Spatial modeling increases accuracy of selection for Phytophthora infestans resistant tomato genotypes

Crop Science ◽  
2021 ◽  
Author(s):  
Mariane Gonçalves Ferreira Copati ◽  
Felipe de Oliveira Dias ◽  
João Romero Amaral Santos de Carval Rocha ◽  
Herika Paula Pessoa ◽  
Gabriella Queiroz Almeida
Keyword(s):  
Phytophthora Infestans ◽  
Spatial Modeling ◽  
Selection For ◽  
Tomato Genotypes

scholarly journals Pathogenic Fitness of Oosporic Progeny Isolates of Phytophthora infestans on Late-Blight-Resistant Tomato Lines

Plant Disease ◽  
2009 ◽  
Vol 93 (9) ◽  
pp. 947-953 ◽  
Author(s):  
Shiri Klarfeld ◽  
Avia (Evgenia) Rubin ◽  
Yigal Cohen
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Field Isolate ◽  
Late Blight Resistance ◽  
The Other ◽  
Host Genotype ◽  
Unit Leaf ◽  
Tomato Genotype ◽  
Different Levels ◽  
Tomato Genotypes

Four A1 field isolates and one A2 field isolate of Phytophthora infestans were crossed to produce oospores in tomato leaves. The oospores were extracted and mixed with perlite and water, and healthy tomato leaves were used as bait for oospore-progeny infection. Twenty-nine lesions were obtained from the four crosses and 283 single-sporangium isolates were recovered and tested on four tomato differential lines carrying different major genes (Ph-0, Ph-1, Ph-2, and 3707) for late blight resistance. The pathogenic fitness (number of sporangia per unit leaf area) of parental and progeny isolates was strongly dependent on the host genotype; it decreased in the order Ph-0 > Ph-1 > Ph-2 > 3707. The A2 parent had a higher pathogenic fitness than the A1 parents on Ph-0 and Ph-1 but similar, lower fitness on Ph-2. Different levels of pathogenic fitness were observed across all isolates on Ph-0, although Ph-0 lacks resistance genes. Pathogenic fitness on one tomato genotype was not related to the pathogenic fitness on the other tomato genotypes. Some isolates exhibited reduced pathogenic fitness relative to the respective A1 parent, whereas others demonstrated a higher pathogenic fitness compared with the A2 parent. The tomato genotype Solanum pimpinellifolium L3707/5 was resistant to all five parental isolates of P. infestans. However, 37 of the 283 progeny isolates from 11 different lesions had compatible reactions with this line, producing up to 31 × 103 sporangia/cm2. Overall, reduced fitness was more frequent among the progeny isolates than increased fitness.

Spontaneous variability of single isolates of Phytophthora infestans. I. Cultural variation

1968 ◽  
Vol 46 (4) ◽  
pp. 329-348 ◽  
Author(s):  
C. E. Caten ◽  
J. L. Jinks
Keyword(s):  
Growth Rate ◽  
Phytophthora Infestans ◽  
Mass Culture ◽  
Cultural Variation ◽  
Phenotypic Characters ◽  
Original Mass ◽  
Mass Cultures ◽  
Single Mass ◽  
Selection For ◽  
Hyphal Tip

The variability in culture of mycelial isolates of Phytophthora infestans was studied by examining the variation among single zoospore, single sporangium, and single hyphal tip subcultures. Extensive variation in rate of growth and sporangium production on artificial medium was detected among the single zoospore progenies of three mass cultures. Differences in colony morphology and viability of zoospores were also apparent but were not studied in detail. Subcultures established by single sporangia or single hyphal tips were much more uniform than zoospore cultures, although significant differences in growth rate could still be detected. While, with continued culture, some of the single zoospore variants tended to revert to their parental type, others showed a remarkable degree of stability.Isolates established from single zoospores gave rise to as much variation in their asexual progenies as the original mass cultures. This persistence of variation was also observed with isolates whose derivation included two successive single zoospore propagations. Selection for high and low growth rate among the zoospore progeny of a single mass culture rapidly led to the production of populations of zoospore cultures with different mean growth rates. Such response to selection implies the existence of a genetic mechanism which allows the transmission of phenotypic characters from one asexual generation to the next.The origin of variation among single zoospore cultures is discussed with reference to five different asexual mechanisms of variation. It is suggested that variation is the result of cytoplasmic differences present in the original mass isolates, although the possibility of other mechanisms can not be completely dismissed. A review of the literature suggests that asexual variation associated with zoospore propagation is widespread in the genus Phytophthora.

scholarly journals Selection for Fungicide Resistance Within a Growing Season in Field Populations of Phytophthora infestans at the Center of Origin

2006 ◽  
Vol 96 (12) ◽  
pp. 1397-1403 ◽  
Author(s):  
Niklaus J. Grünwald ◽  
Anne K. Sturbaum ◽  
Gaspar Romero Montes ◽  
Edith Garay Serrano ◽  
Hector Lozoya-Saldaña ◽  
...  
Keyword(s):  
Phytophthora Infestans ◽  
Genotypic Diversity ◽  
The United States ◽  
Potential Threat ◽  
Center Of Origin ◽  
Wide Range ◽  
Field Season ◽  
Selection For ◽  
Single Field ◽  
Toluca Valley

The central highlands of Mexico should provide an optimal testing ground for evaluating the potential threat of selection for resistance to fungicides in the population of Phytophthora infestans. We evaluated the hypotheses that exposure to the fungicides azoxystrobin, cymoxanil, dimethomorph, fluazinam, mancozeb, metalaxyl, and propamocarb hydrochloride would lead to (i) a shift in the sensitivity distributions (i.e., selection) and (ii) a lower genotypic diversity of the population. We compared populations from unsprayed plots with populations that had been exposed to several applications of each of the fungicides within a single field season. This study provides novel baseline data and shows that the Toluca valley P. infestans population has a wide range of sensitivities to the fungicides fluazinam, cymoxanil, dimethomorph, metalaxyl, and propamocarb. Directional selection toward resistance combined with a reduction in genetic diversity of the P. infestans population was observed only for the fungicide metalaxyl. The results obtained provide direct experimental support for continuing vigilance regarding further introductions of exotic strains of P. infestans into the United States.

Framework for Selecting Vocabulary for Preliterate Children Who Use Augmentative and Alternative Communication

2019 ◽  
Vol 28 (3) ◽  
pp. 1000-1009
Author(s):  
Allison Bean ◽  
Lindsey Paden Cargill ◽  
Samantha Lyle
Keyword(s):  
Language Impairment ◽  
Augmentative And Alternative Communication ◽  
Developmentally Appropriate ◽  
School Age Children ◽  
Alternative Communication ◽  
School Based ◽  
Selection For ◽  
Nonverbal Children ◽  
Grammatical Structures ◽  
Insufficient Knowledge

Purpose Nearly 50% of school-based speech-language pathologists (SLPs) provide services to school-age children who use augmentative and alternative communication (AAC). However, many SLPs report having insufficient knowledge in the area of AAC implementation. The objective of this tutorial is to provide clinicians with a framework for supporting 1 area of AAC implementation: vocabulary selection for preliterate children who use AAC. Method This tutorial focuses on 4 variables that clinicians should consider when selecting vocabulary: (a) contexts/environments where the vocabulary can be used, (b) time span during which the vocabulary will be relevant, (c) whether the vocabulary can elicit and maintain interactions with other people, and (d) whether the vocabulary will facilitate developmentally appropriate grammatical structures. This tutorial focuses on the role that these variables play in language development in verbal children with typical development, verbal children with language impairment, and nonverbal children who use AAC. Results Use of the 4 variables highlighted above may help practicing SLPs select vocabulary that will best facilitate language acquisition in preliterate children who use AAC.

Teaching Partners to Support Communication for Adults with Acquired Communication Impairment

2013 ◽  
Vol 22 (1) ◽  
pp. 4-15 ◽  
Author(s):  
Laura J. Ball ◽  
Joanne Lasker
Keyword(s):  
Practice Patterns ◽  
Communicative Competence ◽  
Communication Disorders ◽  
Communication Impairment ◽  
Communication Partner ◽  
Communication Partners ◽  
Selection For ◽  
Communication Needs ◽  
End Of Life Communication ◽  
Lateral Sclerosis

Abstract For adults with acquired communication impairment, particularly those who have communication disorders associated with stroke or neurodegenerative disease, communication partners play an important role in establishing and maintaining communicative competence. In this paper, we assemble some evidence on this topic and integrate it with current preferred practice patterns (American Speech-Language-Hearing Association, 2004). Our goals are to help speech-language pathologists (SLPs) identify and describe partner-based communication strategies for adults with acquired impairment, implement evidence-based approaches for teaching strategies to communication partners, and employ a Personnel Framework (Binger et al., 2012) to clarify partners? roles in acquiring and supporting communication tools for individuals with acquired impairments. We offer specific guidance about AAC techniques and message selection for communication partners involved with chronic, degenerative, and end of life communication. We discuss research and provide examples of communication partner supports for person(s) with aphasia and person(s) with amyotrophic lateral sclerosis who have complex communication needs.

Identifying Measurement Invariant Item Sets in Cross-Cultural Settings Using an Automated Item Selection Procedure

Methodology ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 177-188 ◽  
Author(s):  
Martin Schultze ◽  
Michael Eid
Keyword(s):  
Measurement Invariance ◽  
Optimal Solution ◽  
Selection Procedure ◽  
Cross Cultural ◽  
Item Selection ◽  
Ant System ◽  
Item Quality ◽  
Ant System Algorithm ◽  
Selection For ◽  
Selection Of

Abstract. In the construction of scales intended for the use in cross-cultural studies, the selection of items needs to be guided not only by traditional criteria of item quality, but has to take information about the measurement invariance of the scale into account. We present an approach to automated item selection which depicts the process as a combinatorial optimization problem and aims at finding a scale which fulfils predefined target criteria – such as measurement invariance across cultures. The search for an optimal solution is performed using an adaptation of the [Formula: see text] Ant System algorithm. The approach is illustrated using an application to item selection for a personality scale assuming measurement invariance across multiple countries.

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