文献类型： 外文期刊

作者： Dang, Jiangbo ¹ ; Li, Cai ⁴ ; Sun, Danni ¹ ; He, Houzheng ¹ ; Wang, Zhuli ¹ ; Tang, Yuqin ⁵ ; Sun, Haiyan ¹ ; She, Sulei ¹ ; Wang, Haiyan ¹ ; Guo, Qigao ¹ ; Han, Guohui ³ ; Liang, Guolu ¹ ;

作者机构： 1.Southwest Univ, Coll Hort & Landscape Architecture, Chongqing 400715, Peoples R China

2.Southwest Univ, Acad Agr Sci, Chongqing 400715, Peoples R China

3.Chongqing Acad Agr Sci, Chongqing 401329, Peoples R China

4.Fuling Ctr Cash Crop Dev, Chongqing 408000, Peoples R China

5.Chongqing Three Gorges Acad Agr Sci, Chongqing 404155, Peoples R China

关键词： Autotetraploid; Nonapomictic citrus; Polyembryonic seeds; Low sequencing depth region

期刊名称：SCIENTIA HORTICULTURAE （ 影响因子：3.9； 五年影响因子：4.3 ）

ISSN： 0304-4238

年卷期： 2024 年 327 卷

页码：

收录情况： SCI

摘要： Tetraploid plays major roles in the polyploid breeding and production of citrus plants. Autotetraploids of nonapomictic citrus varieties are desirable in citrus polyploid breeding due to their high frequencies of hybrid polyploid production, certain genotypes and some predictable phenotypes. However, it is difficult to obtain autotetraploids of nonapomictic citrus varieties. In the present study, the nonapomictic sweet orange variety 'Licheng', which is native to China, was used as the main material. A 'Licheng' tree, LCOYC-04, that produced polyembryonic seeds at a frequency of 34.96 +/- 2.88 % was selected. Plants that grew from self-pollinated polyembryonic seeds of LCOYC-04 were investigated by flow cytometry. Four tetraploids were selected from 550 plants and identified according to chromosome observation. Exonic single-nucleotide polymorphism (SNP) locus genotyping based on genome resequencing showed that 22.18 %-70.49 % of heterozygous loci in the genome of LCOYC-04 were homozygous in the genomes of plants grown from self-pollinated monoembryonic seeds. The proportions of homozygous loci were 2.07 %-2.45 % in the 4 selected tetraploids. These values were close to those in 7 asexual 'Licheng' relatives (1.97 %-2.71 %). Therefore, the 4 tetraploids were confirmed to be autotetraploids of LCOYC-04. Genome sequencing revealed a region of low sequencing depth (approximately 855 kb) on chromosome 4 of all 'Licheng' trees. The CitRWP gene, which is responsible for the occurrence of nucellar embryos in citrus plants, was located in the low sequencing depth region. It was confirmed by quantitative PCR that one of two allelic CitRWP gene was defective in genome of 'Licheng'. The current study indicates that it is possible to induce nonapomictic citrus to mutate into facultatively apomictic citrus through chromosome segment deletion, and provides a reference for excavating autotetraploids which produce polyembryonic and monoembryonic seeds.