Areas of Work

Goins, A., A. Dermer, and M. Sansing - Phylogenics of the Snake Plants Inferred from DNA Sequence Data

The genus Sansevieria contains over 70 species from Africa through to India, several of which are common “houseplants”. Traditionally, this genus has been subdivided into three subgenera based primarily on flower structure. However, no one had yet examined the validity of these morphological groupings using genetic data accurately. In this study, a 1500 bp region of noncoding DNA was amplified from the DNA extracted from 67 different Sansevieria and 8 out-group species. This region was sequenced and analyzed using phylogenetic software. Our research aimed to determine if genetic data supported or contradicted the groupings based on flower structure. Preliminary data (~570 bp of sequence data) from 2011 and (~950 bp) from 2012 suggested that the groupings based on morphology contradict the genetic groupings. However, the variation in this DNA fragment was limited across species (<1% divergence). In an effort to gain more variation this semester, we sequenced an additional section of the fragment (~1200 bp). While the additional DNA sequence data did offer better insight into the phylogenetic relationships within Sansevieria, there was still very little divergence detected for full resolution. Spring 2013.

Belnap, T. et al. - The Sonoran Tiger Salamander: Hanging on by a Tadpole

The Sonoran Tiger Salamander, Ambystoma tigrinum stebbensi, is restricted to a few isolated populations on private ranch land in Cochise County, Arizona and is listed as endangered. A new population of tiger salamanders recently discovered in the vicinity was sampled for molecular identification. Are these individuals the endangered subspecies, or the common subspecies A.t. nebulosum? DNA was extracted from six individuals and a published identifying gene was amplified (following Mech et al., 2003). Two separate subspecies were recovered from our samples indicating that this population is likely a hybrid population. No ‘pure’ A.t. stebbensi was recovered. Further investigation is required for verification, but these preliminary findings do not recommend governmental protection of the population.

Larson, M. et al. - What’s in a name? Phylogeny of the Barrel Cacti

There are many different forms of barrel cacti and they grown in many different shapes and sizes. Many of these species have been classified based on their flower color or shape rather than their DNA. By comparing DNA from 16 different species of barrel cacti, we were able to build a phylogenetic tree. The resulting phylogenetic tree indicates that two species, Leuchtenbergia and Echinocactus grusonii should have their names changed as both are nested within the genus Ferocactus.

Crockett, B. et al. - Multiple Cactation: Steps to Cloning a Cactus

While lab cloning of plants is a common practice in biology and agriculture, few efforts have been made to clone cacti. There are many rare cactus species and unusual mutations of common species that highly prized by collectors. Thus, many of such specimens are illegally poached from the wild. Cloning such specimens would make them available in the plant trade, reducing the poaching pressure. Common plant growth hormones (NAA, BAP, and Kinetin) were applied to saguaro (Carnegia gigantea) and golden barrel cactus (Echinocactus grusonii) tissues individually and in all possible combinations following common published plant cloning techniques. Results showed that NAA + Kinetin and the BAA-only trials offered the most promising outcomes. Golden barrel cacti appeared to respond better to all trials than did saguaros. While we did not produce many clones, these results lead the way for future continuing experiments.

Uhrich, M. et al. - Molecular Phylogeny of Abronia: Which came first, the desert or the plant?

How did the southwest desert plant Abronia (sand verbena), which originated from a tropical ancestor, end up growing in the desert southwest of North America? By extracting DNA from six different species of Abronia and outgroup taxa (Tripterocalyx), amplifying 660 bp of a nuclear gene, we then compared the sequence data to build a phylogenetic tree. Due to extreme lack of genetic variation with in both genera but a relatively high degree between them, it supports the notion that the plants are fairly recent arrivals and have had little time to diverge. Perhaps the desert came first.

Seifter, P. et al. - Which came first, the Desert or the Plant?

The Molecular Phylogeny of Tripterocalyx. Tripterocalyx, a genus of plants descended from an ancestor known to be tropica, has been found in scattered locations throughout the Arizona desert. Considering that the environment that these plants thrive in is a sandy, dune-like habitat, particularly gypsum soils (Douglas, 2007) which at the current time is rare in Arizona. The question is did the desert come first or did the plants? We sequenced 660 bp of a nuclear gene and constructed a phylogeny. The lack of genetic diversity supports the notion that the plants are fairly recent arrivals and have had little time to diverge. Perhaps the desert came first.

Kearney, T. et al. - Illegal Aliens from Southern California: An introduced population of the Ensatina eschscholtzii klauberi salamander in Arizona

The rare large-blotched salamander (Ensatina eschscholtzii klauberi) naturally occurs in the mountains of southern California, inhabiting moist environments, often underground, around 5000’ elevation. In the late 1970’s, a salamander researcher predicted that this species was facing extinction so in 1980, he made an attempt to ‘save the species.’ He located a similar habitat for these salamanders in Arizona and , without permission, released 22 individuals into the mountains of Gila County. Thirty years later, this population was discovered and seven specimens were collected. DNA was extracted from tissues, the cytochrome b gene was amplified and compared. We found almost no genetic difference among these seven specimens suggesting that 30 years is not enough time for variation to accumulate to a detectable level. This serves as an example of founder effect but may offer an opportunity for future population genetics studies.