The Relationship Between a Maleness-associated Region in <i>Diospyros lotus</i> L. and Maleness of Persimmon (<i>D. kaki</i> Thunb.) Cultivars

Abstract

Most persimmon (Diospyros kaki Thunb.) cultivars bear only female flowers, which limits persimmon cross-breeding. Although the genetic and molecular bases of sexuality in persimmon have yet to be determined, a maleness-associated region, DlSx-AF4S, was recently identified in D. lotus L., which is a wild diploid relative of hexaploid/nonaploid D. kaki. This finding suggests that D. lotus has a heterogametic male (XY-type) dioecious sexual system. Here, we investigated the association between DlSx-AF4S genotypes and the maleness (sexuality) of 174 persimmon cultivars. DlSx-AF4S was detected in all but three cultivars that bear male flowers, suggesting that the maleness of persimmon is controlled by a genetic factor similar to that in D. lotus. On the other hand, DlSx-AF4S was also found in 17% of the tested cultivars that were reported to bear only female flowers. Considering that the sexuality of persimmon is more susceptible to environmental factors, some cultivars may hardly bear male flowers under certain conditions even though they have male determinants. In addition, a higher ploidy level in persimmon may also complicate sex expression. This elusive sex expression system in persimmon will be better understood when a male determinant(s) linked to DlSx-AF4S is identified and characterized in the future.

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

“…However, in this study, genotyping via OGI marker amplification of 10 F 1 progeny showed discordance with their gender phenotypes, as shown by Kajita et al. (). Occasional male flowers in some pistillate‐type persimmons, such as the original Japanese cultivars ‘Jirou’ and ‘Fuyuu’ (Yakushiji et al.…”

“…1, Luotian Tianshi (♀); 2, Eshi 1 (♀); 3, Baogai Tianshi (♀); 4, Xiaobaogai Tianshi (♀); 5, Sifang Tianshi (♀); 6, Xiaoguo Tianshi (♀); 7, 90-1-15 (♀); 8, 90-1-34 (♀); 9, 90-3-99 (♀); 10, 97-3-4 (♀); 11, Xiangxi Tianshi (♀); 12, Fuping Jianshi (♀); 13, Gongcheng Shuishi (♀); 14, Mopanshi (♀); 15, 90-1-10 (♀); 16, Sigoushi (♀); 17, Fuyuu (♀); 18, Jirou (♀); 19, Youhou (♀); 20, Maekawa-jirou (♀); 21, Uenishi-wase (♀); 22, Matsumoto-wase (♀); 23, Izu (♀); 24, Watasugikei-jirou (♀); 25, Soshu (♀); 26, Yubeni (♀); 27, Suruga (♀); 28, Hiratanenashi (♀); 29, Sagoksi 1 (♀); 30, Sagoksi 2 (♀); 31, Danseongsi (♀); 32, Hyakume (♀); 33, Shutouhong (♀♂); 34, Taiwan Zhengshi (♀♂); 35, Xiangyang Niuxinshi (♀♂); 36, Huashi 1 (♀♂); 37, Hana-gosho (♀♂); 38, Taishuu (♀♂); 39, Yamafuji (♀♂); 40, Zenjimaru (♀♂); 41, Nishimurawase (♀♂); 42, Shogatsu (♀♂); 43, Akagaki (♀♂); 44, Male 1 (♂); 45, Male 2 (♂); 46, Male 3 (♂); 47, Male 8 (♂); 48, Male 11 (♂); 49, Male 9 (♂); 50, Male 10 (♂); 51, Date plum (♀); 52, Date plum (♂); 53, Chekiang persimmon (♀); 54, Chekiang persimmon (♂); 55, Deyangshi (♀); 56, Deyangshi (♂); 57, Jinzaoshi (♀); 58, Oily persimmon (♀♂); 59, Yemaoshi (♂); 60, Diamond leaf persimmon (♀); 61, Common persimmon (♀); 62, Silvestris persimmon (♀); M, marker (DL 2000) only found in male plants of D. lotus, which may display a male-specific gene locus in Diospyros species. However, in this study, genotyping via OGI marker amplification of 10 F 1 progeny showed discordance with their gender phenotypes, as shown by Kajita et al (2015). Occasional male flowers in some pistillate-type persimmons, such as the original Japanese cultivars 'Jirou' and 'Fuyuu' (Yakushiji et al 1995) and Chinese original cultivars 'Eshi 1' and 'Luotian Tianshi' (Table 1), as well as 'Baogai Tianshi' and 'Mopanshi' (Y. Yang, personal communication), may indicate that sex expression in D. kaki is influenced by environmental factors, especially due to its polyploidy nature in addition to genetic controls.…”

“…OGI encodes a small RNA that in turn triggers transitive RNAi on a feminizing gene, MeGI, which is located on the autosome or the pseudoautosomal region of the sex chromosome. Molecular markers developed from the supposedly flanking regions of OGI were shown to be partially applicable for the molecular marker for maleness in D. kaki, indicating that the genetic control of the maleness expression in D. kaki was based on the OGI/MeGI system (Kajita et al 2015). In this study, phenotype characterization and the genotyping of core regions of the OGI locus were carried out using 205 Diospyros accessions, including D. kaki, F 1 progeny and nine related species (including D. lotus).…”

A male determinant gene in diploid dioecious Diospyros, OGI, is required for male flower production in monoecious individuals of Oriental persimmon (D. kaki)

“…However, hexaploid persimmon (D. kaki) shows flexible sexuality generally not observed in other diploid Diospyros species; it is mainly constituted of female and monoecious trees (Yonemori et al, 1993), with male trees occurring rarely (Xu et al, 2008;Yakushiji et al, 1995). Importantly, preliminary data suggested that the monoecious trait was associated with the existence of the Y-chromosome in D. kaki, although the details remain to be elucidated (Akagi et al, 2014a, b;Kajita et al, 2015).…”

Selection and validation of reference genes for quantitative gene expression analyses in persimmon (Diospyros kaki Thunb.) using real-time quantitative PCR

“…In addition, the male-linked gene locus (OGI) was shown to be tightly linked to the maleness expression in persimmons (Zhang et al, 2016). As a result, we can distinguish flower sexuality using the OGI/MeGI system served as an early sex diagnosis technology for future investigations in persimmon (Kajita et al, 2015;Zhang et al, 2016). Moreover, our previous study showed that high levels genes homologous to IAA32, beta-amyrin 28-oxidase-like, and GA20OX2 may stimulate the development of male floral buds, while the genes homologous to MeGI and ACO showed female promoting effects (Li et al, 2019).…”