scholarly journals A note on phytotoxicity of homodestruxin B – a compound produced by Alternaria brassicae

2005 ◽  
Vol 74 (3) ◽  
pp. 157-160 ◽  
Author(s):  
P.S. Bains ◽  
J.P. Tewari ◽  
W.A. Ayer
Keyword(s):  
Brassica Napus ◽  
Host Plants ◽  
Alternaria Brassicae ◽  
Causal Organism

Homodestruxin B, a compound produced by Alternaria brassicae, the causal organism of the blackspot disease of rapeseed, is known to be phytotoxic to the leaves of Brassica napus. In this study we found that its phytotoxicity was comparable to that of destruxin B, another toxin produced by the pathogen when tested on B. napus. Homodestruxin B caused symptoms of different severities in leaves of various non-host plants. The results suggestthat homodestruxin B is a non-host-specific toxin.

Behavior of Alternaria brassicae and its mycoparasite Nectria inventa on intact and on excised leaves of rapeseed

1978 ◽  
Vol 56 (11) ◽  
pp. 1333-1340 ◽  
Author(s):  
A. Tsuneda ◽  
W. P. Skoropad
Keyword(s):  
Brassica Napus ◽  
Vegetative Growth ◽  
Primary Infection ◽  
Epidermal Cells ◽  
Alternaria Brassicae ◽  
Intact Leaves ◽  
Germ Tubes

On intact leaves of two cultivars (cv.) of rapeseed, Midas (Brassica napus) and Torch (B. campestris), conidia of Alternaria brassicae germinated at a rate of 12.1% and 19.5%, respectively, at 9 h after inoculation. They germinated usually by producing either germ tubes or secondary conidia. Penetration of leaves by A. brassicae was abundant at 24 h and occurred either with or without the formation of appressoria. Penetration of cv. Torch leaves by the fungus occurred either directly through epidermal cells or indirectly through stomata, while cv. Midas leaves were penetrated almost exclusively through stomata. Blackspot lesions developed within 48 h after inoculation.Conidia of Nectria inventa required at least 24 h to initiate germination and 4 days to parasitize A. brassicae on intact leaves. Therefore, N. inventa did not prevent primary infection of the leaves by A. brassicae. Instead, N. inventa suppressed the vegetative growth and sporulation of A. brassicae on excised rapeseed leaves.

NATIVE HOST PLANTS OF THE LARVAE OF THE RED TURNIP BEETLE, ENTOMOSCELIS AMERICANA (COLEOPTERA: CHRYSOMELIDAE)

1984 ◽  
Vol 116 (10) ◽  
pp. 1281-1286 ◽  
Author(s):  
G. H. Gerber
Keyword(s):  
Brassica Napus ◽  
Host Plant ◽  
Introduced Species ◽  
Host Plants ◽  
Food Plant ◽  
Indigenous Species ◽  
Erysimum Cheiranthoides ◽  
Native Host

AbstractThe suitability of four indigenous species (Descurainia pinnata (Walt.) Britt., D. richardsonii (Sweet) O.E. Schulz, Lepidium densiflorum Schrad., and Rorippa palustris (L.) Besser) and one introduced species (Erysimum cheiranthoides L.) of Cruciferae as host plants for the larvae of the red turnip beetle, Entomoscelis americana Brown, was tested in the laboratory using excised true leaves as food and Brassica napus L. and D. sophia (L.) Webb as control treatments. R. palustris was a suitable food plant. D. pinnata, D. richardsonii, E. cheiranthoides, and L. densiflorum were marginally suitable. Of the four indigenous species, R. palustris probably is the only one that normally is a host plant of the larvae in nature.

Proteome-level changes in two Brassica napus lines exhibiting differential responses to the fungal pathogen Alternaria brassicae

Plant Science ◽  
2007 ◽  
Vol 172 (1) ◽  
pp. 95-110 ◽  
Author(s):  
Nidhi Sharma ◽  
Muhammad Hafizur Rahman ◽  
Stephen Strelkov ◽  
Mohan Thiagarajah ◽  
Vipan K. Bansal ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Fungal Pathogen ◽  
Alternaria Brassicae ◽  
Proteome Level ◽  
Differential Responses

Destruxin B produced by Alternaria brassicae does not induce accessibility of host plants to fungal invasion

2007 ◽  
Vol 71 (1-3) ◽  
pp. 48-54 ◽  
Author(s):  
Roxana Y. Parada ◽  
Kumiko Oka ◽  
Daisuke Yamagishi ◽  
Motoichiro Kodama ◽  
Hiroshi Otani
Keyword(s):  
Host Plants ◽  
Alternaria Brassicae ◽  
Fungal Invasion

scholarly journals Heat-dried sclerotia of Sclerotinia sclerotiorum myceliogenically germinate in water and are able to infect Brassica napus

2018 ◽  
Vol 69 (8) ◽  
pp. 765 ◽  
Author(s):  
D. W. Lane ◽  
L. G. Kamphuis ◽  
M. C. Derbyshire ◽  
M. Denton-Giles
Keyword(s):  
Brassica Napus ◽  
Sclerotinia Sclerotiorum ◽  
Host Plants ◽  
Incubation Temperature ◽  
Phytopathogenic Fungus ◽  
Nutrient Source ◽  
Abiotic Conditions ◽  
Moist Sand ◽  
Myceliogenic Germination

The phytopathogenic fungus Sclerotinia sclerotiorum forms dormant structures (termed sclerotia) that germinate myceliogenically under certain environmental conditions. During myceliogenic germination, sclerotia produce hyphae, which can infect leaves or stems of host plants directly from the ground; this is termed basal infection. This study determined which abiotic conditions were most important for promoting myceliogenic germination of sclerotia in vitro. A high sclerotium hydration level and low incubation temperature (15°C) improved mycelial growth in the presence of a nutrient source. Sclerotia incubated without a nutrient source on moist sand, vigorously myceliogenically germinated most frequently (63%) when they had been previously imbibed and then conditioned at −20°C. By far the most consistent amount of vigorous myceliogenic germination (>75%) was produced when sclerotia were heat-dried before being submerged in water. The hyphae of these sclerotia were shown to infect and proliferate on leaves of intact Brassica napus plants. This research provides a better understanding of the abiotic conditions that are likely to increase the risk of basal infection by S. sclerotiorum.

scholarly journals Dark leaf and pod spot (Alternaria brassicae) on oilseeds (Brassica napus) in Lithuania

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 384-387
Author(s):  
I. Brazauskiene ◽  
E. Petraitiene
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Meteorological Conditions ◽  
Alternaria Brassicae ◽  
Flowering Stage ◽  
Winter Oilseed Rape ◽  
Brassica Napus L ◽  
Alternaria Blight ◽  
Severity Of The Disease ◽  
Precipitation And Temperature

Dark leaf and pod spot caused by Alternaria brassicae (Berk.) Sacc. is a serious problem both in winter and spring oilseed rape (Brassica napus L.) in Lithuania. According to ten years’ data, the spread of this disease on winter oilseed rape siliques was 31.2–100%, and the severity 3.4–25.0%. The cultivars Ceres, Accord and Kasimir were used in the trials. Through the years 1997–2001 the incidence of Alternaria blight on spring oilseed rape (cv. Star and Maskot) was 94.5–100% and the severity 1.5–20.5%. Every year the severity of the disease was highly influenced by the meteorological conditions – precipitation and temperature. Fungicides, used at the end of flowering stage (DC 69) or when the first spots of the disease appeared on pods, were effective against dark pod spot.

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