Pears (Pyrus spp.) are economically important fruit trees grown extensively world-wide. To identify QTLs related to key agronomically important fruit traits, we conducted QTL analysis using an interspecific 178 F₁ populations derived from a cross between ‘Manpungbae’ and ‘Oharabeni’. Phenotyping data, including fruit weight, fruit length and diameter, fruit shape index (FSI), soluble sugar content, fruit firmness (FF), and titratable acidity (TA) were investigated from 2016 to 2018. Using the previously constructed genetic linkage map together with the three-year phenotypic dataset, we detected 14 significant QTLs associated with the control of fruit weight, fruit length and diameter, FSI, FF, and TA on linkage groups 3, 10, 11, 12, and 13. These findings provide a useful resource for advancing genetic and genomic studies in pears and will aid breeding efforts to improve major fruit traits.

The range of peach rootstocks currently available worldwide has increased dramatically in the last few decades. However, peach rootstocks in Republic of Korea still primarily use mainly seeds of different species imported from China. This kind of rootstocks is not ideal for clonal production and uniformity since it is a varietal blend of genotypes with differing physical characteristics. We collected genetic resources of 214 native peaches and determined 156 native peaches for breeding the suitable peach rootstock with easy propagation, uniform growth habit, and the resistance to biotic and abiotic stresses under domestic conditions. ‘PR1’ peach rootstock [Prunus persica (Batsch) L.] was originated from open-pollinated seeds of ‘PHJN0129’ collected in 2001 at Suncheon. ‘PR1’ peach rootstock was preliminarily designated as ‘PH193’ in 2002 and then grafted onto ‘Maotao’ (P. persica) wild peach seedling rootstocks. In Hwasung, three grafted trees were observed from 2005 to 2009 and seen to have the properties of ‘PH193’. In Suwon, one-year- old seedlings were observed from 2010 to 2014 and showed to have the commercial availability of ‘PH193’ when compared with 5 peach rootstocks (Tsukuba No.4, GF677, Nemaguard, Yumyeong, and imported peach seeds from China). ‘PH193’ was finally selected in 2014, owing to its superior seed germination, graft compatibility, resistance to nematodes and crown gall, and low mortality. It was named ‘PR1’ to indicate the first peach rootstock in Republic of Korea and was released for commercial use in 2015. (Grant Number 5896).