Breeding report of a Torreya grandis cultivar ‘Zhuyanfei’

Abstract: ‘Zhuyanfei’is a good cultivar bred from an old tree of Torreya grandis through seedling se-lection in Hulu town, Dongyang county, Zhejiang province, and the progenies were expanded massively through grafting subsequently. It was initially selected in 2001 for its more than two eyes on seed nucle-us. It has the feature of strong tree vigor with tree performance of circular or semicircular crown. The tree is a dioecism plant and has mixed floral buds. Ovules are born on the middle part of bearing branch of female plants. The anthesis period is mid April; the mature period is mid September of next year, and the seed development period is 17 months in Dongyang county. The kernal qualities and seed characters were measured after its registration as a good variety of Torrey grandis in 2008. The surface of arillus has straight or twisty vascular bundles. The seed is drupaceous and encircled by arillus. The shape of its seed is long obovate oval. The average single mass of fresh seed is 12 g; the average peel thickness is 0.35 cm; the average index of seed shape is 1.70. The average single mass of fresh nut is 3.45 g (290nuts per kg); the mean index of nut shape is 2.46; the average ratio of fresh nut and seed is 28.10%. The eye number of a nut ranges from 2 to 4, and the type of three-eyes accounts for 20%. The mean ratio of kernel and nut is 61.8%, and the fat content of dry kernel is 48.86%. The stable yield of a mature tree with 8 m in crown breadth is more than 100 kg. The genetic variation was identified by genomic SSR analysis. DNA fingerprints of‘Zhuyanfei’were different from fingerprints of‘Xifei’, and indicate the genetics basis to be a new cultivar. The ploidy level of‘Zhuyanfei’was monitored and suggests a tetra-ploid plant by flow cytometry recently. Its seedlings and young trees like shady environments and avoid high temperature, drought and intense sunlight, but the mature trees are resistant to cold, heat and drought. Its root systems are fleshy and need well drained soil. Its cultivation requirements are the same as those of Torreya grandis‘Xifei’. It is suitable for cultivation throughout the distribution areas of wild Torreya grandis. It requires sandy soil with pH value from subacidity to neutral which is flat and good in retention of moisture and fertilizer. The appropriate attitude should be under 800 m. Virus-free seedlings were planted with row spacing of 4m × (4-5) m and 450-670 plants per hectare, and the con-figuration of pollinizer is 5%. For young trees, the conservation managements should focus on shading from May to Sept., shaping and pruning, and fertilization. For adult trees, the managements should put emphasis on fertilizing, weeding, loosening the soil, increasing the set of fruit, pruning and training properly, strengthening the comprehensive control of pests and diseases.