Drought during the formative stages of a plant’s growth triggers a sequence of responses to maintain optimal growing conditions, but often at the expense of crop productivity. Two field experiments were conducted to determine the effect of drought on 10 high-yielding sugarcane genotypes at two formative stages (the tillering stage (TS) and stalk elongation (SS)), within 30 days after treatment imposition. The experiments followed a split-plot in a randomized complete block design with three replicates per genotype. Agro-physiological responses to drought were observed to compare the differences in the response of sugarcane during the two formative stages. Drought significantly reduced total chlorophyll content (Chl) and stomatal conductance (Gs) for both formative stages, while significantly increasing total scavenging activity (AOA) and electrolyte leakage (EC). A higher level of Chl was observed in the stalk elongation stage compared to the tillering stage; however, lower AOA coupled with higher EC in the stalk elongation stage suggests higher drought susceptibility. Pearson's correlation analysis revealed a stronger correlation between plant height, internode length, Chl, AOA, EC, and Gs at the tillering stage relative to the stalk elongation stage. Moreover, results from the multivariate analysis indicate the different contribution values of each parameter, supplementing the hypothesized difference in response between the two formative stages. Multivariate analysis clustered the 10 genotypes into groups based on the traits evaluated, suggesting the ability of these traits to detect differences in a sample population. The observed relationship among traits during the two formative stages of sugarcane will be significant in screening and identifying drought-susceptible and drought-tolerant genotypes for variety development studies.

中文翻译：

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水分状况，基因型和形成阶段对甘蔗（Saccharum officinarum L.）对干旱的农业生理响应的影响。

植物生长形成阶段的干旱引发一系列响应，以维持最佳生长条件，但通常以作物生产力为代价。在实施处理后的30天内，进行了两个田间试验，以确定干旱对两个成长期（分stage期（TS）和茎伸长（SS））对10种高产甘蔗基因型的影响。实验遵循随机完整块设计中的分裂图，每个基因型重复三个重复。观察到对干旱的农业生理响应，以比较两个形成阶段甘蔗响应的差异。干旱显着降低了两个形成阶段的总叶绿素含量（Chl）和气孔导度（Gs），同时显着提高总清除活性（AOA）和电解质泄漏（EC）。与分er期相比，在茎伸长期观察到更高水平的Chl。然而，在茎伸长期，较低的AOA加上较高的EC表示较高的干旱敏感性。Pearson的相关分析显示，在分er期相对于茎伸长期，株高，节间长度，Chl，AOA，EC和Gs之​​间的相关性更强。此外，多变量分析的结果表明每个参数的贡献值不同，补充了两个形成阶段之间假设的响应差异。多变量分析根据评估的性状将10个基因型分为几类，这些特征表明了检测样本人群差异的能力。在甘蔗的两个形成阶段中观察到的性状之间的关系对于筛选和鉴定对干旱敏感和耐旱的基因型以进行品种开发研究具有重要意义。