Search Results

You are looking at 11 - 20 of 20 items for

  • Author or Editor: Rosanna Freyre x
Clear All Modify Search

Mexican petunia (Ruellia simplex Wright) is a non-native plant that was introduced to Florida sometime in the 1940s and since then has naturalized in most of the state and in other southern states. Since 2007, we have developed at the University of Florida/Institute for Food and Agricultural Science in Gainesville the first Ruellia L. breeding program aiming to develop fruitless plants with different flower colors and growth habits that will not be invasive by seed dispersal. A combination of polyploidization and hybridization methods was used. In 2011, a total of 15 plants were selected and grown in southeastern, north–central, and northwestern Florida (Fort Pierce, Citra, and Quincy) using a randomized block design with three blocks and three plants per plot at each site. Plants were evaluated monthly for landscape performance, flowering, and fruiting. Two hybrids (R10-102 and R10-108) had outstanding potential as new fruitless cultivars for the plant industry having improved landscape performance and flowering.

Free access

Wild Anagallis monelli exhibits blue or orange flower colors in geographically isolated populations. A new red flower color was developed through breeding, and a three-gene model was proposed for the inheritance of flower color in this species. In this study, blue and orange wild diploid accessions were used as parents to develop six F2 populations (n = 19 to 64). Sexual compatibility between blue and orange wild individuals was low with only 29% of the hybridizations producing F1 individuals. Six of 14 cross combinations between F1 siblings produced fruits, and fruiting success ranged from 55% to 90%. The number of seeds per fruit averaged 14.1 and germination rates for the F2s were low (16.8% to 30.7%). In three of six F2 populations obtained, flower color segregation ratios for orange, blue, and red were not significantly different from the expected ratios under a previously proposed three-gene model. White flower color was obtained as a fourth color variant in two of the remaining F2 populations. For one of these populations, segregation ratios were not significantly different from expected ratios for an expanded four-gene model. White flowers did not contain anthocyanidins, suggesting that there was a mutation in the early stage of the anthocyanin pathway. Orange flower color was found to be primarily the result of pelargonidin, blue to malvidin, and red to delphinidin. These three pigments may be present simultaneously, and their ratios play a significant role in determining flower color. Other factors such as copigments, metal ions, or a different molecular conformation of the anthocyanin could also be involved in flower color determination.

Free access

The genetics and anthocyanins responsible for flower color were studied in Ruellia simplex Wright (mexican petunia). An F2 population with 153 individuals segregating for four flower colors was developed from a cross between a maternal individual with white corolla with purple throat (WP) and a paternal individual with pink corolla (PK). All the F1 generation had fully purple flowers (P). The F2 generation segregated 94 P:30 PK:24 WP:5 WPK (WPK is a new color combination of white corolla limb and pink throat). These data were separated into groups for corolla limb color and for throat color. The ratio for corolla limb color segregated 94 P:30 PK:29 W, which fits a 9:3:4 recessive epistasis interaction (P = 0.22). The data for corolla throat segregated 118 P:35 PK, which fits a 3:1 ratio (P = 0.54). High-performance liquid chromatography mass spectrometry analyses were performed to elucidate the anthocyanins responsible for the four obtained flower colors. We found that delphinidin derivatives conferred purple corolla color, whereas pelargonidin derivatives were responsible for the pink corolla color. Purple corolla throat color was the result of delphinidin derivatives, whereas the pink color was the result of peonidin derivatives.

Free access

Domestic production of ginger (Zingiber officinale) and turmeric (Curcuma longa) rhizomes is increasing. The objective of this study was to compare growth and rhizome yield of these crops using different container volumes and planting densities. Two greenhouse experiments that lasted 28 weeks each were conducted. In Expt. I, one sprouted rhizome of a single ginger variety (Bubba Blue) and four turmeric varieties (Hawaiian Red, BKK, White Mango, and Black) were transplanted into either small (1.5 gal) or large (13.3 gal) round containers. In Expt. II, either one or three sprouted rhizomes of two ginger varieties (Bubba Blue and Madonna) and two turmeric varieties (Indira Yellow and Hawaiian Red) were transplanted into either large (13.3 gal) or medium (3.9 gal) round containers. In Expt. I, there were an increase in plant growth and yield with increasing container volume, as both crops produced more than double the shoot, root, and rhizome fresh weight (FW) when grown in large compared with small containers. In Expt. II, rhizome yield of ginger was 44% higher in medium than large containers, and container volume did not affect yield in turmeric. Total dry weight (DW) was higher in plants grown in the larger container volume in both species in Expt. I, and turmeric only in Expt. II. However, ginger in Expt. II had an 18% higher plant DW in the medium compared with the large container. The higher density in Expt. II increased yield and biomass production per container compared with the lower density, regardless of variety and container volume. Overall, net revenue per container was higher in Expt. II than Expt. I because of the higher rhizome yield. In Expt. I, the higher yield of ginger compared with turmeric increased sales revenue of this species, despite a lower sales price per kilogram. In contrast, the higher yield of turmeric in Expt. II resulted in higher sales revenue and net revenue per container compared with ginger. Based on our results, medium containers could be used to minimize material and space costs for ginger and turmeric production under the conditions evaluated in our study.

Open Access

Nettleleaf porterweed (Stachytarpheta cayennensis) is a potentially invasive ornamental plant in Florida. Plant growth, visual quality, flowering, and seed viability were assessed for nettleleaf porterweed and eight closely related alternatives planted in northern and southern Florida. In northern Florida, ‘Mario Pollsa’ porterweed (Stachytarpheta spp.), ‘Violacea’ porterweed (Stachytarpheta mutabilis), ‘Naples Lilac’ porterweed (Stachytarpheta spp.), ‘Red Compact’ porterweed (Stachytarpheta speciosa), and nettleleaf porterweed (Stachytarpheta cayennensis) achieved high flower ratings between 4 (average to good flowering) and 5 (abundant flowering, peak bloom) during 4 or more months. Also, jamaican porterweed (Stachytarpheta jamaicensis), ‘Violacea’ porterweed, ‘Red Compact’ porterweed, and nettleleaf porterweed achieved visual quality ratings between 4 and 5 (good to excellent quality) throughout most of the study. In southern Florida, the same cultivars received high flower ratings but generally for shorter periods of time. Also, ‘Violacea’ porterweed and ‘Red Compact’ porterweed consistently received visual quality ratings that were above 4 (good quality, very desirable). During the course of the 28-week study, nettleleaf porterweed produced the greatest number of spiked inflorescences with 39% to 80% seed viability. At both locations, ‘Violacea’ porterweed did not produce any viable seed and seed viability was less than 10% for ‘Mario Pollsa’ porterweed, coral porterweed (Stachytarpheta mutabilis), and ‘Naples Lilac’ porterweed.

Free access

The objectives were to 1) compare growth and yield of different ginger (Zingiber officinale) and turmeric (Curcuma longa) propagules grown under two photoperiods (Expt. 1); and 2) evaluate whether their growing season could be extended with night interruption lighting (NI) during the winter (Expt. 2). In Expt. 1, propagules included 1) micropropagated tissue culture (TC) transplants, 2) second-generation rhizomes harvested from TC transplants (2GR), and 3) seed rhizomes (R). Plants received natural short days (SDs) or NI providing a total photon flux density (TPFD) of 1.3 µmol·m−2·s−1. Providing NI increased number of new tillers or leaves per plant, rhizome yield (i.e., rhizome fresh weight), and dry mass partitioning to rhizomes in both species. There was no clear trend on SPAD index in response to photoperiod or propagative material. Although TC-derived plants produced more tillers or leaves per plant, 2GR ginger and R turmeric produced a higher rhizome yield. In Expt. 2, seed rhizomes of ginger and turmeric were grown under five treatments with different photoperiods and/or production periods: 1) 20 weeks with NI (20NI), 2) 24 weeks with NI (24NI), 3) 28 weeks with NI (28NI), 4) 14 weeks with NI + 10 weeks under natural SDs (24NISD), and 5) 14 weeks with NI + 14 weeks under natural SDs (28NISD). NI provided a TPFD of 4.5 µmol·m−2·s−1. Lengthening the production period and providing NI increased rhizome yield and crude fiber content in both species. SPAD index decreased when plants were exposed to natural SDs at the end of the production period (NISD treatments). Results demonstrate the potential to overcome winter dormancy of ginger and turmeric plants with NI, enabling higher rhizome yield under natural SDs.

Open Access