Hetero-fertilization together with failed egg–sperm cell fusion supports single fertilization involved in in vivo haploid induction in maize. (11th May 2018)

• Record Type: Journal Article
• Authors: Tian, Xiaolong; Qin, Yuanxin; Chen, Baojian; Liu, Chenxu; Wang, Lele; Li, Xingli; Dong, Xin; Liu, Liwei; Chen, Shaojiang
• Is Part Of: Journal of experimental botany. Volume 69:Number 20(2018)
• Page Start: 4689
• Page End: 4701
• Publication Date: 2018-05-11
• Subjects: Cell fusion -- fertilization recovery -- haploid -- hetero-fertilization -- maize -- single fertilization; Botany -- Periodicals; Botany, Experimental -- Periodicals; Plant physiology -- Periodicals; 580
• DOI: 10.1093/jxb/ery177
• Languages: English
• ISSNs: 0022-0957

Abstract

Abstract : Hetero-fertilization and failed egg–sperm cell fusion indicate that single fertilization plays a key role in in vivo haploid induction in maize. Abstract: In vivo doubled-haploid technology is widely applied in commercial maize breeding programs because of its time-saving and cost-reducing features. The production of maize haploids primarily depends on the use of Stock6-derived haploid inducer lines. Although the gene underlying haploid induction, MTL/ZmPLA1/NLD, was cloned recently, the mechanism of haploid induction is still unknown. Hetero-fertilization can occur via a single fertilization, which provides a means to investigate single-fertilization events by studying the hetero-fertilization phenomenon. In this study, we found that the hetero-fertilization rate increased significantly when female maize lines were first individually crossed with pollen from the inducer CAU5 in dual-pollination experiments 4 h before a second pollination with common lines. We also examined embryogenesis during haploid induction by confocal laser-scanning microscopy and observed single-fertilized ovules, indicating that single fertilization occurred during haploid induction. We therefore postulate that both single fertilization and chromosome elimination contribute to haploid induction in maize. We also propose a scheme for the formation of hetero-fertilized and haploid kernels. Our results provide an efficient approach to identify hetero-fertilized kernels for research on interactions between embryo and endosperm.