Genetic Diversity of Loquat Accessions in Japan as Assessed by SSR Markers

Abstract

The genetic variation of loquat (Eriobotrya japonica (Thunb.) Lindl.) was characterized by SSR markers developed from apple and pear, using 94 loquat accessions in Japan. Fourteen of the 24 SSR markers derived from apple could successfully produce amplified bands in loquat, whereas 10 of the 24 SSR markers derived from pear could generate amplified bands. Nine SSR markers were chosen for evaluation of the genetic diversity among 94 loquat accessions, including 61 cultivars from Japan and other countries and 33 natively grown accessions collected around Japan. A phenogram constructed using the unweighted pair-group method with arithmetic averages based on similarities between genotypes revealed two major groups. One group consisted mainly of cultivars from Japan and other countries, whereas the other group included only natively grown accessions. Some synonyms or mutants were found showing identical SSR genotypes. These results show that SSR markers can be utilized as reliable tools for genetic identification in loquat. The origins of current loquat cultivars in Japan are also discussed.

Quantitative Inheritance of Resistance to Loquat Canker (Pseudomonas syringae pv. eriobotryae, Group C) in Loquat Progenies from Crosses between a Resistant Cultivar, ‘Champagne’, and Susceptible Cultivars

“…Because 'Champagne' is homozygous-dominant for Pse-a (Hiehata et al, 2002b), it is a valuable breeding material to produce cultivars with precocious character. Also, 'Champagne' is less closely related genetically to the mentioned materials that possess pse-c derived from 'Mogi' (Fukuda et al, 2013), it may help breeders to avoid the inbreeding depression that has been reported in fruit bushes and trees such as rabbiteye blueberry (Vaccinium ashei Reede; Lyrene, 1983), persimmon (Diospyros kaki Thunb. ; Yamada, 1993), and japanese pear .…”

“…Seedlings resistant to Group C with the pse-c gene have been produced by the breeding program at the Agricultural and Forestry Technical Development Center, Nagasaki, Japan. However, inbreeding depression might be a concern in breeding for Group C resistance because the number of resistant parent materials that contain pse-c (e.g., 'Mogi', 'Shiromogi') is limited, and there are close relationships among these materials (Fukuda et al, 2013). Although their descendants could be crossed or back-crossed with parents to produce a high proportion of homozygous-recessive seedlings (pse-c/pse-c) that are resistant to Group C, these crosses involve inbreeding and were therefore likely to exhibit inbreeding depression with lower tree vigor or yield.…”

“…The particular usefulness of this loquat is its complete resistance to Groups A, B, and C (Morita, 1988). 'Champagne' is distantly related to 'Mogi', 'Shiromogi', and Japanese cultivars (Fukuda et al, 2013). Thus, it has high potential as a cross-parent for preventing inbreeding depression in breeding for loquat canker resistance, and especially resistance to Group C. The genotype of 'Champagne' has been estimated to be homozygous-recessive (pse-c/pse-c) for the locus (Hiehata et al, 2012), but the resistance of 'Champagne' may be controlled by additional genes at another locus different from the pse-c locus (Hiehata et al, 2003).…”

Complete plastid genome of Eriobotrya japonica (Thunb.) Lindl and comparative analysis in Rosaceae

“…Soriano et al (2005) first demonstrated the usefulness of SSRs markers in genetic analysis and identification in E. japonica . Many researches utilized AFLP and SSRs markers to investigate genetic variation, diversity and identification among loquat accessions (He et al 2011; Fukuda et al 2013; Blasco et al 2014), which provided information for diversity analysis and plant breeding program. However, few molecular markers based on plastomes have been developed since completed plastid genome of E. japonica is not available, lagging behind other species of Rosaceae.…”

Occurrence of a Spontaneous Triploid Progeny from Crosses between Diploid Asparagus (Asparagus officinalis L.) Plants and Its Origin Determined by SSR Markers

“…Simple sequence repeat (SSR) is used for genetic and phylogenetic studies in many plants because of its high polymorphism and co-dominant expression (Fukuda et al, 2013;Goto-Yamamoto et al, 2013;Honsho et al, 2012). SSR markers have been established from expressed sequence tag (EST) in asparagus (Caruso et al, 2008).…”