Inheritance and Linkage Studies in Peach
Inheritance of male sterility in peach [Prunus persica (L.) Batsch] Plant Introduction (PI) 240928 was investigated. Crosses of PI 240928 with five wild-type clones yielded all male-sterile offspring, indicating dominant gene action. Inheritance of the sweet kernel trait in peach was studied in F1 and F2 progeny of `Summer Beaut' nectarine (sweet kernel) × `Biscoe' peach (bitter kernel). All four F1 progeny were bitter. Segregation in an F2 of 80 progeny fit a ratio of 3 bitter: 1 sweet. We propose that the gene controlling the sweet kernel trait be designated sk. Sweet kernel (sk) was linked to nectarine (g) at a map distance of 17 cM. Evaluation of the peach PI collection showed that PI 129678 (`Stanwick' nectarine) and PI 34685 (`Quetta' nectarine) were the only clones with a sweet kernel. Crosses between `Davie II' and `Honeyglo' nectarine (dwdw) confirmed that the gene conferring the dwarf phenotype in progeny of `Davie II' is non-allelic to dw.