This work assessed the responses of Jerusalem artichoke (JA) genotypes experienced to different durations of terminal drought for relative water content (RWC), SPAD chlorophyll meter reading (SCMR), stomatal conductance (SC), leaf area (LA) and specific leaf area (SLA), investigated the significant contributor of physiological traits to yield and yield reduction and diversity of physiological traits in terminal drought tolerance genotypes. Field research was conducted during the late-rainy season for 2 years using a split-plot design with four replications. The three irrigation treatments involved no-drought (SD0), short (SD1) and long (SD2) durations of terminal drought were arranged as main plots, and sub-plots were six genotypes of JA. The current study revealed that RWC, SC, LA, and SLA, were drastically reduced whilst SCMR values slightly increased under SD1 and SD2 compared to SD0. According to multiple linear regression indicated that SLA (SD0), and RWC (SD1 and SD2) had high contributions to tuber fresh weight (TFW), whereas SC had a high contribution to TFW reduction under terminal drought. Principal component analysis also confirmed that the diversity of LA, RWC, and SLA had maximized contributing traits, followed by HI, SCMR and SC in these breeding materials of JA under three irrigation treatments. Our finding emphasized that JA125 (low SLA), HEL256 and JA37 (high SLA) lead to the high performance of TFW under SD0, and they exhibited high TFW under SD1 by performing medium RWC. Likewise, JA4 and JA37 had high TFW under SD2 caused by medium RWC. HEL253 and JA60 were identified as terminal drought-tolerant genotypes because of performed medium SC, which contributed to a low reduction in TFW. Our promising results are the basis for further studies, SLA, RWC and SC are an important keys for screening drought tolerance (low economic yield reduction) and these genotypes studied could be used for parental lines to improved drought tolerance progenies through breeding programs under different durations of terminal drought-prone areas.

中文翻译：

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热带地区不同干旱期菊芋基因型相对含水量、SPAD叶绿素读数、气孔导度、叶面积和比叶面积的变化

这项工作评估了菊芋 (JA) 基因型对不同持续干旱期的相对含水量 (RWC)、SPAD 叶绿素读数 (SCMR)、气孔导度 (SC)、叶面积 (LA) 和比叶面积的响应(SLA)，研究了生理性状对产量和减产的重要贡献以及终端耐旱基因型生理性状的多样性。实地研究在晚雨季节进行了 2 年，使用具有四次重复的裂区设计。以不干旱（SD0）、短（SD1）和长（SD2）绝旱期3个灌溉处理为主区，副区为JA的6个基因型。目前的研究表明，RWC、SC、LA 和 SLA，与 SD0 相比，SD1 和 SD2 下的 SCMR 值显着降低，而 SCMR 值略有增加。根据多元线性回归表明，SLA（SD0）和 RWC（SD1 和 SD2）对块茎鲜重（TFW）有很大贡献，而 SC 在终端干旱下对 TFW 减少有很大贡献。主成分分析还证实，在三种灌溉处理下的 JA 育种材料中，LA、RWC 和 SLA 的多样性具有最大的贡献性状，其次是 HI、SCMR 和 SC。我们的发现强调 JA125（低 SLA）、HEL256 和 JA37（高 SLA）导致 SD0 下的 TFW 的高性能，并且它们通过执行中等 RWC 在 SD1 下表现出高 TFW。同样，JA4 和 JA37 在由中等 RWC 引起的 SD2 下具有高 TFW。HEL253 和 JA60 被确定为终端耐旱基因型，因为执行中等 SC，这有助于 TFW 的低减少。我们有希望的结果是进一步研究的基础，SLA、RWC 和 SC 是筛选耐旱性（低经济减产）的重要关键，这些研究的基因型可用于亲本系，通过不同持续时间的育种计划提高耐旱性后代终端干旱易发地区。