College of Life Sciences, Capital Normal University, Beijing, China.
Beijing Key Laboratory of Crop Genetic Improvement, National Maize Improvement Center of China, China Agricultural University, Beijing, China.
Sci Rep. 2020 Feb 3;10(1):1677. doi: 10.1038/s41598-020-58607-1.
Plant seed germination is a crucial developmental event that has significant effects on seedling establishment and yield production. This process is controlled by multiple intrinsic signals, particularly phytohormones. The gaseous hormone ethylene stimulates seed germination; however, the genetic basis of ethylene production in maize during seed germination remains poorly understood. In this study, we quantified the diversity of germination among 14 inbred lines representing the parental materials corresponding to multiple recombinant inbred line (RIL) mapping populations. Quantitative trait loci (QTLs) controlling ethylene production were then identified in germinating seeds from an RIL population constructed from two parental lines showing differences in both germination speed and ethylene production during germination. To explore the possible genetic correlations of ethylene production with other traits, seed germination and seed weight were evaluated using the same batch of samples. On the basis of high-density single nucleotide polymorphism-based genetic linkage maps, we detected three QTLs for ethylene production in germinating seeds, three QTLs for seed germination, and four QTLs for seed weight, with each QTL explaining 5.8%-13.2% of the phenotypic variation of the trait. No QTLs were observed to be co-localized, suggesting that the genetic bases underlying the three traits are largely different. Our findings reveal three chromosomal regions responsible for ethylene production during seed germination, and provide a valuable reference for the future investigation of the genetic mechanism underlying the role of the stress hormone ethylene in maize germination control under unfavourable external conditions.
植物种子萌发是一个关键的发育事件，对幼苗的建立和产量的产生有重要影响。这个过程受到多种内在信号的控制，特别是植物激素。气态激素乙烯刺激种子萌发；然而，在玉米种子萌发过程中乙烯产生的遗传基础仍知之甚少。在这项研究中，我们量化了 14 个自交系在代表多个重组自交系（RIL）作图群体的亲本材料中的萌发多样性。然后，在来自两个亲本系的 RIL 群体的萌发种子中鉴定了控制乙烯产生的数量性状位点（QTL），这两个亲本系在萌发过程中的萌发速度和乙烯产生上存在差异。为了探索乙烯产生与其他性状的可能遗传相关性，使用同一批样品评估了种子萌发和种子重量。基于高密度单核苷酸多态性遗传连锁图谱，我们在萌发种子中检测到三个与乙烯产生相关的 QTL、三个与种子萌发相关的 QTL 和四个与种子重量相关的 QTL，每个 QTL 解释了性状表型变异的 5.8%-13.2%。没有观察到 QTL 共定位，表明这三个性状的遗传基础有很大的不同。我们的研究结果揭示了三个与种子萌发过程中乙烯产生相关的染色体区域，为进一步研究在不利的外部条件下胁迫激素乙烯在玉米萌发调控中的遗传机制提供了有价值的参考。
