土壤水分对杜仲剥皮再生的影响

Effects of Soil Water on the Growth of Callus and Bark Regeneration in Eucommia ulmoides

分别对12和25年生杜仲进行Ⅰ、Ⅱ、Ⅲ、Ⅳ级供水处理,研究不同水分条件对杜仲愈伤组织和再生皮生长的影响.结果表明：供水改善了林地水分条件,土壤平均含水量和贮水量增大,25年生杜仲消耗土壤水分较多,土壤含水量较12年生杜仲林地的低.杜仲剥皮后,供水能加快愈伤组织的形成,剥皮后第5 d,处理Ⅰ、Ⅱ、Ⅲ均有微绿色的愈伤组织出现,较对照提前5 d左右;剥皮后25 d,12和25年生的愈伤组织厚度分别达到1.00和0.94mm,生长速度分别为0.040和0.037 mm·d-1,分别较对照增加47.1%和80.8%.供水能显著促进杜仲再生皮的生长,剥皮后5个月,12和25年生杜仲Ⅰ、Ⅱ、Ⅲ、Ⅳ级供水处理的再生皮厚度分别较对照增加5.0%、22.5%、75.8%、71.7%和18.5%、29.3%、80.7%、95.0%.6月份是杜仲再生皮生长的关键期,供水对再生皮生长最有利.杜仲水分利用效率在Ⅲ级供水处理时最大,12和25年生分别较对照提高39.3%和37.4%.生长季中,土壤含水量应保持在160～170 g·kg-1.

The effect of soil water on the growth of callus and bark regeneration of Eucommia ulmoides was studied on the 12- year-old and 25-year-old trees by artificial watering with the levels of Ⅰ,Ⅱ,Ⅲ and Ⅳ. The results showed that artificial watering improved the soil water conditions, manifested by the increase of soil water content and water storage capacity in different irrigating levels. 25-year-old trees of E. ulmoides consumed more soil water than those of 12-year-old ones, and made the lower soil water content. Irrigating could accelerate the formation of the callus. The pale green callus were formed in treatment Ⅰ,Ⅱ, and Ⅲ after 5 days debarking and 5 days earlier than those in control treatment. The thickness of callus of 12-year-old and 25year-old trees were 1.00 mm and 0.94 mm respectively after 25 days debarking, the growth speed was 0.040 mm·d^-1 and 0. 037 mm· d^-l respectively, and increased 47.1% and 80.8 % than those in control. The thickness of regenerated bark in 12year-old and 25-year-old trees in the treatments of Ⅰ,Ⅱ,Ⅲ and Ⅳ increased by 5.0% , 22.5% , 75.8% and 71.7% , 18.5% ,29.3% ,80.7% and 95.0% respectively. June was the key period of the growth of regenerated bark and irrigating was most important. The water use efficiency of the trees in treatment Ⅲ was the greatest of all the treatments, increased by 39.3 % and 37.4% respectively in 12-year-old and 25-year-old trees compared with the controls. The favorable soil water content in the growing season should maintain between 160 - 170 g·kg^-1 during growing season.