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  • Author or Editor: Alan Chambers x
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Miracle fruit (Synsepalum dulcificum) is the botanical source of miraculin, a natural, noncaloric sweetener. Miracle fruit plants have a bush-like architecture and produce multiple flushes of attractive red berries each year. The berries consist of a large seed, opaque pulp, and brilliant red peel. The pulp of the fruit contains a glycoprotein, miraculin, that binds to the tongue’s sweet receptors and induces a conformational change in response to acidic stimuli. Thus, a strong sweet sensation is imparted in the absence of sugars. The miracle fruit plant is becoming increasingly popular because of its taste-modifying properties, but the species lacks many of the breeding tools common to other crops. We report miracle fruit pulp transcriptomes from ‘Sangria’, ‘Vermilion’, ‘Flame’, and ‘Cherry’ morphotypes. A consensus transcriptome included 91,856 transcripts. Reads mapping to the miraculin gene had the highest representation in individual miracle fruit pulp transcriptomes. Other abundant transcripts primarily included Gene Ontology categories representing cellular components, nucleus and nucleic acid binding, and protein modification. The transcriptomes were used to design real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR) primers for actin, elongation factor 1α, and the miraculin gene. Analysis by qRT-PCR indicated that miracle fruit pulp and peel tissues had the highest abundance of miraculin transcripts, although other tissues such as leaf, root, and flower also had detectable levels of the target sequence. Overall, these results will support discovery research for miracle fruit and the eventual breeding of this species.

Open Access

Endophytic fungi that are classified into the genus Neotyphodium have developed into a very unique niche. Their specific host plants are the fescues and ryegrasses. Through fungal biosynthesis of secondary metabolites, the host plant receives several benefits. These benefits include resistance to insects such as aphids, chinch bug, and argentine stem weevil, increased drought tolerance, and increased competiveness. These secondary metabolites comprise four groups of alkaloids. The alkaloids are loline, peramine, Lolitrem B, and ergovaline. The quantitative alkaloid profile is unique for each isolate. The characterization of these endophytes is necessary for identification of specific isolates. We report the characterization of ten endophytic strains Lp1, Lp2, Lp3, Lm4, Lm5, Fp6, Fp7 Fp8, Fp9, Fp10. The characterization of each isolate includes: morphology, sporulation, growth rates, microsatellite fingerprint, and alkaloid profile. The isolated colonies bear resemblance to raised brain-like structures and are yellow to tan in color. Growth rates range between 0.1 and 0.25 mm/day. No colonies produced any form of sporulation. Fp6 was found to have the highest loline concentration of any isolate. AFLP analysis was performed on the isolates to test for relatedness. Distinct clades were formed and grouped by host. The main groups were those isolated from Lolium or Festuca varieties. Isolates Fp8 and Fp9 were most related to each other, and have also been found to be doubly infected. The double infection is described to be Phialophora-like, due to the presence of thin highly branched hyphae when observed under light microscopy with aniline blue staining.

Free access

Fragaria vesca is a diploid strawberry species that produces gourmet, aromatic fruits with only limited commercial production because of its relative obscurity. Most F. vesca research focuses on genetics and fruit aroma, but yield and fruit quality data across diploid accessions are lacking. Sixteen F. vesca accessions were grown in replicated field plots in southern Florida to measure field performance and fruit quality over multiple harvests during a single growing season. Accessions ‘Reine des Vallees’, ‘Baron Solemacher’, ‘Fragolina di Bosco’, and ‘Reugen’ all had significantly higher yield (115–140 g/plot/week) and fruit number (117–139 fruit/plot/week) compared with ‘Bowlenzauber’, ‘Attila’, ‘Ali Baba’, and ‘Pineapple Crush’ (31–57 g/plot/week and 32–60 fruit/plot/week) during peak production. Total average yield ranged from 240 g (‘Pineapple Crush’) to 1194 g (‘Baron Solemacher’) per plot of 10 plants. Fruit number and fruit yield were highly correlated (R 2 = 0.96) for all accessions, and there was no significant difference in fruit weight among accessions through the entire season. Total soluble solids ranged from 10.9 to 13.5 °Brix, and fructose, glucose, sucrose, and total sugars ranged from 15.3 to 22.1, 13.5 to 20.0, 0.1 to 2.7, and 29.7 to 42.5 mg/g, respectively, fresh weight. Acidity ranged from 1.00% to 1.18% citric acid and was not consistently significantly different among accessions over multiple harvests. Forty-two aroma compounds were putatively identified over three harvests for each accession and included mostly esters and ketones with a few alcohols, terpenes, and aldehydes. The majority of these compounds were similarly abundant over harvests and among accessions with a few exceptions, including methyl anthranilate. These results are the first in-depth study of yield and fruit quality for a large number of F. vesca accessions that could lead to increased cultivation of this species for local markets.

Free access

Strawberry (Fragaria ×ananassa) is grown during the winter months in subtropical southern Florida and must thrive in higher than average temperatures and limestone soils. This is the first strawberry cultivar trial in southern Florida to include ‘Florida Beauty’, ‘Florida Brilliance’, ‘Strawberry Festival’, ‘Florida Radiance’, ‘Sensation FL127’, and ‘Winterstar’. Overall, ‘Strawberry Festival’ and ‘Sensation FL127’ were the top yielding cultivars, with the highest average total yields of 0.7 and 0.8 kg/plant fresh fruit, respectively. ‘Sensation FL127’ had a 36% greater late-season marketable yield compared with ‘Strawberry Festival’. ‘Sensation FL127’ consistently had the greatest soluble solids content (7.6% to 8.7%). Overall, this study demonstrates significant differences in yield and fruit quality among the cultivars tested in southern Florida.

Open Access

Passionfruits (Passiflora sp.) are widely grown throughout tropical regions of the world. Burgeoning new interest in this fruit in both its fresh and processed forms has led to an increase in planting outside of traditional growing zones. Passionfruit production has increased steadily in the United States and its territories since the 2002 US Department of Agriculture Census of Agriculture; however, little is known about how the industry functions across production areas. To assess passionfruit growers’ production practices and support their needs, we conducted a survey during 2021. That survey consisted of 45 questions pertaining to various aspects of passionfruit production, including horticultural practices, pest management, cultivars grown, and industry challenges and needs. The objectives of the survey were to identify where passionfruit is currently grown in the United States, what production practices are being used, and what problems are being encountered so that researchers and extension personnel could provide remedies in the future. Forty-four surveys were complete and allowed for data analyses. Florida had the most responses (21), followed by Puerto Rico (12), California (6), Hawaii, Louisiana, Mississippi, and the Virgin Islands. Most of the passionfruit production in the United States comprises purple passionfruit (Passiflora edulis f. edulis) or intraspecific red types at 68.2%. This value is driven by the high amounts of purple passionfruit and red passionfruit in Florida and other states. In contrast, nearly all farms in Puerto Rico grow yellow passionfruit (P. edulis f. flavicarpa) and fewer purple types. The main obstacle to obtaining optimum production was labor availability. Managing passionfruit, like many other specialty crops, is labor-intensive and includes many activities that require manual labor, such as weeding, training, pruning, pollination, and harvesting. Other obstacles that were noted were weather variability, vine decline, poor pollination, and availability of high-quality cultivars. Diseases, especially fungal diseases, are of particular concern to growers of passionfruit in the United States, although the identification of specific diseases was limited. Online delivery methods of information ranked high on the list of desired products. Online articles, such as those offered by extension services, were the most preferred, followed by webinars, which comprise a more recently developed method of information delivery. Overall, the survey provided baseline information to further develop initiatives to aid passionfruit production within the United States.

Open Access