Genetic diversity evaluation of a loquat (Eriobotrya japonica (Thunb) Lindl) germplasm collection by SSRs and S-allele fragments Ana Delia Gisbert Æ Carlos Romero Æ Jose ´ Martı ´nez-Calvo Æ Carmen Leida Æ Gerardo Lla ´cer Æ Marı ´a Luisa Badenes Received: 5 November 2008 / Accepted: 5 February 2009 / Published online: 27 February 2009 Ó Springer Science+Business Media B.V. 2009 Abstract Loquat (Eriobotrya japonica (Thunb.) Lindl.) is a minor Rosaceae fruit of growing interest as an alternative to the main fruit crops. In this context, the selection of new cultivars to satisfy the market demand will request the suitable character- ization of the available germplasm. In this work, genetic relationships among 83 loquat accessions from different countries belonging to the European loquat germplasm collection, held at the Instituto Valenciano de Investigaciones Agrarias (IVIA) in Moncada (Spain) were evaluated using microsatel- lites and S-allele fragments. A total of nine single sequence repeats (SSRs) from Malus and Eriobotrya genera revealed 53 informative alleles and the S- RNases consensus primers detected 11 self-incom- patibility putative alleles. The combined data allow to distinguish unambiguously 80 out of the 83 acces- sions studied. Unweighted pair-group method (UPGMA) cluster and principal coordinates analysis (PCoA), based on Dice’s genetic distance, generally grouped genotypes according to their geographic origins and pedigrees. Discrepancies and similarities of the results obtained with other variability analysis, based on pomological traits or molecular markers, on the same loquat collection are discussed. Keywords Eriobotrya japonica (Thunb.) Lindl. Á SSRs Á Germplasm collection Á Genetic diversity Á S-allele fragments Introduction Loquat (Eriobotrya japonica (Thunb.) Lindl) is a subtropical evergreen fruit tree, native to the south- east of China, belonging to the Maloideae subfamily of the Rosaceae. The medium and low region of Dadhue river is considered the primary center of origin for Eriobotrya japonica (Zhang et al. 1990), with the Yunnan region as a secondary center (Yang et al. 2005). Records on loquat in China span over 2,000 years (Lin et al. 1999). Although it is named japonica, the cultivated loquat in Japan was intro- duced from China in ancient times and its cultivation was described as early as 1180 (Ichinose 1995). In the 18th century, loquat was introduced from Japan into Europe as ornamental tree in the National Garden at Paris, and into the Royal Botanical Gardens at Kew, England. Thereafter, loquat was distributed around the Mediterranean countries, including Algeria, Cyprus, Egypt, Greece, Israel, Italy, Spain, Tunisia, and Turkey. Sometime between 1867 and 1870, loquat was introduced to Florida from Europe, and to A. D. Gisbert Á C. Romero Á J. Martı ´nez-Calvo Á C. Leida Á G. Lla ´cer Á M. L. Badenes (&) Fruit Tree Breeding Department, Instituto Valenciano de Investigaciones Agrarias (IVIA), Apartado Oficial, 46113 Moncada, Valencia, Spain e-mail: badenes_mlu@gva.es 123 Euphytica (2009) 168:121–134 DOI 10.1007/s10681-009-9901-z