scholarly journals Identification and mapping of resistance genes to Phakopsora pachyrhizi in soybean (Glycine max L.) accession PI 594767-A

2016 ◽  
Vol 15 (3) ◽  
Author(s):  
G.A.F. Rocha ◽  
D.P. Alves ◽  
J.C. Oliveira ◽  
S.H. Brommonschenkel
Author(s):  
Rawnaq Chowdhury ◽  
Connie Tande ◽  
Emmanuel Z Byamukama

Phytophthora root and stem rot, caused by Phytophthora sojae, is an important disease of soybean (Glycine max L.) in South Dakota. Because P. sojae populations are highly diverse and resistance genes deployed in commercial soybean varieties often fail to manage the disease, this study was initiated to determine P. sojae pathotype distribution in South Dakota. A total of 216 P. sojae isolates were baited from soil collected from 422 soybean fields in South Dakota in 2013-2015 and 2017. The pathotype of each isolate was determined by inoculating 10 seedlings of 13 standard soybean P. sojae differential lines using the hypocotyl inoculation technique. Of the 216 pathotyped isolates, 48 unique pathotypes were identified. The virulence complexity of isolates ranged from virulence on one Rps gene (Rps7) to virulence on 13 Rps genes and mean complexity was 5.2. Harosoy (Rps7), Harlon (Rps1a), Williams 79 (Rps 1c), William 82 (Rps1k), Harosoy 13XX (Rps1b), were susceptible to 98, 80, 78, 73, 72% of the isolates, respectively. These results highlight the highly diverse P. sojae pathotypes in South Dakota and the likely Rps genes to fail in commercial soybean varieties


2007 ◽  
Vol 33 (3) ◽  
pp. 239-244 ◽  
Author(s):  
Marcelo Carvalho Alves ◽  
Edson Ampélio Pozza ◽  
Josimar Batista Ferreira ◽  
Dejânia Viera de Araújo ◽  
João de Cássia do Bomfim Costa ◽  
...  

A Ferrugem Asiática (Phakopsora pachyrhizi H. Sydow & P. Sydow), relatada em diversas regiões do globo terrestre de climas tropicais e subtropicais, causa redução significativa na produtividade da soja [Glycine max (L.) Merr.]. Fatores bióticos como interação patógeno-hospedeiro e abióticos influenciam o progresso da doença. Objetivou-se neste trabalho estudar os efeitos da temperatura e de períodos de molhamento foliar no progresso da Ferrugem Asiática nas cultivares Conquista, Savana e Suprema. O experimento foi conduzido no Departamento de Fitopatologia da Universidade Federal de Lavras, em junho de 2004, em câmaras de crescimento vegetal nas temperaturas de 15, 20, 25 e 30 °C e períodos de molhamento foliar de 0, 6, 12, 18 e 24 horas. A inoculação foi realizada pulverizando-se as plantas com suspensão de 10(4) uredósporos de P. pachyrhizi.mL-1 de água. Dados da incidência e da severidade foram utilizados para avaliar o progresso da doença e integrados por meio da área abaixo da curva de progresso da incidência (AACPI) e da severidade (AACPS). Modelos de regressão não-linear foram ajustados para a AACPI e AACPS. Foi calculado o volume abaixo da superfície de resposta para incidência (VASRI) e severidade (VASRS) em relação à temperatura e molhamentos foliares com o objetivo de detectar diferenças entre cultivares. Molhamentos foliares acima de 15 horas e temperaturas próximas a 20 ºC, nas 3 cultivares avaliadas, determinaram maior intensidade da Ferrugem Asiática. Temperaturas próximas a 30 e 15 ºC ocasionaram menor intensidade da doença. Períodos de molhamento foliar abaixo de 6 horas reduziram a intensidade da doença. Todas as cultivares testadas foram suscetíveis à doença, entretanto, a cultivar Conquista apresentou maior VASRI e VASRS da Ferrugem Asiática comparada às cultivares Savana e Suprema, as quais não diferiram estatisticamente. Houve diferença entre as cultivares para AACPI em cada temperatura e molhamento foliar.


Agrotecnia ◽  
2021 ◽  
pp. 31
Author(s):  
Guillermo A. Enciso-Maldonado ◽  
Marco Maidana-Ojeda ◽  
Pablo R. Machuca Aquino ◽  
Marta A. Fernández Gamarra ◽  
José A. Schlicmann-Tank

Las enfermedades son una de las mayores limitantes fitosanitarias en el cultivo de soja [Glycine max (L.) Merr.], entre ellas las enfermedades de final de ciclo (EFC) son las protagonistas en ausencia de la roya asiática de la soja (Phakopsora pachyrhizi). Este trabajo presenta los resultados de evaluaciones a campo de la eficacia de diferentes fungicidas en el control de las EFC en el cultivo de soja. El ensayo se realizó en Minga Guazú, Alto Paraná, Paraguay. Se utilizó la variedad NA 5909 RR. Los ingredientes activos evaluados fueron Bixafen + Protioconazole + Trifloxistrobin (T2), Picoxystrobin + Protioconazole (T3), Picoxystrobin + Cyproconazole (T4), Fluxapyroxad + Epoxiconazole + Pyraclostrobin (T5), (Benzovindiflupyr + Azoxistrobina) + Difenoconazole + Ciproconazole (T6), Mancozeb (T7) y Carbendazim (T8). Las aspersiones se realizaron según la ocurrencia de los estadios fenológicos R1, R3 y R5. Las principales variables evaluadas fueron la severidad, eficacia de control (EC) y rendimiento en kg ha1 . La menor severidad se observó con el T5, mientras que T8 no fue efectivo para reducir la severidad; los tratamientos T5, T6 y T2 fueron los más eficaces para controlar las EFC, diferenciándose significativamente de los demás tratamientos. Los tratamientos T2, T3, T4, T5, T6 y T7 obtuvieron los mejores rendimientos y fueron estadísticamente similares. El T8 mostró el menor rendimiento y peso de mil semillas. En conclusión, la mayoría de los fungicidas presentaron un buen control sobre las EFC, así también sobre el rendimiento de la soja.


2014 ◽  
Vol 37 (3) ◽  
pp. 225 ◽  
Author(s):  
María de los Ángeles Peña-del-Río ◽  
Nicolás Maldonado-Moreno ◽  
Arturo Díaz-Franco

La roya asiática (Phakopsora pachyrhizi) de la soya (Glycine max (L.) Merr.), hizo su aparición en 2005 en México. Las variedades comerciales comúnmente sembradas han mostrado susceptibilidad al patógeno, por lo que el presente estudio tuvo el objetivo buscar fuentes de resistencia genética a la enfermedad, a través de la reacción de 197 genotipos de soya evaluados en campo. Se establecieron dos fechas de siembra (24 de febrero y 24 de abril, 2007) y las inoculaciones se hicieron a inicio de la floración. La severidad se evaluó en la etapa R6, mediante una escala de 1(0 %) a 3 (> 30 %). Se identificaron 23 genotipos de soya resistentes a P. pachyrhizi, en ambas fechas de siembra, los cuales no exhibieron lesiones foliares.


Plant Disease ◽  
1998 ◽  
Vol 82 (5) ◽  
pp. 555-559 ◽  
Author(s):  
D. E. Kyle ◽  
C. D. Nickell ◽  
R. L. Nelson ◽  
W. L. Pedersen

Phytophthora rot, caused by Phytophthora sojae, is a damaging disease of soybean (Glycine max (L.) Merr.) throughout the soybean-producing regions of the world. The discovery of new sources of resistance in soybean is vital in maintaining control of Phytophthora rot, because races of the pathogen have been discovered that can attack cultivars with commonly used resistance genes. The objectives of this study were to investigate the distribution and diversity of Phytophthora-resistant soybean in southern China and identify sources that confer resistance to multiple races for implementation into breeding programs. Soybean accessions obtained from southern China were evaluated for their response to races 1, 3, 4, 5, 7, 10, 12, 17, 20, and 25 of P. sojae using the hypocotyl inoculation technique in the greenhouse at Urbana, Illinois in 1996 and 1997. Accessions were identified that confer resistant responses to multiple races of the pathogen. These accessions may provide sources of resistance for control of Phytophthora rot of soybean in the future. The majority of the accessions with resistance to eight or more of the ten races tested were from the provinces of Hubei, Jiangsu, and Sichuan in southern China. Based on the evaluated accessions, these provinces appear to be valuable sources of Phytophthora-resistant soybean.


2012 ◽  
Vol 14 (1) ◽  
pp. 18-25 ◽  
Author(s):  
R.M. Mussury ◽  
R. Betoni ◽  
M.A. Silva ◽  
S.P.Q. Scalon

Folhas de Glycine max (L.) Merril,infectadas pelo fungo Phakopsora pachyrhizi H. Sydow & Sydow e tratadas com extratos vegetais foram avaliadas, visando determinar in vivo as modificações anatômicas nas diferentes estruturas/tecidos foliares, além de reconhecer prováveis mecanismos de defesa. Folhas de soja cultivar 181 provenientes do quinto nó foram inoculadas com fungo e tratadas com diferentes extratos vegetais, água e álcool 70%. Para comparação foram analisadas a anatomia das folhas sadia e infectada e realizadas medidas nas estruturas/tecidos foliares. Na folha infectada, observou-se destruição da epiderme e parênquima lacunoso, visível proliferação de tricomas e cutícula espessada, principalmente na face abaxial. Observou-se a presença de compostos fenólicos nas células da epiderme quando rompida, em função do crescimento micelial. Nas folhas infectadas e tratadas com os extratos vegetais de Azadirachta indica, Maytenus ilicifolia e Allium sativum, as estruturas/tecidos vegetais apresentaram aumento de espessura por alongamento celular.


2015 ◽  
Vol 14 (4) ◽  
pp. 17718-17729 ◽  
Author(s):  
B. Rodrigues ◽  
F. Serafim ◽  
A.P.O. Nogueira ◽  
O.T. Hamawaki ◽  
L.B. de Sousa ◽  
...  

2020 ◽  
Vol 7 (4) ◽  
Author(s):  
Edevan Bedin ◽  
Andréia Caverzan ◽  
Diógenes Cecchin Silveira ◽  
Geraldo Chavarria

The Asian Soybean Rust caused by the fungus Phakopsora pachyrhizi is one of the serious phytosanitary problems faced by soybean [Glycine max (L.) Merrill], which cause up to 80% yield loss. An alternative for the integrated management of the disease is the use of mineral nutrition together with phytosanitary treatments. Thus, the objective of this study is to understand the effect of foliar fortification with copper (Cu) along with phytosanitary treatments in the soybean reaction to Rust by lignin content variation in leaf tissues, and how it reflects the yield. The experimental design was a randomized block with four replicates. Four concentrations Cu (30, 60, 90, 120 g Cu ha-1) were tested in two distinct sources (cuprous oxide and copper carbonate) together with phytosanitary treatments. Evaluations were made to determine the progression of Asian Rust severity, micronutrient content in leaves and grains, as well as lignin content in leaves. The grain yield components and productivity were also evaluated. The Cu contents in the soybean leaves and grains were influenced by foliar spraying. Foliar spray with Cu retarded the disease progression, reducing the severity of Asian Rust and positively impacting grain yield. The amount of lignin present in the leaves was altered considerably with the application of the Cu associated with phytosanitary treatments. The results suggest that the leaf nutrition with copper together with phytosanitary treatments, may reduce the rust severity and improvement the plant performance. Future research with Cu application and analysis of specific enzymes, secondary metabolites and cell wall thickness may further contribute to the understanding of the role of Cu in defence against Asian Soybean Rust.


Sign in / Sign up

Export Citation Format

Share Document