越冬低温及栽期对偏低海拔区当归生长的影响

Effect of overwintering low temperatures and planting dates on Angelica sinensis growth cultivated at lower altitude region

【目的】探讨偏低海拔区当归苗的越冬温度和成药生长光温对早薹及成药根产量的影响。【方法】采用甘肃漳县当归苗,越冬期按根直径分类后分别进行0和-5℃处理,次年与当地同期、晚15d和晚30d分3个时期进行分期栽植,以观察早薹及成药根农艺性状对越冬温度和分期栽植的反应。【结果】根直径大于0.45cm的当归苗具有明显的早薹现象,根直径为0.55~<0.65cm的当归苗早薹高于根直径为0.45~<0.55cm的苗,根直径小于0.65cm的同类大小苗经0和-5℃冬储处理及分期栽植后,相同大小的各类苗间早薹差异不明显。当归成药根主根直径、鲜质量和干质量与苗大小成正比,苗大小不同、冬储温度不同形成的侧根数也不同。当归成药根的产量随栽期的延后而减小。【结论】根直径0.65cm以下的当归苗可在0与-5℃温区越冬,偏低海拔区适宜栽植根直径偏小的苗,栽前萌动、栽期严重影响当归的产量,随栽期延后成药根产量减小。

[Objective] To investigate the effect of seedlings overwintering temperature and cultivation photo-thermo conditions on the lower-altitude-cultivated Angelica sinensis （01iv.） Diels early bolting and yield of medicine-formed root. [Method] Angelica sinensis seedlings provided by County Zhang medicine farmer were used in this study,and were stored at 0 and --5 ℃ in winter storage, respectively. In the fol- lowing spring, seedlings were transplanted to the field at intervals, synchronizing with local planting date, later 15 and 30 days,respectively,to observe the responses of their early bolting and medicine-formed root agronomic traits to winter storage temperatures and thermo-photo variations in growth caused by the inter- val planting. [Result] The early bolting responses of seedlings with root apex diameter bigger than 0.45 cm were apparently observed,and the early bolting rate of seedlings between 0. 55 -〈0. 65 cm is higher than that of 0. 45-0. 55 cm. The early bolting differences of seedlings smaller than 0.65 cm that are of the same size, overwintered at 0 or -5 ℃ and followed interval plantations were unapparent. The main root diameters, fresh and dry weight of medicine-formed roots are in proportional to seedling root sizes. Seed- lings in different sizes subjected to different overwintering temperatures exhibited different tendency toproduce side roots. The yield of medicine-formed root was decreasing as planting dates extending. [Conclu- sion] Angelica sinensis seedlings with root diameter smaller than 0.65 cm may be stored at temperature between 0 and --5 ℃ for winter storage,relatively smaller seedlings may be used in lower altitude region, root apex germinating prior to field plantation and planting dates strongly affected Angelica sinensis yield which is decreasing as planting date extension.