A new Citrus cultivar 'Qianyang Bingtang Navel Orange'

Abstract: 'Qianyang Bingtang Navel Orange' is a new sweet orange variety selected from ordinary bud mutation of‘Bingtang Orange'plants in Hongjiang county. It was initially selected in 2000 for its large fruit size, closed navel, few seeds or seedless fruits. Through bud mutation of‘Qianyang Bingtang Navel Orange'from three individual plants(i.e. No.1 Shaping, No.3 Shaping and No.5 Shajiang), the scions were collected, and then grafted and planted for plant propagation. To evaluate regional adaptability, the new variety was tested at four sites(i.e. Pingyuan village, Jiankang village, Fuche village and Potian village) from 2001 to 2004. The results indicated that No.1 Shaping has superior traits and heterozygotes with four variant types. The four variety types were then tested and compared from 2005 to2008. The results also showed that genetic traits of No.1 and No.3 Shaping were stable. Lastly, through investigations on botanical/biological characteristics and fruit quality during the citrus bearing seasons over five years, the new variety was finally selected in 2013. The fruit is spherical in shape and medium in size, averaging a 1.05 fruit shape index with a smooth orange color peel, and closed navel. Additionally, the color of the pulp is yellow, the segment wall thickness is thin, the pulp texture is crisp, melting,and fragrant, the eatable proportion is high, and there is no seed. The fruit is 75.6 mm long, 72.0 mm in diameter, weighing about 192 g with a pericarp thickness of 5.1 mm. The juice content is 52.79%, the total soluble solid is 12.67%, the titratable acidity is 0.71%, and the ascorbic acid is 61.6 mg · 100 mL-1.The mature period of the fruit is late November, germination period in March, flowering period in early to late April on Hongjiang county in Hunan province. The fruit has a decent storage-life, the same as‘Bingtang Orange'. It is resistant to drought and cold, but susceptible to Citrus Canker and Citrus Tristeza Virus. Suitable cultivation regions of‘Qianyang Bingtang Navel Orange'are the same as Sweet Orange planting locations. Using 362 pairs of SSR primers for PCR amplification, SSR analysis revealed that 3 pairs of SSR primers had significant genetic difference in‘Qianyang Bingtang Navel Orange'and‘Bingtang Orange'.