scholarly journals Water Transfer in a Papaya/Corn Split-root Culture System

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 476C-476
Author(s):  
Thomas E. Marler ◽  
Haluk M. Discekici

`Honey Jean #3' sweet corn was planted in one-half of a split-root culture system containing `Tainung 1' or `Known You 1' papaya seedlings to determine if papaya roots could transfer water to the corn seedlings. After the corn seedlings were established, water was withheld from both compartments (2/2) or only the compartment containing the corn seedlings (1/2). Control plants were grown with both halves well-watered. Pre-dawn relative water content (RWC) of corn leaves was measured as an indicator of drought stress. Following 11 days, root competition was relieved in half of the 1/2 plants by cutting the papaya root connection between the half with corn from the rest of the papaya culture system. RWC of 1/2 corn plants was maintained above that of 2/2 plants, but below that of control plants. After relieving root competition, the 1/2 plants in competition with papaya roots maintained higher RWC than the 1/2 plants relieved of competition. Leaf tissue of all corn plants except the control plants was necrotic by 30 days. The results indicate that development of drought stress in corn using this culture system was retarded by watering a portion of the papaya roots not associated with the corn roots. Drought stress was accelerated by relief of competition with papaya, which is evidence that water was being supplied by the papaya roots within the papaya/corn system.

Plant Disease ◽  
1997 ◽  
Vol 81 (2) ◽  
pp. 228-228 ◽  
Author(s):  
R. Sdoodee ◽  
D. S. Teakle ◽  
R. Louie

Maize stripe tenuivirus (MStV) and its planthopper vector, Peregrinus maidis, occur in many tropical and subtropical regions worldwide (2). However, MStV has not been reported from the southeastern Asia continent. In January 1990, five of 200 Sorghum bicolor plants growing in Hat Yai, Thailand, showed symptoms typical of MStV, i.e., chlorotic spots, streaks, and wide bands on the younger leaves. Colonies of P. maidis also were present in leaf whorls of both symptomatic and asymptomatic sorghum plants. In December 1991, two sweet corn plants (Zea mays cv. Thai Super Sweet Composite 1 DMR) growing in the same area showed similar symptoms and were infested with P. maidis. When examined by phase-contrast microscopy, sap from chlorotic leaf tissue of one sweet corn plant had needle-shaped crystals typical of MStV infection (1). Sap from asymptomatic sweet corn plants had no crystals. In April 1996. maize cv. Chieng Mai 90 with MSt-like symptoms and also infested by P. maidis was collected from Hat Yai. Leaves were freeze dried, sent to Ohio, and tested by F(ab′)2 enzyme-linked immunosorbent assay (ELISA). Positive control samples were fresh or freeze-dried leaves of sweet corn infected with MStV from Australia, Costa Rica, Malawi, Mauritius. and the U.S. Leaves of asymptomatic glasshouse-grown sweet corn seedlings were negative controls. In the ELISAs, the OD values at A 405 of the Thailand sample with MStV symptoms was 1.00, compared with 0.33 to 1.52 for the positive control samples and 0.00 to 0.02 for fresh or freeze-dried negative controls. The microscopic and serological results indicate the occurrence of MStV in Thailand. References: (1) O. E. Bradfute and J. H. Tsai. Phytopathology 80:715, 1990. (2) R. E. Gingery et al. J. Gen. Virol. 64:1765, 1983.


2020 ◽  
Vol 20 (2) ◽  
Author(s):  
Datik Lestari

ABSTRAKPenelitian ini bertujuan untuk mempelajari pengaruh cekaman kekeringan dan dosis pupuk K serta interaksinya terhadap fisiologis dan pertumbuhan pada tanaman jagung manis. Penelitian ini dilaksanakan di rumah kaca Jurusan Agroteknologi Fakultas Pertanian Universitas Riau dari bulan September hingga November 2017. Penelitian dilakukan menggunakan rancangan acak lengkap (RAL) dengan 2 fakor yaitu cekaman kekeringan dan pupuk K dengan 3 ulangan. Faktor  pertama yang terdiri dari 2 taraf antara lain: A1 = normal dan A2 = cekaman kekeringan. Faktor kedua terdiri dari empat taraf yaitu : K1 = 120 kg K2O ha-1, K2 = 150 kg K2O ha-1 dan K3 = 180 kg K2O ha-1. Hasil sidik ragam berbeda nyata maka dilanjutkan dengan menggunakan uji BNJ pada taraf 5%. Parameter yang diamati terdiri dari faktor fisiologis yaitu kandungan klorofil umur 30 HST dan 60 HST serta kadar prolin. Faktor pertumbuhan terdiri dari volume akar, berat basah dan berat kering tanaman. Hasil penelitian menunjukkan bahwa cekaman kekeringan menurunkan parameter fisiologis dan pertumbuhan tanaman kecuali kadar prolin. Pemberian pupuk K meningkatkan kandungan klorofil tanaman umur 30 HST dan volume akar. Interaksi cekaman kekeringan dengan pemberian pupuk K tidak meningkatkan fisiologis dan pertumbuhan tanaman jagung manis.  Kata kunci: Cekaman kekeringan, pupuk K dan tanaman jagung manis.


2017 ◽  
Vol 6 (06) ◽  
pp. 5399 ◽  
Author(s):  
Neelima Singh* ◽  
B. P. Shinde

This study was carried out to investigate the effect of drought stress on biochemical contents of sweet corn cultivars. The plants of sweet corn were grown in pots without mycorrhiza and with mycorrhiza i.e. control and experimental. The pots were placed under shade net and watered with normal water for one month at an interval of 4 days. The water stress treatment was started after one month at an interval of 4, 8 and 12 days. The biochemical analysis was carried out from leaves and kernels of sweet corn plants. The amount of chlorophyll, protein and starch has been decreased significantly due to increase in drought stress. The amount of proline and carbohydrates has been increased significantly with the increase in drought stress. However, these contents were more in mycorrhizal plants as compared to control plants. The results indicated that AM symbiosis alleviates the toxic effect of drought stress via improving water status of plants.


2021 ◽  
Vol 13 (5) ◽  
pp. 2923
Author(s):  
Botir Khaitov ◽  
Munisa Urmonova ◽  
Aziz Karimov ◽  
Botirjon Sulaymonov ◽  
Kholik Allanov ◽  
...  

Water deficiency restricts plant productivity, while excessive soil moisture may also have an adverse impact. In light of this background, field trials were conducted in secondary saline soil (EC 6.5 dS m−1) at the experimental station of Tashkent State Agrarian University (TSAU), Uzbekistan to determine drought tolerance of licorice (Glycyrrhiza glabra) by exposure to four levels of water deficit, namely control (70–80%), moderate (50–60%), strong (30–40%) and intense (10–20%) relative water content (WC) in the soil. The moderate drought stress exhibited positive effects on the morphological and physiological parameters of licorice, and was considered to be the most suitable water regime for licorice cultivation. Plant growth under the 50–60% WC treatment was slightly higher as compared to 70–80% WC treatment, exhibiting weak water deficit promotes licorice growth, root yield and secondary metabolite production. In particular, secondary metabolites i.e., ash, glycyrrhizic acid, extractive compounds and flavonoids, tended to increase under moderate water deficit, however further drought intensification brought a sharp decline of these values. These results contribute to the development of licorice cultivation technologies in arid regions and the most important consideration is the restoration of ecological and economical functions of the dryland agricultural system.


2007 ◽  
Vol 34 (7) ◽  
pp. 589 ◽  
Author(s):  
Tuan Ngoc Le ◽  
Cecilia K. Blomstedt ◽  
Jianbo Kuang ◽  
Jennifer Tenlen ◽  
Donald F. Gaff ◽  
...  

The desiccation tolerant grass Sporobolus stapfianus Gandoger can modulate cellular processes to prevent the imposition of irreversible damage to cellular components by water deficit. The cellular processes conferring this ability are rapidly attenuated by increased water availability. This resurrection plant can quickly restore normal metabolism. Even after loss of more than 95% of its total water content, full rehydration and growth resumption can occur within 24 h. To study the molecular mechanisms of desiccation tolerance in S. stapfianus, a cDNA library constructed from dehydration-stressed leaf tissue, was differentially screened in a manner designed to identify genes with an adaptive role in desiccation tolerance. Further characterisation of four of the genes isolated revealed they are strongly up-regulated by severe dehydration stress and only in desiccation-tolerant tissue, with three of these genes not being expressed at detectable levels in hydrated or dehydrating desiccation-sensitive tissue. The nature of the putative proteins encoded by these genes are suggestive of molecular processes associated with protecting the plant against damage caused by desiccation and include a novel LEA-like protein, and a pore-like protein that may play an important role in peroxisome function during drought stress. A third gene product has similarity to a nuclear-localised protein implicated in chromatin remodelling. In addition, a UDPglucose glucosyltransferase gene has been identified that may play a role in controlling the bioactivity of plant hormones or secondary metabolites during drought stress.


2022 ◽  
Vol 23 (2) ◽  
pp. 686
Author(s):  
Sifan Sun ◽  
Xu Li ◽  
Shaopei Gao ◽  
Nan Nie ◽  
Huan Zhang ◽  
...  

WRKY transcription factors are one of the important families in plants, and have important roles in plant growth, abiotic stress responses, and defense regulation. In this study, we isolated a WRKY gene, ItfWRKY70, from the wild relative of sweet potato Ipomoea trifida (H.B.K.) G. Don. This gene was highly expressed in leaf tissue and strongly induced by 20% PEG6000 and 100 μM abscisic acid (ABA). Subcellar localization analyses indicated that ItfWRKY70 was localized in the nucleus. Overexpression of ItfWRKY70 significantly increased drought tolerance in transgenic sweet potato plants. The content of ABA and proline, and the activity of SOD and POD were significantly increased, whereas the content of malondialdehyde (MDA) and H2O2 were decreased in transgenic plants under drought stress. Overexpression of ItfWRKY70 up-regulated the genes involved in ABA biosynthesis, stress-response, ROS-scavenging system, and stomatal aperture in transgenic plants under drought stress. Taken together, these results demonstrated that ItfWRKY70 plays a positive role in drought tolerance by accumulating the content of ABA, regulating stomatal aperture and activating the ROS scavenging system in sweet potato.


Genetika ◽  
2012 ◽  
Vol 44 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Ahmad Golparvar

Mode of gene action, heritability and determination of the effective breeding strategy for improvement of physiological and traits specifically in drought stress conditions is very important. Therefore, this study was conducted by using two drought susceptible and tolerant wheat cultivars. Cultivars Sakha8 (tolerant) and Pishtaz (susceptible) as parents along with F1, F2, BC1 and BC2 generations were sown in a randomized complete block design with three replications in drought stress conditions. Results of analysis of variance indicated significant difference between generations as well as degree of dominance revealed over-dominance for the both traits. Fitting simple additive-dominance model designated that this model was not able to account for changes of traits relative water content and mean of grain filling rate. It was revealed that m-d-h-i-j model for relative water content and m-d-h-i model for mean of grain filling rate are the best models. Estimation of heritability and mode of gene action indicated that selection for improvement of traits studied in stress condition and specifically in early generations have medium genetic gain. In conclusion, grain filling rate is better than relative water content as indirect selection criteria to improve plant grain yield in drought stress condition.


2019 ◽  
Vol 18 (6) ◽  
pp. 75-84
Author(s):  
Alireza Motallebi-Azar ◽  
István Papp ◽  
Anita Szegő

Dehydrins are proteins that play a role in the mechanism of drought tolerance. This study aimed at establishing dehydrin profile and accumulation in four local melon varieties of Iran: Mino, Dargazi, Saveii, and Semsori, as well as in a commercial variety Honeydew. Plants were treated with drought stress by adjusting the soil water content to 75, 50, 40, 30 and 20% of field capacity (FC) by withholding water. Water status of plants was monitored based on the seedling fresh weight (FW) and relative water content of leaves (RWC). Total protein content was extracted, then heat-stable protein (HSP) fraction was isolated for each variety and water stress treatment. After SDS-PAGE of HSP, Western blotting analysis was carried out with Anti-dehydrin rabbit (primary) and Goat anti rabbit (secondary) antibodies. ANOVA results showed that with decreasing FC below 75%, FW and RWC decreased, but these changes significantly varied among genotypes. On the basis of FW and RWC data under different drought stress treatments, the following drought-tolerant ranking was established: Mino > Dargazi > Saveii and Honeydew > Semsori, from tolerant to sensitive order. Results of Western blot analysis showed that expression of some proteins with molecular weights of 19–52 kDa was induced in the studied varieties under drought stress (% FC). Expression level of the dehydrin proteins in different varieties was variable and also depending on the drought stress level applied. However, dehydrin proteins (45 and 50 kDa) showed strong expression levels in all varieties under severe drought stress (20% FC). The abundance of dehydrin proteins was higher in tolerant varieties (Mino and Dargazi) than in moderate and drought sensitive genotypes. Consequently, dehydrins represent a potential marker for selection of genotypes with enhanced drought tolerance.


2020 ◽  
Author(s):  
zahra khazaei ◽  
Asghar Estaji

Abstract Background: Drought is also one of the most widespread abiotic stresses that adversely effects the growth and development of plants. To investigate the effect of salicylic acid and drought stress on several physiological and chemical reactions in sweet pepper plants, the experiment was achieved as a factorial based on a completely randomized design in greenhouse. Drought stress levels were non-stress conditions (irrigation with field capacity), moderate stress (30% field capacity irrigation) and intense water stress (60% field capacity irrigation) and three concentrations of salicylic acid included 0 (as control), 0.5 and 1 mM were sprayed on the plant in three to four leaf stages. Results: The results showed that drought decreased fresh and dry weight of shoots and roots, leaf relative water content (RWC), fruit diameter and length, the index including chlorophyll and leaf area and increased electrical conductivity (EC), antioxidant activity, total phenolic content, ascorbate, polyphenol oxidase (PPO) and ascorbate peroxidase (APX) activity. After application of foliar salicylic acid, all of the above parameters, except the electrical conductivity content, increased. Conclusions: From the results of this experiment it is concluded that salicylic acid provides a better tolerance for drought stress in pepper plant through its influence on vegetative, biochemical and physiological characteristics.


2021 ◽  
Vol 74 ◽  
Author(s):  
Piyaporn Phansak ◽  
Supatcharee Siriwong ◽  
Nantawan Kanawapee ◽  
Kanjana Thumanu ◽  
Wuttichai Gunnula ◽  
...  

Abstract Drought isa major constraint in many rainfed areas and affects rice yield. We aimed to characterize the physiological changes in rice in response to drought using Fourier transform infrared (FTIR) spectroscopy. Eighty rice landrace seedlings were subjected to drought in the greenhouse using a PEG 6000. Physiological parameters, including total chlorophyll content, relative water content, electrolyte leakage, and biochemical changes were evaluated. Based on the FTIR results, the landraces were divided into three main groups: tolerant, moderately tolerant, and susceptible. Principal component analysis revealed spectral differences between the control and drought stress treatment groups. Lipid, pectin, and lignin content increased after drought stress. The biochemical components of plants at different drought tolerance levels were also compared. The lipid (CH2 and CH3), lignin (C=C), pectin (C=O), and protein (C=O, N–H) contents were the highest in the drought-tolerant cultivars, followed by the moderately tolerant and susceptible cultivars, respectively. Cultivar 17 and 49 were the most tolerant, and the functional groups were identified and characterized using FTIR. Overall, these results will be useful in selecting parental cultivars for rice breeding programs.


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