核桃叶缘焦枯病与其养分含量的相关性回归分析

Correlation and regression analysis between leaf margin scorch diseases and leaf nutrient content of walnut

【目的】研究与核桃叶缘焦枯病相关的主因子,为叶缘焦枯病机理研究及其防治措施提供理论参考。【方法】以新疆核桃主栽品种新丰和扎-343作为研究对象,以新疆野生核桃作为对照材料,测定不同程度焦叶的2个核桃品种叶片SPAD值、全氮(N)、全磷(P)、钾(K)、钙(Ca)、镁(Mg)、锰(Mn)、铁(Fe)、铜(Cu)和锌(Zn)等指标,分析各指标之间的相关性。【结果】随着2个核桃品种叶片焦枯程度的加重,其叶片SPAD值均缓慢下降趋势,新丰正常叶(X-CK)SPAD值与野生核桃正常叶(T-CK)间均无显著差异,扎-343正常叶(Z-CK)SPAD值显著低于T-CK,新丰不同处理的叶片SPAD值均明显大于扎-343。2个核桃品种叶片不同养分含量随着焦叶程度的加重而呈现不同程度的变化趋势,其中新丰核桃叶片N和Ca均表现上升趋势,P、K、Mg、Mn、Fe和Cu均表现下降趋势,Zn呈现先上升后下降趋势,新丰核桃焦叶程度与其SPAD值、K、Mg和Cu含量成极显著负相关,与Ca含量间成极显著正相关性;扎-343核桃叶片N和Ca均表现上升趋势,其K、Mg、Mn、Fe和Cu均表现下降趋势,P和Zn呈现先上升后下降趋势,其中叶片SPAD值、Fe和Cu与其焦叶程度之间的负相关性均达极显著水平,叶片Ca含量与其焦叶程度之间的正相关性达极显著水平。影响新丰核桃叶片焦枯程度的相关指标因子大小的排序依次为Cu>Ca,回归方程为Y=10.968-2.193 X_(1)+4.388 X_(2);影响扎-343核桃叶片焦枯程度的相关指标因子大小的排序依次为Cu>K>P,回归方程为Y′=215.075-2.366 X′_(1)-7.902 X′_(2)-33.966 X′_(3)。【结论】新丰和扎-343核桃叶缘开始焦枯后,叶片中Cu、Ca、K和P的吸收受到显著影响。

【Objective】To explore the main factors related to walnut leaf margin scorch disease,and provide theoretical reference for the mechanism research and control measures of leaf margin scorch disease.【Methods】The main walnut varieties Xinfeng and Zha-343 in Xinjiang were taken as the research objects,and the wild walnut in Xinjiang was taken as the control material.The SPAD value,total nitrogen(N),total phosphorus(P),potassium(K),calcium(Ca),magnesium(Mg),manganese(Mn),iron(Fe),copper(Cu),zinc(Zn)and other indicators of the leaves of two walnut cultivars with different scorched leaves were mainly measured,the correlation analysis and regression analysis were conducted among the indicators.【Results】The leaf SPAD values of the two walnut cultivars decreased slowly with the aggravation of the degree of leaf scorch.There was no significant difference between the SPAD values of Xinfeng normal leaves(CK)and that of wild walnut normal leaves(T-CK).The SPAD values of Zha-343 normal leaves(CK)were significantly lower than that of T-CK,and the SPAD values of′Xinfeng′leaves under different treatments were significantly higher than that of Zha-343.Different nutrient contents in the leaves of the two walnut varieties showed varying degrees of change with the aggravation of leaf scorch degree.Among them,N and Ca in the leaves of Xinfeng walnut showed an upward trend,P,K,Mg,Mn,Fe and Cu showed a downward trend,Zn showed an upward trend first and then a downward trend,and the degree of scorched leaves of Xinfeng walnut was significantly negatively correlated with its SPAD value,K,Mg and Cu contents.There was an extremely significant positive correlation with Ca content,N and Ca in leaves of Zha-343 walnut showed an upward trend,K,Mg,Mn,Fe and Cu showed a downward trend,P and Zn showed an upward trend first and then a downward trend,in which the negative correlation between SPAD value,Fe and Cu in leaves and their scorched degree reached an extremely significant level,and the positive correlation between Ca content in leaves and their scorched degree reached an extremely significant level.That the order of the factors affecting the scorching degree of Xinfeng leaves was Cu>Ca,and the regression equation was Y=10.968-2.193 X_(1)+4.388 X_(2);The order of factors affecting the scorching degree of Zha-343 leaves is Cu>K>P,and the regression equation was Y′=215.075-2.366 X′_(1)-7.902 X′_(2)-33.966 X′_(3).【Conclusion】In arid areas,after the leaf edges of Xinfeng and Zha-343 walnuts start to scorch,the absorption of Cu,Ca,K,and P in the leaves is significantly affected.