  
Vol 31 (4) ◽  
pp. 221-226 ◽  
Author(s):  
G.C. Percival
Keyword(s):  
Root Rot ◽  
Crop Production ◽  
Prunus Avium ◽  
European Beech ◽  
Dry Weight ◽  
Urban Trees ◽  
Horse Chestnut ◽  
Phytophthora Root Rot ◽  
Tree Vitality ◽  
Lesion Severity

Mulching as a means of controlling Phytophthora root rot pathogens has become recognised as a potential cultural management system within the arboricultural, nursery and landscape industry. The influence of a pure mulch, i.e., mulch derived solely from one tree species, on reducing Phytophthora root rot severity has received little study. The purpose of the conducted research was to determine if a range of pure mulches derived from European beech (Fagus sylvatica L.), common hawthorn (Crataegus monogyna JACQ), silver birch (Betula pendula ROTH.), common cherry (Prunus avium L.), evergreen oak (Quercus ilex L.) and English oak (Q. robur L.) could reduce the development and impact of pathogen severity caused by Phytophthora cactorum and P. criticola on containerised horse chestnut (Aesculus hippocastanum). Irrespective of Phytophthora pathogen, leaf area, leaf, shoot, root and total plant dry weight following application of a pure mulch was higher than non-mulched controls. Likewise, leaf chlorophyll content, chlorophyll fluorescence Fv/Fm ratios, photosynthetic rates and root carbohydrate concentration as measures of tree vitality were higher in pure mulched compared to non-mulched control trees. Application of a pure mulch had a significant influence on Phytophthora root rot lesion severity. In the case of P. cactorum root rot lesion severity was reduced by 39–63%. In the case of P. criticola root rot lesion severity was reduced by 33–61%. In conclusion, pure mulches offer positive benefits for those involved in the care and maintenance of urban trees as well as nursery, forestry, orchard and horticultural crop production where Phytophthora pathogens are problematic.

scholarly journals Evaluating the Efficacy of the Systems Approach at Mitigating Five Common Pests in Oregon Nurseries

2014 ◽  
Vol 32 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Nancy K. Osterbauer ◽  
Melissa Lujan ◽  
Gary McAninch ◽  
S. Lane ◽  
Aaron Trippe
Keyword(s):  
Root Rot ◽  
Systems Approach ◽  
Phytophthora Root Rot ◽  
Potted Plants ◽  
Foliar Blight ◽  
Total Percentage ◽  
Phytophthora Spp ◽  
Root Weevils ◽  
Pest Incidence ◽  
Point Inspection

In Oregon, the U.S. Nursery Certification (USNCP), Grower Assisted Inspection (GAIP), and Shipping Point Inspection (SPI) programs are used to certify nursery plants as pest free. To compare the programs' effectiveness for mitigating pest risk, potted plants grown within two USNCP, two GAIP, and two SPI nurseries were surveyed for Phytophthora root rot (Phytophthora spp.), Phytophthora foliar blight (Phytophthora spp.), bittercress (Cardamine spp.), snails and slugs (Class Gastropoda), and root weevils (Otiorhynchus spp.). A total of 1,635 plots were surveyed in the nurseries, with one or more pests detected in 1,003 plots. Based on the total percentage of plots found infested with a pest, significantly fewer were detected in the GAIP nurseries (55%) than in the USNCP nurseries (68%). However, bittercress incidence was significantly higher in GAIP nurseries (21%), while snails and slugs incidence was significantly higher in USNCP nurseries (49%), and Phytophthora root rot incidence was significantly higher in SPI nurseries (31%). Also, the plant families grown by the nurseries had a significant impact on pest incidence for two of the target pests, Phytophthora root rot and root weevils. While the GAIP seemed the best at mitigating pest incidence overall, none of the certification programs was consistently the most effective against all five target pests.

Factors contributing to poor lucerne persistence in southern Queensland

1977 ◽  
Vol 17 (89) ◽  
pp. 998 ◽  
Author(s):  
JAG Irwin
Keyword(s):  
Bacterial Wilt ◽  
Root Rot ◽  
Crown Rot ◽  
Wide Spread ◽  
Phytophthora Megasperma ◽  
Phytophthora Root Rot ◽  
Colletotrichum Trifolii ◽  
Disease Survey ◽  
Disease Surveys ◽  
Made In

Lucerne disease surveys made in southern Queensland have shown the presence of seven fungal root and crown diseases. The two most wide spread and serious diseases are Phytophthora root rot (Phytophthora megasperma) and Colletotrichum crown rot (Colletotrichum trifolii). The general disease survey did not reveal the presence of bacterial wilt (Corynebacterium insidiosum) in Queensland. Studies made on the survival of lucerne populations for 2.5 years at three sites in Queensland have shown that disease was the major cause of all detected plant deaths.

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