Sheri B. Crabtree

Clonality of Pawpaw (Asimina triloba) Patches in Kentucky

Abstract Pawpaw [Asimina triloba (L.) Dunal] is a tree-fruit (see overleaf, page 2) native to the southeastern region of the United States. Kentucky State University serves as the USDA-National Clonal Germplasm Repository for pawpaw, therefore assessing genetic diversity across the pawpaws native range is a high priority. Pawpaw is usually found in large patches as an understory tree and root suckering likely occurs. To determine if native pawpaw patches are clonal, DNA was extracted from leaf samples collected from trees in six native patches in three counties in central Kentucky. Two ISSR-PCR primers yielded three polymorphic and six monomorphic markers in the six patches. Three patches did not display any polymorphic markers in each patch, suggesting they were clonal. However, three other patches did show polymorphic markers within each patch, indicating these patches were not clonal and contained trees of at least two genotypes within each patch. This study suggests that to assess the genetic diversity of a pawpaw patch or local population, more intensive sampling strategies will be required.

The Pawpaw Peduncle Borer, Talponia plummeriana Busck (Lepidoptera: Tortricidae): A Pest of Pawpaw Fruit

ABSTRACT The pawpaw peduncle borer, Talponia plummeriana Busck (Lepidoptera: Torticidae), is a pest of pawpaw flowers often boring into the peduncle and causing flower drop. Here we document the first occurrence of this insect infesting ripe pawpaw fruit. Infested fruit that had been collected at the Kentucky State University Research and Demonstration Farm in Franklin County, Kentucky were dissected and small tan colored larvae with brown head capsules were discovered in the fruit. Pawpaw peduncle borer adults were reared from fruit held at room temperature in the laboratory.

Pawpaw Patch Genetic Diversity, and Clonality, and its Impact on the Establishment of Invasive Species in the Forest Understory

ABSTRACT The pawpaw (Asimina triloba) is a native understory tree of 26 states of the Eastern and Midwestern United States. Pawpaws genetic diversity and clonality in relation to this trees ability to compete with local invasive species in Kentucky has not been examined. The objectives of this study were two-fold: to determine the genetic diversity and clonality displayed in seven native pawpaw patches located at the Kentucky State University Environmental Education Center (KSU-EEC), The Kentucky River, Cove Spring Park, and the KSU Research and Demonstration Farm in Franklin County using DNA microsatellite markers; and to determine if patches reduced the incidence of invasive species. Twenty-five trees from seven patches in the four different locations were sampled for genetic analysis. Leaf samples were extracted using the DNAmite Plant Extraction Kit and products from four microsatellite loci were analyzed using a 3130 Applied Biosystems Gene sequencer. String grids were created and invasive plants c...

Genetic Diversity in Kentucky Spicebush Populations using Simple Sequence Repeat Markers

ABSTRACT Spicebush (Lindera benzoin L.) is a small native shrub that grows in the moist, understory areas of Appalachia and has potential as a new niche crop for small farmers. Native Americans and early settlers used this plant traditionally as a tea, and used the berries for jam, to spice food, and possibly for health benefits. Native spicebush patches may serve an important role in forest ecosystems in terms of fruit production for animals, soil erosion control, and enhancing insect biodiversity. Spicebush may also serve to hold ecological niches by outcompeting invasive plants compared to those in unchallenged areas. Genetic diversity of native spicebush populations in Kentucky has not been examined. The objective of this study is to determine the genetic diversity in spicebush populations in Kentucky using simple sequence repeat (SSR) DNA marker systems. Leaf samples were collected from 120 spicebush plants in the forests at the Kentucky State University Environmental Education Center (EEC), at a loc...