两种核桃蚜虫危害对核桃光合特征的影响

Effects of Two Walnut Aphids on Photosynthetic Characteristics of Walnut

[目的]明确核桃黑斑蚜和核桃全斑蚜危害对不同生长期核桃叶片光合作用的影响。[方法]在核桃的速生生长期、硬核期和脂化期,利用便携式叶绿素测定仪(SPAD-502plus)和LI-6400便携式光合作用系统测定了核桃不同生长时期受到不同密度的两种核桃蚜虫危害不同时长后叶片的SPAD值、光合速率(P_(n))、蒸腾速率(T_(r))等光合特性指标,并测定了受不同核桃蚜虫危害后的核桃果实质量、出仁率等。[结果]在速生生长期受到核桃黑斑蚜或核桃全斑蚜短期危害1~5 d,核桃叶片SPAD值无显著差异,而在硬核期和脂化期受核桃黑斑蚜、核桃全斑蚜和混合蚜虫危害均导致叶片SPAD值呈下降趋势。两种核桃蚜虫危害后核桃叶片的光合速率(P_(n))和蒸腾速率(T_(r))均显著下降,且蚜虫密度不同下降程度不同。受核桃黑斑蚜和核桃全斑蚜危害后核桃单果质量(青皮)和干果质量均呈下降趋势;受不同种类蚜虫危害后的核桃出仁率均出现下降。[结论]蚜虫危害对核桃叶片光合作用产生负面影响,导致核桃果实出仁率下降。因此,对两种核桃蚜虫的防治应该采取紧急措施,以保护核桃产量和质量。

[Objective]To investigate the impacts of two aphid species,Chromaphis juglandicola Kaltenbach and Panaphis juglandis Goetze on photosynthesis of walnut.[Method]During the rapid growth,hard core,and fatty stages of walnuts,the portable chlorophyll analyzer(SPAD-502plus)and LI-6400 portable photosynthesis system were used to measure the SPAD value,photosynthetic rate(P_(n)),transpiration rate(T_(r)),and other photosynthetic characteristics of the leaves of walnuts that were damaged by different walnut aphids.The fruit weight and kernel yield of walnuts were also measured after being damaged by different walnut aphids.[Result]There was no significant difference in the SPAD value of walnut leaves when exposed to short-term damage by P.juglandis or C.juglandicola for 1-5 days.However,during the hard core and lipid stage,exposure to the P.juglandis,C.juglandicola,and mixed aphid led to a downward trend in the SPAD value of leaves.The photosynthetic rate(P_(n))and transpiration rate(T_(r))of walnut leaves significantly decreased after being damaged by two types of walnut aphids,and the degree of decline varied with different density of aphids.The fresh fruit weight and dried fruit weight of walnuts showed a decreasing trend after being damaged by P.juglandis and C.juglandicola.The walnut kernel yield decreased after being affected by different types of aphids.[Conclusion]The walnut aphids has a negative impact on the normal photosynthetic process of the leaves,leading to a decline in the kernel percentage of walnut fruits.Therefore,urgent measures should be taken to control both walnut aphid species in order to protect walnut yield and quality.