杨树单宁对青杨天牛的抗虫性

为了研究杨树单宁含量与青杨天牛(Saperda populnea (Linnaeus))产卵时寄主选择和幼虫发育的关系,测定了中黑防、3930杨、107杨、美×青、新疆杨、银中杨6个杨树品系木质部和韧皮部中的单宁含量.结果表明,供试的杨树品系在生长季节韧皮部单宁含量略高于木质部,但差异不显著.木质部和韧皮部单宁含量最低时期均在5月(美×青木质部和107杨韧皮部除外),最高时期普遍在7、8月份.各月份之间韧皮部单宁含量存在显著差异.美×青单宁含量无论在韧皮部还是在木质部中都明显高于其他品系,中黑防韧皮部和新疆杨木质部中的单宁含量都明显低于其它品系.采用实验林田间生物测定法研究了青杨天牛对6个供试杨树品系的寄主选择及生长发育情况,发现品系间幼虫发育率排列顺序为:中黑防＞3930杨＞107杨＞美×青＞新疆杨＞银中杨,青杨天牛幼虫发育率与木质部单宁总含量相关关系不显著;产卵痕密度的排列顺序为:美×青＞107杨＞中黑防＞3930杨＞银中杨＞新疆杨.5月份韧皮部单宁含量与品系间产卵痕密度无显著相关关系,表明供试杨树枝条韧皮部中的单宁含量不是影响其选择寄主的关键因子.

Relationship between Resistance of Poplar to Saperda populnea and Tannin Content

An experiment was conducted to measure tannin contents in xylem and phloem of six poplar strains in order to study the relationships between tannin content and host selectivity,larva development of Saperda populnea Linnaeus.Results showed that the tannin content in the phloem of different poplar strains was higher than that in the xylem during May and October,but the difference was not obvious.The tannin contents were higher in xylem and phloem during July and August and were the lowest in May(except the xy...