Scab, caused by Venturia effusa, is the most destructive disease affecting pecan (Carya illinoinensis). Developing scab-resistant cultivars offers a sustainable solution for disease management. To elucidate the metabolic basis of resistance, we applied a pathway-based metabolomics that examines metabolites within pathways relevant to plant-pathogen interactions across 15 orchard-grown pecan cultivars with varying resistance levels. Machine learning models including support vector machine, random forest, and linear regression identified biomarkers predictive of resistance, achieving over 97% classification accuracy. Resistant cultivars showed elevated levels of metabolic precursors supporting lignin biosynthesis, energy metabolism, and antioxidant turnover, such as syringin, proline, and galactono-1,4-lactone, indicating a proactive and coordinated defense strategy. In contrast, susceptible trees accumulated defense-related end-products (e.g., salicylate glucoside, ascorbic acid) and nitrogen-rich amino acids, but showed limited availability of precursors, potentially contributing to increased susceptibility. These metabolic traits will support breeding of disease-resilient cultivars and improve disease management strategies in pecan orchards.

`Ga. 03-6-72' is a new pecan (Carya illinoinensis) cultivar released by the University of Georgia (UGA) College of Agricultural and Environmental Sciences for use in commercial orchards in the southeastern United States. It produces large nuts (9.3 g) with consistently high kernel percentage (59.6%). Kernels shell easily into complete halves and have an attractive light golden color. Harvest occurs in early October in southern Georgia. Yields of `Ga. 03-6-72' have been strong and comparable to established commercial cultivars such as `Sumner', `Huffman', and `Tom'. The cultivar also shows good resistance to pecan scab (Venturia effusa), exhibiting minimal disease in orchards managed with moderate fungicide programs and only moderate disease levels in unsprayed plantings. `Ga. 03-6-72' is recommended for commercial trial in the southeastern U.S. in orchards where fungicide applications are part of standard management. As with all new UGA pecan releases, the UGA pecan breeding program recommends that growers limit initial plantings of any new cultivar until mature tree performance, including long-term scab resistance stability, has been confirmed under commercial orchard conditions.

Pecan scab (Venturia effusa) is a devastating fungal disease affecting commercial pecan production. Developing resistant cultivars remains the most sustainable strategy, but this has been hindered by limited mechanistic understanding of resistance and the presence of diverse pathogen pathotypes. Current resistance phenotyping methods rely on microscopic assessments, which are labor-intensive and prone to inconsistency due to sample preparation and interpretation variability. A pathway-based metabolomics approach combined with machine learning was employed to identify early biomarkers of resistance in pecan. Metabolite profiles were obtained from the pecan cultivar 'Desirable' in response to the virulent scab isolate De-Tif-11 (susceptible reaction) and the avirulent scab isolate Pa-OK-11 (resistant reaction) from 0 to 7 days post inoculation (DPI). Logistic regression with L1 regularization followed by linear regression identified potential marker compounds with high sensitivity and specificity for resistant and susceptible reactions. Three major defense mechanisms were identified that differentiate scab-resistant from susceptible reactions. In the resistant reaction, salicylic acid and 3-hydroxy-3-methylglutaryl-coenzyme A were rapidly upregulated at 1–2 DPI, prioritizing immune activation over energy metabolism. Once defense signaling was initiated, the resistant reaction shifted towards biochemical defense by accumulating flavonoids at 3–4 DPI, reinforcing pathogen restriction. The susceptible reaction exhibited delayed and ineffective defense responses throughout the infection period. These results reveal early functional shifts in hormone signaling and secondary metabolism that differentiate resistant from susceptible reactions. The identified biomarkers may serve as robust indicators of resistance and facilitate accurate, early-stage screening in pecan breeding programs.

Muscadine (Muscadinia rotundifolia Michx) is a fruit crop native to the southeastern United States that is well-adapted to warm and humid subtropical environments. However, most available muscadine cultivars exhibit several limitations that hinder commercial production. This study evaluated four commercial cultivars and 10 advanced selections from the Muscadine Breeding Program of the University of Georgia over a 4-year period to assess their annual yield, agronomic traits, production performance, and fruit quality traits. Significant genotypic variability was observed across all traits evaluated, thus reinforcing the strong genetic influence on muscadine productivity and fruit characteristics. 'Granny Val' exhibited the highest total yield (TY) and commercial yield (CY), whereas Ga. 6-6-358 showed comparable TY, CY, and percentage of sound berries (SB%) values. Ga. 6-1-269 also performed well, consistently exhibiting high percentage of CY (CY%) and low susceptibility to field berry decay, indicating strong potential for commercial production under warm and humid conditions. Additionally, it showed earlier maturity and an extended harvest period, which are traits that could help prolong the muscadine availability window in the southeastern United States. In contrast, the high rotten berry percentage (RB%) observed in Ga. 10-1-294 and Ga. 12-3-22 and the low total soluble solids (TSS) contents in Ga. 13-4-79 and Ga. 12-5-46 limit their suitability for commercial use. Although low-yielding, Ga. 10-1-329 exhibited high TSS and dark berry pigmentation, which are traits associated with sweetness and high antioxidant content. Overall, these results provide essential information for cultivar selection and muscadine breeding efforts aimed to improve adaptation, fruit quality, and productivity under subtropical growing conditions.

Leaf shape in plants plays a vital role in water use, tolerance to abiotic stresses, and formation of canopy structures. Muscadine grapes (Vitis rotundifolia) are native to the southeastern United States and typically have unlobed leaves. A previous breeding effort successfully introduced the lobed-leaf trait of Vitis vinifera into the muscadine cultivar Southern Home via a series of interspecific hybridizations. A linkage-based high-density genetic map was developed using a biparental mapping population from a cross between the muscadine selection Ga. 8-1-313 (female, unlobed leaves) and 'Southern Home' (hermaphroditic, lobed leaves) to map quantitative trait loci (QTLs) associated with leaf lobing. The mapping population consisted of 130 F1 progeny that were genotyped via a genotyping by sequencing method (GBSpoly). Single nucleotide polymorphism (SNP)-based genetic maps were constructed and verified by mapping the grape sex locus. Mature leaf samples from both parents and progeny were collected, digitally scanned, and 17-point landmarks were placed in well-defined biologically homologous points of each leaf image. The x, y coordinates of these landmarks were then used to analyze leaf shape using generalized Procrustes analysis (GPA). Significant variations in leaf shape were identified via principal component analysis (PCA). The principal component (PC) scores were used as phenotypes to perform QTL analysis, and a major QTL determining leaf lobing was identified on chromosome 1 in 'Southern Home', which explained 75.1% to 76.6% of total phenotypic variance. Further study of the identified QTL region can be carried out to identify candidate genes involved in leaf lobing in grapes.

This study presents the first report on the postharvest responses of ‘Gold Delight’ muscadine as newly developed bronze cultivar compared with three bronze commercial muscadines ‘Granny Val’, ‘Triumph’, and ‘Hall’ during 28 d of cold storage at 4 °C. Weight loss differed markedly among cultivars, with ‘Gold Delight’ showing the lowest final loss (2.11% ± 0.05%) and ‘Hall’ the highest (3.29% ± 0.11%). Firmness decreased in all cultivars, with reductions from 190.8 ± 3.0 to 171.9 ± 1.6 g·mm−1 in ‘Gold Delight’ and from 202.9 ± 3.2 to 159.8 ± 4.0 g·mm−1 in ‘Triumph’, confirming the greater firmness retention of ‘Gold Delight’. Total soluble solids (TSS) remained relatively constant, titratable acidity (TA) decreased gradually, and pH increased slightly during storage. By day 28, ‘Triumph’ showed the highest TSS/TA ratio (27.04 ± 0.45), followed by ‘Hall’ (25.47 ± 0.50). Total phenolic content showed slight reductions by day 28, with final values of 33.11 ± 0.54 mg·L−1 gallic acid equivalents (GAE; (‘Gold Delight’), 26.03 ± 0.63 mg·L−1 GAE (‘Granny Val’), 35.98 ± 0.75 mg·L−1 GAE (‘Triumph’), and 39.40 ± 0.62 mg·L−1 GAE (‘Hall’). Total antioxidant activity decreased moderately across cultivars, ending at 54.42 ± 1.35, 49.20 ± 1.22, 66.65 ± 1.24, and 77.35 ± 1.87 μmols TE·L−1 for ‘Gold Delight’, ‘Granny Val’, ‘Triumph’, and ‘Hall’, respectively. Color parameters showed only minor changes across cultivars. Overall, this evaluation demonstrated clear cultivar-dependent differences in postharvest behavior, providing practical guidance for selecting muscadines best suited for fresh-market consumption and cold-storage handling.

This study explored the mechanisms underlying raw pecan flavor biosynthesis using pathway-based metabolomics and statistical correlation analysis. Three pecan cultivars-'Avalon,' 'Desirable,' and 'Sumner'-were collected and evaluated. Ten major flavor formation pathways were identified and targeted, including glycolysis, sucrose metabolism, the citric acid cycle, 2,3-butanedione and 3-penten-2-one biosynthesis, valine-derived volatiles, terpenoid backbone biosynthesis, lipoxygenase pathway, flavonoid biosynthesis, phenylpropanoid pathway, and shikimic acid pathway. Overall, consistent metabolic linkages were observed between flavor precursors, intermediates, and their corresponding flavor products. For example, lipoxygenase-derived aldehydes and glycolysis-related precursors, along with downstream 2,3-butanedione, were consistently abundant in 'Sumner,' while the precursor chlorogenic acid and downstream flavonoids were observed predominantly in 'Desirable.' These results, together with odor and taste activity values, revealed key pathways and mechanisms responsible for flavor formation in raw pecans. This work provides a valuable foundation for future research and breeding programs aimed at improving or maintaining pecan flavor quality.

'Ga. 6-1-269' is a hermaphroditic muscadine grape (Vitis rotundifolia) with bronze berries that was released by the University of Georgia (UGA) College of Agriculture and Environmental Sciences. Yields of 'Ga. 6-1-269' in Tifton, GA and Citra, FL trials were similar to other popular fresh-market muscadine cultivars. Berry size is very large (15-16 g) and similar to the cultivars 'Ga. 6-2-26' (Paulk (R)) and 'Supreme'. Fruit rot susceptibility of 'Ga. 6-1-269' was less than the bronze check cultivar 'Ga. 1-1-48' (Hall (R)) and similar to the black check cultivars 'Ga. 6-2-26' and 'Supreme'. Harvest time of 'Ga. 6-1-269' was about 5 days after 'Ga. 1-1-48' and about a week before 'Ga. 6-2-26' and 'Supreme'. 'Ga. 6-1-269' is recommended as an early-midseason fresh market bronze muscadine cultivar.

Genetic maps are essential tools for gene positional cloning and marker-assisted breeding. A pecan (Carya illinoinensis) mapping population of 119 F1 trees was developed from a cross of the widely planted cultivars ‘Pawnee’ and ‘Elliott’. Whereas ‘Pawnee’ is susceptible, ‘Elliott’ has long-standing resistance to pecan scab caused by the fungal pathogen Venturia effusa. Molecular markers were developed using genotyping by sequencing, and linkage maps were constructed for each parent following the two-way pseudo-test-cross strategy used for cross-pollinated species. The ‘Pawnee’ and ‘Elliott’ maps contain 1347 and 1050 single-nucleotide polymorphism markers spanning a genetic distance of 4493 and 3758 centimorgans, respectively. While these map lengths are likely inflated due to genotyping errors, a high level of synteny between genetic and physical distances of the markers in both parental maps was achieved. Scab resistance was evaluated through controlled inoculations in the greenhouse using two scab isolates, and a significant quantitative trait locus (QTL) for scab resistance was identified on chromosome 5 in ‘Elliott’. Candidate gene searches within the 2-logarithm of the odds interval of the scab-resistant QTL identified a number of disease resistance–related genes, including genes encoding wall-associated receptor kinases, cytochrome P450s, leucine-rich repeats receptor–like serine/threonine-protein kinases, a pectinesterase inhibitor, a cellulose synthase, a flavonol synthase, a 4-coumarate–coenzyme A ligase, caffeic acid 3-O-methyltransferase, and a myeloblastosis (MYB) domain transcription factor.

Nut kernel color is a crucial quality indicator affecting the consumers first impression of the product. While growing evidence suggests that plant phenolics and their derivatives are linked to nut kernel color, the compounds (biomarkers) responsible for kernel color stability during storage remain elusive. Here, pathway-based metabolomics with machine learning algorithms were employed to identify key metabolites of postharvest pecan color stability. Metabolites in phenylpropanoid, flavonoid, and anthocyanin biosynthetic pathways were analyzed in the testa of nine pecan cultivars using liquid chromatography–mass spectrometry. With color measurements, different machine learning models were compared to find relevant biomarkers of pecan color phenotypes. Results revealed potential marker compounds that included flavonoid precursors and anthocyanidins as well as anthocyanins (e.g., peonidin, delphinidin-3-O-glucoside). Our findings provide a foundation for future research in the area, and will help select genes/proteins for the breeding of pecans with stable and desirable kernel color.

Muscadines (Muscadinia rotundifolia Michx) have a thick peel that is often discarded by consumers. To better understand the potential nutritional loss due to this practice, total anthocyanin concentration (TAC), total phenolic content (TPC), total antioxidant activity (TAA), and chemical attributes in peel and flesh of eight purple muscadine genotypes were evaluated to determine the nutritional value of each part. Muscadine genotypes that were used in this study included two commercial cultivars ('Supreme' and 'Paulk') and six selections ('Ga.10-1-222', 'Ga.10-1-294', 'Ga.10-1-329', 'Ga.12-5-46', 'Ga.12-3-22', 'Ga.13-4-79'). Bioactive compounds, antioxidant activity, and titratable acidity (TA) were higher in the peel of all muscadine genotypes, while the flesh had more sucrose, glucose, and fructose. In the peel, TAC (20.68-37.53 mg L- 1), TPC (382.84-577.31 mg GAE L- 1), ellagic acid (5.44-15.5 mu g mL- 1), TAA (436.07-1258.26 mu moles TE L- 1), total soluble solids (TSS, 11.45-16.62%), TA (0.64-1.17%), TSS/TA ratio (10.92-24.46), pH (3.42-3.82), sucrose (13.73-69.49 mg mL- 1), glucose (58.42-77.69 mg mL- 1), and fructose (19.26-26.84 mg mL- 1) varied significantly among different cultivars. Similarly, in the flesh, the ranges of TAC (0.38-2.33 mg L- 1), TPC (11.48-26.52 mg GAE L- 1), ellagic acid (0.02-0.3 mu g mL- 1), TAA (14.65-21.62 mu moles TE L- 1), TSS (12.25-17.3%), TA (0.43-0.73%), TSS/TA ratio (19.44-35.34), and pH (3.44-3.73), sucrose (39.33-124.02 mg mL- 1), glucose (71.75-92.86 mg mL- 1), and fructose (24.25-32.25 mg mL- 1) were significantly different among different cultivars. The 'Supreme' peel exhibited the highest TAC, TPC, and TAA, while the peel of 'Ga.12-3-22' had the lowest values. In 'Supreme' fruit, the TAC values ranged from 0.382 mg L- 1 in the flesh to 37.53 mg L- 1 in the peel. The TPC values showed variability between 17 and 577 mg GAE L- 1 in both flesh and peel. Furthermore, TAA values ranged from 1258 to 16 mu moles TE L- 1 in both peel and flesh. The peel contained over 90% of the ellagic acid in the fruit, with 'Ga.12-5-46' peel having the highest ellagic acid overall. The ellagic acid content in the peel of 'Ga.12-5-46' was 15.5 mu g mL- 1, which was 144 times greater than that in its flesh. 'Ga.13-4-79' had the highest TA in both peel and flesh. The highest sucrose content in both peel and flesh occurred in 'Ga.10-1-329' and 'Ga.12-3-22', while 'Ga.12-5-46' and 'Ga.13-4-79' had comparatively lower sucrose in flesh. Given the substantial phytochemical content present in muscadine peel, discarding the peel constitutes a missed opportunity of considerable magnitude to obtain the full nutritional benefits of muscadines.

Pecan scab, caused by the fungal pathogen Venturia effusa, is the most devastating disease of pecan (Carya illinoinensis) in the southeastern United States. Resistance to this pathogen is determined by a complex interaction between host genetics and disease pathotype with even field-susceptible cultivars being resistant to most scab isolates. To understand the underlying molecular mechanisms of scab resistance in pecan, we performed a transcriptome analysis of the pecan cultivar, ‘Desirable’, in response to inoculation with a pathogenic and a non-pathogenic scab isolate at three different time points (24, 48, and 96 hrs. post-inoculation). Differential gene expression and gene ontology enrichment analyses showed contrasting gene expression patterns and pathway enrichment in response to the contrasting isolates with varying pathogenicity. The weighted gene co-expression network analysis of differentially expressed genes detected 11 gene modules. Among them, two modules had significant enrichment of genes involved with defense responses. These genes were particularly upregulated in the resistant reaction at the early stage of fungal infection (24 h) compared to the susceptible reaction. Hub genes in these modules were predominantly related to receptor-like protein kinase activity, signal reception, signal transduction, biosynthesis and transport of plant secondary metabolites, and oxidoreductase activity. Results of this study suggest that the early response of pathogen-related signal transduction and development of cellular barriers against the invading fungus are likely defense mechanisms employed by pecan cultivars against non-virulent scab isolates. The transcriptomic data generated here provide the foundation for identifying candidate resistance genes in pecan against V. effusa and for exploring the molecular mechanisms of disease resistance.

Assessments of the severity of scab (Venturia effusa), an economically significant disease of pecan, are critical for determining pecan cultivar susceptibility, disease epidemiology, and integrated disease management approaches. We developed a standard area diagram (SAD) set to aid in assessments of pecan leaflet scab. Leaflets with scab lesions were harvested and scanned using a flatbed scanner at 600 dpi, and Fiji (ImageJ) was used to determine the actual percent disease severity. The SADs had 10 leaflets ranging in severity from 0.2 to 48.9%. Forty "small" (1.34 to 7.43 cm2) and 40 "large" (7.67 to 25.9 cm2) leaflet images were randomized for rater assessments. The images were assessed twice by 36 raters, first without and then with the SADs as a guide. Data were subjected to analysis using Lin's concordance correlation coefficient (LCC, pc) to determine the accuracy of ratings and by intraclass correlation coefficient (ICC) analysis to determine interrater reliability. The effects of rater experience, rater location, and leaflet size were also determined. The SADs significantly improved the agreement between raters and the actual values (LCC, pc = 0.70 and 0.84 without and with the SADs, respectively). The reliability of estimates was improved (ICC = 0.54 and 0.82 without and with the SADs, respectively). The effect of rater location on overall concordance was significant without and with the SADs based on an analysis of variance using a generalized linear model and lsmeans separation (P < 0.05). A generalized linear mixed model analysis revealed that there was a significant interaction between rater location, experience, and the use of the SADs, with some raters having greater improvement in generalized bias and concordance. Raters had a significantly better accuracy when rating "small" leaves (LCC, pc = 0.86) compared with "large" leaves (LCC, pc = 0.82) when using the SADs, highlighting the impact of psychophysics on field evaluations of plant disease severity. The proposed SADs will serve as an improved tool for performing pecan leaflet scab assessments by the pecan research community.

Muscadines face limitations to fresh market production due to high manual labor costs. Mechanical harvesting holds promise for reducing the costs associated with muscadine production but requires cultivars with easily detached fruit at maturity. This study aimed to determine muscadine fruit and pedicel characteristics influencing fruit detachment force (FDF) and to unravel the genes, hormones, and regulatory networks governing muscadine abscission. We characterized the FDF of muscadine fruit across 18 genotypes and at four developmental stages. Following this, we performed a transcriptome analysis using the mature pedicel tissue of two genotypes, a genotype with high FDF at maturity and a genotype with low FDF at maturity, to identify differentially expressed and uniquely expressed genes contributing to fruit detachment. We found that pedicel length, pedicel-fruit junction area, and fruit diameter positively correlated with FDF. This study also identified novel candidate genes, transcription factor families, and pathways associated with muscadine fruit abscission. These findings provide valuable knowledge on the progression of fruit abscission and insights for reducing FDF, particularly in developing machine-harvestable muscadine cultivars and fostering sustainability and efficiency in muscadine production.

Muscadine grapes (Vitis rotundifolia) are native to the southeastern U.S., where they are valued for their unique flavor and fruity aroma. Despite having a diverse aroma profile, muscadine germplasm is virtually unexplored in terms of its aroma volatile content and composition, which is crucial in determining the value of its products. The aim of this research was to characterize 24 muscadine genotypes with distinct uses and origin for their aroma-related volatile profiles using the headspace solid-phase microextraction method coupled with gas-chromatography mass spectrometry. In total, 63 volatile compounds were detected, and genotypes significantly differed for 43 of the volatile compounds. We also profiled the aroma volatile content and composition of the commercially cultivated muscadine cultivar Carlos at various stages of berry ripeness. Characteristic differences were observed in the composition of the volatile compounds as ripening progressed. This is the first study to have evaluated the aroma volatile composition of a wide variety of muscadine germplasms, including juice and fresh fruit cultivars, as well as the related species Vitis popenoei and its complex hybrids between V. rotundifolia and Vitis vinifera. The results obtained from this study will help identify muscadine genotypes and better design crosses to produce fresh fruit and wine selections with the desired aroma profiles. This knowledge will lead to the development of new muscadine cultivars and significantly contribute to the expansion of muscadine use in the future.

Carya illinoinensis (Wangenh.) K.Koch production has expanded beyond the native distribution as the genetic diversity of the species, in part, has allowed the trees to grow under broad geographic and climatic ranges. Research in other plant species has demonstrated that the phytobiome enhances their ability to survive and thrive in specific environments and, conversely, is influenced by the prevailing environment and plant genetics, among other factors. We sought to analyze the microbiota of pecan seedlings from the controlled cross ‘Lakota’ × ‘Oaxaca’ that were made in Georgia and Texas, respectively, to determine if the maternal geographical origin influences the microbiome of the resulting progeny. No significant differences in bacterial communities were observed between the seeds obtained from the two different states (p = 0.081). However, seed origin did induce significant differences in leaf fungal composition (p = 0.012). Results suggest that, in addition to some environmental, epigenetics, or host genetic components, ecological processes, such as dispersal mechanisms of the host, differentially impact the pecan microbiome, which may have ramifications for the health of trees grown in different environments. Future studies on the role of the microbiome in plant health and productivity will aid in the development of sustainable agriculture for improved food security.

The transition of muscadine grapes ( Vitis rotundifolia Michx.) from a wild fruiting plant to a domesticated crop has taken place in the last 150 years. Muscadine grapes are one of only two species in the Muscadinia subgenera of the Vitis genus. The Muscadinia differ substantially genetically and morphologically from the other Vitis species (subgenus Vitis ). Chromosomal differences between Muscadinia (2 x = 2 n = 40) and Vitis (2 x = 2 n = 38) have generally, although not completely, prevented the movement of genes between the subgenera. Partly due to this genetic isolation, muscadine grapes have been domesticated into a unique fruit crop with many differences from other grape cultivars. Muscadine grapes are grown throughout the southeastern United States and are one of the few fruit crops well suited to this hot and humid growing environment. Muscadines are prized in this region for their unique flavor and aroma and are grown as juice and wine grapes as well as for fresh consumption. Muscadine grapes are also gaining recognition for their high levels of beneficial phytochemicals. Despite these advantages, muscadines are not well known outside of the southeast United States. This is due in part to difficulties in long-term storage of the crop and also to the inherent difficulties in marketing an unfamiliar product. Several long-term breeding programs have transformed this crop from a functionally dioecious species bearing small berries with a tough skin and soft pulp to a hermaphroditic vine with large berries having a firm flesh and crisp skin. Recent success in intersubgeneric hybridization has resulted in the successful incorporation of stenospermocarpic seedlessness into muscadine. These breeding advances have opened exciting possibilities and positioned muscadine to transform from a niche to a mainstream crop.

Nut shape is an important trait in determining the value of a pecan ( Carya illinoensis ) nut crop. Nut shape influences attractiveness to consumers, nut filling, ease of mechanical cracking, and is distinctive enough that it is the primary means of cultivar identification. Narrow sense heritability (h 2 ) of a trait is the fraction of phenotypic variance attributed to variation in genes with additive effect. Estimation of h 2 is key to breeding programs as it determines the method of selection and amount of genetic gain in each breeding cycle. In the present study, we estimated the heritability of pecan nut shape characters following two different approaches. First, image-based phenotypes of pecan nuts from 34 full-sib families generated from random crosses between 31 different parents were generated and analyzed for 10 different morphometric traits using the computer program Tomato Analyzer. The narrow-sense heritability for each trait was estimated using the mid-parent offspring regression method. Second, a separate set of 19 pecan genotypes were phenotyped for the same shape traits for two years and heritabilities were estimated by variance component analysis. Heritability estimates ranged from 0.41 to 0.83 for the mid-parent offspring regression method and from 0.26 to 0.78 for variance component method. Additionally, elliptical Fourier transform was performed to study the overall variation in nut shape. The first three principal components obtained from Elliptical Fourier transform explained 65.9% of the total variation in shape attributed to the nut’s roundness and angularity of proximal and distal ends. The use of the image-based high-throughput method of phenotyping and the heritability estimates obtained in this study directly benefit pecan breeding programs focusing on nut shape traits.