scholarly journals Ecophysiological Responses of two Xerophytes Atraphaxis frutescens and Elaeagnus angustifolia to the Change of Groundwater Depth in Arid Area I. Changes in Liaf Nutrient, Chlorophyll, Soluble Sugar and Starch Contents

2003 ◽  
Vol 27 (2) ◽  
pp. 228-234
Author(s):  
ZHAO Guang-Dong ◽  
LIU Shi-Rong ◽  
MA Quan-Lin
2002 ◽  
Vol 29 (7) ◽  
pp. 805 ◽  
Author(s):  
María Dolores Fernández ◽  
Wilmer Tezara ◽  
Elizabeth Rengifo ◽  
Ana Herrera

We evaluated the effects of an elevated [CO2] on photosynthesis and growth of cassava plants grown in open-top chambers with an adequate supply of water and N and a sufficient rooting volume. Cassava plants (Manihot esculenta Crantz. cv. Motilona) showed higher photosynthetic rates (Pn) when grown and measured at elevated [CO2] (680 µmol mol-1) than when grown and measured at ambient [CO2] (480 µmol mol-1). No downregulation of photosynthesis due to elevated [CO2] was found, since carboxylation efficiency increased after 220 d in spite of a decrease in leaf soluble protein, Rubisco, and leaf N content. Soluble sugar and starch contents decreased with time under elevated [CO2], the decrease in starch content coinciding with the beginning of the increase in root mass. Canopy Pn by leaf area decreased with time under elevated [CO2] but, when canopy Pn was expressed by ground area, higher and constant rates were observed, suggesting a higher productivity in plants grown at elevated [CO2]. The absence of differences between growth [CO2] in root : shoot ratio observed suggests that elevated [CO2], while causing increases in the shoot as well as the root, did not affect the pattern of biomass allocation. Acclimation responses of gas exchange parameters changed during the experiment. The absence of downregulation of photosynthesis was associated with a decrease in leaf sugar and starch contents of plants grown at elevated [CO2], which suggests a favourable source/sink relationship.


Forests ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 34 ◽  
Author(s):  
Xiaolong Zhang ◽  
Tianyu Guan ◽  
Jihua Zhou ◽  
Wentao Cai ◽  
Nannan Gao ◽  
...  

2020 ◽  
Author(s):  
Ji Qian ◽  
Juan Zhou ◽  
Bao Di ◽  
Yang Liu ◽  
Gang Zhang

Abstract Background Soluble sugar and starch, as carbon sources, directly participate in plant metabolism by providing energy. Conventional determination of plant starch and soluble sugar content usually involves destructive sampling, complicated procedures, and considerable amounts of chemicals and labor. Therefore, there is an urgent need to develop a non-destructive and rapid method for determining plant starch and soluble sugar contents. Electrical impedance tomography (EIT) technology has been used to determine the physiological state and cold resistance of plant tissues. However, so far there have been no reports on the use of EIT for the rapid estimation of soluble sugar and starch contents. Results In this study, EIT was used to obtain reconstructed voltage values and estimate starch and soluble sugar contents in the stems of three Rosa hybrida cultivars during February to May. Stems from two of the cultivars were used for establishing regression models for starch and soluble sugar contents as functions of reconstructed voltage values. The third cultivar was used to test the accuracy of the regression models. The results showed that the reconstructed voltage value significantly correlated with soluble sugar and starch contents. The quadratic regression model was best for determining soluble sugar content and the logarithmic regression model was best for determining starch content. Conclusions Thus, we preliminarily established and verified regression models for estimating soluble sugar and starch contents using reconstructed voltage values of rose stems. These data provide technical support for using EIT to analyze changes in physiological parameters and to rapidly estimate physiological indexes of plants.


2013 ◽  
Vol 14 (1) ◽  
pp. 15 ◽  
Author(s):  
Yudhistira Nugraha ◽  
Georgiana V. Vergara ◽  
David J. Mackill ◽  
Abdel Bagi Ismail

Two types of floods can be happen in rice crops, i.e. flash floods and  stagnant floods. Flash floods cause complete submergence for up to 2 weeks, while stagnant floods (SF) could partially submerge part of rice  plant. To overcome yield loss due to the floods, introgression of SUB1 gene, known as a gene suppressing cell elongation and carbohydrate  metabolism, to rice genotype can increase plant tolerance to complete submergence for 10 days or more. The study aimed to evaluate the response of 18 rice genotypes, including the recently developed sixth pair SUB1 near isogenic lines (NILs) of mega-rice varieties (Swarna, Sambha Mahsuri, IR64, TDK1, BR11, and CR1009), to various flooding conditions. The rice genotypes were planted at field ponds at Los Banos, Philippines, in the wet season (WS) of 2009. The treatments were 15 days  submergence, SF, SF follows submergence and normal conditions. Each treatment was arranged in completely randomized block design with three<br />replications. The results showed that the SUB1 introgression rice lines had higher survival compared to the non-SUB1 and did not much elongate their shoots during submergence. Nevertheless, under SF the rice genotypes should elongates their shoots to allow restoring contact with the air. SF and SF follows submergence decreased the panicle number, grain<br />number per panicle and panicle fertility. Consequently, the yield declined. It suggests that sensitive genotypes are mostly sourcelimited during grain filling. The SUB1 introgression lines had higher chlorophyll concentration and less depletion in soluble sugar and starch after submergence. Under SF, soluble sugar and starch contents between the SUB1 NILs and  non-SUB1 lines were not significantly different. Introgression of the SUB1 into high-yielding varieties improved submergence tolerance without affecting yield potential. The study indicates that introgression of the SUB1 into taller type rice varieties should be done to compensate the effect of suppressed elongation. <br />


Author(s):  
Long Yan ◽  
Min-jian Chen ◽  
Peng Hu ◽  
Di-li Li ◽  
Yong Wang

Abstract The West Liaohe Plain is a typical semi-arid area, where the process of rainfall infiltration to replenish groundwater is a key link in its vertical hydrological cycle. In this paper, we compare and analyze the impact upon soil moisture movement and water infiltration after the shift of irrigation method from flood irrigation to mulched drip irrigation under mulch through setting up in-field in-situ observation points and carrying out groundwater depth dynamic observation. The results show that compared with mulched drip irrigation under mulch, flood irrigation has a stronger response to rainfall infiltration and a quicker response time in the rise of underground depth. With the decrease of groundwater level, the effect of rainfall infiltration to replenish groundwater is significantly weakened. In the flood irrigation area, the groundwater depth at about 8 m already has no obvious response to a small amount of rainfall. However, the groundwater depth at 6 m in the area of mulched drip irrigation under mulch already has no response to rainfall. Therefore, when groundwater extraction is carried out in irrigation areas, reasonable groundwater extraction levels should be designated in light of different irrigation methods to maintain the sustainable utilization of groundwater.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yong Zeng ◽  
Chengyi Zhao ◽  
Fengzhi Shi ◽  
Michael Schneider ◽  
Guanghui Lv ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document