The Evaluation Criteria of Some Botanical Quantitative Characters of Peach Genetic Resources

There were two peach descriptors systems: one from IPRGI in 1980 and the other from China in 1990. The former had only reference cultivars without quantity grades; the latter had only a list of some characteristics. This makes it difficult sharing of genetic resource information for breeders. To describe the main quantitative characteristics, a new system was established. Ten characteristics of 346-476 peach cultivars were investigated from 1986 to 2002 in the National Peach Genetic Collection in Zhengzhou City, China. These characteristics and their coefficients of variation were as follows: flower diameter 19.55%, vertical diameter of fruit 14.24%, cheek diameter of fruit 10.36%, suture diameter of fruit 11.44%, stone length 19.04%, stone width 10.86%, stone thickness 11.19%, leaf length 7.9%, leaf width 10.55%, and leaf stalk length 19.03%, respectively. Grade index and reference cultivars were given by statistical data for peach description.These grade indexes were recorded on 1-5 grades, and the third grade as a middle one occupied 39% or more of the distribution. In general, two reference cultivars for each grade were chosen, one is USA cultivar and the other is Chinese cultivar. This paper tried to use them as the reference cultivars, which are planted or used widely by Chinese breeders.