不同龄级马尾松对松材线虫病抗性的探讨

STUDY ON THE RESISTANCES OF VARIOUS YEAR CLASSES OF PINUS MASSONIANA TO PINE WOOD NEMATODE (PWN),BVRSAPHEIENCHUS SYLOPHILUS

从松褐天牛（Ｍｏｎｏｃｈａｍｕｓａｌｔｅｒｎａｔｕｓ）成虫活体上分离用ＰＤＡ平板灰葡萄孢（Ｂｏｔｒｙｔｉｓｃｉｎｅｒｅａ）培养的松村线虫（Ｂｕｒｓａｐｈｅｌｅｎｃｈｕｓｘｙｌｏｐｈｉｌｕｓ）对不同龄级和不同生长势的马尾松（Ｐｉｎｕｓｍａｓｓｏｎｉａｎａ）的接种试验表明，１４年生以下和生长势旺盛的马尾松幼树抗松材线虫病；１６年生以上和长势弱的马尾松中龄、成熟和过熟林树对松材线虫病的抗性较弱，并随树龄的增加和长势的减弱抗病能力减弱。对各龄级马尾松的化学内含物萜类和树脂酸的组成分析，长叶烯、α－烯和去氢枞酸的含量随树龄的增加而增加，并与其抗性呈负相关；β－蒎烯、单萜和枞酸型树脂酸的含量随树龄的增加而减少，并与其抗性呈正相关。有相关性的化学内含物加入ＰＤＡ灰葡萄孢平板培养基培养松材线虫，与接种试验有相同趋势，长叶烯和去氢枞酸加入量的增大有利于线虫繁殖；β－蒎烯、单萜和枞酸型树脂酸则相反，加入量增大（与树内量相近）线虫的繁殖量减少，说明含量高时对线虫的生存和繁殖有抑制作用。

Artificial inoculation tests are conducted on Masson pine of different ages and growth vigorwith PWN severed from the adults of Monochamus alternatus and cultured by Botrytis cinerea on PDA.Results showed that young Masson pine(under 14 years) with exuberant growth vigor has strong resistance to PWN, but pine over 16 year-old and with weak growth vigor──with middle, mature andover-mature Masson pine sound──has nonresistunce to PWN.Masson pine over 16 years has strongnegative correlations betweent age class and resistuncibility. Some terpene fractions and resin acid composition of different-aged Masson pine correlated with the resistance against PWN.The test resultsshowed that the content of longifolene,2-copaene and dehydroabietic acid increased with Masson'spine age, showing a negative correlation with resistance against PWN.Young Masson's pine with highresistance has no 2-copanene and low content of longifolene and dehydroabietic acid. As the Masson'spine age increased the content of β-pinene, monoterpene and abietic-type resin decreased, showing apositive correlation with the resistance against PWN. Young Masson pine with high resistance has highcontent of β-pinene, monoterpene and abietic-type resin acid. Similar resultS were obtained from theculturing PWN on PDA of Botrytis cinerea by using the several compounds above.High content of β-pinene, monoterpene and abietic-type resin acid and low content of longifolene and dehydroabietic acid(the young Masson's Pine have) can curtail PWN's propegation.