scholarly journals Heterodera glycines Infection Increases Incidence and Severity of Brown Stem Rot in Both Resistant and Susceptible Soybean

Plant Disease ◽  
2003 ◽  
Vol 87 (6) ◽  
pp. 655-661 ◽  
Author(s):  
G. M. Tabor ◽  
G. L. Tylka ◽  
J. E. Behm ◽  
C. R. Bronson
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Stem Rot ◽  
Growth Chamber ◽  
Susceptible Genotype ◽  
Brown Stem Rot ◽  
Soybean Cultivars ◽  
Phialophora Gregata ◽  
Soybean Genotypes

Growth chamber experiments were conducted to investigate whether parasitism by Heterodera glycines, the soybean cyst nematode, increases incidence and severity of brown stem rot (BSR) of soybean, caused by Phialophora gregata, in both resistant and susceptible soybean cultivars. Soybean genotypes with various combinations of resistance and susceptibility to both pathogens were inoculated with P. gregata alone or P. gregata plus H. glycines. In most tests of H. glycines-susceptible genotypes, incidence and severity of internal stem discoloration, characteristic of BSR, was greater in the presence than in the absence of H. glycines, regardless of susceptibility or resistance to BSR. There was less of an increasing effect of H. glycines on stem symptoms in genotypes resistant to both BSR and H. glycines; however, P. gregata colonization of these genotypes was increased. Stems of both a BSR-resistant and a BSR-susceptible genotype were colonized earlier by P. gregata in the presence than in the absence of H. glycines. Our findings indicate that H. glycines can increase the incidence and severity of BSR in soybean regardless of resistance or susceptibility to either pathogen.

scholarly journals Soybean Stem Colonization by Genotypes A and B of Cadophora gregata Increases with Increasing Population Densities of Heterodera glycines

Plant Disease ◽  
2006 ◽  
Vol 90 (10) ◽  
pp. 1297-1301 ◽  
Author(s):  
G. M. Tabor ◽  
G. L. Tylka ◽  
C. R. Bronson
Keyword(s):  
Population Density ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Stem Rot ◽  
Population Densities ◽  
Brown Stem Rot ◽  
Phialophora Gregata ◽  
Soybean Genotypes ◽  
Genotype A

Growth chamber experiments were conducted to investigate whether parasitism by increasing population densities of Heterodera glycines, the soybean cyst nematode, increases the incidence and severity of stem colonization by the aggressive genotype A and the mild genotype B of Cadophora gregata (Phialophora gregata), causal agents of brown stem rot of soybeans. Soybean genotypes with three combinations of resistance and susceptibility to H. glycines and genotype A of C. gregata were inoculated with each genotype of C. gregata alone or each genotype with two population densities of H. glycines eggs, 1,500 or 10,000 per 100 cm3 of soil. Stems of two H. glycines-susceptible soybeans were more colonized by both aggressive and mild genotypes of C. gregata in the presence of high than in the presence of low H. glycines population density.

scholarly journals Resistance to Phialophora gregata Is Expressed in the Stems of Resistant Soybeans

Plant Disease ◽  
2003 ◽  
Vol 87 (8) ◽  
pp. 970-976 ◽  
Author(s):  
G. M. Tabor ◽  
G. L. Tylka ◽  
S. C. Cianzio ◽  
C. R. Bronson
Keyword(s):  
Stem Length ◽  
Stem Rot ◽  
Growth Chamber ◽  
Inoculation Methods ◽  
Brown Stem Rot ◽  
Phialophora Gregata ◽  
Foliar Symptoms ◽  
Soybean Genotypes ◽  
Soybean Plants ◽  
Resistant Genotypes

Growth chamber experiments were conducted to determine if resistance to Phialophora gregata, the causal agent of brown stem rot (BSR) of soybean, is expressed in the stems of resistant soybean genotypes. Upon introduction of the pathogen into the base of stems of 2-week-old seedlings, the fungus advanced with the growing tips of plants of susceptible genotypes but lagged behind in resistant genotypes. Five weeks after introduction of the pathogen, both mean percent stem length colonized by P. gregata and mean percentage of symptomatic trifoliate leaflets were significantly less for resistant than for susceptible genotypes. These results indicate that resistance can be expressed in the stems of resistant soybean plants and suggest that stem inoculation methods may be useful for assessing resistance to P. gregata. Also, in our experiments, internal stem discoloration was not as useful as colonization and foliar symptoms in discriminating resistant from susceptible genotypes.

scholarly journals Genetics of resistance to soybean cyst nematode, Heterodera glycines ichione (Race 3), in a brazilian soybean population

1999 ◽  
Vol 22 (2) ◽  
pp. 257-260 ◽  
Author(s):  
Antonio Orlando Mauro ◽  
Antonio Luiz de Oliveira ◽  
Sonia Marli Z. Mauro
Keyword(s):  
Soybean Cyst Nematode ◽  
Environmental Effect ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Genetics Of Resistance ◽  
Soybean Cultivars ◽  
Soybean Genotypes ◽  
Qualitative Nature ◽  
Very High

A study was made of the genetics of resistance to the soybean cyst nematode, race 3, in a population derived from crosses between the Brazilian soybean genotypes BR 90-4722 and FT-Cristalina. Crosses between the two parents were made, the F1 and F2 generations were obtained and the population was analyzed for the number of cysts found in each plant of each generation as well as the type of reaction to the nematode. The results showed that resistance to the cyst nematode in this soybean population is of a qualitative nature and conditioned by three genes, one dominant and two recessives. The heritability of the character was very high (0.96), with minimum environmental effect, which means that this population is suitable for the development of soybean cultivars resistant to the cyst nematode.

scholarly journals Brown Stem Rot and its Interaction with the Soybean Cyst Nematode

2006 ◽  
Author(s):  
G. M. Tabor ◽  
G. L. Tylka ◽  
C. R. Bronson
Keyword(s):  
Soybean Cyst Nematode ◽  
Cyst Nematode ◽  
Stem Rot ◽  
Brown Stem Rot

Registration of ‘IAR1902 SCN’ Cultivar Resistant to Soybean Cyst Nematode and Brown Stem Rot

2019 ◽  
Vol 13 (3) ◽  
pp. 334-344
Author(s):  
S. R. Cianzio ◽  
P. R. Arelli ◽  
S. Swaminathan ◽  
M. K. Bhattacharyya ◽  
G. Gebhart ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Cyst Nematode ◽  
Stem Rot ◽  
Brown Stem Rot

scholarly journals Resistance to Brown Stem Rot in Soybean Germ Plasm with Resistance to the Soybean Cyst Nematode

Plant Disease ◽  
2004 ◽  
Vol 88 (7) ◽  
pp. 761-768 ◽  
Author(s):  
T. J. Hughes ◽  
N. C. Kurtzweil ◽  
B. W. Diers ◽  
C. R. Grau
Keyword(s):  
Soybean Cyst Nematode ◽  
Field Experiments ◽  
Germ Plasm ◽  
Cyst Nematode ◽  
Stem Rot ◽  
Brown Stem Rot ◽  
Resistant Cultivars ◽  
Greenhouse Experiments ◽  
Scn Resistance ◽  
Pi 88788

The soybean cyst nematode (SCN) and Phialophora gregata f. sp. sojae, the causal agent of brown stem rot (BSR), are two pathogens of soybean commonly found in the same field throughout the north-central United States. Field experiments designed to study the role of SCN-resistant germ plasm in soybean production have led to data suggesting that some sources of SCN resistance also may provide resistance to BSR. Soybean germ plasm with resistance to SCN was evaluated in greenhouse and field environments for resistance to BSR development based on the percentage of host tissue symptomatic of BSR. Comparison of SCN-resistant cultivars and plant introductions (PI) to standard BSR-resistant and -susceptible checks were conducted in two greenhouse experiments using a root-dip inoculation with a single isolate of P. gregata. For both greenhouse experiments, PI 209332 was the only source of SCN resistance with resistance to BSR similar to standard BSR-resistant checks. Nine other sources of SCN resistance, including PI 88788 and Peking, expressed BSR symptom severity similar to BSR-susceptible checks. Cultivars derived from most SCN-resistant sources, including PI 209332, also were susceptible to BSR development, while four of the five cultivars derived from PI 88788 were highly resistant to BSR development. SCN-resistant cultivars derived from PI 88788, Peking, and PI 209332 were planted along with standard BSR-resistant and -susceptible checks at two field locations naturally infested with P. gregata and SCN or P. gregata alone. As in greenhouse experiments, four of the five cultivars derived from PI 88788 expressed resistance to BSR development equal to or better than standard BSR-resistant checks at both locations. In contrast, cultivars derived from PI 209332 and Peking expressed varying levels of disease development depending on field environment. Yields observed for PI 88788-derived cultivars were higher than BSR-resistant checks regardless of the presence of SCN. Data from both greenhouse and field experiments suggest that cvs. Williams and Williams 82 may contain a gene or genes for BSR resistance that require one or more modifier genes, possibly located in the genome of PI 88788, for complete expression.

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