【作者】 张志敏；

【导师】 赵政阳；

【作者基本信息】 西北农林科技大学 ， 果树学， 2009， 硕士

【摘要】 苹果再植障碍已成为世界性一大难题,它的影响因素归纳为3个因素:微生物、根系分泌物、营养元素的亏缺。本文主要从微生物方面来研究造成苹果再植障碍的因素。本实验于2007年～2009年,在渭北黄土高原白水县,对2a、5a、10 a、15 a、20 a生果园土取样进行分析,探讨了果树根区不同水平距离、不同深度的土壤中镰刀菌时空变化,并结合盆栽砧木苗试验,研究了不同根区土壤对砧木生长发育的影响。主要研究结果如下:1渭北旱地苹果园根区不同区域土壤中镰刀菌数量的变化存在较大差异,在距树干基部50～100cm、40～60cm土层的区域范围内,根系分布较为集中,镰刀菌的数量也明显多于其它区域,表明果园土壤中镰刀菌数量的消长变化与果树根系分布密切相关。2脲酶、蔗糖酶、磷酸酶、蛋白酶在距树干基部50～100cm、40～60cm土层的区域范围内活性比较大,随着就树干距离的增加活性逐渐减小,在20～40cm土层内4种酶的活性大,60～80cm土层内4种酶的活性小。酶活性的空间变化趋势和镰刀菌数量的空间变化趋势相一致,经相关性分析,镰刀菌的数量与土壤酶活性存在一定的相关性。3一年中镰刀菌的数量是一个变化的过程,其中6月份各个根区土壤中镰刀菌的数量比较多。树龄对镰刀菌的数量有很大的影响,随着树龄的增加镰刀菌的数量也增加。这表明镰刀菌数量与苹果的的栽培年限有一定的关系。4不同砧木类型对苹果再植障碍表现不同,经盆栽砧木苗生长发育指标调查发现,新疆野苹果在重茬土中生长发育比较好,其次是楸子,山定子、八楞海棠在重茬土壤上生长发育相对比较差。5渭北旱地苹果园镰刀菌可能是果树根区土壤中重要的真菌类型。在镰刀菌数量多的果树根区土壤盆栽砧木苗的生长发育较差,再植障碍表现明显,说明土壤镰刀菌可能是引起苹果园再植障碍的重要因素之一。6在距树干基部150~200cm区域内,再植砧木苗生长比较好,因而在生产实践中,老果园新植幼树应尽可能选择果树行距中间区域,以便减少再植病害的发生。更多还原

【Abstract】 Apple replant disease was one of difficult problem in the world.It’s effect factor can conclude three aspects:microorganism、root exudates、nutrient deficiency.This article studied mainly the factors of caused apple replant disease in microorganism.This experiment take two years from 2007 to 2009.Soil samples were collected from 2a、5a、10 a、15 a、20 a orchard and analysed in weibei loess plateau, Baishui country.It analysed temporal and spatial variation of Fusarium quantity in different horizontal distance and different depth of root-zone.and With potted rootstocks seedling experiment, Different root-zone soil effected on growth of rootstock.Main results were summarized as follows.1 Change of Fusarium quantity was very difference during different root-zone in weibei dry land orchard.Root distributed comparatively concentration in regions where were 500～100cm from trunk and 40～60cm soil layer. Fusarium quantity were obviously more than others regions.This showed that there was closely related between Fusarium quantity and root distribution.2 Urease、Invertase、Protease、Phosphatase had more stronger activity in regions where were 500～100cm from trunk and 40～60cm soil layer.The futher from trunk,The weaker the enzymatic activity.The enzymatic activity were strong in 20～40cm soil layer,and weak in 60～80cm soil layer. Spatial variation of enzyme activity consistent to spatial variation of Fusarium quantity, There was certain correlation between Fusarium quantity and enzymatice activity through correlation analysis.3 Fusarium quantity were change of process during a year,Fusarium quantity were most in June inall root-zone. Tree age effected mostly on Fusarium quantity, Fusarium quantity gradually increase with tree age older. This showed that there was certain relationship between Fusarium quantity and apple replant disease.4 Growth and development of different roostock showed obviously differenc in continuous cropping soil.Though index of growth and development of potted rootstock Investigated we found that Malus sieversii grew more better, Malus Prunifolia Boukh and Malus baccarat(L.)Burch ranked secondly, Malus Robusta grew weakest 5 This experiment found that Fusarium was possibly one of the most important fungi in root-zone soil. Potted rootstocks seedling grow weak in root-zone which quantity of Fusarium are more,Replant disease showed obviously,This proved that Fusarium is possibly one of factors caused apple replant disease,6 Replant rootstock grew very well in region where was 150～200cm from the trunk.So process of production and practice,Young tree should be plant on the midlle between two trees when we replant yong tree in old orchard,and to reduce replant diseas happened.更多还原