Breeding report of a new tangerine cultivar‘Guiju No.1'tangerine

‘Guiju No.1'tangerine is a new early maturing tangerine cultivar. The seeding was derived from a bud mutation of‘Miguangju'tangerine. The variation maternal plant was discovered in an orchard of‘Nanfeng tangrine'which was planted in 1974 in Chengdong village, Jieshou town, Xing'an county.The variation maternal plant was protected and replanted in resources nursery of Guangxi Citrus Research Institute in 2007. Tree of‘Guiju No.1'tangerine is semi-vigorous, spheroid. The average height of 6-year- old tree with trifoliate orange rootstock is 284.0 cm, average trunk girth is 21.2 cm and average crown size is 228.1 cm×186.6 cm. Leaves on spring shoots are 5.41-9.01 cm long, 2.12-3.88 cm wide,narrow ovate, leaf index is 2.04-2.63. The flowers are small, complete flower. The petals of flower are lanceate, 11.6-13.5 mm long,5.2-5.6 mm wide. Stamen number is 18-21. The fruit is oblate. The fruit peel is yellowish orange with luster. the fruit surface is smooth. Its flesh is yellowish orange, melting, pure sweet and fragrant. The average fruit mass is 46.77 g, maximum fruit mass is 63.3 g, fruit shape index is0.72; seed numbers per fruit is 0.85, Single embryo, cotyledon light green. The fruit edible rate is 78.01%,juice yield is 61.31%, the content of total soluble solid is 12.29%, total sugar 11.02%, titratable acid0.64%, sugar-acid ratio19.85, vitamin C 212.0 mg·L-1. The fruit quality is excellent. The fruit maturation period is early to middle October in Xing'an county of Guilin and 20 to 25 days earlier than normal‘Nanfeng tangrine'. Suitable cultivation region of‘Guiju No.1'tangerine includes the northern Guilin and Liuzhou which are suitable for‘Nanfeng tangerine'planting. Select virus-free seedlings. spacing in the rows and spacing between rows are 3 m×(3-5)m and the best field planting density is 660 to 1 110 per hectare. Tree form is spheroid crown, main stem is 0.4-0.5 m high, 2-3 main branches. Fruit should be harvested timely and sustains the inherent color and inner quality. Great attention should focus on the disease and insect preventing, especially Huanglongbing control.