Parameters Necessary for In Vitro Hydroponic Pea Plantlet Flowering and Fruiting

Flowering in vitro has been reported infrequently in tissue culture and the subsequent occurrence of fruiting structures from these flowers is rare (Al-Juboory et al., 1991; Bodhipadma & Leung, 2003; Dickens & Van Staden 1985; 1988; Franklin et al., 2000; Ishioka et al., 1991; Lee et al., 1991; Pasqua et al., 1991; Rastogi & Sawhney 1986; Tisserat & Galletta 1993; 1995). Fruits are complex organs composed of unique tissues that are a source of many important food products, nutrients and phytochemicals. The biosynthesis of phytochemicals common in fruits by cultured vegetative cells and tissues is difficult and usually not achievable; when achieved they usually occur at lesser yields than in vivo derived fruits (Tisserat et al., 1989a; 1989b). Unfortunately, fruit tissues and organs are difficult to establish, maintain and proliferate in vitro as such, mainly because they fail to retain their unique tissue and organ integrity within a sterile environment and often generate into a undifferentiated mass (i.e. callus) with an altered biochemical metabolism compared to that obtained from the original fruit tissues (Hong et al., 1989; Tisserat et al., 1989a; 1989b). Nevertheless, development of sterile fruit production systems would be useful in order to study the reproductive processes, provide a source of important secondary natural products in vitro, provide sterile produce for at-risk populations with weakened immune systems, and aid in breeding projects (Bodhipadma & Leung, 2003; Butterweck, 1995; Kamps, 2004; Ochatt et al., 2002; Pryke & Taylor, 1995).