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Plant Pathology Commons

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Full-Text Articles in Plant Pathology

Does The Fungal Pathogen (Botryosphaeria Dothidea) Exceed The Dehydration Tolerance Of Its Chaparral Host?, Cristian M. Garcia Mar 2018

Does The Fungal Pathogen (Botryosphaeria Dothidea) Exceed The Dehydration Tolerance Of Its Chaparral Host?, Cristian M. Garcia

Seaver College Research And Scholarly Achievement Symposium

We tested the hypothesis that an opportunistic endophytic fungus Botryosphaeria dothidea that frequently infects and causes dieback in several different species of chaparral shrubs in the Santa Monica Mountains continues to elongate and grow in host tissues at dehydration levels that exceed host survival. This was done by collecting several large branches from the field from three dominant species of co-occurring chaparral shrubs, Malosma laurina, Ceanothus spinosus, and Ceanothus megacarpus. We allowed branches to dehydrate at increasing lengths of time, from a few days to one week, in an air-conditioned laboratory, then sealed in plastic bags to allow tissuewater equilibration, …


Hydraulic Mechanisms Of Fungal-Induced Dieback In A Keystone Chaparral Species During Unprecedented Drought In California, Natalie M. Aguirre, Marissa E. Ochoa, Helen I. Holmlund, Frank E. Ewers, Stephen D. Davis Mar 2017

Hydraulic Mechanisms Of Fungal-Induced Dieback In A Keystone Chaparral Species During Unprecedented Drought In California, Natalie M. Aguirre, Marissa E. Ochoa, Helen I. Holmlund, Frank E. Ewers, Stephen D. Davis

Seaver College Research And Scholarly Achievement Symposium

Between 2012-2016, southern California experienced unprecedented drought that caused dieback in Malosma laurina, a keystone species of chaparral shrub communities. Dieback was especially severe in coastal exposures of the Santa Monica Mountains, leading to whole plant mortality exceeding 50% at some sites. We hypothesized that the endophytic fungus causing the dieback, Botryosphaeria dothidea, was successful in invading the xylem tissue of M. laurina because of protracted water stress, carbon starvation, or a combination of the two. We tested these possibilities in a controlled pot experiment by comparing three treatments, each inoculated with the fungus: (1) irrigated controls (2) …


Root Hydraulic Conductance In Malosma Laurina Experiencing Severe Dieback In The Santa Monica Mountains, Natalie M. Aguirre 5861995, Avery Davis, Sarah Nelson Apr 2016

Root Hydraulic Conductance In Malosma Laurina Experiencing Severe Dieback In The Santa Monica Mountains, Natalie M. Aguirre 5861995, Avery Davis, Sarah Nelson

Seaver College Research And Scholarly Achievement Symposium

Malosma laurina is a dominant species in coastal chaparral ecosystems The deep root systems of M. laurina provide structural support for the steep Santa Monica Mountains and allow M. laurina to tap into the deep water table. M. laurina dieback is prevalent in coastal exposures of the SMM, presumably due to historic drought predisposing plant tissues to infection by the fungal pathogen Botryosphaeria dothidea. In ecosystems that experience annual dry periods, a high hydraulic conductance in roots is necessary to provide plants with sufficient water. A recent study has examined the effect of Botryosphaeria on the hydraulic conductance of M. …