Identification of 21 novel S-RNase alleles and determination of S-genotypes in 66 loquat (Eriobotrya) accessions.

Yang, Qin; Fu, Yan; Wang, Yongqing; Liu, Lunpei; Li, Xingyuan; Peng, Shu

As observed in other self-incompatible species in the Pyrinae subtribe, loquat (Eriobotrya japonica) demonstrates gametophytic self-incompatibility that is controlled by the S-locus, which encodes a polymorphic stylar ribonuclease (S-RNase). This allows the female reproductive organ (style) to recognize and reject the pollen from individuals with the same S-alleles, but allows the pollen from individuals with different S-alleles to effect fertilization. The S-genotype is therefore an important consideration in breeding strategies and orchard management. In an attempt to optimize the selection of parental lines in loquat production, the S-RNase alleles of 35 loquat cultivars and their 26 progeny, as well as five wild loquat species, were identified and characterized in this study. The best pollinizer cultivar combinations were also explored. A total of 28 S-alleles were detected, 21 of which constituted novel S-RNase alleles. The S-haplotypes S2 and S6 were the most frequent, followed by S29, S31, S5, S24, S28, S33, S34, S32, and S15, while the rare alleles S1, S9, S14, S16, S17, S18, S19, S20, S21, S22, S23, S27, and S35 were only observed in one of the accessions tested. Moreover, the S-genotypes of five wild loquat species (E. prinoides, E. bengalensis, E. prinoides var. dadunensis, E. deflexa, and E. japonica) are reported here for the first time. The results will not only facilitate the selection of suitable pollinators for optimal orchard management, but could also encourage the crossbreeding of wild loquat species to enhance the genetic diversity of loquat cultivars.

GENOTYPES; LOQUAT; RIBONUCLEASES; FERTILIZATION (Biology); POLLEN

Molecular Breeding, 2018, Vol 38, Issue 5, p1

1380-3743

Academic Journal

10.1007/s11032-018-0800-7