Anagallis monelli is an ornamental annual used for hanging baskets and as a bedding plant because of its very bright and unusual flower colors. This genus currently belongs to the Primulaceae, although recent studies based on three chloroplast genes and morphology locate it in the Myrsinaceae (Källersjö et al., 2000). Genetic information about A. monelli is scarce, but it is known to exhibit gametophytic self-incompatibility (Gibbs and Talavera, 2001; Talavera et al., 2001), and sampling of several wild populations detected only diploid (2n = 2x = 20) plants (Šveřepová, 1972; Talavera et al., 1997; Valdés, 1970).
Wild individuals of A. monelli are native to the Mediterranean region and have small flowers, which are either blue or orange. Populations with these two flower colors are geographically isolated; plants with blue flowers are found in southern Spain, whereas plants with orange flowers are found in southern Italy and Morocco (Talavera, personal communication). Until recently, blue and orange were the only flower colors available in commercial cultivars Skylover Blue and Sunrise, respectively. Since 2002, the Ornamental Breeding program at the University of New Hampshire (UNH) has released additional commercial cultivars of Anagallis in the ‘Wildcat’™ series with blue, orange, dark orange, and red flower colors.
Genes involved in the anthocyanin pathway that are responsible for flower color variation have been widely studied, mostly in Petunia and Antirrhinum majus (Brouillard, 1988; Gerats et al., 1982; Holton and Cornish, 1995). In Anagallis, Harborne (1968) detected the flavonols quercetin and kaempferol in flowers of A. arvensis and A. linifolia; and 3- and 3,5-glycosides of malvidin, delphinidin, and pelargonidin were detected in different color forms in A. arvensis. Ishikura (1981) identified malvidin 3-rhamnoside, luteolin, luteolin 7-glucoside, and quercetin 3-rhamnoside in blue-flowered A. arvensis. Elsherif (2000) isolated the enzymes chalcone synthase and flavanone 3-hydroxylase from flowers of A. monelli ‘Skylover Blue’ and ‘Sunrise’ and reported finding only pelargonidin derivatives in flowers of ‘Sunrise’ and only malvidin derivatives in flowers of ‘Skylover Blue’.
At UNH, hybridizations between the blue- and orange-flowered A. monelli cultivars Gentian Blue and Sunrise, respectively, produced progeny populations from which plants with a new red flower color were isolated (Freyre and Griesbach, 2004). Genetic and biochemical analyses were performed on 65 plants comprising a pooled set of four F2 populations derived by selfing and reciprocally mating two F1 plants obtained from the cross ‘Gentian Blue’ × ‘Sunrise’. High-performance liquid chromatography (HPLC) confirmed that orange color is attributable primarily to pelargonidin, blue to malvidin, and red to delphinidin. A three-gene genetic model for flower color inheritance with an expected F2 generation segregation pattern of 52 orange:9 blue:3 red was proposed (Freyre and Griesbach, 2004).
The objective of this study was to further investigate the genetic basis for flower color variation in A. monelli, this time focusing on wild-collected germplasm of potential value to a breeding program. In this study, blue- and orange-flowered diploid plants collected in the wild were hybridized to create several F2 populations, and color segregation ratios were analyzed. To better understand the biochemistry of flower color in this species, a sample of individuals with different tones for each flower color was analyzed for anthocyanidin content.
Asen, S., Stewart, R.N. & Norris, K.H. 1977 Anthocyanin and pH involved in the color of ‘Heavenly Blue’ Morning Glory Phytochem. 16 1118 1119
Elsherif, T. 2000 Genetik und Enzymologie der Bildung außergerwöhlicher Anthocyanidin-Muster in Blüten höherer Pflanzen Munich Technical Univ Munich, Germany PhD Diss.
Gerats, A.G.M., de Vlaming, P., Doodeman, M., Al, B. & Schram, A.W. 1982 Genetic control of the conversion of dihydroflavonols into flavonols and anthocyanins in flowers of Petunia hybrida Planta 155 364 368
Gibbs, P.E. & Talavera, S. 2001 Breeding system studies with three species of Anagallis (Primulaceae): Self-incompatibility and reduced female fertility in A. monelli L Ann. Bot. (Lond.) 88 139 144
Griesbach, R.J. 1993 Characterization of the flavonoids from Petunia× hybrida flowers expressing the A1 gene of Zea mays HortScience 28 659 660
Griesbach, R.J. & Austin, S. 2005a Comparison of the Munsell and Royal Horticultural Society's Color Charts in describing flower color Taxon 54 771 773
Hall, M.C. & Willis, J.H. 2005 Transmission ratio distortion in intraspecific hybrids of Mimulus guttatus: Implications for genomic divergence Genetics 170 375 386
Harborne, J.B. 1968 Comparative biochemistry of the flavonoids—VII. Correlations between flavonoid pigmentation and systematics in the family Primulaceae Phytochemistry 7 1215 1230
Huits, H.S.M., Gerats, A.G.M., Kreike, M.M., Mol, J.N.M. & Koes, R.E. 1994 Genetic control of dihydroflavonol 4-reductase gene expression in Petunia hybrida Plant J. 6 295 310
Ishikura, N. 1981 Flavonoid in petal cells of Anagallis arvensis f. coerulea containing a blue crystalline anthocyanin Z. Pflanz. Bd. 103 Suppl 469 473
Källersjö, M., Bergqvist, G. & Anderberg, A.A. 2000 Generic realignment in primuloid families of the Ericales s.l.: A phylogenetic analysis based on DNA sequences from three chloroplast genes and morphology Amer. J. Bot. 87 1325 1341
Li, Z., Pinson, S.R.M., Paterson, A.H., Park, W.D. & Stansel, J.W. 1997 Genetics of hybrid sterility and hybrid breakdown in an intersubspecific rice (Oryza sativa L.) population Genetics 145 1139 1148
Quintana, A., Albrechtova, J., Griesbach, R.J. & Freyre, R. 2007 Anatomical and biochemical studies of anthocyanidins in flowers of Anagallis monelli L. (Primulaceae) hybrids Sci. Hort. 112 413 421
Talavera, S., García Pérez, L., Arista, M. & Ortiz, P.L. 1997 Números cromosómicos de plantas occidentales Anal. Jard. Bot. Madrid 55 136
Talavera, S., Gibbs, P.E., Fernández-Piedra, M.P. & Ortiz-Herrera, M.A. 2001 Genetic control of self-incompatibility in Anagallis monelli (Primulaceae: Myrsinaceae) Heredity 87 589 597
Tutin, T.G., Heywood, V.H., Burges, N.A., Moore, D.M., Valentine, D.H., Walters, S.M. & Webb, D.A. 1972 Flora Europaea 3 Cambridge University Press Cambridge, UK
Yu, H.R. & Davis, T.M. 1995 Genetic linkage between runnering and Phosphoglucoisomerase allozymes, and systematic distortion of monogenic segregation ratios in diploid strawberry JASHS 120 687 690