PRODUCTION OF INTERSPECIFIC HYBRIDS BETWEEN PELARGONIUM CRISPUM AND P. RAPACEUM THROUGH OVULE CULTURE AND THEIR CHARACTERISTICS

In order to develop new breeding materials in Pelargonium, reciprocal crosses were made to produce interspecific hybrids between two cultivars of Pelargonium crispum, ‘Lemon crispum’ and ‘Prince Rupert’ (2n=22) within section Pelargonium, and P. rapaceum within section Hoarea, followed by ovule culture to rescue the hybrid embryos. The developed ovules were then cultured on agar medium 6 to 22 days after pollination. The culture media were basic White (1963) supplemented with 150 ml/L coconut milk, 0.5 mg/L NAA, and 2.5 mg/L kinetin for callus induction; Murashige and Skoog (1962) supplemented with 0.5 mg/L NAA and 2.5 mg/L kinetin for shoot formation; and Murashige and Skoog (1962) with 0.5 g/L active charcoal for rooting. All cross combinations gave F1 plants. High numbers of healthy plants were obtained when P. crispum was used as a female parent, while a few plants grew poorly when it was used as a male parent. The hybridity of plants was confirmed by morphological characteristics such as plant height, leaf and flower shape, oil components of leaves, flower color and pollen fertility. Intermediate traits of parents were observed on F1 plants which were true hybrids.