Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 6 of 6

Full-Text Articles in Life Sciences

Sweetpotato Storage Root Rots: Flooding-Associated Bacterial Soft Rot Caused By Clostridium Spp. And Infection By Fungal End Rot Pathogens Prior To Harvest, Washington Luis Da Silva Jan 2013

Sweetpotato Storage Root Rots: Flooding-Associated Bacterial Soft Rot Caused By Clostridium Spp. And Infection By Fungal End Rot Pathogens Prior To Harvest, Washington Luis Da Silva

LSU Master's Theses

Sweetpotato production in the southern United States is being threatened by a soft rot that develops in storage roots when fields are flooded and by an important post-harvest disease caused mainly by the fungi Fusarium solani and Macrophomina phaseolina. To identify the pathogens responsible for development of the soft rot, samples were collected from storage roots with soft rot from intentionally flooded fields and decayed tissue was streaked on plates of nutrient dextrose agar plus 0.05% cysteine and incubated anaerobically. Two distinct groups of Gram positive strict anaerobic bacteria were re-isolated from rotting storage roots. Endospores were observed in ...


Proteomics-Based Study Of Host-Fungus Interaction Between Soybean And Phakopsora Pachyrhizi Using Recombinant Inbred Line (Ril) Derived Sister Lines, Mala Ganiger Jan 2013

Proteomics-Based Study Of Host-Fungus Interaction Between Soybean And Phakopsora Pachyrhizi Using Recombinant Inbred Line (Ril) Derived Sister Lines, Mala Ganiger

LSU Master's Theses

Phakopsora pachyrhizi, the causal agent of Asian soybean rust (ASR), has the potential to cause severe yield losses as all United States commercial soybean varieties are susceptible. In this study, 10 soybean recombinant inbred line (RIL) derived sibling lines of two populations (RN06-32-2 and RN06-16-1) were evaluated for differences in response to infection by P. pachyrhizi. These lines, which had previously shown differential responses to Florida soybean rust isolates, were evaluated using Louisiana soybean rust isolates under both detached leaf assay and greenhouse in planta inoculation conditions. Sibling lines showed significant differences in response to P. pachyrhizi infection under both ...


The Influence Of Commerce Silt Loam Soil Texture On Reproduction And Pathogenicity Of Rotylenchulus Reniformis On Cotton, Déborah Magalhães Xavier Jan 2013

The Influence Of Commerce Silt Loam Soil Texture On Reproduction And Pathogenicity Of Rotylenchulus Reniformis On Cotton, Déborah Magalhães Xavier

LSU Master's Theses

Greenhouse and microplot studies were conducted to evaluate the influence of soil texture on reproduction and pathogenicity of Rotylenchulus reniformis (reniform nematode) on cotton. A 45 day duration greenhouse experiment confirmed the pathogenicity of an isolate of R. reniformis from Avoyelles Parish on Stoneville LA887 cotton. A series of greenhouse experiments were conducted with three geographic isolates of R. reniformis (identified as Avoyelles, Evangeline, and Rapides to indicate the Parish of origin) on Stoneville LA887, Stoneville 5288B2F, and Phytogen 375WF cotton growing in soils with varying textures for 60 days. Soil types with sand, silt, and clay contents ranging from ...


A Phylogenetic Analysis Of Species Diversity, Specificity, And Distribution Of Mycodiplosis On Rust Fungi, Donald Jay Nelsen Jan 2013

A Phylogenetic Analysis Of Species Diversity, Specificity, And Distribution Of Mycodiplosis On Rust Fungi, Donald Jay Nelsen

LSU Master's Theses

There are more than 7800 species of Pucciniales (rust fungi) described. Aeciospores and urediniospores of rust fungi are a food source for the larval stage of members of the fly genus Mycodiplosis, hence these could be of interest as potential biological control agents. Currently, Mycodiplosis contains 49 described species based on adult male morphology. A survey of 1,350 rust-infected plants from 44 countries was recently conducted to assess the occurrence of Mycodiplosis fly larvae across a broad spectrum of Pucciniales. Larvae were found on 261 collections from 25 countries. Statistical analyses explored the distribution of larvae in relation to ...


Potential Roles Of Wrky Transcription Factors In Resistance To Aspergillus Flavus Colonization Of Immature Maize Kernels, Jake Clayton Fountain Jan 2013

Potential Roles Of Wrky Transcription Factors In Resistance To Aspergillus Flavus Colonization Of Immature Maize Kernels, Jake Clayton Fountain

LSU Master's Theses

The infection and colonization of maize (Zea mays L.) by the necrotrophic fungal pathogen Aspergillus flavus results in contamination of kernel tissues with carcinogenic mycotoxins known as aflatoxins, resulting in severe economic losses as well as negative effects on human and animal health. Resistance to A. flavus is mediated by both inducible and constitutively expressed defense proteins; however the mechanism regulating the expression of these defenses is poorly understood. This study examined the potential roles of six maize WRKY transcription factors, ZmWRKY19, ZmWRKY21, ZmWRKY53, ZmWRKY53.1, ZmWRKY67, and ZmWRKY68, in regulating defense responses against ...


Influence Of Soil Nutrients On Reproduction And Pathogenicity Of Rotylenchulus Reniformis On Cotton, Herath Mudiyanselage Manjula Thaminda Kularathna Jan 2013

Influence Of Soil Nutrients On Reproduction And Pathogenicity Of Rotylenchulus Reniformis On Cotton, Herath Mudiyanselage Manjula Thaminda Kularathna

LSU Master's Theses

Among the variety of pathogens of cotton (Gossypium hirsutum), nematodes play a major role in reducing yield. Across the U.S. cotton belt, millions of dollars are lost annually due to nematode infestation. In the Mid-South and Southeast United States, root-knot nematode (Meloidogyne incognita) and reniform nematode (Rotylenchulus reniformis) are responsible for the highest percentage of damage. Crop rotation and nematicides are currently the most commonly used management strategies for nematode management. Soil fertility, which has a direct effect on plant growth, is also known to influence disease severity. Therefore, soil fertility would be an additional factor to consider for ...