In order to investigate a better soilless culture medium and the possibility of grass clippings as alternative substrate for peat moss to grow Begonia cucullata Willd. in pots, the seedlings of widely cultivated B. cucullata were grown in pots with eight types of soilless substrates: T1(peat: perlite=1:1), T2(peat: perlite: pine bark=1:1:1), T3(corn stover: perlite: pine bark=1:1:1), T4(corn stover: perlite: pine bark=2:1:1), T5(grass clipping: perlite: pine bark=1:1:1), T6(grass clipping: perlite:pine bark=2:1:1), T7(vermiculite: perlite: pine bark=1:1:1) and T8(vermiculite: perlite: pine bark=2:1:1), respectively, in a shade house of Shanghai Chenshan Botanical Garden to evaluate plant growth performance. The results showed that the stem diameter of B. cucullata increased significantly from day 30 to day 60 after potting,and the plant height, leaf number and leaf area increased largest from day 60 to day 90 after potting in all treatments. The growth of plants performed best in T6,with the highest branch number, leaf thickness, flower number, aboveground fresh and dry weights and relative chlorophyll content. Therefore, the substrate with grass clipping: perlite: pine bark=2:1:1 was the best culture medium for growing B. cucullata in this study, and the grass clippings could replace peat moss as alternative substrate for growing B. cucullata in containers.
《中国植物志》和Flora of China关于秋海棠(Begonia grandis)的种内分类存在争议,根据两者的分类依据在实践中无法操作,显然该种的种内单元分类还存在问题。为了全面理解秋海棠的种内多样性,在此基础上对其种内单元进行合理分类,以39个秋海棠居群为研究材料,对33个表型性状进行多样性及数量分类分析。通过数量性状变异分析、质量性状遗传多样性分析、主成分分析和R形聚类分析从33个性状中筛选出主要性状进行Q型聚类分析。结果显示:秋海棠的表型多样性丰富,数量性状变异系数为0.077~0.441,质量性状多样性指数为0.287~1.483。主成分分析结果表明:33个性状可综合为6个主成分,其累计贡献率达72.28%。R型聚类分析结果表明:除叶形和花形大小指标相关外,各性状相对独立。Q型聚类结果显示:39个秋海棠居群按雄花大小、叶片大小、植株大小和叶色分为四组,同Flora of China将该种分成3个亚种处理不一致。因此,对秋海棠的种内单元的划分今后有必要综合分子生物学方面的证据来讨论才更合理。有趣的是发现日本秋海棠的自然化居群的祖先极可能为浙江天目山居群。