Androgenesis has become the most frequently chosen method of doubled haploid (DH) production in major crops. Theoretically, plantlets derived from in vitro cultured microspore encompass half of the normal chromosome number of donor plants and thus, considered to be haploid. However, depending on species/genotype and the method of haploid production, either via anther or isolated microspore culture, different ratios of spontaneous DHs and diploid (2n) or even polyploid plants originating from somatic tissues or unreduced gametes may also arise in the cultures. Adopting the method of haploid identification, anti-microtubular agent for restoring fertility, and discriminating spontaneous DHs from undesired heterozygote plants will substantially affect the success of androgenesis in breeding programs. The recent advances in the last 2 decades have made it possible to characterize the in vitro regenerants efficiently either prior to genome duplication or using in breeding programs. The herein described approaches and antimicotubular agents are, therefore, expected to improve the efficiency of DH-based breeding pipeline through the in vitro androgenesis.

中文翻译：

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体外雄激素生成：自发与人工基因组加倍以及再生剂的表征。

雄激素生成已成为主要农作物中单倍体产量增加的最常用方法。从理论上讲，源自体外培养的小孢子的小植株包含供体植物正常染色体数的一半，因此被认为是单倍体。但是，取决于物种/基因型和通过花药培养或分离的小孢子培养产生单倍体的方法，在培养物中也可能会出现不同比例的自发DH和二倍体（2n）甚至来源于体细胞组织或未还原配子的多倍体植物。采用单倍体鉴定的方法，用于恢复生育力的抗微管剂以及从不需要的杂合子植物中鉴别出自发的DHs，将在育种程序中极大地影响雄激素的成功。最近二十年来的最新进展使得在基因组复制之前或在育种程序中有效地表征体外再生子成为可能。因此，本文所述的方法和抗微管剂有望通过体外雄激素形成提高基于DH的育种管道的效率。