祁连圆柏和圆柏色素含量及其花青苷合成酶活性的季节性变化

以祁连圆柏（Sabina przewalskii）和圆柏（S.chinensis）为材料,测定2种植物花青苷、类黄酮、紫松果黄素、叶绿素和类胡萝卜素的含量及花青苷合成过程中关键酶苯丙氨酸解氨酶（PAL）和类黄酮糖基转移酶（UFGT）的活性,并分析了各值的季节性变化。结果表明,祁连圆柏和圆柏叶片中PAL及UFGT的活性、花青苷、类黄酮﹑紫松果黄素以及类胡萝卜素的含量在低温季节均明显高于其它季节;叶绿素含量在低温季节低于其它季节;并且祁连圆柏中花青苷含量及其合成酶PAL和UFGT的活性以及类黄酮、紫松果黄素和叶绿素含量始终高于圆柏。结果说明花青苷是圆柏属植物中具有抗冻特性的重要次生代谢物,是抵御低温和辐射胁迫的一种重要保护物质;紫松果黄素等色素对圆柏属植物抵抗低温诱导的光抑制起重要作用。     

冬季融冻过程中白三叶叶片抗氧化酶活力和渗透调节物含量变化与抗冻性的关系

入冬气温大幅变化引起的冻融既是抗冻植物抗冻力形成的重要阶段也是非抗冻植物大量死亡的主要原因,但是抗冻植物为何能在冬季融冻条件下生存的生理机理尚不清楚。以生长在烟台地区抗冻白三叶(Trifolium repens)为材料,分析研究了不同微生态环境下生长的白三叶在冬季融冻过程中叶片抗氧化物酶活性、渗透调节物含量、丙二醛和细胞膜透性的变化,以了解它们在白三叶抗冻中的作用。结果表明:在气温突然下降至零度以下(融-冻阶段),三样地白三叶叶片冻结,叶片细胞膜透性在经历短暂下降后迅速急剧增加2倍,MDA含量增加85%,叶片中脯氨酸和蛋白质含量、抗氧化酶(过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、过氧化物酶(POD))活力增加。在气温上升至日均温零度以上(冻-融阶段), 叶片开始融化,白三叶叶片膜透性、丙二醛和脯氨酸含量、POD和CAT活力先增加后降低,SOD活力和蛋白质含量持续增加。由此可见,快速增强的抗氧化物酶活力和快速增加的渗透调节物及时清除氧自由基防止细胞内膜脂过氧化保护了细胞膜的完整性而使细胞能在冷冻条件下生存,这可能是白三叶能在反复融冻过程中正常生长的重要生理机理。     

外源水杨酸对低温胁迫下圆柏属植物幼苗生理特性的影响

以3年生圆柏和祁连圆柏幼苗为材料,采用不同浓度水杨酸(SA)预处理两种圆柏属植物幼苗,测定-4℃低温胁迫处理第6天叶片相对含水量(RWC)、相对电导率(REC)、丙二醛(MDA)、可溶性糖(SS)、可溶性蛋白(SP)、脯氨酸(Pro)和类胡萝卜素(Car)含量及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸氧化酶(APX)和谷胱甘肽还原酶(GR)活性,分析外源 SA 对低温胁迫下圆柏属植物叶片膜脂过氧化、渗透调节物质及抗氧化酶系统的影响,为培育较多品种的抗冷冻常绿植物提供理论依据。结果表明：低温胁迫下,一定浓度的 SA 预处理能有效保护幼苗叶片膜系统的稳定性、增加渗透调节物质含量和提高抗氧化酶活性,其中200 mg/L SA 预处理对提高圆柏抗寒性效果最好,30 mg/L SA 预处理对提高祁连圆柏抗寒性效果最好,且在外源 SA 预处理下,祁连圆柏的抗寒性比圆柏的强。因此,施用适合浓度的 SA 在提高圆柏属植物抗寒性方面具有较好的应用价值。     

栀子叶片生理特性与抗寒性的关系

以低温半致死温度(LT50)为评价指标,研究自然降温过程中栀子(Gardenia jasminoides Ellis)叶片生理特性与抗寒性的关系. 结果表明, 随气温的降低, 栀子叶片的 LT50不断降低, 由秋季9月中旬的-4.99℃降到冬季最冷 1月中旬的-8.42℃,同时叶片相对含水量、自由水和淀粉含量均不同程度下降,束缚水、可溶性糖和可溶性蛋白质含量增加.这些渗透调节物含量的适应性变化导致LT50的下降.栀子的抗寒性与气温密切相关.     

祁连圆柏和圆柏色素含量及其花青苷合成酶活性的季节性变化

以祁连圆柏(Sabina przewalskii)和圆柏(S. chinensis)为材料, 测定2种植物花青苷、类黄酮、紫松果黄素、叶绿素和 类胡萝卜素的含量及花青苷合成过程中关键酶苯丙氨酸解氨酶(PAL)和类黄酮糖基转移酶(UFGT)的活性, 并分析了各值的季节性变化。结果表明, 祁连圆柏和圆柏叶片中PAL及UFGT的活性、花青苷、类黄酮﹑紫松果黄素以及类胡萝卜素的含量在低温季节均明显高于其它季节; 叶绿素含量在低温季节低于其它季节; 并且祁连圆柏中花青苷含量及其合成酶PAL和UFGT的活性以及类黄酮、紫松果黄素和叶绿素含量始终高于圆柏。结果说明花青苷是圆柏属植物中具有抗冻特性的重要次生代谢物,是抵御低温和辐射胁迫的一种重要保护物质; 紫松果黄素等色素对圆柏属植物抵抗低温诱导的光抑制起重要作用。     

干旱胁迫对甘草幼苗生长和渗透调节物质含量的影响

采用人工控制水分模拟干旱的处理方法,研究了干旱胁迫对甘草幼苗生长状况、水分状况和主要渗透调节物质含量的影响.结果显示:轻度干旱胁迫有利于甘草幼苗根系生长,植株根冠比加大.干旱胁迫下甘草根叶组织中相对含水量下降,束缚水/自由水升高.甘草幼苗组织中渗透调节物质可溶性蛋白、游离脯氨酸、可溶性糖含量在干旱胁迫下也均显著增加;且...     

内蒙古高原不同生境条件下甘蒙锦鸡儿水分调节特性和抗逆性的比较研究

对分布于内蒙古和林格尔（半干旱地区）和阿拉善（强干旱地区）地区的甘蒙锦鸡儿种群水分调节特性和抗逆性进行了比较研究.结果表明,阿拉善种群比和林格尔种群的叶片渗透调节物质含量高、渗透势低、渗透调节能力强,叶片含水量和自由水含量低、束缚水含量和束缚水/自由水比值高,叶水势和气孔导度低,表明阿拉善种群比和林格尔种群有更强的水分调节能力.阿拉善种群丙二醛(MDA)含量大于和林格尔种群,但细胞膜相对透性和超氧自由基含量小于和林格尔种群,表明阿拉善种群自由基清除能力强、细胞膜稳定性高.有效的水分调节能力和较强的抗逆性是甘蒙锦鸡儿适应干旱环境的重要生理基础.     

C的海拔响应及其机理

以分布于祁连山北麓中段的两种优势乔木祁连圆柏(Sabina przewalskii)和青海云杉(Picea crassifolia)为研究对象, 分析了高山乔木叶片δ¹³C值对海拔(2 600–3 600 m)、土壤含水量和叶片含水量、叶片碳氮含量的响应及其机理。结果表明, 这两种乔木叶片δ¹³C值均随海拔升高呈增重趋势, 与海拔呈显著正相关关系(p < 0.000 1)。海拔2 600–3 600 m阳坡树种祁连圆柏叶片的δ¹³C值显著高于同海拔梯度阴坡树种青海云杉。祁连圆柏和青海云杉叶片的δ¹³C值均与年平均气温呈显著负相关关系(p < 0.000 1), 与年平均降水量呈显著正相关关系(p < 0.000 1)。祁连圆柏叶片δ¹³C值与土壤含水量(p < 0.000 1)、叶片含水量(p = 0.01)和叶片碳氮比(C/N) (p < 0.000 1)呈显著正相关关系, 与叶片全氮呈显著负相关关系(p < 0.000 1)。而青海云杉叶片δ¹³C值与土壤含水量、叶片全氮、叶片碳氮比和叶片含水量不相关。说明海拔变化引起的水热条件的改变, 尤其是温度变化对高山乔木叶片碳同位素分馏起主要作用, 但各个因子综合对高山植物叶片碳同位素分馏的作用机制可能比较复杂, 需进一步深入研究。     

酸枣叶对土壤水分的生理生化响应

酸枣(Ziziphus jujuba var.spinosa)分布广、适应性强、极耐旱,是研究植物响应干旱气候的优良试验材料。通过覆膜技术控制酸枣根系附近土壤水分含量,研究了不同土壤水分条件对酸枣叶片组织含水量、叶绿素含量、丙二醛、可溶性糖含量等生理生化指标的影响,以期探明酸枣适应干旱的生理机制。结果显示：随着土壤含水量的降低,处理组酸枣叶片的相对含水量与绝对含水量均降低,但都保持在较高水平,与对照相比,差异显著（p<0.05）;自然饱和亏呈下降趋势且维持在较低水平,较对照差异均显著（p<0.05）;随着土壤水分的减少,处理组酸枣叶片较对照组组织水势和渗透势减小（p<0.05）,较对照差异显著（p<0.05）,吸水能力提高;处理组酸枣叶片的叶绿体色素含量随土壤干旱程度的加深,均表现为低于对照且逐渐减少（p<0.05）;随着处理时间的延长,处理组与对照组相比,电导率随之增大,MDA含量也随之升高,质膜受到损伤;处理组酸枣叶片中渗透调节物质可溶性糖含量和游离脯氨酸含量均有不同程度的增加,平均增幅为1.29、1.5倍。结果表明,酸枣叶片在不同的土壤水分条件下,具有积极的生理响应方式,适应性强,具有较强的抗旱耐旱能力。     

干旱胁迫下白桦（Betula plathphylla）实生苗叶片的水分代谢与部分渗透调节物质的变化

在土壤干旱胁迫进程中,白桦实生苗叶片的自然含水量呈下降趋势;相对含水量的总的变化趋势与自然含水量相同;束缚水含量及束缚水/自由水比值显著升高,复水后,三者又重新恢复至正常水平。随着土壤水分逐渐减少,可溶性蛋白质的含量呈现减少趋势,复水后,可溶性蛋白质含量又可恢复至正常水平。白桦实生苗叶片可溶性糖含量增加,复水后可溶性糖含量降至趋于对照水平。     

低温胁迫对两种圆柏属植物亚细胞抗氧化酶活性的影响

以祁连圆柏和圆柏幼苗为材料,研究不同处理时间下低温胁迫对圆柏属植物叶片亚细胞抗氧化酶活性的影响,探讨其在圆柏属植物叶片中的亚细胞定位。结果表明：低温胁迫下,丙二醛(MDA)含量和抗氧化酶活性随时间变化均呈先升后降趋势,祁连圆柏中抗氧化酶的种类比圆柏的多且活性强,而 MDA 含量低于圆柏,表明祁连圆柏在低温胁迫下具有更广泛的适应性。此外,两种圆柏植物叶片超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)定位为叶绿体＞细胞溶质＞线粒体,过氧化氢酶(CAT)定位为线粒体＞叶绿体＞细胞溶质,谷胱甘肽还原酶(GR)定位为线粒体＞细胞溶质＞叶绿体,祁连圆柏过氧化物酶(POD)定位为细胞溶质＞叶绿体＞线粒体,圆柏POD定位为细胞溶质＞线粒体＞叶绿体,且抗氧化酶SOD、APX和 GR在亚细胞中分布差异达到极显著,这说明抗氧化酶在其中一种亚细胞中发挥主要作用,为克隆亚细胞组分中的抗氧化酶基因提供了理论依据。     

Response of stem sap flow and leaf photosynthesis in <Emphasis Type="Italic">Tamarix chinensis</Emphasis> to soil moisture in the Yellow River Delta,China

Soil moisture is the main limiting factor for vegetation growth at shell ridges in the Yellow River Delta of China. The objective of this study was to explore the soil moisture response of photosynthetic parameters and transpiration in Tamarix chinensis Lour., a dominant species of shell ridges. Leaf photosynthetic light-response parameters and sap flow were measured across a gradient of relative soil water content (RWC), from drought (23%) to waterlogging (92%) conditions. Leaf photosynthetic efficiency and stem sap flow of T. chinensis showed a clear threshold response to soil moisture changes. Leaf net photosynthetic rate, water-use efficiency (WUE), light-saturation point, apparent quantum yield, maximum net photosynthetic rate, and dark respiration rate peaked at moderately high RWC, decreasing towards high and low values of RWC. However, peak or bottom RWC values substantially differed for various parameters. Excessively high or low RWC caused a significant reduction in the leaf photosynthetic capacity and WUE, while the high photosynthetic capacity and high WUE was obtained at RWC of 73%. With increasing waterlogging or drought stress, T. chinensis delayed the starting time for stem sap flow in the early morning and ended sap flow activity earlier during the day time in order to shorten a daily transpiration period and reduce the daily water consumption. The leaf photosynthetic capacity and WUE of T. chinensis were higher under drought stress than under waterlogging stress. Nevertheless, drought stress caused a larger reduction of daily water consumption compared to waterlogging, which was consistent with a higher drought tolerance and a poor tolerance to waterlogging in this species. This species was characterized by the low photosynthetic capacity and low WUE in the range of RWC between 44 and 92%. The RWC of 49–63% was the appropriate range of soil moisture for plant growth and efficient physiological water use of T. chinensis seedlings.     

Seasonal changes in anthocyanin contents and in activities of xanthophyll and ascorbate–glutathione cycles in Sabina species derived from different environments

Qilian Juniper (Sabina przewalskii Kom.) and Chinese juniper [Sabina chinensis (Lin.) Ant.] are overwintering plants. S. przewalskii, a protected species in China, is distributed in subalpine and alpine area on the Qinghai-Tibet Plateau. S. chinensis is distributed in plain area. We investigated seasonal changes in photoprotective stress compounds such as anthocyanins, activities of three enzymes of ascorbate–glutathione pathway, as well as xanthophyll size and conversion in these species. Ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) levels were higher in the low-temperature months, which was associated with changes in anthocyanins and in de-epoxidation index [(A + Z)/(V + A + Z)]. Photochemical efficiency of PSII (Fv/Fm) was lower (<0.70) during winter and late autumn in both species. During the low-temperature months, S. przewalskii had higher levels of photoprotective stress compounds than S. chinensis. The results suggested that these two species possess cold-induced photoinhibition functions and show the inherent, season-dependent differences in the amounts of the stress-related compounds.     

内蒙古科尔沁沙地两种沙生植物冷蒿和差不嘎蒿竞争策略的生理生态学依据(英文)

Gas exchange, water relations and leaf chemical characteristics were examined of twodominant psammophytes: Artemisia frigida Willd and A halodendron Turcz. ex Bess in Horqin sandy land, NeiMongol, China under different water regimes. The measurements were conducted by submitting the plantsto five different irrigation levels. A. fTigida was characterized by lower photosynthetic rate (Pn), lowertranspiration rate ( TR and lower shoot water potential (ψuw) relative to A. halodendron. Foliage of A frigdahad higher values of relative water deficit (RWD), bound water content (BWC), ratio of bound water contentto free water content (BWC/FWC) and integrated drought-resistant index (DI than that of A. halodendron.Water relations differed significantly between two species in response to soil water availability. ψw, BWCand BWC/FWC ratio of A halodendron exhibited large variation with gradual decrease of soil moisture.However, in terms of these parameters, A. fRIGIDA was characterized by higher capacity of water holding anddrought tolerance relative to A halodendron. Proline and total soluble sugar contents of A frigida and Ahalodendron tended to increase with decrease of soil moisture and the former had a larger increaseamplitude than the latter. This shows that A frigida has a higher osmotic regulation ability than A halodendron.Under the extreme drought conditions, ψw, RWD, BWC and BWC/FWC of two species were approximate,but soluble proteins degraded largely. A large amount of accumulation of organic matter, proline and totalsoluble sugars were observed in both A halodendron and A frigida. The increase in proline and total solublesugar contents and soluble protein degradation of A frigida far exceeded those of A. halodendron. Webelieve that the accumulated materials at this moment are mostly of nutrient substances available for therecovery of plants after the drought. This is one of the reasons why A halodendron plants died while Afrigida plants survived under extremely drought condition. Our results suggest that these ecophysiologicalfeatures of A frigida are favorable to its growth in the fixed sandy land compared with A halodendron, whichoften lost its dominance due to weak competition for water sources under lower soil water availability andare major factors resulting in replacement of A. halodendron by A. frigida in the later stage of sandyvegetation succession in Horqin.     

内蒙古科尔沁沙地两种沙生植物冷蒿和差不嘎蒿竞争策略的生理生态学依据

研究了中国内蒙古科尔沁沙地两种优势灌木冷蒿(Artemisiafrigida Willd)和差不嘎蒿(Artemisia halodendronTurcz.ex Bess)在不同土壤水分状况条件下的气体交换、水分关系和叶片的化学特性.测定设置了5个土壤水分梯度:土壤最大含水量(体积含水量,30%)、田间持水量(对照,20%)、轻度水分胁迫(10%)、极端干旱(＜4%)和旱后复水(20%).冷蒿的净光合速率(Pn)、蒸腾速率(TR)和水势(ψw低于差不嘎蒿,相对水分亏缺(RWD)、束缚水含量(BWC)、束缚水与自由水的比值(BWC/FWC)和综合抗旱性指数(DI)高于差不嘎蒿.两种灌木对不同土壤含水量的响应不同,随着土壤含水量的逐渐下降,差不嘎蒿的ψw、BWC和BWC/FWC出现大幅度的波动,波动幅度远远的大于冷蒿,冷蒿则显示了一个较差不嘎蒿高的持水能力和抗旱能力.冷蒿和差不嘎蒿的脯氨酸和总可溶性糖含量随土壤含水量的降低均呈增加的趋势,冷蒿增加的幅度大于差不嘎蒿,说明冷蒿的渗透调节能力在干旱过程中有较大提高.在长期极端干旱条件下,两种灌木的ψw,RWD,BWC和BWC/FWC的终极值相近;有机物、脯氨酸和总可溶性糖含量大量累积;冷蒿的脯氨酸和总可溶性糖含量增加的幅度和可溶性蛋白质降解的幅度远远超过差不嘎蒿;我们认为此时累积的物质主要作为营养物质,以供植物的旱后恢复,此时冷蒿的恢复能力超过差不嘎蒿,这是极端干旱条件下差不嘎蒿死亡而冷蒿存活的主要原因之一.我们的研究结果显示,相对于差不嘎蒿而言,冷蒿在水分胁迫条件下的生理生态学特性更有利于其在固定沙地的生长,差不嘎蒿则由于对水资源微弱的竞争丧失了生存优势,是引起科尔沁沙地植被演替过程中冷蒿替代差不嘎蒿的主要原因.     

Seasonal changes in non-structural carbohydrates and sucrose metabolism enzymes in two Sabina species

Evergreen plants need to store reserves to allow for their survival during the winter months and for new leaf growth in the following spring. In many of the tree species, these reserve functions are mainly carried out by starch, which is degraded to soluble carbohydrates during the dormant season to maintain active respiration and provide protection against freezing. In the present study, two evergreen woody plants, S. przewalskii Kom. (SP) and S. chinensis (Lin.) Ant.(SC), were used to investigate the patterns of seasonal variation in the concentrations of soluble sugars, sucrose, fructose and starch, and the activities of sucrose-phosphate synthase (SPS), sucrose synthase (SUSY), neutral invertase (NI) and soluble acid invertase (SAI). Foliar soluble sugar, sucrose, fructose, and starch concentrations were markedly higher in SC than in SP; moreover, the activities of SPS, SUSY, NI and SAI were also higher in SC than in SP. There were generally higher concentrations of soluble sugars, sucrose and fructose and SPS activities in the winter than in the summer for both Sabina trees, which was consistent with the necessity for protection against freezing; however, opposite results were found with regards to starch concentrations and the activities of SUSY, NI and SAI. In contrast with the activities of SUSY, NI and SAI, the negative correlation observed between SPS and air temperature was likely a reflection of its crucial role in the acquisition of freezing tolerance by sucrose metabolism in the winter. These results suggest that higher carbon reserves do not give S. chinensis (Lin.) Ant. a competitive advantage in tolerating cold temperatures and that only SPS, but not SUSY, NI and SAI, may play a positive role in freezing tolerance by increasing soluble sugar.     

CaCl2对金叶女贞茎抗寒性和电阻抗图谱参数的影响

为探明CaCl₂处理对金叶女贞(Ligustrum vicaryi)茎抗寒性和电阻抗图谱参数的影响,找出抗寒性和电阻抗图谱参数的关系,2006年9月15日开始对金叶女贞当年生扦插苗进行CaCl₂处理,对照为清水;分别用电阻抗图谱法和电导法估测其抗寒性,并进行比较分析。结果表明：CaCl₂处理能在抗寒锻炼初期使金叶女贞茎的抗寒性提高3.5℃,金叶女贞茎的抗寒性与未冷冻处理茎的弛豫时间τ、冷冻处理后茎的胞外电阻率r_e、含水量之间均存在较高的相关性。     

南方红豆杉生长发育及其紫杉醇含量与环境因子的关系

研究了人工种植的3年生南方红豆杉的生长发育特征及其枝叶中紫杉醇的含量,并观测了其生长环境因子的动态特征。通过对南方红豆杉的生长发育特征以及其枝叶中紫杉醇含量与生长环境因子进行相关分析发现,南方红豆杉生长发育与空气和土壤湿度呈极显著的正相关,与空气和土壤温度、土壤N和K含量、土壤有机质和土壤紧实度呈正相关,与净辐射和土壤P含量呈负相关,但相关关系不显著,说明高温、高湿以及遮荫有利于南方红豆杉的生长,且对土壤P含量有较高需求;南方红豆杉枝叶中紫杉醇含量与空气和土壤湿度、土壤N、P和K含量呈负相关,与净辐射、空气和土壤温度、土壤有机质和土壤紧实度呈正相关,但相关关系均不显著,说明高温、高光强和干旱促进南方红豆杉枝叶中紫杉醇含量的增加,且紫杉醇含量的增加对土壤中N、P和K含量有一定的需求,尤其是N和K,对P需求不大;南方红豆杉生长发育与其枝叶中紫杉醇含量呈负相关,相关关系也不显著,推测紫杉醇可能是南方红豆杉的防御物质,以促使南方红豆杉抵御高温、干旱和高光强等不良环境。     

Responses of pigmentation and δ13C in Qilian juniper to cold and drought stresses under natural conditions in the Qilian Mountains,China

The seasonal changes of pigments and stable carbon isotope composition (δ¹³C values) were investigated in needles of Qilian juniper (Sabina przewalskii Kom.) from two typical sites, one drier and the other wetter, in the Qilian Mountains, China. The anthocyanins and rhodoxanthin content from both sites were much higher in winter than in summer. Plant needles contained more carotenoids and xanthophylls in winter at the wetter site, while no seasonal difference appeared at the drier site. However, lower chlorophyll content and higher proline and δ¹³C were observed at the drier site. Average tree height was shorter at the drier site trees than at the wetter site. Our results suggested that under natural conditions, pigmentation in S. przewalskii may serve to improve the energy balance of the photosynthetic apparatus under cold and drought stresses. Proline and δ¹³C could be used as drought indicators for S. przewalskii.     

Evolution mechanism of non-hydraulic root-to-shoot signal during the anti-drought genetic breeding of spring wheat

The objectives of this study were to: (1) characterize the evolutional tendency of the non-hydraulic root-sourced signal (NRS) from wheat wild relatives to its modern hexaploid species, and (2) test whether species sensitivity to the NRS was allied with their drought tolerance profiles. The NRS was judged to begin when there was a significant lowering of stomatal conductance without change in leaf relative water content (RWC). The lethal soil water content (LSWC) was operationally characterized as the soil water content (SWC) at the drying lethal point of wheat plants. The threshold of soil water content (TSWC) at which the NRS was triggered, and the LSWC differed amongst six wheat species. For “MO1” and “MO4” representing ‘diploid’ species, the TSWC and the LSWC were initiated successively at about 51% FWC (field water capacity) and about 30% FWC, respectively. Conversely, “Plateau 602” and “Longchun 8139-2” (modern hexaploid species) exhibited the TSWC and the LSWC between about 68% FWC and less than 14% FWC, a much wider threshold range (TR). Increasing TSWC was significantly correlated with decreasing LSWC (r = 0.9464^**). The widened TR from the TSWC to the LSWC was also significantly correlated with longer survival days (SD) and higher maintenance ratio of grain yield (MRGY), respectively (r = 0.9411^** and 0.8068^*, respectively). Meanwhile, those species having higher TSWC had the least reduction ratio of stomatal conductance under the decreasing soil moisture from −0.2 to −1 MPa. This suggests that advances in yield performance and drought tolerance would be made evolutionally by targeted selection for an earlier onset of NRS.