不同种松树对松树蜂毒素抗性的初步研究

松树蜂(Sirex noctilio Fabricius)是一种重要的国际检疫性蛀干害虫。目前在我国松树蜂潜在寄主范围内,不同树种对松树蜂毒素抗性之间的差异尚不明确。本文以室内栽培的2~3 a生油松、樟子松、红松、湿地松、马尾松及雪松这6种树种为供试寄主,培育3个月后分别接种毒素、毒素真菌混合液并测定每株枝条针叶的RGB值以及叶绿素含量。结果表明,形态上油松和樟子松幼苗接种毒素、毒素真菌混合液后一段时间内,均出现了比较明显的针叶枯黄、脱落的现象,且混合组长势萎蔫,脱落严重,对照组无明显变化。马尾松幼苗只有接种混合液后变化明显,雪松、红松、湿地松接种后长势强劲,长出新芽。从数值化的角度,油松和樟子松幼苗接种毒素、毒素和真菌混合液后,针叶的RGB值减小及叶绿素含量值显著降低。马尾松幼苗只有接种混合液后,RGB值和叶绿素含量才减小。雪松、红松、湿地松接种毒素以及毒素真菌混合液后,RGB值及叶绿素含量均没有明显变化。以上可以看出樟子松和油松对于松树蜂毒素、毒素真菌混合液的抗性较弱,马尾松对松树蜂毒素具有一定的抗性,对毒素真菌混合液的抗性较弱,红松、湿地松、雪松对两者都具有一定的抗性。该结果可为明确松树蜂在我国潜在的寄主范围及寄主选择性提供科学依据。

Resistance to Sirex noctilio venom in different pine species

Sirex noctilio Fabricius is an important wood boring pest and international quarantine pest.At present,the difference resistance to Sirex noctilio venom of different pine species is not clear in our country's potential host range.In this study the 2-3 year pine seedlings of Pinus tabulaeformis,P.sylvestris,P.koraiensis,P.elliottii,P.massoniana and Cedrus deodara were choosed as research objects.Each species were planted and vaccinated with the same volume of venom solution,venom and fungal mixture after 3 months’cultivation.The RGB values and the chlorophyll content of the vaccinated shoots were analyzed.The results showed that there were obvious signs of yellowing and shedding in the needles of P.tabulaeformis and P.sylvestris inoculated with venom solution and venom fungus mixture.The mixed group was wilting and severely shed,and the control group had no obvious change.The needles of P.massoniana varied significantly only after venom fungus inoculation,and there was strong growth with new sprout in the needles of P.koraiensis,P.elliottii and C.deodara after vaccination.The RGB values and chlorophyll content of P.tabulaeformis and P.sylvestris were decreased both in the venom group and the mixed group.In the mixed group,RGB values and chlorophyll content of P.massoniana decreased,but it remained stable in the venom and control group.The RGB values and chlorophyll content of P.koraiensis,P.elliottii and C.deodara were basically unchanged.The above results can conclude that resistance to S.noctilio venom and symbiotic fungi was weak in P.sylvestris and P.tabulaeformis.P.massoniana had certain resistance to venom and weak resistance to venom and fungal mixture.At the same time,P.koraiensis,P.elliottii and C.deodara exhibited relatively strong resistance.The results can provide a scientific basis for clarifying the potential host range and host selectivity of S.noctilio in China.