Light microscope observations of susceptible, host resistant, and nonhost resistant interactions of alfalfa with Phytophthora megasperma

1984 ◽  
Vol 62 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Sally A. Miller ◽  
Douglas P. Maxwell
Keyword(s):  
Glycine Max ◽  
Light Microscopy ◽  
Host Resistance ◽  
Light Microscope ◽  
Nonhost Resistance ◽  
Root Cells ◽  
Phytophthora Megasperma ◽  
Susceptible Host ◽  
Glycine Max L ◽  
Medicago Sativa L

Susceptibility and host resistance in alfalfa (Medicago sativa L.) to Phytophthora megasperma Drechs. f. sp. medicaginis (Pmm), an alfalfa pathogen, and nonhost resistance to P. megasperma f. sp. glycinea (Pmg), a pathogen of soybean (Glycine max (L.) Merr.) but not alfalfa, were compared by light microscopy. Zoospores of Pmm and Pmg were attracted to and became encysted upon roots of Pmm-resistant and Pmm-susceptible alfalfa seedlings within 60 min after inoculation. Cysts germinated and grew toward the roots, and penetration was usually intercellular. The extent of colonization by Pmm and Pmg was similar in all cases at 2 h after inoculation, but at 12 and 24 h colonization was much more extensive in the susceptible interaction than in the host resistant or nonhost resistant interactions. In both the host resistant and nonhost resistant interactions, root cells in contact with hyphae were plasmolyzed and (or) necrotic. Although numerous similarities exist between host resistance to Pmm and nonhost resistance to Pmg in alfalfa seedlings, nonhost resistance is apparently triggered more rapidly and (or) is more effective than host resistance in this system.

Ultrastructure of susceptible, host resistant, and nonhost resistant interactions of alfalfa with Phytophthora megasperma

1984 ◽  
Vol 62 (1) ◽  
pp. 117-128 ◽  
Author(s):  
Sally A. Miller ◽  
Douglas P. Maxwell
Keyword(s):  
Cell Walls ◽  
Hyphal Growth ◽  
Host Cells ◽  
Compatible Interaction ◽  
Root Cells ◽  
Phytophthora Megasperma ◽  
Susceptible Host ◽  
Glycine Max L ◽  
Wall Appositions ◽  
Medicago Sativa L

Zoospores of Phytophthora megasperma Drechs. f. sp. medicaginis (Pmm), an alfalfa (Medicago sativa L.) pathogen, and P. megasperma f. sp. glycinea (Pmg), a pathogen of soybean (Glycine max (L.) Merr.), were used to inoculate alfalfa seedlings from the Pmm-susceptible cultivar 'Vernal' and the Pmm-resistant breeding line M193. The susceptible interaction ('Vernal'–Pmm) was characterized by rapid disruption of host mitochondria in cells adjacent to intercellular hyphae, dissolution of host cell walls, and death of host cells 12–24 h after inoculation. Colonization of roots was extensive, and hyphae usually appeared healthy. Both host resistant (M193–Pmm) and nonhost resistant (M193 or 'Vernal' – Pmg) interactions were characterized by hyphal growth inhibition, production of cell wall appositions in root cells in contact with hyphae, and rapid necrosis of root cells. Wall appositions were more numerous in root cells in contact with Pmg than with Pmm, and rapid cell necrosis was more extensive in the nonhost resistant interaction than in the host resistant interaction. Numerous abnormalities were observed in Pmg hyphae. Nonhost resistance was expressed more rapidly and appeared to be more effective than host resistance in limiting hyphal growth. An examination of a compatible interaction of Pmg with soybean indicated that its mode of pathogenesis may be fundamentally different from that of Pmm in alfalfa.

Penetration and growth of compatible and incompatible races of Phytophthora megasperma var. sojae in soybean hypocotyl tissues differing in age

1980 ◽  
Vol 58 (24) ◽  
pp. 2594-2601 ◽  
Author(s):  
P. Stössel ◽  
G. Lazarovits ◽  
E. W. B. Ward
Keyword(s):  
Glycine Max ◽  
Epidermal Cells ◽  
Mechanisms Of Resistance ◽  
Hypocotyl Growth ◽  
Phytophthora Megasperma ◽  
Cell Layers ◽  
Glycine Max L ◽  
Incompatible Reaction ◽  
Race 4 ◽  
Incompatible Interactions

Intact 6-day old soybean hypocotyls (Glycine max L., cv. Altona) were inoculated with zoospores of Phytophthora megasperma Drechs. var. sojae Hildeb. either at the top (susceptible to compatible races, resistant to incompatible races) or the bottom (resistant to both compatible and incompatible races) and, after a 22-h incubation, were examined by light microscopy. Penetration at the top and bottom by both compatible (race 6) and incompatible (race 4) P. megasperma var. sojae was predominantly between anticlinal walls of epidermal cells. Both races, but especially race 4, also penetrated directly into the outer walls of epidermal cells, but epidermal cells rarely were invaded. Both races grew mainly intercellularly, but race 6 produced haustoria more frequently than race 4. Race 6 haustoria at the top of the hypocotyl were usually encased, those of race 4 were not. Growth of both races was equally dense in the first few cell layers, but the numbers of race 4 hyphae decreased rapidly while those of race 6 became more abundant in the deeper layers. With race 4, but not with race 6, most cells in the infected tissue were necrotic. Differences between the compatible and the incompatible interactions were not absolute; there were many unsuccessful invasion attempts by race 6 and individual hyphae of race 4 spread deeply into the tissue. At the bottom of the hypocotyl, growth of both races was more restricted. Race 6 produced fewer haustoria than at the top, and similarities to the incompatible reaction with race 4 at the top suggest that similar mechanisms of resistance may be involved.

Glycine max (L.) Merr., Vigna radiata L. and Medicago sativa L. sprouts: A natural source of bioactive compounds

2013 ◽  
Vol 50 (1) ◽  
pp. 167-175 ◽  
Author(s):  
Luís R. Silva ◽  
Maria J. Pereira ◽  
Jessica Azevedo ◽  
Rui F. Gonçalves ◽  
Patrícia Valentão ◽  
...  
Keyword(s):  
Glycine Max ◽  
Medicago Sativa ◽  
Bioactive Compounds ◽  
Vigna Radiata ◽  
Natural Source ◽  
Glycine Max L ◽  
Medicago Sativa L

OAC Musca soybean

1991 ◽  
Vol 71 (2) ◽  
pp. 497-498 ◽  
Author(s):  
W. D. Beversdorf ◽  
D. J. Hume ◽  
P. Gostovic ◽  
J. C. Muscat ◽  
S. Pararajasingham
Keyword(s):  
Glycine Max ◽  
Key Words ◽  
Soybean Cultivar ◽  
Clay Soils ◽  
Phytophthora Megasperma ◽  
Low Field ◽  
Glycine Max L ◽  
Cultivar Description

OAC Musca is a soybean (Glycine max (L.) Merr.) cultivar which is 3 d earlier than Hodgson and 2% higher in yield in Ontario trials. It has exhibited low field losses to Phytophthora megasperma f. sp. glycinea in Ontario testing, is a tall cultivar and is intended for use on clay soils. Key words: Soybean, cultivar description

RCAT Persian soybean

1991 ◽  
Vol 71 (1) ◽  
pp. 175-176
Author(s):  
G. R. Ablett ◽  
W. D. Beversdorf
Keyword(s):  
Glycine Max ◽  
Root Rot ◽  
Yield Potential ◽  
Maturity Group ◽  
Phytophthora Megasperma ◽  
Phytophthora Root Rot ◽  
Group I ◽  
Glycine Max L ◽  
Cultivar Description ◽  
Late Maturity

RCAT Persian is a mid-late Maturity Group I soybean [Glycine max L. (Merr.)] cultivar with excellent yield potential, good lodging tolerance and resistance to most races of phytophthora root rot caused by Phytophthora megasperma f. sp. glycinea (Pmg) found in Ontario. Key words: Soybean, cultivar description

Evaluation of four Japanese soybean cultivars for Rps alleles conferring resistance to Phytophthora megasperma f. sp. glycinea

1992 ◽  
Vol 72 (1) ◽  
pp. 217-220 ◽  
Author(s):  
B. D. Rennie ◽  
V. D. Beversdorf ◽  
R. I. Buzzell ◽  
T. R. Anderson
Keyword(s):  
Glycine Max ◽  
Key Words ◽  
Phytophthora Megasperma ◽  
Soybean Cultivars ◽  
Glycine Max L ◽  
Phytophthora Resistance

Four Japanese soybean (Glycine max (L) Merr.) cultivars (Fujiotome (PI 360836), Misaodaizu (PI 360839), Nezumisaya (PI 360841) and Honiku 65 (PI 360837)) were evaluated for Rps alleles conferring resistance for Phytophthora megasperma (Drechs.) f. sp. glycinea (Hildeb.) Kuan & Erwin. Fujiotome contains Rps1-a and Rps5; Misaodaizu contains Rsp1-c and Rps3; and Nezumisaya contains Rps1-b and a new allele, designated Rps? (Nezumisaya). Honiku 65 is susceptible but two variants obtained from it each contain a new Rps allele designated Rps? (OX939) and Rps? (OX940).Key words: Soybean, Phytophthora resistance

scholarly journals Carbono e nitrogênio nas frações granulométricas da matéria orgânica do solo, em sistemas de culturas sob plantio direto

2014 ◽  
Vol 38 (3) ◽  
pp. 980-989 ◽  
Author(s):  
Bruna Raquel Winck ◽  
Fabiane Machado Vezzani ◽  
Jeferson Dieckow ◽  
Nerilde Favaretto ◽  
Rudimar Molin
Keyword(s):  
Triticum Aestivum ◽  
Zea Mays ◽  
Glycine Max ◽  
Zea Mays L ◽  
Lolium Multiflorum ◽  
Triticum Aestivum L ◽  
Vicia Villosa ◽  
Avena Strigosa ◽  
Glycine Max L ◽  
Medicago Sativa L

A qualidade do solo em plantio direto está relacionada ao sistema de culturas e pode ser avaliada pelo teor de matéria orgânica particulada (>53 ∝m), em razão da funcionalidade que essa fração proporciona ao solo e à sua sensibilidade às diferenças de manejo. Visando estudar a qualidade do solo em sistemas de culturas em plantio direto, este trabalho foi conduzido em experimento de longa duração (21 anos) em Latossolo Vermelho distrófico típico nos Campos Gerais do Paraná. Seis sistemas de culturas foram avaliados, em que trigo-TR (Triticum aestivum L.), soja-SO (Glycine max L.), milho-MI (Zea mays L.), aveia-preta-AV, para cobertura (Avena strigosa Schreb.), ervilhaca-ER, para cobertura (Vicia villosa Roth); azevém-AZ, para feno (Lolium multiflorum Lam.); ou alfafa-AL, para feno (Medicago sativa L.) compuseram os seguintes sistemas: TR-SO (referência), ER-MI-AV-SO-TR-SO, ER-MI-TR-SO, AV-MI-TR-SO, AZ-MI-AZ-SO e AL-MI (milho a cada três anos). Os estoques de carbono orgânico total (COT), nitrogênio total (NT) e de C e N na matéria orgânica (MO) particulada (>53 µm) e associada aos minerais (<53 µm) foram determinados em 0-5, 5-10 e 10-20 cm. O sistema semiperene AL-MI apresentou os maiores estoques de COT e NT na camada de 0-20 cm (63,6 Mg ha-1 COT e 4,6 Mg ha-1 NT), com incrementos anuais de 0,23 Mg ha-1 COT e 0,03 Mg ha-1 NT, em relação ao sistema TR-SO. O sistema AL-MI também teve os maiores estoques de C e N na MO particulada nessa camada (12,5 e 0,91 Mg ha-1, respectivamente), por causa da maior adição de fitomassa pelas raízes e a proteção física dos resíduos orgânicos. Os menores estoques de COT e NT na camada 0-20 cm ocorreram no sistema ER-MI-TR-SO (57,8 Mg ha-1 COT e 4,03 Mg ha-1 NT), sem apresentar incremento anual em relação ao sistema TR-SO. Os estoques de C e N na MO particulada foram de 10,4 e 0,67 Mg ha-1, respectivamente. Essa tendência repetiu-se para as camadas individuais, com diferença significativa entre os sistemas na camada de 0-5 cm e não significativa, para as de 5-10 e 10-20 cm. Na média dos sistemas, a MO particulada contribuiu em torno de 30 % para o estoque total de C na camada 0-5 cm. Rotação de culturas com espécies que tenham sistema radicular ativo por mais tempo, como o sistema semiperene AL-MI, tem potencial de incrementar o estoque total de C e N, especialmente da fração MO particulada, proporcionando funcionalidade ao solo e, consequentemente, qualidade.

RCAT ALLIANCE SOYBEAN

1990 ◽  
Vol 70 (3) ◽  
pp. 855-856
Author(s):  
G. R. ABLETT ◽  
W. D. BEVERSDORF
Keyword(s):  
Glycine Max ◽  
Soybean Cultivar ◽  
Maturity Group ◽  
Phytophthora Megasperma ◽  
Group I ◽  
Glycine Max L ◽  
Cultivar Description ◽  
Late Maturity

RCAT Alliance is a late Maturity Group I soybean [Glycine max L. (Merr.)] cultivar which carries the Rps1-c gene for resistance to the major races of Phytophthora megasperma f. sp. glycinea in Ontario.Key words: Soybean, cultivar description

RCAT Angora soybean

1993 ◽  
Vol 73 (1) ◽  
pp. 179-180
Author(s):  
G. R. Ablett ◽  
J. W. Tanner
Keyword(s):  
Glycine Max ◽  
Key Words ◽  
Root Rot ◽  
Yield Potential ◽  
Maturity Group ◽  
Phytophthora Megasperma ◽  
Phytophthora Root Rot ◽  
Glycine Max L ◽  
Cultivar Description ◽  
Late Maturity

RCAT Angora is a mid-late Maturity Group II soybean (Glycine max (L.) Merr.) cultivar with excellent yield potential and resistance to most races of phytophthora root rot caused by Phytophthora megasperma f. sp. glycinea (RMG) found in Ontario. Key words: Soybean, cultivar description

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