Abstract The genus Lachenalia J. Jacq. ex Js. Murray (Asparagaceae) comprises 136 species endemic to South Africa and Namibia. These bulbous geophytes are considered to have excellent horticultural potential due to their morphological and genetic diversity, and thus have been chosen for the initiation of a breeding program to develop new cultivars that suitable for commercial use. From breeding perspective, studies on pollen viability and morphology are of great importance, since pollen quality represents an essential factor that influences crossbreeding processes. Therefore, to comprehensively characterize the pollen of selected Lachenalia cultivars, we conducted a multi-level analysis in which we investigated the processes of microsporogenesis and pollen grain development, as well as evaluated pollen morphology and viability. We also performed somatic chromosome counts and flow cytometry, thereby providing, for the first time, valuable cytogenetic data on the chromosome numbers and nuclear DNA contents of these cultivars. Morphologically, all the pollen grains were classified as medium-sized, subspheroidal in shape, and monosulcate with a single elongated aperture. Their exine ornamentation was categorized as reticulate with a heterobrochate reticulum. The pollen viability analysis revealed one of the cultivars to be nearly completely sterile, however, we were able to explain this phenomenon and found that this cultivar was affected by meiotic abnormalities associated with its triploid nature. Based on the obtained results, three of the studied cultivars may be considered as suitable pollinizers. From the perspective of applied research, the findings of our research offer important information for selecting appropriate donors for cross-pollination in the development of new Lachenalia cultivars.

中文翻译：

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用基因组大小和染色体数目测定 Lachenalia 品种花粉的发育和质量

摘要 Lachenalia J. Jacq 属。前 Js。Murray (Asparagaceae) 包括 136 种南非和纳米比亚特有的物种。由于它们的形态和遗传多样性，这些球根状土生植物被认为具有出色的园艺潜力，因此被选为启动育种计划以开发适合商业用途的新品种。从育种的角度来看，花粉活力和形态的研究非常重要，因为花粉质量是影响杂交过程的重要因素。因此，为了全面表征选定 Lachenalia 品种的花粉，我们进行了多层次分析，研究了小孢子发生和花粉粒发育的过程，并评估了花粉形态和活力。我们还进行了体细胞染色体计数和流式细胞术，从而首次提供了有关这些品种的染色体数量和核 DNA 含量的有价值的细胞遗传学数据。在形态上，所有的花粉粒都被归类为中等大小、近球形、单槽、具有单个细长孔。它们的外壁装饰被归类为带有异形网状的网状纹饰。花粉活力分析显示其中一个品种几乎完全不育，但是，我们能够解释这种现象，并发现该品种受到与其三倍体性质相关的减数分裂异常的影响。根据获得的结果，三个研究的栽培品种可以被认为是合适的传粉媒介。从应用研究的角度来看，