胡桃短体线虫在江苏桃园内的群体动态和分布规律的研究

POPULATION DYNAMICS AND DISTRIBUTION CHARACTERISTICS OF PRATYLENCUS VULNUS IN PEACH ORCHARDS IN JIANGSU

运用平行跳跃式定点取样方法研究桃园中胡桃短体线虫(Pratylenchusvulnus)群体动态。在徐州桃根围土壤中,胡桃短体线虫的群体密度分别在5～6月和10～11月出现两个明显高峰;在一年中,土壤中胡桃短体线虫群体密度以1月最低,10月最高。此外,桃根内胡桃短体线虫群体密度季节变化规律与土壤中群体密度季节变化规律相似。并且,桃根内外胡桃短体线虫群体密度季节变化与桃根的生长节奏和温度的季节变化规律密切相关。在徐州和南京的自然条件下,胡桃短体线虫能以大量群体在桃根内越冬,成为来年的重要初侵染来源。 胡桃短体线虫在桃园中的分布很不均匀。本文还对土壤中植物线虫群体动态调查的采样方法进行了讨论。

The investigation of population densities of Pratylenchus vulnus in peach orchards was conducted by systematic sampling method, from 1985～1986. The population dynamics of P. vulnus in soil showed two distinct peaks, one being from May to June, and the other from Octorber to November. During a year period, the lowest population density was in January, while the hightest one was in October. The trend of population dynamics of P. vulnus in roots was similar to that in soil. Both the population dynamics of P. vulnus in roots and that in soil were highly relevant to the growth tempo of peach roots.It was eomfirmed that the population distribution of P.vulnus throughout the same field was very uneven. Sampling methods are also discussed.