Antixenosis Resistance of Plum Genotypes and Cultivars to the Plum Fruit Moth Grapholitha funebrana (Treitschke) under the Environmental Conditions of Karaj in Iran

Plum fruit moth Grapholita funebrana (Treitschke) is one of the important pests of plums. The aim of this study was to assess the antixenosis resistance of plum genotypes/cultivars and the effect of fruit physico-chemical characteristic on it. Twenty seven plum genotypes/cultivars in fruits tree genetic resources collection in Kemalshahr in Karaj, Iran, were considered and evaluated from 2019 to 2021 seasons. Antixenosis resistance indices were estimated by sampling larvae population during the seasons. The plum geneotypes/cultivars were grouped using cluster analysis, and the relationship between different fruit characteristics and antixenosis resistance was investigated using Pearson correlation. The antixenosis resistance indices had significant relationship with fruit length, width, diameter, engineering diameter, spherical index and fruit surface area. The minimum antixenosis index of larvae establishment ratio in Bukhara, Genotype 19 and Uromieh 20 was 0.02, and its maximum was 0.06 in Anjelo, Friar, G-98, Kh-Mashhad and Sosourmi. The minimum larval non-preference index was 91.96 in G-Melayer and its maximum was 98.81 in Bukhara. The minimum larvae preference was 0.03 in Sosourmi, and its maximum was 1.03 in Zojlo. The minimum larvae crowding index was 24.6 in Bukhara, and its maximum was 66.42 in G-98. Finally, Black Star, Queen Rosa, G99, G98, Qomi, Santa Rosa, Sosurmi, Anjelo, Black Amber, and GR-Rezaieh genotpes/cultivars were more resistant, and Kermanshah genotype was the most sensitive to plum fruit moth. The results of this research are part of the supplementary information for selection of suitable plum cultivars for development of plum orchards in Karaj and other similar envirmonetal conditions.