Callas lilies and ‘Deja Vu’
The calla lily or arum lily, of the family Araceae, is native to temperate regions of Africa, and has been adapted to temperate and tropical highland areas in Mexico. The main producing states are Veracruz, Puebla, Jalisco, Chiapas, Oaxaca, Colima and the State of Mexico. If not cultivated, it can be found naturally in tropical and subtropical forest ecosystems. The most common calla lily in Mexico is the white-spathed 'Criollo', which is perennial. Other calla lilies such as the white-spathed variety with greenish spots or the ‘Green Goddess’ (Cruz-Castillo, Torres-Lima, Alfaro-Chilmagua, Albores-Gonzales, & Murguia-Gonzalez, 2008) appear in some markets and both are classified as Zantedeschia aethiopica (L.) Spreng. In addition, deciduous varieties of other colors belonging to other species such as Z. rehmannii Engl. (Espinal-Montes, Vázquez-Peña, Arteaga-Ramírez, López-Cruz, & Juárez-Hernández, 2012), Z. albomaculata (Hook) Baill. (Cruz-Castillo, Mendoza, & Torres-Lima, 2001) and Z. elliotiana (Watson) Engl. (Juárez-Hernández, Martínez-Solís, Curiel-Rodríguez, & García-Santos, 2011; Trejo-Téllez et al., 2013) have been introduced into Mexico.
The genus Zantedeschia includes six species and two sub-species that show disparity in their characteristics, enabling their division into two groups. The first is represented by Zantedeschia aethiopica, which is a species of perennial habit and its main organ of reproduction is a rhizome. This group includes the white calla lily, which grows in many parts of Mexico, and 'Deja Vu'. The latter is the first calla lily variety registered in Mexico with plant breeder’s title number 1478 (Secretaría de Agricultura, Ganadería, Desarrollo Rural, Pesca y Alimentación - Servicio Nacional de Inspección y Certificación de Semilla [SAGARPA-SNICS], 2016).
The remaining species present a dormancy period and deciduous leaves, and their storage organ is a tuber. The calla lilies of this group have very bright colors, grow mainly in greenhouses and have been introduced into Mexico from Holland and New Zealand. Although all belong to the same genus, there is a genetic barrier that prevents the crossing of Z. aethiopica plants with individuals of the second group (Kuobo, Inaba, & Mori., 2006).
The only registered experience with calla lily breeding in Mexico is 'Deja Vu'. In other countries, calla lily breeding has been mainly focused on obtaining new varieties of the deciduous group with very bright spathe colors. In addition, they have attempted to incorporate genes into calla lilies to make them tolerant to bacterial disease caused by Pectobacterium carotovorum subsp. Carotovorum, also known as Erwinia carotovora subsp. Carotovora (Kuobo et al., 2006), which is one of the main constraints on calla lily production in the world.
Breeding of Z. aethiopica for stressful environmental conditions
Ngamau (2008) cultivated in vitro seeds of Z. aethiopica cv Green Goddess under different salinity and temperature conditions and subsequently made a selection. He then acclimatized and cultivated them in a greenhouse; from this, he obtained plants tolerant to elevated NaCl levels. This is one of the few works that show the breeding of the calla lily with self-fertilization and a focus on tolerating adverse environments.
Cultivars of Z. aethiopica
Among the most striking cultivars of the perennial group of Z. aethiopica are ‘Green Goddess’, ‘Green Desire’, ‘Red Desire’ and ‘Hercules’. ‘Green Desire’ was generated in Holland by the Hoff Quality First company and is very similar to 'Green Goddess', which no longer pays royalties. The same company developed 'Red Desire', which features pink tones. ‘Hercules’, registered in the United States, is an extremely vigorous cultivar that can reach up to 1.80 m in height, has very large leaves and white spathes and could be used as a vigor promoter for other calla lilies; additionally, the maculation of its leaves could be incorporated into the ‘Criollo’ or ‘Deja Vu’ calla lily.
Origin, obtaining and advantages of 'Deja Vu' with respect to other calla lilies in Mexico
‘Deja Vu’ was selected in 2011 in Huatusco, Veracruz, Mexico, for the colors of its spathe, contrasting with ‘Green Goddess’, ‘Criollo’ (white) and ‘Pink Mist’ seedlings. This new cultivar has three colors in its spathe: white, pink and green (Figures 1 and 2), and its leaves are not maculated (Figure 2).
‘Deja Vu’ arose by crossing ‘Green Goddess’ (father) X ‘Pink Mist’ (mother) seedlings. The individual turned out to be slightly deformed, having a pink color with some green. Subsequently, it was pollinated with ‘Green Goddess’ and an individual of this cross was self-fertilized, resulting in 'Deja Vu'. Once this cultivar was identified, it was propagated asexually by shoots and its characteristics were retained through successive propagations. Its characterization was carried out using the guidelines for conducting the examination of distinctness, uniformity and stability of Zantedeschia sp, issued by the International Union for the Protection of New Varieties of Plants (Unión Internacional para la Protección de las Obtenciones Vegetales [UPOV], 2001).
A 'Deja Vu' plant grown for 3 years under a 35 % shade polyethylene mesh and established at 2,000 masl in Huatuso, Veracruz, is 90 cm high, the spathe is 30 cm long and 14 cm wide, and the floral scape is 85 cm long. It can produce between three and five floral scapes a year, only with compost applied once a year. The agronomic management of this new variety is similar to that used with the white 'Criollo' calla lily; therefore, the small producer can produce it properly.
The propagation of 'Deja Vu', by means of small shoots, is recommended to be carried out six months or more after establishment, when there is adequate soil moisture available (Cruz-Castillo, Torres-Lima, & Mendoza, 2010). To date, ‘Deja Vu’ has not been propagated in vitro (Ruiz-Sifre, Rosa-Márquez, & Flores-Ortega, 1996).
In Mexico, the white or 'Criollo' calla lily is sold. The introduction of new varieties, as well as their diffusion, represents the possibility of new market niches. Calla lilies of colors other than white are attractive for consumers looking for novel cut flowers.