干旱胁迫对扁桃砧木幼苗叶片结构和根系形态的影响

Effects of drought stress on leaf structure and root morphology of almond rootstock seedlings

【目的】通过水分控制盆栽试验,研究扁桃6个不同砧木资源当年生实生苗的叶片解剖结构和根系形态特征对周期为60 d的中度土壤干旱胁迫的响应,旨在筛选出抗旱性强的扁桃砧木资源,为优良抗旱砧木资源的开发与利用提供抗旱材料。【方法】以新疆本地2种桃巴旦资源(SC64、SC28)、3种扁桃资源(SC30、SC3和SC47)和普通桃为试验材料,通过光学显微镜观察和根系扫描处理获取相关指标,并进行生物学统计分析。【结果】中度干旱胁迫下,SC3、SC47和毛桃的叶片厚度、上表皮细胞厚度、叶肉细胞孔隙度和比叶面积(SLA)等结构指标值出现不同程度的减少(P<0.05);同时,干旱胁迫促进其根冠比的增加和根系的生长(P<0.05)。通过主成分分析,选取上表皮细胞厚度、地下生物量、直径大于0.5 mm的细根生物量比重、叶肉细胞紧实度和SLA值这5个代表指标。隶属函数结果表明,抗旱能力排序为SC30>SC47>SC3>SC28>SC64>普通桃。【结论】扁桃资源的抗旱性强于桃巴旦和桃资源,桃巴旦资源处于中等抗旱水平,而普通桃对土壤干旱最敏感,抗旱性较弱。

[Objective]Through a water controlled pot experiment,the leaf anatomical structure and root morphological characteristics of six different rootstock resources of almonds were studied in response to moderate soil drought stress with a period of 60 d.The aim was to screen out almond rootstock resources with strong drought resistance and provide drought resistant materials for the development and utilization of excellent drought resistant rootstock resources.[Method]Using two local peach almond resources(SC64,SC28),three almond resources(SC30,SC3 and SC47)and peach as experimental materials,a total of related indicators were obtained through optical microscope observation and root scanning treatment,and biological statistical analysis was conducted.[Result]Under moderate drought stress,structural indicators such as leaf thickness,upper epidermal cell thickness,mesophyll cell porosity,and specific leaf area(SLA)of SC3,SC47 and peach decreased to varying degrees(P<0.05);meanwhile,drought stress promoted an increase in root to shoot ratio and root growth(P<0.05).Through principal component analysis,five representative indicators were selected,including upper epidermal cell thickness,underground biomass,specific gravity of fine root biomass with a diameter greater than 0.5 mm,mesophyll cell compactness,and SLA value.The results of membership function indicated that their drought resistance ability was ordered as SC30>SC47>SC3>SC28>SC64>peach.[Conclusion]The drought resistance of almond resources is stronger than that of peach almond and peach resources.Peach almond resources are at a moderate drought resistance level,while peach is the most sensitive to soil drought and has weaker drought resistance.