柑橘砧木新品种‘蒲江香橙’的选育

A new citrus rootstock 'Pujiang Xiangcheng'(Citrus junos)

‘蒲江香橙’是从四川省蒲江县白云乡实生野生香橙中经过多年观察和试验比较选择育成的柑橘砧木新品种。作为砧木,该品种树势强健,树冠圆头形,植株高大,枝条较硬、直立而密生、伸展。果实椭圆近扁圆形,果皮橙黄色,单果质量78.1~112.8 g,单果种子数32~43粒,平均37.5粒,种子质量占果实的10.1%左右,盛年期每株树可产种子3.5~5.5 kg。用作柑橘砧木,嫁接亲和性好,接穗品种早结、丰产、稳产,果实品质优良,遗传性状稳定。抗寒、抗涝、耐碱性土壤。适合在四川柑橘主产区作砧木使用。

＇Pujiang Xiangcheng＇ is a novel citrus rootstock selected from wild Citrus junos resources in Baiyun village of Pujiang county in Sichuan province. Until the 1940s, many wild C. junos seedlings dis- tributed in the mountain at an altitude of 800 to 1 000 m in Baiyun village. From 1970s, the local farmers tried to use C. junos seedlings as rootstock for citrus cultivation. They found that the grafted Citrus varieties have good compatibility with C. junos, and perform early fruiting, high and stable yield. In addition, wild C. junos has outstanding advantages such as resistance to cold and alkaline soil. Due to above charac- ters, it was approved as a new rootstock cultivar by Sichuan Crop Variety Certification Committee on No- vember, 2016, named ＇Pujiang Xiangcheng＇ （C. junos） （No. 2016017）. The cuhivar has vigorous growth, spherical crown, upright and dense hard branches. Its unifoliate compound leaf is lanceolate with short petiole. It has solitary flower, whose lateral petals are purple from bud to bloom, with flower diameter of 2.0 cm. Compared with ＇Ziyang Xiangcheng＇, also selected from wild C. junos resources, ＇Pujiang Xiangcheng＇ has more advantages, such as taller plants, harder branches. Furthermore, ＇Pujiang Xiangcheng＇ shows stable genetic characters, and reveals dramatically genetic difference from ＇Ziyang Xiangcheng＇ by SSR （simple sequence repeats） markers. The fruit is oblong to flat round, with an average weight of 78.1 to 112.8 grams per fruit. Most fruits have flat top, obvious seal ring, with radioactive grooves. The fruit has orange peel and rough surface, big oil cell, white spongy layer. Fruit flesh is white- yellow, with thick capsule, which tastes very sour. There are 32 to 43 seeds in each fruit, which count for about 10.1% of the fruit weight. It can produce as much as 3.5 to 5.5 kilograms seeds per treein one year. Plump seeds are white, smooth, with gap. Green monogerm or white polyembryony per seed has purple big chalaza. In Pujiang county, the cultivar burgeons by early or middle March, buds by late March, blooms on April, fades by early May, fruit colors by late September, and ripe by late October, respectively. Various citrus species grafted on ＇Pujiang Xiangcheng＇ exhibit extensive compatibility, give early bearing,high productivity with great fruit quality as well. This rootstock give high resistance to cold weather and ro- bust adaptation to basic soil conditions. It is suitable for rootstock on different citrus varieties in main pro- ducing region in Sichuan. The fresh seeds should be sowed in loose and fertile soil immediately after 3 to 4 hours removed from fruits on Autumn. It is necessary for young seedlings to adopt heat preservation in winter. The young seedlings can be transplanted nexl year when they have 4 to 10 true leaves. Fertilization for them should hold principle of applying a small amount of manure frequently. Traditional method is chosen to graft with various citrus.