A new seedless orange ‘Juxiangyuan' selected from ‘Succari Orange' mutant

Abstract: ‘Juxiangyuan', a new seedless orange, was selected from the Succari mutant. In 2007, a bud variation of the‘Succari Orange'was discovered in the citrus grove center of Hunan Agricultural University. It shows obvious characteristics of fewer seeds or no seeds. The propagation and characteristics observations were performed in 2009. The variety comparison tests had been carried out in the countryside of Chengjiao, Yongxing, Chenzhou and Changan Village, Ganshan, Changsha from 2010 to 2014, respectively. Through four years of investigation on botanical/biological characteristics and fruit quality during the citrus bearing seasons, it was showed that genetic traits of‘Juxiangyuan'were stable. As a result, it was selected for commercialization in 2016. The‘Juxiangyuan'tree is open and stands upright, with a natural round head-shaped canopy and dense branches. The‘Juxiangyuan'leaves have an elliptical shape with smaller winglets. The average spring shoots length, leaf width, and leaf shape index is 75.19 mm, 34.5 mm and 1.68, respectively. SSR analysis revealed there was one different band about 300 bp in Juxiangyuan comparing with Succari.‘Juxiangyuan'has small, complete, solitary flowers, with 4-5 white petals (ranged 6.56-7.65 mm in width and 18.97-22.95 mm in length) . The fruit is globe spherical shaped, with average 0.95 fruit shape index and 173 g fruit weight. The fruit is relatively uniform with a smooth surface and orange-yellow flesh. According to fruit quality test, it has 0.4 seed per fruit, 77.09% edible rate, 54.6% juice yield, 13.63 TSS, 0.14% TA, and 60.57 mg · 100 mL-1 vitamin C. The average fruit development period is 260 d and it matures in middle to late November in Yongxing, Hunan province. The tree of‘Juxiangyuan'is also noted for its vigorous growth. In Yongxing, Hunan Province, the sapling can flush three times a year, growing substantially to form a decent sized canopy. After an average four-year growth period, the tree is about 210 cm high and the trunk is 480 cm×465 cm. It is resistant to drought, cold, and diseases, which is similar to‘Succari Orange'.‘Juiangyuan'fruit has a long storage life, and fruits stay fresh in ventilated storage for up to 2 months. Suitable cultivation region of‘Juxiangyuan'are suitable for Succari orange planting. For grove management, ‘Juiangyuan'should be planted in neutral sandy soil in a relatively flat area that has good moisture and fertilizer retention. Spacing within and between rows should be 3 m × 4 m. In addition to higher production, the method of ring cutting can control tree size and maintain tree vigor.