Characterizing leaf gas exchange responses of cotton to full and limited irrigation conditions     

Jonghan Ko  Giovanni Piccinni 《Field Crops Research》2009

Plant responses to water deficit need to be monitored for producing a profitable crop as water deficit is a major constraint on crop yield. The objective of this study was to evaluate physiological responses of cotton (Gossypium hirsutum) to various environmental conditions under limited water availability using commercially available varieties grown in South Texas. Soil moisture and variables of leaf gas exchange were measured to monitor water deficit for various varieties under different irrigation treatments. Lint yield and growth variables were also measured and correlations among growth parameters of interest were investigated. Significant differences were found in soil moisture, leaf net assimilation (A_n), stomatal conductance (g), transpiration rate (T_r), and instantaneous water use efficiency (WUE_i) among irrigation treatments in 2006 while no significant differences were found in these parameters in 2007. Some leaf gas exchange parameters, e.g., T_r, and leaf temperature (T_L) have strong correlations with A_n and g. A_n and WUE were increased by 30–35% and 30–40%, respectively, at 600 μmol (CO₂) m⁻² s⁻¹ in comparison with 400 μmol (CO₂) m⁻² s⁻¹. Lint yield was strongly correlated with g, T_r, WUE, and soil moisture at 60 cm depth. Relative A_n, T_r, and T_L started to decrease from FTSW 0.3 at 60 cm and FTSW 0.2 at 40 cm. The results demonstrate that plant water status under limited irrigation management can be qualitatively monitored using the measures of soil moisture as well as leaf gas exchange, which in turn can be useful for describing yield reduction due to water deficit. We found that using normalized A_n, T_r, and T_L is feasible to quantify plant water deficit.  相似文献   

辣椒光合特性研究   总被引：30，自引：2，他引：28  

霍振荣  庞金安 《华北农学报》1998,13(3):121-124

系统测定了辣椒的净光合速率及其日变化。结果表明,参试品种的净光合速率在１２－１４μｍｏｌＣＯ２．ｍ＾－２、ｓ＾－１之间,部分品种差异显著或极显著。不同叶位间净光合速率明显不同,幼叶净光合净速率较高,老叶净光合速率较低,健壮叶片净光合速率最高,光合速率日变化为双峰曲线,有明显的“午休”现象,造成光合“午休”的原因。在１０：００之后以非气孔限制因素为主。光量子通量密度明显影响辣椒净光合速率,光饱和点和  相似文献   

大棚黄瓜光合作用日变化及环境因素对光合作用的影响   总被引：16，自引：0，他引：16  

马德华  庞金安 《河北农业大学学报》1998,21(4):59-63

以长春密刺黄瓜为试材,对大棚黄瓜的光合作用规律进行了探讨。大棚黄瓜存在的明显的光合“午休”现象,中午叶温升高,大气湿度下降造成气孔导度下降是形成光合“休午”的外部原因。温度和光量子通道密度明显影响黄瓜的光合作用,其中光合适温为２８～３５℃光饱和点为１８００μｍｏｌ．ｍ＾－２．ｓ＾－１,补偿点为４５．７７６μｍｏｌ．ｍ＾－２．ｓ＾－１老叶的光饱和点补偿点均比健壮叶片低。适当提高白天棚温度,尽量增加加  相似文献   

短期亚适宜温光对黄瓜氮吸收运转相关酶活性和基因表达的影响   总被引：1，自引：0，他引：1  

姚娟  李衍素  郭允娜  贺超兴  闫妍  于贤昌 《园艺学报》2013,40(7):1289-1297

 以‘中农106’黄瓜为试材,对其进行不同温度和光照强度[正常温光25/15 ℃,光强（700 ±30）μmol · m^-2 · s^-1;亚适宜温光18/12 ℃,光强（200 ± 20）μmol · m^-2 · s^-1;低温弱光12/8 ℃,光强75 ~100 μmol · m^-2 · s^-1]处理,研究亚适宜温光条件对结果期黄瓜生长、生理特性和氮（N）吸收的影响。结果表明,与正常温光处理相比,亚适宜温光和低温弱光处理下黄瓜株高、叶面积、果实大小与产量均明显下降,根系活力、叶绿素含量、果实品质和谷氨酰胺合成酶（GS）、谷氨酸合成酶（GOGAT）、谷氨酸脱氢酶（GDH）活性也随处理温度和光照强度降低而降低。亚适宜温光条件下,结果期黄瓜根系、叶片、果实中N 含量均有所下降,亚适宜温光和低温弱光处理降低了结果期黄瓜N 运转蛋白基因的表达,且温度和光照强度越低,黄瓜根系、叶片和果实中N 运转蛋白基因表达量越低。说明亚适宜温光可能通过降低N 运转蛋白基因的表达,抑制了N 的吸收,降低N 含量,进而抑制了黄瓜生长。  相似文献