Partial resistance in lettuce to downy mildew (Bremia lactucae). 2. Differential interactions between plant genotypes and fungus races and the relationship of latent period, infection frequency and number of infected leaves with the level of partial resistance

Euphytica ◽  
1982 ◽  
Vol 31 (1) ◽  
pp. 73-83 ◽  
Author(s):  
A. H. Eenink ◽  
W. Bijker ◽  
A. Den Toom
Keyword(s):  
Latent Period ◽  
Downy Mildew ◽  
Partial Resistance ◽  
Infection Frequency ◽  
Bremia Lactucae ◽  
Relationship Of ◽  
The Relationship

scholarly journals Evaluation of Components of Partial Resistance to Oat Crown Rust Using Digital Image Analysis

Plant Disease ◽  
2003 ◽  
Vol 87 (6) ◽  
pp. 667-674 ◽  
Author(s):  
J. E. Díaz-Lago ◽  
D. D. Stuthman ◽  
K. J. Leonard
Keyword(s):  
Image Analysis ◽  
Latent Period ◽  
Digital Image ◽  
Partial Resistance ◽  
Digital Image Analysis ◽  
Digital Images ◽  
Crown Rust ◽  
Infection Frequency ◽  
Sources Of Resistance ◽  
Resistance Components

Digital image analysis is an objective and nondestructive method potentially capable of providing accurate and precise estimates of disease resistance components. This study was conducted to quantify components of partial resistance to crown rust through the analysis of sequential digital images of inoculated leaves of adult oat plants, and to compare components found in two sources of resistance unrelated genetically. Uredinium density, relative infection frequency, latent period, days to first pustule appearance, uredinium size, and disease progress rates were assessed on three oat lines (RS-line 3W-C2R-9-3b, MN-841801, Starter) in two greenhouse experiments. Resistant lines had fewer and smaller uredinia, and these appeared later than in the susceptible check. Relative infection frequency, latent period, and uredinium size were equally important components in the expression of the partial resistance to crown rust, and the two sources of resistance could not be differentiated by any of the variables studied. The analysis of sequential digital images of diseased leaves produced precise estimates of partial resistance components and disease progress rates.

scholarly journals Modeling Leaf Age-Related Susceptibility and Rust Eruption Dynamics in Peanut

2000 ◽  
Vol 27 (1) ◽  
pp. 7-10 ◽  
Author(s):  
Z. Z. Wang ◽  
K. H. Lin
Keyword(s):  
Leaf Age ◽  
Relative Number ◽  
Eruption Dynamics ◽  
Infection Frequency ◽  
Degree Days ◽  
Age Related ◽  
Relationship Of ◽  
The Relationship ◽  
Field Inoculum ◽  
Over Time

Abstract To improve simulation of epidemics of peanut rust, information on the effects of leaf age and pustule eruption dynamics is needed. An analysis was made of the change of leaf susceptibility of rust with leaf aging using plants exposed to field inoculum. The youngest leaf was most susceptible to rust infection. As leaves aged, susceptibility decreased quickly. The relationship of infection frequency (Y, relative number of pustules) to leaf age (X, leaf position downward on the main stem) was described by a mathematical model Y = 2.17X(-0.83). The dynamics of pustule eruption also was studied using artificial inoculation. Analysis showed that after inoculation, pustule eruption over time was distributed in a logistic pattern. Rust eruption began at 130 and reach a peek at 250 rust degree days—that is, between 7 and 15 d after inoculation. Mathematical models of leaf age-related susceptibility and rust eruption dynamics will be incorporated into simulation model of rust epidemics.

Reaction Of Barley Genotypes To Bipolaris Sorokiniana

1970 ◽  
Vol 36 (1) ◽  
pp. 123-128 ◽  
Author(s):  
MM Rahman ◽  
AKMM Alam ◽  
N Naher ◽  
SM Sharifuzzaman ◽  
MAN Uddin
Keyword(s):  
Bipolaris Sorokiniana ◽  
Lesion Size ◽  
Leaf Blight ◽  
Infection Frequency ◽  
Components Of Resistance ◽  
Barley Leaf ◽  
Relationship Of ◽  
The Relationship ◽  
Barley Genotypes ◽  
100 Seed Weight

A study on response of 29 barley genotypes resistant to Bipolaris leaf blight (Bipolaris sorokiniana) was conducted to investigate the relationship of the components of resistance of 29 barley genotypes. Data on five components of resistance viz., infection frequency (number of lesions per plant), lesion size (mm2), percent leaf area affected by lesion, percent necrotic area on leaf, and disease severity were recorded as components of resistance. The genotypes fall into four clusters. Cluster I was to be the largest having 11 genotypes which was followed by cluster III, IV, and II. Considering the overall mean performances of different clusters, genotypes of cluster II showed better performance against resistance. From the cannonical variate analysis, it was found that three components like lesion size, necrosis, and 100-seed weight were found positive for the both vector, and these characters contributed maximum towards the divergence for disease development of the barley accessions.   Keywords: Bipolaris sorokiniana; barley; leaf blight DOI: http://dx.doi.org/10.3329/bjar.v36i1.9236 BJAR 2011; 36(1): 123-128

Sign in / Sign up

Export Citation Format

Share Document