Location: Fruit and Tree Nut ResearchTitle: Diversity of low chill peaches from Asia, Brasil, Europe and the USA Author
|Carmo Bassola Rasier, Maria|
Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2010
Publication Date: 8/5/2010
Citation: Anderson, N., Byrne, D.H., Castro, C., Carmo Bassola Raseira, M., Boonprakob, U., Wang, L., Okie, W.R. 2010. Diversity of low chill peaches from Asia, Brasil, Europe and the USA [abstract]. HortScience. 45(8):S53. Interpretive Summary: A large group of peach varieties from around the world were studied to see how inter-related they were. Most were from various lowchill peach growing areas such as Florida, Thailand, China, Brazil and Mexico. Varieties clustered based on where they originated. US low-chill peaches were more related to high peaches since many had been used as parents to improve quality in US low-chill breeding programs. Asian and Brazilian types were more distinct and segregated into several groups. Local varieties tended to vary, but were more similar than peaches from another region. A high level of diversity is thought to be desirable in terms of reducing the likelihood of a catatrosphic disease outbreak.
Technical Abstract: One hundred fifty-five peach (Prunus persica) cultivars, from Asia, Brazil, Europe, and the USA, were examined using eleven SSRs to study the genetic relationships among low chill as compared to high chill peach germplasm. Data was analyzed by NTSYSpc to form a similarity matrix using Nei and Li’s Dice similarity coefficient. This similarity matrix was then subjected to a cluster analysis and a dendrogram was constructed using the UPGMA method. A wide range of diversity was detected, from 0.33 coefficient of similarity amongst the Thai peaches to 0.97 between two Brazilian peaches. The most distant clusters were the low chill peaches from Thailand and Taiwan and the local cultivars (both fruit and ornamental types) from China. Among the improved germplasm, there were distinct clusters for the Chinese/Japanese cultivars, three clusters for the Brazilian cultivars and one for the cultivars from the USA and Europe. The Brazilian materials clustered according to breeding programs in São Paulo and Pelotas reflecting the different sets of local cultivars used in the breeding efforts. The largest group investigated was the European/USA peaches. This group subdivided into three distinct clusters, with a general clustering of the low chill germplasm. The low chill accessions from Asia were genetically distant from the improved low chill peaches from the USA or Brazil. The low chill peaches from the Americas were more closely related to the high chill peaches developed in the USA and China/Japan due to the recent introgression of this germplasm into a low chill background.