关键词: 大白菜, 早熟, 品种

Abstract: ‘Duokang 55’is a new early-maturing Chinese cabbage hybrid cultivar，with high quality and diseases resistance，which crossed by self-incompatibles cultivar‘XZ55’and autogamy cultivar‘Xiaobao’. Its growth development period is 55 days. Its height is 29.4 cm，and expansion is 54.6 cm × 51.4 cm. The head is ball. The out leaves color is light green. The leaves inside is fresh and tender，less fiber. Texture is lightly sweet，fragile and tender. Soft leaves rate is 58.2%. The average ball weight is 1.6 kg，net rate is 75%. The average yield is 90 000–97 500 kg • hm-2. The head ball will not crack over 55 days in growth period. It is resistant to downey mildew，virus disease and black rot，heat-resisting. It can be planted in Hebei Province and the area with climate similar to Hebei.

Key words: Chinese cabbage, early-maturing, cultivar