Achievements in Citrus Breeding

  Relying on the abundant citrus germplasm resources, the Citrus Research Institute of the Chinese Academy of Agricultural Sciences has bred many new varieties and developed new methods since its establishment in the 1960s. New cultivars like the Zhongyu 7 sweet orange, the seedless Xuegan, the Late-honey mandarin No. 1, the Ponkan Nucellar Line No. 3, and the Tarroco Nucellar Line have been widely planted throughout the nation.


  A. Zhongyu seedless Xuegan

  The Zhongyu seedless Xuegan is a seedless sweet orange variety obtained by irradiation. The branches of Xuegan, a seedy local variety of south China, were irradiated using 60Co-γ in 1981 at the Citrus Research Institute of the CAAS. Few-seed and seed-free mutations were found, and a seedless super strain was selected in the following breeding process. The strain was certified to be a new variety and was named the Zhongyu seedless Xuegan by the Chongqing Crops Variety Certification Committee in June, 2003. The variety is seed-free with large fruit, a brilliant peel color, high inner quality, high juice yield, a high a stable yield, and is easy to manage. According to the tests by the Supervision and Test Center of the Citrus Seedlings and Fruit Quality (MOA), the average weight of the fruit is 194.6g, there are 0.7 seeds per fruit, the juice yield is 58%, and the total soluble solids content is 12.8%. In 100 ml of juice, there is 10.74g of invert sugar, 0.69g of citric acid, and 57.17mg of vitamin C. The variety is good for both fresh consumption and for processing.

  B. Tarroco Nucellar Line

  The Tarroco Nucellar Line is an excellent new Tarroco variety, bred from seedlings of seeds introduced from Italy by the CRI, CAAS. In 2003, it was approved and released by the Chongqing Crops Variety Certification Committee. The fruit of this variety is excellent for the fresh market, being large and seedless, the flesh lightly blooded, very juicy, crisp, tender, and having a rose aroma. According to the tests by the Supervision and Test Center of Citrus Seedlings and Fruit Quality (MOA), the average weight of the fruit is 180-240g, there are 0 seeds per fruit, and the total soluble solids content is 11%. The invert sugar is 9.38g/100ml, the citric acid is 0.8g/100ml, the vitamin C is 62.55mg/100ml, and the edible rate is 74.63%.


  C. Late-honey mandarin No.1

  The Late-honey mandarin No. 1 is a seedless late-season tangor bred from the 1960s to the 1980s at the CRI, CAAS. Its seed parent was a Satsuma and its pollen parent was a local sweet orange, strain S8. Its pollen is highly sterile and is the main cause of its seedlessness. Its fruit becomes mature in January of the following year, and the rind color is deep orange. It is easier to peel than sweet orange. The average weight of the fruit is about 120g, there are 0.6 seeds per fruit, and the total soluble solids content is 11.5%. Ub 100ml of juice, there are 9.8g of invert sugar and 1.0g of citric acid.