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2.11 IN VITRO FLOWERING<br />

Literature review<br />

Florogenesis is divided into six phases for most geophytes. These include induction,<br />

initiation, differentiation, floral stalk elongation, maturation and growth <strong>of</strong> the floral<br />

organs, and anthesis. (FLAISHMAN & KAMENETSKY, 2006). Factors that affect<br />

florogenesis include the genetics <strong>of</strong> the plant and its environment (FLAISHMAN &<br />

KAMENETSKY, 2006). After induction <strong>of</strong> flowering the vegetative meristem ceases<br />

leaf production during flower initiation to allow for more resources for flower initiation<br />

(FLAISHMAN & KAMENETSKY, 2006).<br />

Smoke and smoke solutions have been used to promote flowering in geophytes.<br />

These include Narcissus tazetta, a freesia hybrid and Watsonia spp. (IMANISHI,<br />

1983; UYEMURA & IMANISHI, 1984; LIGHT et al., 2007). LIGHT et al., (2007) found<br />

that a 1:500 (v/v) smoke water solution promoted the flowering <strong>of</strong> corms <strong>of</strong> Watsonia<br />

spp., which is in the same subfamily as Romulea. Corms <strong>of</strong> Freesia sp., a species in<br />

the same tribe as Romulea, were stimulated to flower using a smoke treatment<br />

(UYEMURA & IMANISHI, 1984).<br />

In a study <strong>of</strong> the plant-soil relationship in the habitat <strong>of</strong> R. columnae it was found that<br />

soil N, P and K was reduced during the generative growth stage whereas the soil<br />

organic matter, pH, and CaCO3 levels were increased (KÖK et al., 2007).<br />

It is better to use large plants with large, matured storage organs for florogenesis<br />

studies, as it is common for a plant with a small storage organ not to flower<br />

(FLAISHMAN & KAMENETSKY, 2006).<br />

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