In this work, we describe an improved protocol for induced parthenogenesis and ovule culture of carrot (Daucus carota L.). The effects of pollination with parsley pollen and/or 2,4-dichlorophenoxyacetic acid (2,4-D) treatment on the stimulation of parthenogenesis were studied using heterozygous donor plants of 30 varieties and breeding populations of carrots. Isolated ovules, cultured in vitro, enlarged and developed embryos or calli. The application of 2,4-D on pollinated flowers stimulated callus development but did not increase the frequency of embryo development from ovules and, thus, was not useful for increasing the frequency of haploid plant recovery. The efficiency of embryo development was accession-dependent and varied from 0 to 24.29%. In optimized conditions, most accessions responded by embryo development exclusively. The highest frequency of embryo development was observed from ovules excised from ovaries 20-22 d after pollination with parsley pollen. Among several media used for ovule culture, 1/2-strength Murashige and Skoog medium with 0.06 μM indole-3-acetic acid (IAA) was the best. It allowed the production of embryos at a similar frequency as on the media supplemented with kinetin, gibberellic acid, putrescine, or thidiazuron, but restricted callus development. Most plants obtained were haploids and diploids derived from parthenogenesis, as evidenced by homozygosity at three independent loci based on isozyme and PCR analyses. In total, considering haploids and embryo-derived homozygous diploids together, 72.6% of regenerated plants were of gametic origin.

中文翻译：

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使用体外诱导孤雌生殖和胚珠切除的胡萝卜单倍体和双单倍体植物生产的改进方案。

在这项工作中，我们描述了一种用于诱导胡萝卜（Daucus carota L.）孤雌生殖和胚珠培养的改进方案。使用 30 个品种的杂合供体植物和胡萝卜育种群体研究了用欧芹花粉和/或 2,4-二氯苯氧乙酸 (2,4-D) 处理对刺激孤雌生殖的影响。离体胚珠，体外培养，扩大和发育的胚胎或愈伤组织。2,4-D 在授粉花上的应用刺激了愈伤组织的发育，但没有增加胚珠发育的频率，因此对增加单倍体植物恢复的频率没有用。胚胎发育的效率取决于种质，从 0 到 24.29% 不等。在优化条件下，大多数种质仅通过胚胎发育作出反应。从用欧芹花粉授粉后 20-22 天从卵巢中切除的胚珠观察到胚胎发育的最高频率。在用于胚珠培养的几种培养基中，含有 0.06 μM 吲哚-3-乙酸 (IAA) 的 1/2 强度 Murashige 和 Skoog 培养基是最好的。它允许以与在补充有激动素、赤霉酸、腐胺或噻二唑脲的培养基上相似的频率生产胚胎，但限制了愈伤组织的发育。获得的大多数植物是源自孤雌生殖的单倍体和二倍体，这由基于同工酶和 PCR 分析的三个独立基因座的纯合性证明。总的来说，考虑到单倍体和胚胎来源的纯合二倍体，72.6% 的再生植物是配子起源的。