【作者】 王辉；

【导师】 徐继忠；

【作者基本信息】 河北农业大学 ， 果树学， 2020， 硕士

【摘要】 矮砧密植的栽培方式以其经济利用土地、早产、丰产、利于管理等优点已成为目前我国苹果生产发展的方向。矮化砧木的利用是实现树体矮化的主要措施之一。矮化砧木可以合理调控树势,促进花芽分化从而达到早花早果、优质高产的目的。而我国华北地区受季风性气候影响导致降雨量不够充沛,且年际间差异大,水资源的匮乏成为了影响树体发育的主要原因,而对于抗旱矮化性砧木研究较少,且砧木的筛选工作费时、费力、工作效率低,因此,本试验旨在通过导管分子特征参数等指标,为苹果矮化砧木及抗旱砧木的快速筛选提供理论依据。本试验以不同矮化程度及不同抗旱程度的砧木为试材,通过解剖及离析的方法研究了砧木不同木质化程度的枝条及SH系砧木根系导管分子管腔直径、导管密度、导管总面积占木质部比例、长、宽、端尾长度、端壁倾斜角等指标,并测定不同砧木木质化枝条栓塞脆弱性及最大导水率差异,旨在为矮化及抗旱砧木的初步筛选提供依据,主要结果如下:1、SH系砧木根皮率从大到小依次为SH38、SH40、SH29、SH28,通过根皮率并结合不同砧木嫁接品种后的树高、品种干径、总枝量等指标确定SH38、SH40为矮化砧木,SH28、SH29为半矮化砧木。2、乔化砧木八棱海棠枝条导管分子管腔直径、管腔面积、导管总面积占木质部比例较矮化砧木高。M系及SH系各砧木间枝条导管分子管腔直径及管腔面积随矮化程度的增高而降低,各砧木间管腔总面积占木质部比例无显著性差异。SH系砧木根系导管分子管腔面积及管腔直径随矮化程度的增高而降低,导管密度及管腔总面积占木质部比例随矮化程度的增高而增高。3、M系及SH系矮化砧木半木质化枝条导管分子长度小于乔化砧木八棱海棠半木质化枝条导管分子长度;M系及SH系矮化砧木木质化枝条导管分子长度小于乔化砧木八棱海棠木质化枝条导管分子长度,M系矮化砧木木质化枝条导管分子端尾长度较八棱海棠小,M系和SH系砧木木质化枝条导管分子端壁倾斜角均显著小于八棱海棠导管分子端壁倾斜角;SH系砧木根系导管分子尾长随矮化程度增高而降低。4、矮化砧木中除MM106、SH38外其余砧木抗栓塞能力都随管腔直径的增大而降低。M系砧木与八棱海棠最大导水率随矮化程度的增高而降低,SH系砧木与八棱海棠最大导水率对比,除SH40导水率较高外,其他砧木也符合上述规律。SH系砧木水分运输速率快慢与矮化程度相反,即矮化程度越高,运输速率越低。5、抗旱性强的砧木较抗旱性弱的砧木导管分子管腔面积、管腔直径及管腔总面积占木质部比例低,导管密度与树体抗旱程度无相关性。不同砧木半木质化枝条导管分子长度随抗旱性增强而增大,导管直径随抗旱性的增强而减小。导管分子长度上,强抗旱性砧木SH40、冀砧1号与中等抗旱性砧木黄6、冀砧2号,弱抗旱性砧木24-5、X3N1有显著性差异。抗旱性强的砧木端尾长度及端壁倾斜角较抗旱性弱的砧木大。6、对不同抗旱性砧木栓塞脆弱性研究表明,抗旱性强的砧木具有较强的栓塞能力,中等抗旱和抗旱性弱的砧木抵抗栓塞能力较差。最大输水能力上,强抗旱性砧木与中等抗旱性砧木的最大导水率随抗旱性增强而增强。更多还原

【Abstract】 High density planting with dwarfing rootstocks has become the main cultivation form for apple in China for its advantages of high field efficiency,early fruiting,high yield and simple management.Utilization of dwarfing rootstock is one of the methods for dwarfing.Dwarfing rootstock reasonably regulates tree growth potential and promote floral bud development so as to achieve the purpose of early flowering and fruiting,high quality and yield.Northern China lacks of rainfall for the monsoon climate,and rainfall varies between the interannual.The shortage of water resources has become the major influential factors of tree growth,while studies on drought resistance dwarfing rootstocks is inadequate.The rootstocks selection is a time-consuming,laborious work with low work efficiency.Therefore,this study is to provide theoretical basis for the rapid drought and dwarf rootstocks selection through the vessel element characteristic parameters and other indicators.In this experiment,rootstocks with different dwarfing degrees and drought-resistant degrees were used as test materials.The diameter,density,ratio of total area of vessel to xylem,length,width,length of end and tail,and inclination angle of end wall of root vessel molecules of branches and SH lines rootstocks with different lignification degree were studied by dissection and segregation,and the embolism vulnerability of woody branches of different rootstocks was measured to provide basic dwarfing and drought-resistant rootstocks selection.The main results are as follows:1.The root phloem ratio of SH lines rootstock was SH38,SH40,SH29 and SH28 from the largest to the smallest.SH38 and SH40 were identified as dwarfing rootstock and SH28 and SH29 as semi-dwarfing rootstock by the indexes of tree height,trunk diameter and total number of branches of different rootstock grafted varieties.2.The proportion of vessel diameter,area and total area of vessel in xylem of the branch of Begonia octagona was higher than that of dwarf rootstock.The diameter and area of vessel molecular lumen decreased with the increase of dwarfing degrees in M and SH lines,but there was no significant difference in the proportion of total lumen area to xylem.With the increase of dwarfing degree,the area and diameter of vessel molecular lumen decreased,while the density of vessel and the proportion of total lumen area to xylem increased.3.The element length of semi-lignified branches vessel of M and SH dwarf rootstocks was smaller than that of vigrous rootstocks(Malus robusta Rehd).The vessel element length of lignified branches of M and SH dwarf rootstocks was smaller than that of vigrous rootstocks(Malus robusta Rehd).The vessel elements end tail length of lignified branches of M line dwarf rootstocks was smaller than that of vigrous rootstocks(Malus robusta Rehd).The vessel element end wall tilt angle of lignified branches of M and SH dwarfing rootstocks was smaller than that of vigrous rootstocks(Malus robusta Rehd).The element tail length of root vessel of SH rootstock decreased with the increase of dwarfing degree.4.Except MM106 and SH38,the anti-embolism ability of dwarfing rootstocks decreased with the increase of lumen diameter.The maximum hydraulic conductivity of M-rootstock and Crabapple decreased with the increase of dwarfing degrees.Compared with that of SH line and Crabapple,except for the higher hydraulic conductivity of SH40,other rootstocks also conform to the above rules.The water transport rates of SH rootstocks were opposite to the dwarfing degree,that is,the higher the Dwarfing degree is,the lower the transport rate is.5.The area,diameter and total area of vessel in the xylem of rootstocks with strong drought-resistance were lower than those with weak drought-resistance.The density of vessel had no correlation with the degree of drought resistance.The length of vessel increased with the increase of drought resistance,and the diameter of vessel decreased with the increase of drought resistance.In terms of vessel molecular length,there were significant differences between strong drought resistant rootstocks SH40,J1 and medium drought resistant rootstocks,Huang6 and J2,weak drought-resistant rootstocks 24-5 and X3N1.The length of end and tail and the inclination angle of end wall of rootstocks with strong drought resistance were larger than those with weak drought resistance.6.The study on the vulnerability of different drought resistant rootstocks showed that the rootstocks with strong drought resistance had strong anti-embolism ability;Rootstocks with medium drought-resistance and weak drought resistance have poor anti-embolism ability.In terms of maximum water carrying capacity,the maximum water carrying capacity of strong and medium drought-resistant rootstocks increased with the increase of drought resistance.更多还原