Preliminary Selection of Different Species of Genus Pear (Pyrus) for Dwarfing and Nutrients Uptake

Dwarfing and nutrient uptake ability are among the important traits in pear rootstocks breeding programs. In this research, growth characteristics and macronutrients and iron uptake ability was compared in seedlings of 13 native and introduced species of genus pear (Pyrus), one commercial interspecies hybrid and three common clonal rootstocks of Pyrodwarf, Quince EMA and Quince BA29 from the species of genus Cynodonia (Cydonia oblonga Mill.). Evaluation was carried-out under controlled conditions using completely randomized design with 10 replicates in 2022. Growth characteristics and chlorophyll index in 70, 120, and 160 days after establishment were evaluated and measured. Nitrogen, phosphorus, potassium and iron uptake was evaluated and compared in Pyrus and Cydonia rootstocks 160 days after seedlings establishment. The results showed that the highest dwarfing rate belonged to P. syriaca followed by the clonal rootstocks, and the highest growth rate was measured in seedling rootstocks of P. communis derived from cv. Dargazi followed by P. bretschneideri. In P. syriaca, the lowest internode length was observed after 160 days with an average of 1.61 cm, which indicated the effect of dwarfing on slowing the growth of this species. Regarding the uptake of nutrient, P. hyrcana, P. nivalis, and P. pashia had the highest nitrogen uptake, P. amygdaliformis and P. nivalis had the highest phosphorus uptake and P. syriaca had the highest leaf potassium content. Considering the results of this research, future researches should focus on e evaluation of using P. syriaca as a dwarf rootstock for in establishment of intensive/ highly intensive pear orchards, or as the parent for dwarfing traits in pear breeding programs.