The maturity stage at harvest influences the postharvest quality and storage life of fruit. Harvesting jackfruit (Artocarpus heterophyllus Lam.) at the optimum maturity stage is more important due to the very large size of the fruit. Therefore, the present investigation was conducted to determine the impact of four different maturity stages on physicochemical parameters and fruit-softening enzymes in two jackfruit genotypes (Accession 242 and Accession 341). Fruit for the initial three stages were harvested at 10 days intervals commencing 90 days after flowering (DAF), while fruit for the final stage were harvested based on traditional maturity parameters (142 and 153 DAF) in Accession 341 and Accession 242 respectively. Results indicated an increase in fruit size, seed and bulb weight with the advancement of fruit maturity in both accessions. Moreover, there was a concurrent decline in spine density and an increase in spine flatness with the progression of fruit maturity. Whilst pulp percentage increased, there was a decrease in rag and core percentage at advanced maturity stages. However, peel and seed percentage were not influenced significantly by the advancement of fruit maturity. Additionally, there was a decrease in L* value with a concomitant increase in a*, b*, and C* values of the bulb with the advancement of fruit maturity. In both accessions, bulb firmness, and moisture content were highest in fruit harvested at 90 DAF. The decline in bulb firmness was associated with higher activities of polygalacturonase, pectin methyl esterase, cellulase, and pectate lyase. In both accessions, soluble solid content (SSC), DPPH radical scavenging activity, total flavonoids, and ascorbic acid content were higher in fruit harvested during the last stages of maturity while titratable acidity and total phenolics content were comparatively lower in advanced maturity stages. These findings highlight that the earlier stages (90 and 120 DAF) are suitable as meat alternatives due to better texture, while the most favourable stages for fresh consumption are 142 ± 4.7 and 153 ± 5.7 DAF in ‘Accession 341’ and ‘Accession 242’ due to better colour, higher pulp percentage, higher SSC and antioxidant activity, respectively.
Foundation Professor Horticultural Science, Edith Cowan University
Zora Singh is a Foundation Professor Horticultural Science in the School of Science with noteworthy expertise in Production technology and Postharvest physiology of fresh horticultural produce, undergraduate teaching and research training to domestic and international MSc and PhD... Read More →
Papaya (Carica papaya) is an herbaceous perennial plant native to the tropical Americas. It thrives in tropical and subtropical climates. While the United States is the world’s largest papaya importer, it also cultivates a modest number of papayas, primarily in Hawaii, California, Texas, and Florida. The subtropical climate in Mississippi offers favorable conditions for papaya cultivation. However, frosts in late fall or early spring could pose threats to both plants and fruits. Appropriate cultivar selection and management strategies are critical for successful papaya production in MS. Currently, limited information is available on growing papayas in MS. The objective of this study was to investigate the potential of growing papaya as an alternative crop for specialty crop growers in MS. Preliminary data suggest that papaya plants can grow well in Mississippi. Different cultivars exhibited variations in plant size and vigor. Plants produced papaya fruits with variations in fruit number, size, and shape, as well as timing to fruiting among different cultivars. However, the relatively shorter growing season in MS compared to tropical climates resulted in insufficient time for most fruits to ripen before the onset of frost in late fall. Further research will involve evaluating additional cultivars, adjusting production schedules, employing season extension techniques, and assessing economic feasibility.
Comparing The Effect Of Potyviruses On The Yield Of Different Generations Of Beauregard Sweetpotato Variety - Sathish Ponniah “Midnite” and “Festival”: Combining Caribbean and African Hibiscus sabdariffa - Thomas Zimmerman Metabolomic Survey of Puffy Skin Date Fruit - Yoko Hiraoka Identifying the formation of aroma compounds in mango using a multi-omics approach - Yu Wang Establishment of Avocado trees in the United States Virgin Islands - Samuel Joseph
Sweetpotatoes (Ipomoea batatas) have become increasingly popular over the last two decades. It is higher in beta-carotene than many other vegetables and a source of potassium, fiber, and vitamins A and C. Orange-fleshed varieties have a significant role in addressing vitamin A deficiencies, especially in pregnant women and children in developing countries. Sweetpotatoes are vegetatively propagated and susceptible to viruses that accumulate with each planting cycle (generation), leading to cultivar decline. This can affect the yield and quality of the sweetpotato roots. Over 30 viruses have been identified in sweetpotato. In U.S. commercial production fields, four potyviruses such as Sweetpotato feathery mottle virus (SPFMV), Sweetpotato virus G (SPVG), Sweetpotato virus 2 (SPV2), and Sweetpotato virus C (SPVC) are often commonly found. Potyviruses are aphid transmitted in a non-persistent manner. The potyvirus, Sweetpotato feathery mottle virus (SPFMV), is, by far, the most common sweetpotato virus. The objectives of the study are to compare the level of virus infection in five different generations (G1, G2, G3, G4, G6) with the yield performance in the Beauregard variety under field conditions. The different generation roots were collected from the previous experiments, and slips were multiplied under greenhouse conditions of the University of Arkansas at Pine Bluff (UAPB) farm. The slips were planted 12 inches apart with a 30-inch row spacing in four replications using a randomized block design during the summer of 2023. The roots were collected and cured to measure the various yield parameters like total marketable yield, U.S. No. 1, Jumbos Canners, and Culls. The random roots were selected to quantify the viral infections across the five generations using multiplex Reverse Transcription-Polymerase Chain Reaction (mRT-PCR). We observed significant differences in the U.S. No. 1 roots and Canners across the generations. In total marketable yield, 42.5% reduction was observed between the younger generation (G1, G2) and the older (G6) generation. Here, SPFMV was found to be dominant across the generations. Overall, a higher rate of virus infections was detected in the older generation (G6) than in younger generations (G1, G2).
Hibiscus sabdariffa, regionally referred to as sorrel, is a popular annual fruiting crop in the Caribbean. During the winter holiday season, sorrel calyxes are used for making flavorful and refreshing deep crimson red juices and teas. Through years of breeding and selection among Caribbean and African lines, from Ghana and Nigeria, the University of the Virgin Islands developed and released two new cultivar “Midnite” and “Festival”. “Midnite” has 20% greater production over standard Caribbean cultivars. The dark crimson-black calyxes, of both new cultivars, are full of anthocyanins and bioflavonoids. “Festival” begins bearing a month earlier than photoperiodic cultivars and production can extend to early May. Being day-neutral, “Midnite” can be grown year-round but has heavier production during late summer to late Spring. “Midnite” is being widely used in the U.S. Virgin Islands and has potential to expand its use in other commercial industries.
Date palm, Phoenix dactylifera L., is one of the oldest fruit crops grown in the arid regions of the Arabian Peninsula, North Africa and the Middle East and plays a significant role in the economy, society, and environment in these areas. ‘Medjool’ is considered one of the most desirable date varieties worldwide. Skin separation, also known as “puffy skin”, is a widespread phenotypic phenomenon mostly seen in soft varieties such as‘Medjool’ and ‘Barhee’. Skin separation is a market defect that is a commercial disadvantage. In this study, we conducted a metabolomic study of 'Medjool’ fruits at the date genebank maintained in Thermal, California by the United States Department of Agriculture Agricultural Research Service. Date fruit were harvested at the tamar stage (the fruit development stage in which the puffy skin phenotype develops). The metabolomes found in mature date fruits exhibiting non-puffy and puffy phenotypes were characterized. In this study, targeted central carbon metabolism analysis was carried out to identify 126 total metabolites with 95 significant metabolites (p-value < 0.05) (75.4%). Principal Component Analysis (PCA) was carried out, revealing that specific metabolites were associated with the non-puffy skin phenotype, and other metabolites with the puffy skin phenotype.. These metabolomes included those associated with skin elasticity and integrity, supporting studies suggesting the involvement of mechanical properties of date fruit skin.
Mango (Mangifera indica L.) is a fruit renowned for its delectable flavor, making it a staple in tropical and subtropical regions and the second most significant fruit crop in horticulture. Despite its widespread popularity, the specific compounds responsible for its distinctive aroma remain elusive. Our study aimed to bridge this gap by employing untargeted metabolomics and proteomics approaches to investigate aroma compound biosynthesis in three mango cultivars: 'Ah Ping', 'Rosa', and 'Rosigold'. Through integrated metabolomics and proteomics analysis, we identified key pathways and enzymes involved in aroma compound biosynthesis. Fatty acid metabolism, amino acid metabolism, pentose and hexose metabolism, and terpenoid metabolism emerged as pivotal pathways influencing mango flavor diversity. In 'Ah Ping', upregulation of lipoxygenase, hydroperoxide lyase, and alcohol dehydrogenase led to the accumulation of C6 and C9 volatile compounds, contributing to its distinct aroma profile. Conversely, 'Rosa' exhibited varied contents of straight-chain volatile compounds facilitated by the upregulation of enzymes involved in fatty acid degradation. Amino acid metabolism played a crucial role, with glutamate, valine, and phenylalanine serving as precursors for the biosynthesis of butyl esters and aromatic compounds in all three cultivars. Differential expression of enzymes such as aminotransferase and decarboxylase further modulated aroma compound production. Additionally, variations in furan and pyran volatile compounds were linked to differentially expressed enzymes in pentose and hexose metabolism. Our findings provide a comprehensive metabolic and proteomic map elucidating the biosynthesis of specific aroma compounds across mango cultivars. By unraveling the molecular mechanisms underlying mango flavor, this study offers valuable insights for breeding programs aimed at enhancing mango varieties with superior flavor quality. Overall, our research sheds light on the interplay between metabolism and aroma compound biosynthesis in mango, paving the way for targeted breeding strategies and improved mango flavor profiles.
Avocado (Persea americana Mill.), also known as pear in the Caribbean, is a staple fruit in the United States Virgin Islands (USVI) and has one of the fastest expanding markets in Europe and North America. Multiple West Indian cultivars exist. The objective of this study was to evaluate the establishment of 13 avocado varieties in the USVI. Thirteen cultivars were sourced from Florida, these cultivars are ‘Brogdon’, ‘Catalina’, ‘Choquette’, ‘Day’, ‘Donnie’, ‘Lula’, ‘Marcus Pumpkin’, ‘Monroe’, ‘Oro Negro’, ‘Pollock’, ‘Russell’, ‘Thompson Red’, and ‘Uh La La’. These grafted cultivars were planted on July 7, 2022, at 5.5 m spacing with drip irrigation installed as a 1 m diameter around the trees. Data on vertical stem growth after planting and the number of lateral shoots was collected monthly. Walk-throughs are conducted biweekly to identify when each cultivar begins flowering. Similarities in vertical stem growth and flowering were observed after 2 years. ‘Day’, ‘Marcus Pumpkin’, ‘Monroe’, ‘Oro Negro’, ‘Russell’, and ‘Thompson Red’ all grew an average of 98 cm. ‘Brogdon’ grew 137 cm which was the most vertical growth of all the cultivars and ‘Catalina’ grew only 43 cm which was the least. By the second year ‘Brogdon’, ‘Catalina’, ‘Oro Negro’, ‘Pollock’, ‘Russell’, and ‘Thompson Red’ all began flowering from January through April with ‘Pollock’ flowering the earliest in January. Avocado cultivars ‘Day’, ‘Russell’, ‘Oro Negro’, ‘Thompson Red’, and ‘Marcus Pumpkin’ have shown similarities in vertical growth over 20 months with only ‘Oro Negro’, ‘Russell’, and ‘Thompson Red’, flowering during the same months.
