Liu Yiming, Zhang Xunzhong, Tran Hong, Shan Liang, Kim Jeongwoon, Childs Kevin, Ervin Erik H, Frazier Taylor, Zhao Bingyu
Department of Crop and Soil Environmental Science, Virginia Tech, 367 Smyth Hall, 185 Ag Quad Ln, Blacksburg, VA 24061 USA.
Department of Statistics, Virginia Tech, Blacksburg, VA USA.
Biotechnol Biofuels. 2015 Sep 22;8:152. doi: 10.1186/s13068-015-0342-8. eCollection 2015.
Switchgrass (Panicum virgatum L.) is a warm-season C4 grass that is a target lignocellulosic biofuel species. In many regions, drought stress is one of the major limiting factors for switchgrass growth. The objective of this study was to evaluate the drought tolerance of 49 switchgrass genotypes. The relative drought stress tolerance was determined based on a set of parameters including plant height, leaf length, leaf width, leaf sheath length, leaf relative water content (RWC), electrolyte leakage (EL), photosynthetic rate (Pn), stomatal conductance (g s), transpiration rate (Tr), intercellular CO2 concentration (Ci), and water use efficiency (WUE).
SRAP marker analysis determined that the selected 49 switchgrass genotypes represent a diverse genetic pool of switchgrass germplasm. Principal component analysis (PCA) and drought stress indexes (DSI) of each physiological parameter showed significant differences in the drought stress tolerance among the 49 genotypes. Heatmap and PCA data revealed that physiological parameters are more sensitive than morphological parameters in distinguishing the control and drought treatments. Metabolite profiling data found that under drought stress, the five best drought-tolerant genotypes tended to have higher levels of abscisic acid (ABA), spermine, trehalose, and fructose in comparison to the five most drought-sensitive genotypes.
Based on PCA ranking value, the genotypes TEM-SEC, TEM-LoDorm, BN-13645-64, Alamo, BN-10860-61, BN-12323-69, TEM-SLC, T-2086, T-2100, T-2101, Caddo, and Blackwell-1 had relatively higher ranking values, indicating that they are more tolerant to drought. In contrast, the genotypes Grif Nebraska 28, Grenville-2, Central Iowa Germplasm, Cave-in-Rock, Dacotah, and Nebraska 28 were found to be relatively sensitive to drought stress. By analyzing physiological response parameters and different metabolic profiles, the methods utilized in this study identified drought-tolerant and drought-sensitive switchgrass genotypes. These results provide a foundation for future research directed at understanding the molecular mechanisms underlying switchgrass tolerance to drought.
柳枝稷（Panicum virgatum L.）是一种暖季型C4草本植物，是目标木质纤维素生物燃料物种。在许多地区，干旱胁迫是柳枝稷生长的主要限制因素之一。本研究的目的是评估49个柳枝稷基因型的耐旱性。基于包括株高、叶长、叶宽、叶鞘长度、叶片相对含水量（RWC）、电解质渗漏（EL）、光合速率（Pn）、气孔导度（gs）、蒸腾速率（Tr）、胞间CO2浓度（Ci）和水分利用效率（WUE）等一系列参数来确定相对干旱胁迫耐受性。
SRAP标记分析确定，所选的49个柳枝稷基因型代表了柳枝稷种质的一个多样化基因库。对每个生理参数的主成分分析（PCA）和干旱胁迫指数（DSI）表明，这49个基因型在干旱胁迫耐受性方面存在显著差异。热图和PCA数据显示，在区分对照和干旱处理时，生理参数比形态参数更敏感。代谢物谱分析数据发现，在干旱胁迫下，与五个最敏感的基因型相比，五个最耐旱的基因型往往具有更高水平的脱落酸（ABA）、精胺、海藻糖和果糖。
根据PCA排名值，基因型TEM-SEC、TEM-LoDorm、BN-13645-64、阿拉莫、BN-10860-61、BN-12323-69、TEM-SLC、T-2086、T-2100、T-2101、卡多和布莱克韦尔-1具有相对较高的排名值，表明它们更耐旱。相比之下，基因型格里夫内布拉斯加28、格林维尔-2、中艾奥瓦种质、岩洞、达科他和内布拉斯加28被发现对干旱胁迫相对敏感。通过分析生理响应参数和不同的代谢谱，本研究中使用的方法鉴定出了耐旱和干旱敏感的柳枝稷基因型。这些结果为未来旨在了解柳枝稷耐旱分子机制的研究奠定了基础。
Zotero 插件
