‘Ganqi 4',a new early-ripening navel orange cultivar

Abstract:‘Ganqi 4'is a new early-ripening navel orange cultivar, which was selected from the common‘Newhall'navel orange. It has excellent characteristics, such as early maturity, easy peeling, high fruit setting rate, and high yielding. The trees vigor are medium, the topmost internodes length are slightly shorter. Leave blade are elliptical shape and involute, the wing leaves are slightly bigger. Number of the flowers are medium, inflorescence branch with leaf and single top flowers branch are major. Fruit is round or oblate, average weight is 220-240 g, fruit shape index is 0.9-1.0, the fruit apex is a bit flat, pedicel has 5-7 radiation ditch. Thickness of peel is 0.45-0.5 cm, and peeling easily; most navel are close. When the fruits are ripen, they have good quality with beautiful appearance, and the pulp is crisp and abundant juice. The soluble solid content is 12.1%, total acid is 0.47%, vitamin C content is 633.0 mg·L^-1. The multiple spots regional trial and test showed that the maturity period is from late September to early October.In 2005 years, a good bud mutation branches that the fruits are ripen earlyer was found from a 20 years‘Newhall'navel orange tree. The fruits begin to color at the end of August and completely turn into orange at the end of September, maturity is more than 30 days earlier than‘Newhall'. At the end of September, the soluble solid is 10.4%, total acid is 0.65%, vitamin C is 545.0 mg·L^-1. While the‘Newhall'fruits soluble solid is 9.2%, total acid is 0.87%, vitamin C is 485.0 mg·L^-1. In 2010, we top grafted the mutation on the Newhall'trees with sour orange,‘Navelina'‘Fengjie'navel orange,‘Skaggs Bonanza'as intermedial rootstocks and trifoliate orange, as base rootstocks, trees grew well after grafting, the genetical stability were confirmed, the fruit appearance, fruit internal quality, maturity were exactly as the same as themother plant. The genetic variation was checked with SRAP approach. From 99 pairs of primers we screened one polymorphic primer could tell from‘Newhall'and varation. After that, cultivation experiments were carried out at Ganzhou and Xinfeng county. In December 2014, this variation was certificated by crop variety certification committee of Jiangxi province and named as‘Ganqi 4'navel orange.