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  • Author or Editor: Jessica Brown x
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As the demand for locally grown specialty cut flowers increases, cultivars of Pycnosorus globosus and Caryotperis incana are becoming more available for growers to produce as cuts. However, protocols for year-round greenhouse production are limited. Therefore, our objective was to determine if the photoperiod influences flower induction and development, time to harvest, yield, and morphology of billy buttons (Pycnosorus globosus) ‘Paintball Globe’ and ‘Paintball Poppy’ and bluebeard (Caryopteris incana) ‘Pagoda Lagoon’ and ‘Pagoda Dark Pink’ to facilitate commercial greenhouse production. Shoot-tip cuttings were rooted and transplanted into bulb crates and placed in a greenhouse with a mean daily air temperature of 20 °C and 9-, 10-, 11-, 12-, 13-, 14-, 15-, or 16-hour photoperiods or a 9-hour short day (SD) with a 4-hour night interruption (NI) from 2200 to 0200 HR for 11 weeks. Billy buttons initiated inflorescences and developed flowers under all daylengths; however, the greatest stem lengths were recorded under long days (LDs). Bluebeard inflorescences initiated under all daylengths were tested. Time to visible inflorescence and flower was hastened under daylengths ≤14 hours, whereas inflorescences under the 16-h photoperiod or 4-h NI never fully developed. For ‘Pagoda Lagoon’ and ‘Pagoda Dark Pink’, the critical daylengths for flower development were 14 hours and 15 hours, respectively. On average, only bluebeard ‘Pagoda Lagoon’ harvested under photoperiods ≥10 hours developed marketable stem lengths (>40 cm). To hasten time to visible inflorescence and harvest and ensure marketable stem lengths, billy buttons should be grown under daylengths ≥13 hours. Based on these results, we recommend growing bluebeard under a 16-hour photoperiod or NI for 4 to 6 weeks to promote vegetative growth, followed by an 11- to 14-hour photoperiod for flower induction and development. We classify billy buttons as a day-neutral plant for flower induction and a facultative LD plant for flower development. Similarly, bluebeard can be classified as a facultative SD plant for flower induction and an obligate SD plant for flower development.

Open Access

Fusarium wilt of tomato (Solanum lycopersicum), caused by fungal pathogen Fusarium oxysporum f. sp. lycopersici (Fol), is one of the most important diseases in tomato production. Three races of the pathogen are described, and race-specific resistance genes have been applied in commercial tomato cultivars for controlling the disease. Race 3 (Fol3) threatens tomato production in many regions around the world, and novel resistance resources could expand the diversity and durability of Fol resistance. The wild tomato species, Solanum pennellii, is reported to harbor broad resistance to Fol and was the source of two known Fol3 resistance genes. In this study, we evaluated 42 S. pennellii accessions for resistance to each fusarium wilt race. F1 plants, developed from crossing each accession with the Fol3 susceptible line ‘Suncoast’, were evaluated for Fol3 resistance, and BC1F1 plants were screened to determine the likelihood that Fol3 resistance was based on a novel locus (loci). Nearly all accessions showed resistance to Fol3, and many accessions were resistant to all races. Evaluation of F1 plants indicated a dominant resistance effect to Fol3 from most accessions. Genetic analysis indicated 24 accessions are expected to contain one or more novel Fol3 resistance loci other than an allele near the I-3 locus. To investigate genetic structure of the S. pennellii accessions used in this study, we genotyped all 42 accessions using genotyping by sequencing. Approximately 20% of the single nucleotide polymorphism (SNP) loci were heterozygous across accessions, likely due to the outcrossing nature of the species. Genetic structure analysis at 49,120 unique SNP loci across accessions identified small but obvious genetic differentiations.

Open Access