Sevilleno Samantha Serafin, An Hye Ryun, Cabahug-Braza Raisa Aone M, Ahn Yun-Jae, Hwang Yoon-Jung
Department of Convergence Science, Sahmyook University, Seoul 01795, Republic of Korea.
Floriculture Research Division, National Institute of Horticultural & Herbal Science, Rural Development Administration, Wanju 55365, Republic of Korea.
Plants (Basel). 2023 Jul 31;12(15):2828. doi: 10.3390/plants12152828.
Intergeneric and interspecific hybridization has been employed for the breeding of to transfer desirable traits between species, producing novel phenotypes with improved size, color, form, and flower-bearing ability. These characteristics are often enhanced; however, many of these hybrids are triploids and have reduced or complete sterility, for example, Queen Beer 'Mantefon', an important novelty-type cultivar in Asia, particularly in China, Japan, and Republic of Korea. Despite the increasing demand for the crop for ornamental purposes, little is known about its cytogenetics, which is essential for breeding and, consequently, crop improvement. In this study, karyotyping using fluorescence in situ hybridization, meiotic chromosome behavior analysis, pollen staining, and in vitro viability germination tests were performed to understand the cause of hybrid sterility and pollen abnormality in Queen Beer 'Mantefon' from a cytogenetic perspective. Viability tests revealed pollen infertility at all flower developmental stages, confirmed by the absence of pollen tube growth. Aberrant chromosomal behavior was observed in pollen mother cells (PMCs), frequently forming univalents, chromosomal bridges, and laggards during the entire meiotic process. PMCs were also divided irregularly into sporads with varying numbers of micronuclei, which may be responsible for pollen sterility in this cultivar. Altogether, the cytogenetic analyses provided insights into the pollen development of Queen Beer 'Mantefon' and the conceivable causes of its infertility.
属间和种间杂交已被用于育种，以在物种间转移理想性状，产生具有改善的大小、颜色、形态和开花能力的新表型。这些特征通常会得到增强；然而，这些杂种中有许多是三倍体，具有降低的或完全的不育性，例如亚洲，特别是中国、日本和韩国的重要新奇品种皇后啤酒‘曼特丰’。尽管对该作物用于观赏目的的需求不断增加，但对其细胞遗传学却知之甚少，而细胞遗传学对于育种以及作物改良至关重要。在本研究中，进行了荧光原位杂交核型分析、减数分裂染色体行为分析、花粉染色和体外活力萌发试验，以从细胞遗传学角度了解皇后啤酒‘曼特丰’杂交不育和花粉异常的原因。活力试验显示在所有花发育阶段花粉不育，这通过花粉管生长的缺失得到证实。在花粉母细胞（PMC）中观察到异常的染色体行为，在整个减数分裂过程中经常形成单价体、染色体桥和落后染色体。PMC也不规则地分裂成具有不同数量微核的四分体，这可能是该品种花粉不育的原因。总之，细胞遗传学分析为皇后啤酒‘曼特丰’的花粉发育及其不育的可能原因提供了见解。
