Abstract:
Intergeneric and interspecific hybridization has been employed for the breeding of Phalaenopsis 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, Phalaenopsis 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 Phalaenopsis 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 Phalaenopsis Queen Beer \'Mantefon\' and the conceivable causes of its infertility.
摘要:
属间和种间杂交已用于蝴蝶兰的育种,以在物种之间转移所需的性状,产生具有改进大小的新表型,颜色,形式,和承载花朵的能力。这些特性通常会得到增强;然而,这些杂种中有许多是三倍体,不育性降低或完全不育,例如,蝴蝶兰皇后啤酒\'Mantefon\',亚洲重要的新颖性品种,尤其是在中国,Japan,和大韩民国。尽管对用于装饰目的的作物的需求不断增加,对它的细胞遗传学知之甚少,这对繁殖至关重要,因此,作物改良。在这项研究中,使用荧光原位杂交进行核型分析,减数分裂染色体行为分析,花粉染色,并进行了体外活力萌发试验,从细胞遗传学的角度了解蝴蝶兰皇后啤酒“Mantefon”杂种不育和花粉异常的原因。活力测试显示花粉不育在所有花发育阶段,通过没有花粉管生长证实。在花粉母细胞(PMC)中观察到异常的染色体行为,经常形成单价,染色体桥,在整个减数分裂过程中落后。PMC也不规则地划分为具有不同数量的微核的零星,这可能是该品种花粉不育的原因。总之,细胞遗传学分析提供了有关蝴蝶兰皇后啤酒\'Mantefon\'的花粉发育及其不育原因的见解。