| Abstract: | Pecan (Carya illinoinensis) is an important tree nut species in the United States with average annual in-shell nut production value of $430 million in 2020 according to the NASS. The present research characterized a core collection of 107 pecan and wild relative accessions housed within the National Collection of Genetic Resources (NCGR)-Pecans and Hickories, utilizing 14 novel simple sequence repeat (SSR) genetic markers targeting regions of the genome harboring key horticultural traits and 40 SSR markers created in previous SSR marker development efforts. Furthermore, a diagnostic PCR- based assay for unambiguously distinguishing dichogamy type in pecan was successfully developed herein. Secondly, a mapping population of 151 full-sibling progeny from controlled crosses between two pecan cultivars, 'Elliott' and 'VC1-68' was phenotyped over two years for various morphological traits pertaining to fruit size and shape. Regions of the pecan genome were identified pertaining to important nut morphology traits including nut length, width, height, total volume, shell thickness, distal angle, and kernel weight. These efforts provide the impetus for implementing marker-assisted selection (MAS) of nut morphology traits in pecan improvement programs. The electronic version of this dissertation is accessible from https://hdl.handle.net/1969.1/197936 |
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