Validation of a male‐linked gene locus (OGI) for sex identification in persimmon (Diospyros kaki Thunb.) and its application in F₁ progeny

Abstract

It is crucial to develop a rapid technique for identifying sexuality in the seedling stage of persimmon (Diospyros kaki Thunb.), and the elimination of male progeny has been regarded as an important strategy for enhancing breeding efficiency. In this study, phenotype characterization and genotyping of the male‐linked OGI marker were carried out using 205 accessions, including persimmon cultivars, F1 progeny and nine related Diospyros species. All persimmon cultivars displayed consistent results regarding OGI amplification and sex phenotype. A total of 143 F1 progeny were derived from 11 crosses, among which 95 individuals had flowered. In the flowering full‐sib families, the amplification of the OGI marker in agreement with the sex phenotype was obtained in 85 plants (89.5%). The segregation of OGI in ‘Huashi 1’ × ‘Luotian Tianshi’ and ‘Huashi 1’ × Male 3 F1 populations fit a 1 : 1 ratio. Furthermore, high OGI transferability was observed in nine related species. Overall, the results indicated that the OGI locus could be used to distinguish male from female persimmon plants at an early stage.

Study of Sexual-Linked Genes (OGI and MeGI) on the Performance of Androecious Persimmons (Diospyros kaki Thunb.)

“…Results of termination codons and compositions of bases in these OGI sequences were in accordance with a previous report that the coding sequence of OGI presented multiple disruptive stop codons [ 7 ]. BLAST analysis revealed that our androecious OGI sequences had high sequence identity of over 95% with that of monoecious persimmons, as reported before [ 10 ]. Additionally, results of RT-qPCR indicated that the OGI gene could have a basal, but not too much, expression level in androecious D. kaki bud/flower based on the same primer put forward by Akagi et al [ 9 ].…”

“…In the sequencing of our seven OGI fragments, 54–57 termination codons consisting of 17.65–18.79% bases were found, and TAG was the most common type, followed by TAA ( Table 2 ). It was also observed that the compositions of bases in OGI sequences derived from our D. kaki samples displayed a trend of A > T > G > C. To further investigate the universality, the OGI sequences were compared with the fragments obtained from Zhang et al [ 10 ]. DNA sequence alignment analysis of OGI among androecious and monoecious D. kaki individuals revealed that the OGI sequence identity was over 95% ( Figure 5 ), confirming the sequence is conserved and indispensable in androecious persimmons.…”

“…In the present study, we make full use of the specific materials of androecious D. kaki to study the expression of OGI and MeGI , and compare the results to the findings reported by Akagi et al [ 9 ] and Zhang et al [ 10 ]. Hence, this finding will contribute to improving the D. kaki gender theory model, meanwhile providing the foundation for appropriate management during the flowering period, and having the potential to cultivate excellent male germplasm which is valuable in cross-breeding work.…”

“…OGI 1–7 represent the OGI sequence of Yunjiashan-8, Mulan-38, Luotian Yeshi-1, Jiangsu Yeshi 2, Jiangxi Yeshi-1, Hunan Yeshi-1, and Yunjiashan-3, respectively, which were all obtained from our androecious D. kaki . Male 1–3 represent androecious D. kaki isolate plant 1–3, and Zenjimaru, Taishu, and Shougatsu were monoecious D. kaki , which were all obtained from Zhang et al [ 10 ].…”

“…The finding provides great significance for the sex determination in monoecious D. kaki . According to the above situation, using androecious genotype patterns and some F1 progeny, Zhang et al [ 10 ] claimed that the OGI gene marker could be used to distinguish D. kaki sexuality at an early stage. However, the molecular mechanism of sex determination in androecious types of D. kaki remains elusive due to the limited number of androecious individual available.…”