| Research Abstract |
Introduction of the gene from wild-related Brassica to cultivated ones was tried by using the technique of ovary culture in vitro. Culrivated plants used in the experiment were Brassica campestris subsp. chinensis and subsp. pekinensis. Wild-related plants of B. oleracea used in the experiment were B. bourgeaui and B. montana. The medium used in the experiment was the minerals of Nitsch and Nitsch (1969) with 50g/1 sucrose and 300 mg/1 casein hydrolysate. Ovaries of B. campestris x B. bourgeaui and B. campestris x B. campestris x B. montana were explanted in the medium four days after pollination. The F_1 interspecific hybrids were obtained in all cross combinations. The production rate of the hybrid (number of hybrids obtained/number of capsules examined x 100) ranged from 34.1 (subsp. pekinensis x B. montana) to 231.8 (subsp. chinensis x B. bourgeaui), with mean 120.0. Most frequent type of chromosome configuration at the first meiotic cell division showed 9_<II>+1_I, follwed by 1_<I
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II>+8_<II>. most F_1 hybrids had no pollen fertility. In crossability of the F_1 hybrids, seeds were obtained in open pollination, F_1 x B. campestris and F_1x B.napus. Many seeds were obtained in the progeny of F_2, V_1 andother hybrid (F_1 x B. napus). It suggested that the wild-related species of B. oleracea. B. bourgeaui, B. montana, may become gene sources in cultivated Brassica.
In the relation between sucrose concentration in the medium and hybrid production, ovaries were cultured in the cross of Brassica compestris x B. oleracea.The medium used in the experiment was the minerals of Nitsch and Nitsch and Nitsch with 300mg/1 casein hydrolysate. Concentration of sucrose ranged from 30g/1 to 150g/1. The best result obrained was in the medium with 30g/1 sucrose followed by 50g/1 and 90g/1. In the relation between day cultured after pollination and hybrid production, ovaries were cultured in the cross of B. campestris x B. oleracea. The medium used in the experiment was the minerals of Nitsch and Nitsch with 50g/1 sucroese and 300mg/1 casein hydrolysate. Day cultured after pollination was from two days to 12 days. The best result obtained was two days after pollination, followed by four days. The F_1 hybrids were obrained in the ovaries cultured 12 days after pollination. Less
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