Şuteu Dana, Băcilă Ioan, Haș Voichița, Haș Ioan, Miclăuș Mihai
National Institute of Research and Development for Biological Sciences, Cluj-Napoca, Romania.
Agricultural Research and Development Station, Turda, Romania.
PLoS One. 2013 Dec 31;8(12):e85501. doi: 10.1371/journal.pone.0085501. eCollection 2013.
Maize has always been under constant human selection ever since it had been domesticated. Intensive breeding programs that resulted in the massive use of hybrids nowadays have started in the 60s. That brought significant yield increases but reduced the genetic diversity at the same time. Consequently, breeders and researchers alike turned their attention to national germplasm collections established decades ago in many countries, as they may hold allelic variations that could prove useful for future improvements. These collections are mainly composed of inbred lines originating from well-adapted local open pollinated varieties. However, there is an overall lack of data in the literature about the genetic diversity of maize in SE Europe, and its potential for future breeding efforts. There are no data, whatsoever, on the nutritional quality of the grain, primarily dictated by the zein proteins. We therefore sought to use the Romanian maize germplasm as an entry point in understanding the molecular make-up of maize in this part of Europe. By using 80 SSR markers, evenly spread throughout the genome, on 82 inbred lines from various parts of the country, we were able to decipher population structure and the existing relationships between those and the eight international standards used, including the reference sequenced genome B73. Corroborating molecular data with a standardized morphological, physiological, and biochemical characterization of all 90 inbred lines, this is the first comprehensive such study on the existing SE European maize germplasm. The inbred lines we present here are an important addition to the ever-shrinking gene pool that the breeding programs are faced-with, because of the allelic richness they hold. They may serve as parental lines in crosses that will lead to new hybrids, characterized by a high level of heterosis, nationwide and beyond, due to their existing relationship with the international germplasm.
自玉米被驯化以来，它一直处于人类的持续选择之下。如今导致大量使用杂交种的集约化育种计划始于20世纪60年代。这带来了显著的产量增长，但同时也降低了遗传多样性。因此，育种者和研究人员都将注意力转向了许多国家几十年前建立的国家种质库，因为这些种质库可能拥有对未来改良有用的等位基因变异。这些种质库主要由源自适应性良好的当地开放授粉品种的自交系组成。然而，文献中总体上缺乏关于东南欧玉米遗传多样性及其未来育种潜力的数据。关于主要由醇溶蛋白决定的籽粒营养品质，也没有任何数据。因此，我们试图以罗马尼亚玉米种质为切入点，来了解欧洲这一地区玉米的分子组成。通过在来自该国不同地区的82个自交系上使用均匀分布于整个基因组的80个SSR标记，我们能够解析群体结构以及这些自交系与所使用的八个国际标准（包括参考测序基因组B73）之间的现有关系。将分子数据与所有90个自交系的标准化形态、生理和生化特征相结合，这是对东南欧现有玉米种质进行的首次全面此类研究。我们在此展示的自交系是对育种计划所面临的不断缩小的基因库的重要补充，因为它们拥有丰富的等位基因。由于它们与国际种质的现有关系，它们可作为杂交亲本系，在全国乃至更广泛地区培育出具有高度杂种优势的新杂交种。
