北美产七叶树引种栽培技术研究

从北美东部引进红花七叶树、光叶七叶树、黄花七叶树、欧洲七叶树等在浙江桐庐开展引种栽培试验.连续4 a的引种试验表明,较之于浙江七叶树,北美产七叶树早期生长较慢,树高生长期较短.在引种的4种北美产七叶树中,黄花七叶树、红花七叶树和光叶七叶树生长表现较好,虽然在苗期和1 ～2年生时的叶和芽在夏季比渐江七叶树更易受高温灼伤,但随着树龄的增大,抗灼伤等适应能力增强,年生长量不断增加;而欧洲七叶树易受冻害,生长不良,不宜引种.观察发现,红花七叶树和光叶七叶树分别在1年生和3年生时就始花始果,黄花七叶树营养生长最旺,生长速度不亚于浙江七叶树.七叶树种子适时采收,并利用具有自动喷雾设施的温室大棚沙藏,可使七叶树失活和腐烂种子的比率低于10%.在气温较低的冬季采用小包装方式进行长途运输可保证七叶树种子的质量.通过种子沙藏催芽和切根移床可促进根系发达和苗木生长.在苗期,夏季高温期间宜用50%透光度遮阳网遮阳.圃地培育大苗要求控制定植密度,施足基肥,加强水肥管理,以利苗木生长.

Studies on Introduction and Cultivation ofAesculus from North American

Aesculus pavia,A, glabra,A, octandraand A. hippocastanum from North America were introduced and cultivated in Tonglu of Zhejiang, China. A four-year introduction experiment showed that Aesculus from North America grew more slowly than that of Zhejiang buckeye in early stage. Of the four introduced Aesculus species,A, octan- dra ,A. pavia, and A. glabra, showed better growth performance. Though the young seedlings and 2 years old sprout and leaf of introduced Aesculus were more sensitive to the injury by high temperature in comparison with Chinese buckeye , their adaptation to high temperature and growth increment would increase continuously with age. Thus, they were fit to be introduced into East of China, while A. hippocastanum, which was sensitive to low temperature and grew more slowly, was unfit for introduction. Observations showed that A. pavia and A. glabra could bloom at 1 year and 3 years old respectively, while A. octandra had the fastest growing speed, which was not less than that of Zhejiang buckeye. Seeds of Aesculus may easily rot and lose vigor, but timely harvest and storing in sand of greenhouse could control the ratio of rotting being lower than 10 %. For long transportation of seeds in winter, little packing would be helpful for keeping seed quality. The number of lateral root of Aesculus was little, but stimulating germination by storing seed in sand and transplanting with cutting root might enhance root development and seedling growth. In high-temperature summer at seedling stage, shading by black net with light transmittance 50 % was helpful for seedlings growth. Cultivation of good-sized seedlings in nursery require controlled planting density, ample fertilizer, plenty water and fine management, which might promote the formation of plump top bud and would be good for the growth of next year.