不同培育时间侧柏种基盘苗根系生长和分布

以3月直接在培养池中播种培育的侧柏种基盘苗作对照,将同期播种的侧柏种基盘苗进行悬空培养,于6月、8月和10月分别移栽到培育池(分别称为种基盘苗、6月移栽苗、8月移栽苗、10月移栽苗),并于翌年3月挖根,研究不同培育时间对移栽后侧柏幼苗根系生长和分布的影响。结果表明:苗木株高、根分布最大深度、根和地上部干重由大到小依次为:6月移栽苗>8月移栽苗>种基盘苗>10月移栽苗。根冠比由大到小依次为6月移栽苗>8月移栽苗>10月移栽苗>种基盘苗,但除了种基盘苗与6月移栽苗之间差异性显著外,其它处理之间差异性不显著。随着悬空培育时间的延长,空气断根限制了侧柏主根的生长,促进了侧根生长,降低了主侧根长度比。但经悬空培育后,任何处理的移栽苗都没有发生根系盘绕现象,移栽后主根的再生没有受到影响。

The growth and distrubution of Platycladus orientalis Seed-base seedling root in different culture periods

In order to clarify the effects of different culture periods on the growth and root distrubution of Platycladus orientalis seedling, we cultured seedlings directly seeded in Seed-bases buried in culture groove in March, and seedlings seeded at the same time in Seed-bases which were put on a net first, and then transplanted in culture groove in June, August and October (intituled as Seed-base seedling, Jun transplanted seedling, Aug transplanted seedling and Oct transplanted seedling, respectively). The growth of seedlings were investigated and roots were dug out in the next March for root surveying. The results showed that seedling height, maximal root depth, dry weight of root and shoot decreased as the fllowing order: Jun transplanted seedling > Aug transplanted seedling > Seed-base seedling> October transplanting seedlings. Root-shoot ratio decreased as the fllowing order: Jun transplanted seedling > Aug transplanted seedling > Oct transplanted seedling > Seed-base seedling. As the increasing of Seed-base culture time on net, the growth of main root was limited, and the taproot-lateral root length ratio was decreased because of air root-pruning. However, root roping phenomenon did not appear at any culture periods in this study, and the taproot regrowth after transplantation was not damaged.