Effects of Two Walnut Aphids on Photosynthetic Characteristics of Walnut
[Objective]To investigate the impacts of two aphid species,Chromaphis juglandicola Kalten-bach 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-6 400 portable photosynthesis system were used to measure the SPAD value,photosynthetic rate(Pn),transpiration rate(Tr),and other photosynthetic characteristics of the leaves of walnuts that were damaged by different wal-nut aphids.The fruit weight and kernel yield of walnuts were also measured after being damaged by differ-ent 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(Pn)and transpiration rate(Tr)of walnut leaves significantly decreased after being damaged by two types of walnut aphids,and the degree of decline var-ied with different density of aphids.The fresh fruit weight and dried fruit weight of walnuts showed a de-creasing trend after being damaged by P.juglandis and C.juglandicola.The walnut kernel yield de-creased 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.
万方数据
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