Читать книгу Cucurbits - James R. Myers - Страница 30

Tissue culture is used in cucurbits for embryo rescue, propagation, embryogenesis and organogenesis. Success in producing interspecific plantlets by embryo culture has been achieved in Cucurbita (C. pepo × C. moschata, C. pepo × C. ecuadorensis) and Cucumis (C. metuliferus × C. zeyheri Sond.). Other crosses, such as African horned melon and melon, have been difficult. So far, there are no reports of the successful use of protoplast fusion in creating interspecific hybrids of cucurbits.

Cultivars within a cucurbit crop often differ in their ability to be regenerated through tissue culture. Embryos have been obtained from various plant tissues (e.g. leaf callus, hypocotyl explants, protoplast-derived callus), but their development into plants has been sporadic. Cotyledons and hypocotyls have proved to be the best explant tissues for organogenesis, but leaves, fruit and embryos have also been used.

In their production of transgenic melon plants, Gonsalves et al. (1994) cultured the developing tissue on Murashige and Skoog medium according to plant developmental stage (i.e. regeneration, shoot elongation and rooting stages). They also performed regeneration experiments in which they found that proximal explants produced a higher percentage of regenerated shoots than distal tissue samples, with most shoots arising from the proximal side of the square-cut piece of cotyledon.