Sex determination in plants gives rise to unisexual flowers. A better understanding of the regulatory mechanism underlying the production of unisexual flowers will help to clarify the process of sex determination in p...Sex determination in plants gives rise to unisexual flowers. A better understanding of the regulatory mechanism underlying the production of unisexual flowers will help to clarify the process of sex determination in plants and allow researchers and farmers to harness heterosis. Androecious cucumber(Cucumis sativus L.) plants can be used as the male parent when planted alongside a gynoecious line to produce heterozygous seeds, thus reducing the cost of seed production. The isolation and characterization of additional androecious genotypes in varied backgrounds will increase the pool of available germplasm for breeding. Here, we discovered an androecious mutant in a previously generated ethyl methanesulfonate(EMS)-mutagenized library of the cucumber inbred line ‘406’. Genetic analysis, whole-genome resequencing, and molecular marker-assisted verification demonstrated that a nonsynonymous mutation in the ethylene biosynthetic gene 1-AMINOCYCLOPROPANE-1-CARBOXYLATE SYNTHASE 11(ACS11) conferred androecy. The mutation caused an amino acid change from serine(Ser) to phenylalanine(Phe) at position 301(S301F). In vitro enzyme activity assays revealed that this S301F mutation leads to a complete loss of enzymatic activity. This study provides a new germplasm for use in cucumber breeding as the androecious male parent, and it offers new insights into the catalytic mechanism of ACS enzymes.展开更多
The androecious genotype of Diospyros spp. ‘Male 8', which is distributed in Dabie Mountain area of the central China, was probably derived from the hybrids or natural variation of Chinese pollination constant an...The androecious genotype of Diospyros spp. ‘Male 8', which is distributed in Dabie Mountain area of the central China, was probably derived from the hybrids or natural variation of Chinese pollination constant and non-astringent(CPCNA) persimmon. Its application potential as the breeding parent of pollination constant and non-astringent(PCNA) is undefined. In this study, we identified the astringency type of a hybrid individual(H8-2) derived from the cross between ‘Huashi 1'(pollination variant and astringent, PVA) and ‘Male 8'. Through comparison with the known genotypes of CPCNA, Japanese PCNA(JPCNA) and non-PCNA, the results of soluble/insoluble tannin content and tannin cell size measure showed that H8-2 was a PCNA genotype with the characteristic of natural deastringency of CPCNA. According to the currently known genetic features of PCNA persimmon, a new individual of PCNA may be generated in F1 population when two JPCNA genotypes are crossed or when the CPCNA genotype is used as a parent. Thus, the study verifies that androecious genotype ‘Male 8' carries the dominant gene locus that controls the non-astringent trait of CPCNA, indicating its potential to be used as pollen donor for the genetic improvement of PCNA persimmon.展开更多
基金supported by the National Key Research and Development Program of China (2018YFD1000803)the National Natural Science Foundation of China (31701933 and 32002036)the Shandong Provincial Natural Science Foundation, China (ZR2020QC157)。
文摘Sex determination in plants gives rise to unisexual flowers. A better understanding of the regulatory mechanism underlying the production of unisexual flowers will help to clarify the process of sex determination in plants and allow researchers and farmers to harness heterosis. Androecious cucumber(Cucumis sativus L.) plants can be used as the male parent when planted alongside a gynoecious line to produce heterozygous seeds, thus reducing the cost of seed production. The isolation and characterization of additional androecious genotypes in varied backgrounds will increase the pool of available germplasm for breeding. Here, we discovered an androecious mutant in a previously generated ethyl methanesulfonate(EMS)-mutagenized library of the cucumber inbred line ‘406’. Genetic analysis, whole-genome resequencing, and molecular marker-assisted verification demonstrated that a nonsynonymous mutation in the ethylene biosynthetic gene 1-AMINOCYCLOPROPANE-1-CARBOXYLATE SYNTHASE 11(ACS11) conferred androecy. The mutation caused an amino acid change from serine(Ser) to phenylalanine(Phe) at position 301(S301F). In vitro enzyme activity assays revealed that this S301F mutation leads to a complete loss of enzymatic activity. This study provides a new germplasm for use in cucumber breeding as the androecious male parent, and it offers new insights into the catalytic mechanism of ACS enzymes.
基金supported by the Special Fund for Agroscientific Research in the Public Interest (201203047)Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains (2015TD01)
文摘The androecious genotype of Diospyros spp. ‘Male 8', which is distributed in Dabie Mountain area of the central China, was probably derived from the hybrids or natural variation of Chinese pollination constant and non-astringent(CPCNA) persimmon. Its application potential as the breeding parent of pollination constant and non-astringent(PCNA) is undefined. In this study, we identified the astringency type of a hybrid individual(H8-2) derived from the cross between ‘Huashi 1'(pollination variant and astringent, PVA) and ‘Male 8'. Through comparison with the known genotypes of CPCNA, Japanese PCNA(JPCNA) and non-PCNA, the results of soluble/insoluble tannin content and tannin cell size measure showed that H8-2 was a PCNA genotype with the characteristic of natural deastringency of CPCNA. According to the currently known genetic features of PCNA persimmon, a new individual of PCNA may be generated in F1 population when two JPCNA genotypes are crossed or when the CPCNA genotype is used as a parent. Thus, the study verifies that androecious genotype ‘Male 8' carries the dominant gene locus that controls the non-astringent trait of CPCNA, indicating its potential to be used as pollen donor for the genetic improvement of PCNA persimmon.
