Deanna McCullough

Ph.D., Oklahoma State University, 1973

Associate Professor of Biology

Office: N-607
Email: mcculloughd@uhd.edu
Phone: 
713-221-8487 (office)

Courses currently teaching: 
Biology 1301 General Biology I
Biology 1302 General Biology II 
Biology 1101 Gen Bio I Lab
Biology 1102 Gen. Bio. II Lab
Biology 1303 Anatomy & Physiology I
Biology 1103 Anatomy & Physiology I Lab
Biology 3310 Plant Identification
Biology 3110 Plant Identification Lab
Biology 3302 General Ecology
Biology 3102 General Ecology Lab

Research Interest:  Plant Taxonomy, Plant Systematics, Ecology

Re-evaluating the Schrankia (Fabaceae) complex within the genus Mimosa :
 The genus Schrankia has been incorporated, taxonomically, within the Mimosa genus of the legume family. We are looking at two genes, the rRNA gene and the rbc L chloroplast gene to determine if this taxonomic change is valid. We are sequencing these genes from the 15 species of Mimosa that are found in Texas and plan to analyze the data using some or all of the following programs to create phylogenetic trees showing relationships between these taxa in an attempt to answer this question: PHYLP, neighbor joining, and maxim mum likelihood

 An analysis of the Mimosa quadravalvis complex:
 The 5 species of Schrankia that were incorporated into the Mimosa genus were initially classified under the species name quadravalvis with each being represented as a variety within that species. If indeed the Schrankia members do belong within the Mimosa genus, the question of their status needs to be clarified. At first they were put within the quadravalvis complex and later elevated to the level of individual species. The question remains - which taxonomic designation is the most correct for these members of Mimosa. Using molecular analysis of
 sequences of the rRNA and rbc L genes we hope to answer these questions.

Re-evaluation of Mimosa strigillosa:
 Mimosa strigillosa is always described in taxonomic keys as being herbaceous and unarmed (no prickles) while the rest of the Mimosa group are armed with prickles. M. strigillosa is found in many counties along the Texas Gulf Coast and we do see variations between the members in the upper Gulf Coast region and members in the Rio Grande valley. Specimens collected in the valley frequently have some prickles (a few) and tend to have woody stem bases, unlike their herbaceous members. Using molecular analysis of the rRNA gene and the
rbc L chloroplast gene we hope to answer this question.

Celtis laevigata, sugar hackberry, has three varietal forms that are difficult to distinguish morphologically and there is some disagreement of the naming of these varieties. Some feel that one of them should have a species designation. We will investigate this taxonomic problem using the molecular techniques mentioned above.

Ecological restoration at Sheldon Lake State Park
 I have been involved with the Sheldon Lake State Park Grassland Restoration and Succession Study for several years. This is a collaborative study involving several members of the Department of Natural Sciences at UHD. A large area of the park has been under cultivation for over 50 years but TPWD is now trying to return it to its natural state of a Gulf Coastal Prairie. I have evaluated the plant life within a woodland adjacent to the to-be-restored prairie. The prairie area is characterized by low areas that hold water during wet periods and raised areas called mima mounds that act as areas of microhabitat. As the Parks Department sows native Texas grass seeds, we will
 study the distribution of the native grasses throughout the prairie looking for areas of preferential growth and compare that with changes in soil microbes and fungal populations as the area undergoes ecological change. Research is underway on characterizing soil microbes and fungi but I am waiting on the Parks Department to sow the grass seeds. We hope to determine if restoration of a native grass prairie is possible by comparing the changes occurring at Sheldon Lake State Park with a remnant of native Gulf Coastal Prairie located near
 League City and owned by the University of Houston. My work should resume in the spring of 2005.

Environmental Assessment of the Presence of Xylella fastidiosa in native Gulf Coastal plants. Working with Dr. Lisa Morano I have been involved in identifying plants in the area that we are testing for the presence of Xylella fastidiosa, a bacterium that causes Pierce's Disease of grapes. 


Professional Associations:
 

Member - American Botanical Society
Member - Texas Academy of Sciences


 

 

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