scholarly journals A comparison of tuber slice and whole tuber tests for the assessment of potato resistance to tuber blight Phytophthora infestans (Mont.) de Bary

2013 ◽  
Vol 43 (1-2) ◽  
pp. 95-107 ◽  
Author(s):  
Hanna Zarzycka
Keyword(s):  
Potato Tuber ◽  
Phytophthora Infestans ◽  
Significant Influence ◽  
Fungal Growth ◽  
Depth Of Penetration ◽  
Covered Area ◽  
Tuber Blight ◽  
Potato Resistance ◽  
Different Order ◽  
Cut Rose

The resistance of potato tuber tissues to colonization by <i>Phytophthora infestans</i> was compared in 10 selected cultivars in two trials: on tuber slices and whole tubers with cut rose ends. When resistance to sporulation was used as the discriminating criterion, the selected cultivars segregated in a distinctly different order than when arranged according to other resistance components. Both the tuber slice test and the whole tuber test allowed resistance to sporulation to be assessed in the tested group of cultivars. The results obtained in both trials were reproducible and both criteria, i.e. the percentage of mycelium-covered area as well as sporulation intensity were equally useful for the assessment. No significant influence of the fungal growth though the tuber slice tissue was observed on the assessment of sporulation in comparison to the whole tuber test where the fungus grew directly on the wounded tissue after inoculation. Assessment of the percentage of the area of the tuber slice exhibiting visible necrosis was found to be useless due to the lack of correlation with two criteria of resistance to colonization used in the whole tuber test, i.e. the rate and depth of penetration. The most useful parameter of the whole tuber test appeared to be assessment of the depth of penetration of the tuber tissues. This parameter showed the least variability and good correlation with other criteria used to evaluate resistance to colonization.

scholarly journals Assessment of Barriers to Prevent the Development of Potato Tuber Blight Caused by Phytophthora infestans

Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 521-528 ◽  
Author(s):  
J. R. Glass ◽  
K. B. Johnson ◽  
M. L. Powelson
Keyword(s):  
Potato Tuber ◽  
Phytophthora Infestans ◽  
Sandy Loam ◽  
Russet Burbank ◽  
Polyethylene Film ◽  
Black Film ◽  
Tuber Infection ◽  
Tuber Blight ◽  
Hill Area ◽  
The Hill

Experiments were conducted in an irrigated, sandy loam soil to evaluate mulches and hill sizes as barriers to prevent the development of potato tuber blight caused by Phytophthora infestans. In mulching experiments, five treatments were applied to field plots of cv. Red LaSoda: 1, no mulch; 2, polyurethane spray foam in an 8-cm-diameter area immediately surrounding the plant stem; 3, black polyethylene film over the entire hill except near the stem; 4, a combination of treatments 2 and 3; and 5, a water-permeable, agricultural textile treated with copper hydroxide applied over the same hill area as in treatment 3. In 1998, the incidence of tuber blight in plots mulched with black film (treatments 3 and 4) averaged 32% compared with 56% in plots without this mulch (treatments 1 and 2). In 1999, incidence of tuber blight in plots with and without black film averaged 9 and 20%, respectively. Mulching the stem area with spray foam (treatments 2 and 3) did not reduce the incidence of blighted tubers when compared with the appropriate control. The copper-treated textile mulch (treatment 5) provided reductions in the incidence of tuber blight similar to those observed with the use of black polyethylene film. In a hill size experiment conducted once in 1998 and twice in 1999, three hill size treatments were established on cvs. Red LaSoda, Shepody, and Russet Burbank. Red LaSoda was the most susceptible and Russet Burbank the least susceptible to tuber blight. Comparison of blight incidence in tubers classified by depth in the hill revealed few differences among the hill size treatments, although over all treatments, tubers covered with more than 15 cm of soil had a lower incidence of blight (1 to 14%) than tubers with less soil cover (13 to 59%). Most tuber infections were apparently initiated in eyes and were not concentrated on a portion of the tuber such as the stolon (proximal) or distal end. The fact that black film and textile mulches reduced tuber infection indicates that inoculum of P. infestans can move from foliage to tubers through soil and that inoculum movement is not limited to large channels in the hill such as those created by the potato stems. The mulch treatments, however, provided only partial protection of tubers, limiting the practicality of such treatments to commercial producers. Hill size treatments had little effect on tuber blight incidence, indicating that adequate suppression of tuber infection in an environment conducive to late blight may be inseparably linked to adequate suppression of the foliar phase.

Validation of tuber blight (Phytophthora infestans) prediction model

2011 ◽  
Vol 30 (5) ◽  
pp. 547-553 ◽  
Author(s):  
R.O. Nyankanga ◽  
O.M. Olanya ◽  
P.S. Ojiambo ◽  
H.C. Wien ◽  
C.W. Honeycutt ◽  
...  
Keyword(s):  
Prediction Model ◽  
Phytophthora Infestans ◽  
Tuber Blight

The molecular mechanisms of Phytophthora infestans in response to reactive oxygen species (ROS) stress

2021 ◽  
Author(s):  
Xiumei Luo ◽  
Tingting Tian ◽  
Maxime Bonnave ◽  
Xue Tan ◽  
Xiaoqing Huang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Late Blight ◽  
Phytophthora Infestans ◽  
Molecular Mechanisms ◽  
Reactive Oxygen ◽  
Microbial Pathogens ◽  
Dependent Manner ◽  
Oxygen Species ◽  
Tor Signaling ◽  
Potato Resistance

Reactive oxygen species (ROS) are critical for the growth, development, proliferation, and pathogenicity of microbial pathogens; however, excessive levels of ROS are toxic. Little is known regarding the signaling cascades in response to ROS stress in oomycetes such as Phytophthora infestans, the causal agent of potato late blight. Here, P. infestans was used as a model system to investigate the mechanism underlying the response to ROS stress in oomycete pathogens. Results showed severe defects in sporangium germination, mycelial growth, appressorium formation, and virulence of P. infestans in response to H2O2 stress. Importantly, these phenotypes mimic those of P. infestans treated with rapamycin, the inhibitor of target of rapamycin (TOR, 1-phosphatidylinositol-3-kinase). Strong synergism occurred when P. infestans was treated with a combination of H2O2 and rapamycin, suggesting that a crosstalk exists between ROS stress and the TOR signaling pathway. Comprehensive analysis of transcriptome, proteome and phosphorylation omics showed that H2O2 stress significantly induced the operation of the TOR-mediated autophagy pathway. Monodansylcadaverine (MDC) staining showed that in the presence of H2O2 and rapamycin, the autophagosome level increased in a dosage-dependent manner. Furthermore, transgenic potatoes containing double-stranded RNA of PiTOR (TOR in P. infestans) displayed high resistance to P. infestans. Taken together, TOR is involved in the ROS response and is a potential target for control of oomycete diseases, as host-mediated silencing of PiTOR enhances potato resistance to late blight.

StPOPA, encoding an anionic peroxidase, enhances potato resistance against Phytophthora infestans

2020 ◽  
Vol 40 (2) ◽  
Author(s):  
Yu Yang ◽  
Rui Jiang ◽  
Hongyang Wang ◽  
Zhendong Tian ◽  
Conghua Xie
Keyword(s):  
Phytophthora Infestans ◽  
Anionic Peroxidase ◽  
Potato Resistance
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