樟子松嫩枝扦插技术

Softwood Cutting Technique of Pinus sylvestris var. mongolica

研究了樟子松嫩枝扦插生根的特点以及插穗生根与母树年龄、扦插基质、扦插时间、生根促进剂质量分数、温度的关系。结果表明:①樟子松属于愈伤组织生根型,只有极少数为皮部生根,生根时间为2～4个月。扦插期间地表温度过低(低于20℃)不利于生根。②扦插的最好时间为6月上中旬,此时扦插的穗条处于半木质化时期。③樟子松扦插生根的最佳组合为:蛭石基质,插穗为2年生母树的穗条,生根促进剂为L2号。母株年龄对樟子松扦插生根有极为显著的影响,母树的年龄效应是樟子松穗条扦插生根的主要限制因子,2年生到5年生的插穗生根率从90%降到2.5%;而扦插基质之间和生根促进剂之间对生根率没有显著影响。基质对插穗生根影响的顺序从大到小为蛭石,草炭,珍珠岩+草炭(1∶1),河沙。生根促进剂以质量分数为1×10-4L2号最好,生根率达到67%,质量分数太小(0.5×10-4)或太大(3×10-4、5×10-4)都使得成活率下降。3种处理对生根率影响的顺序从大到小顺序为:插穗的母树树龄,扦插基质,生根促进剂。

An experiment was conducted to study the rooting characteristics of softwood cuttings of Pinus sylvestris var. mongolica and the relationships between root formation and age of stock plants, culture medium, cuttage time, concentration of rooting promoter and cutting temperature. Results show that the adventitious roots of P. sylvestris var. mongolica are developed from callus, and only a few are from cortex. The duration for root formation is usually about 2 to 4 months, and low surface temperature of bed （lower than 20 degrees C） during this period is unfavorable for rooting. The preferred cuttage time is during the first ten days of June and the middle ten days of June, and the shoots are semi-lignified at this period. The best rooting effect could be obtained when use vermiculite as culture medium, 2-year-old seedlings as shoots, and the rooting promoter L2 as auxin. Age of stock plants has remarkable influence on the cutting rooting, and the rooting rate declined from 90% to 2. 5% as age of stock plants increased from 2-year-old to 5-year-old The age effect of stock plants is the main restriction factor of the cutting rooting. However, neither medium nor rooting promoter has remarkable effect on rooting rate. The sequence of medium in terms of the effect on rooting is vermiculite 〉 peat moss 〉 perlite ＋ peat moss （ 1：1 ） 〉 river sand. As for rooting promoters, the L2 at a concentration of 1 × 10^-4 is the best promoter, and the rooting rate can reach 67%. The rooting rate may decline whenever the concentration of rooting promoter is too low （0.5× 10^-4 ） or too high （3 × 10^-4 , 5 × 10^-4 ）. The effects of three factors on rooting rate is sequenced as the age of stock plant 〉 culture medium 〉 rooting promoter.