Genetically modified organism (GMO) crops provide new trait(s) that may benefit floral designers and consumers. A limited array of GMO cut flower cultivars exist in the floral markets worldwide: nine carnations (Dianthus caryophyllus) and one rose (Rosa ×hybrida). Labeling GMO flowers in the United States is not required. Thus, most distributors, flower auctions, brokers, wholesalers, floral designers and consumers are not aware that they exist. To test the acceptance of GMO cut flowers with potential future floral designers, n = 121 students enrolled in Floral Design (HORT 1013) at the University of Minnesota during 2005–07, 2009, and 2011, designed with standard and miniature GMO Moon™ series carnations. Each student created a Hogarth design with both types of carnations and assembled a price sheet. Students examined the differences between GMO lavender/purple carnations and those created with classic methods of spraying, dipping, or infusion. In 2009 only, students were also assigned to write a marketing paragraph about their GMO floral design. Each year, students were given an identical question on a subsequent midterm examination to determine their position on GMO cut flowers, including development of a floral shop policy to inform customers. Student examination responses ranged from not carrying GMO products [1/121 (0.8% response)], offering GMO/non-GMO carnation options to the consumer [81/121 (66.9% response)], or only selling only GMOs [33/121 (27.3% response)] that differed significantly from a 1:1:1 chi-square (χ2). A significant majority of students would inform their customers of the GMO crops [89/121 (73.6% response)]. In several instances, consumers were not to be informed of the GMO nature unless they queried about the higher price point. Similarly, marketing paragraphs did not uniformly highlight the GMO nature of the flowers. Implications for the next generation of floral designers demonstrate that, with the exception of students in 2005–06, most would sell both GMO and non-GMO flowers with a majority of shops clearly identifying GMOs.
Neil O. Anderson and Natalie J. Walker
Neil O. Anderson and Richard T. Olsen
Luther Burbank (1849–1926) was a prolific ornamental plant breeder, who worked with 91 genera of ornamentals, from Abutilon to Zinnia, and released nearly 1000 cultivars to the industry. His innovative work included both herbaceous and woody plant materials as well as ornamental vegetables such as corn, tomatoes, and spineless cacti. His most popular ornamental release, the shasta daisy hybrids—first released in 1901, is still on the global market. This article focuses on Luther Burbank’s breeding techniques with ornamental plants and how both the germplasms that he developed and his methodologies used permeate modern flower breeding. Genera with the highest number of cultivars bred and released by Burbank include Amaryllis, Hippeastrum, and Crinum followed by Lilium, Hemerocallis, Watsonia, Papaver, Gladiolus, Dahlia, and Rosa. With Lilium, he pioneered breeding the North American native lily species, particularly those from the Pacific coastal region, producing the eponymous Lilium ×burbankii. Burbank’s breeding enterprise was designed to be self-sustaining based on profits from selling the entire product line of a new cultivar or crop only to wholesale firms, who then held exclusives for propagation and selling, although financial hardships necessitated selling retail occasionally. Entire lots of selected seedlings were sold to the highest bidder with Burbank setting the price in his annual catalogs such as the Burbank Hybrid Lilies lot for U.S. $250,000 or some of the “very handsome, hardy ones” for U.S. $250 to U.S. $10,000 each. Other flower cultivars also commanded high prices such as seedling Giant Amaryllis that sold for U.S. $1.55/bulb in 1909. Cacti were another area of emphasis (he released more than 63 cultivars) from the spineless fruiting and forage types (Opuntia ficus-indica, O. tuna, O. vulgaris) to flowering ornamentals such as O. basilaris, Cereus chilensis, and Echinopsis mulleri. Interest in cacti during 1909–15 rivaled the Dutch Tulip mania with exorbitant fees for a single “slab” of a cultivar, speculative investments, controversy with noted cacti specialists (particularly David Griffiths), and lawsuits by The Burbank Company. Although most cultivars have been lost, Burbank’s reputation as the Father of American Ornamental Breeding remains admirable from critics and devotees alike.
Neil O. Anderson, Adnan Younis, and Ye Sun
The large genome size of easter lily [Lilium longiflorum (77.1 pg/2C nucleus)], coupled with repetitive DNA sequences, makes it difficult to use molecular techniques to identify or fingerprint lily (Lilium) species, hybrids, and clones. Previous research demonstrated that amplified fragment length polymorphisms could not be optimized for consistency and repeatability to obtain reliable genetic variation assessments of lily species and clones. The objective of this research was to analyze the effectiveness and stringency of intersimple sequence repeats (ISSRs) to determine genetic differences between L. longiflorum ‘Nellie White’ clonal ramet populations from bulb growers over years. DNA from closely related clones of L. longiflorum ‘Nellie White’ included 2002 (n = 11 bulb lots) and 2003 (n = 12 bulb lots). Comparison cultivars and species were also included. Five University of British Columbia (UBC) primers (P808, P810, P811, P814, and P818) that were used produced 56 polymorphic loci. ISSR banding patterns were consistent among three replications within ‘Nellie White’ clonal genotypes. ‘Nellie White’ clones differed significantly within (82%) and among (18%) growers in 2002 and 2003. ‘Nellie White’ clones are not uniform or part of a single ramet population. Principal clades within years separated at Nei's genetic distances (GDs) of GD = 0.6 (growers 2, 4, and 12) to GD = 0.82 (grower 6) in 2002 and GD = 0.51 (grower 4) to GD = 0.78 (grower 14). The most closely related ‘Nellie White’ clones within growers ranged from GD = 0.8 to 0.95 in 2002 and GD = 0.7 to 0.91 for 2003. Five top-performing growers (1, and 3–6) from previous morphological studies and, particularly growers 3 and 5, were in similar clades, cosegregating with phenotypic traits of stem emergence and flowering dates. The lack of a meiotic sieve (Muller's ratchet) may be responsible for the high level of mutational differences present in the ‘Nellie White’ clones and significantly affects the ability of commercial greenhouse growers to produce a uniform easter lily crop, particularly in years when the Easter holiday is early.
Jaser A. Aljaser and Neil O. Anderson
Gladiolus (Gladiolus ×hybridus) is an asexually propagated, herbaceous perennial and an economically important cut flower crop. In commercial production, gladioli have tall flower stalks, which limit their use to cut flowers and annual garden plants. The gladiolus breeding program at the University of Minnesota has bred and selected rapid generation cycling (RGC) cycle 1 gladiolus, which can flower in <1 year from seed instead of the norm of 3 to 5 years (which are vegetatively propagated as corms). Gibberellin inhibitors, such as ancymidol, are used as plant growth retardants to control height in potted plants. Higher concentrations can inhibit flowering along with other negative side effects. The aim of this study was to investigate the growth, flowering, and corm/cormel production response of cycle 1 gladiolus to the gibberellin inhibitor, ancymidol (0, 100, and 400 mg·L−1 soak) in comparison with noncycle 1 genotypes and commercial cultivars for potted gladiolus production. Cycle 1 genotypes flowered with all ancymidol concentrations while noncycle 1 genotypes had significantly fewer flowers or were completely nonflowering under higher concentrations. All tested genotypes had increased leaf width as ancymidol concentration increased. Conversely, flower stalk heights were shorter as the ancymidol concentration increased while the number of stalks was nonsignificant. Corms, cormel number, and fresh weights decreased in all genotypes except for one cycle 1 genotype, which had an increase in both corm number and fresh weight when treated with 100 mg·L−1 ancymidol. Cycle 1 gladiolus are more resilient to this gibberellin inhibitor even at high concentrations and can potentially be used for gladiolus potted plant production.
David C. Zlesak and Neil O. Anderson
Potted Easter lily (Lilium longiflorum Thunb.) ranks among the top five potted flowering plants in the United States in economic value. One clone (‘Nellie White’) dominates the North American market. It is grown by less than 10 bulb producers, each maintaining their own propagation stock and practicing intraclonal strain selection. Greenhouse forcers attest to forcing differences depending on the bulb grower. The objective of this study was to determine the extent and sources of morphological variability among bulb growers. Bulb lots were obtained in 2002 (S1) and 2003 (S2) (n = 11 and n = 12 lots respectively) with 12 or 15 bulbs/lot. Grower's identification was confidential but kept consistent across shipment years. Bulbs were obtained as the 20.3 to 22.9-cm circumference commercial class, and S1 and S2 shipments were control temperature forced over two forcing cycles (FC1, FC2). Data collection included initial bulb weight and circumference; days to stem emergence (SEM), visible flower bud (VFB), and anthesis (AN); plant and inflorescence height; number of stems, leaves, flowers, and ovules per first flower/stem reaching AN; percentage of ovules forming viable seeds; leaf length and width; major lily viruses (presence/absence, relative optical density); leaf length-to-width ratios; AN-SEM, AN-VFB, and VFB-SEM. Significant differences were found among bulb lots for every trait except AN-VFB. Variability among bulb lots can be attributed to variation in initial bulb size, previous forcing cycle environment, variable lily symptomless virus (LSV) titer, and underlying genetic/epigenetic differences. Bulb circumference had the highest standardized canonical coefficient for canonical variable one in S2-FC1 and was a significant covariate in analysis of covariance; larger bulbs tended to produce larger plants. Forcing over two cycles allowed for less phenotypic variability among bulb lots in FC2 because of a common FC1 environment. All lilies were positive for LSV and negative for four other viruses tested. Significant negative correlations in S2 between relative optical density and plant height (FC1), initial bulb weight (FC2), and initial bulb circumference (FC2) indicate an effect of relative LSV titer on plant morphology. The role of LSV titer and genetic/epigenetic intergrower variability in ‘Nellie White’ warrants further investigation. Likewise, a lack of breeder/producer companies and the corollary independent grower strain selection has significant genetic consequences and complicates identification of superior ‘Nellie White’ clones.
Neil O. Anderson and Peter D. Ascher
Commercial chrysanthemums are short day (SD) plants. Recently, several day neutral (DN) garden genotypes have been identified. Both glasshouse and garden cultivars vary in heat delay insensitivity (HDI). This research analyzed yield components (seed set, germination, yield potential) and tested a DN/HDI ideotype for its effectiveness. Progeny from a 6 × 6 diallel were embryo rescued, clonal ramats were grown in two environments (glasshouse—long days; field—long to short days) and evaluated for flowering, early flowering response groups, thermozero temperature response, low long day leaf number (LDLN), high leaf initiation rates, and low mean stem lengths of the terminal shoot. Self seed set ranged from 0% to 8% while outcross seed set was 0% to 92%. General and specific combining ability were highly significant for seed set, the reciprocals, and their interactions. Germination averaged 67%, while yield potential was 44%. Cotyledon pigmentation in embryo rescued seedlings was 7% albinos, 15% anthocyanin (transposable elements), and 78% normal (green). SD parents did not flower in either photoperiod although PPSL-10 carried alleles for DN. SD x DN crosses produced some DN progeny and fit a 1:3 chi square ratio (DN:SD), indicating DN to be recessive. However, DN x DN crosses also fit a 3:1 chi square ratio, due to HDI. No progeny flowered within the 3 to 6 week ideotype; visible bud date had a heritability of h 2 = 0.50. Most progeny were within the LDLN range (h 2 = 0.72). Several leaf initiation rates exceeded the ideotype (h 2 = 0.003); plant height also matched the ideotype (h 2 = 0.66). Both visible bud and flowering dates require significant improvement before progeny match the DN/HDI ideotype.
Neil O. Anderson, Peter D. Ascher, and Emily E. Hoover
Decreases in fertility are most common among interspecific, wide crosses of Phaseolus; intraspecific hybrids are less likely to exhibit sterility. Intraspecific CBC hybrid pedigrees were created to test for comparative fertility losses. Eight P. vulgaris cultivars from different centers of origin, polymorphic for seed proteins (15, 20, 50 kDa), were used to create 16 CBC populations: dry (`Cuarenteño', `Great Northern Harris', `Sulfur', `Swedish Brown') and snap beans (`Purple Pod Pole', `Romano Bush', `Royal Burgundy Bush', `White Half Runner'). Despite repeated attempts, two crosses failed to produce primary hybrids. Primary hybrids had decreased percent stainable pollen from the parents. Female sterility was more severe, necessitating the screening of the F1–F3 before producing the next CBC. Yield was significantly lower than midparent values for all F3 CBC pedigrees. In several cases, phaseolin was no longer the major seed protein. Other hybrid breakdown symptoms were similar to those found with wide crosses, indicative of incongruity between centers of origin.
Michael R. Evans, Neil O. Anderson, and Harold F. Wilkins
Various durations of rooting at 15C and storage at 5.X and exogenous GA, (1000 ppm) application were used on dormant unrooted peony (Paeonia lactiflora Pall.) tubers of `Sarah Bernhardt', `Festiva Supreme' `Krinkled White', and `Scarlet O'Hara'. Four weeks of cooling were sufficient to break dormancy. Days to emergence, first bud color, and anthesis were reduced as the length of cold storage increased from 4 to 20 weeks. Height and number of shoots emerging per pot increased with increased cooling. All flower buds aborted when tubers were cooled for 20 weeks. When noncooled tubers were given a 1000-ppm GA, soil drench, shoots emerged within 7.5 days; untreated tubers failed to emerge after 5 months. When tubers were treated with GA,, all flower buds aborted.
Neil O. Anderson, Peter D. Ascher, and James J. Luby
The change from asexual to sexual propagation for annual and perennial bedding plants has been successfully accomplished for floral crops, e.g., Pelargonium. Seed-propagated cultivars do not necessarily possess the clonal uniformity of vegetatively propagated cultivars. In the development of F1 hybrid garden chrysanthemums, this lack of uniformity was assessed with the use of consumer sensory evaluations. Seedlings (n = 10–20 plants/cross) were transplanted for field trials in St. Paul and five Minnesota branch stations each year during 1988–94 to test for G × E. Early flowering F1 hybrids, developed from inbred parents with general combining ability, were evaluated for flowering earliness, plant uniformity, and a general rating. Consumer rankings of top performers were not significantly different (5% level) from mum breeders. The top performers for all three ratings were selected each year for repeat evaluation the next year. The two highest performing F1 hybrids were submitted for All American Selection Trials in 1995.
Dave I. Thompson, Neil O. Anderson, and Johannes Van Staden
Polyploidy represents a useful tool for increasing marketability of floriculture crops. The efficacy of 250 μM colchicine [0.01% (w/v)] as a means of inducing polyploidy in six South African Watsonia species (W. borbonica subsp. ardernei, W. humilis, W. laccata, W. lepida, W. pulchra, and W. vanderspuyiae), as determined through high-resolution flow cytometry, is reported. Exposure to colchicine during imbibition and as 24-, 48-, or 72-h pulse treatments for in vitro-germinated seeds resulted in seedlings with increased ploidy, reaching a maximum of 60% induction after the 72-h pulse treatment. The greatest proportions of induced individuals from both the pre- and post-germination exposure treatments were of mixed ploidy. These mixoploids were induced in five species. Non-chimeric tetra- and octaploids were produced in low frequencies only for W. vanderspuyiae during radicle-pulse exposure of 24 and 48 h. Increasing colchicine exposure at radicle emergence manifested as aberrant phenotypic expression and was typified by a reduction in leaf length and rooting capacity in vitro coupled with overall slowed growth. In vitro regeneration and multiplication is easily achievable for the genus and should allow for the capture and refinement of desirable polyploid tissues.