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1.
《Plant Production Science》2013,16(2):135-140
Abstract

The changes in biomass production, root length, mineral nutrition, potassium absorption efficiency (KAE), and potassium use efficiency (KUE) of the halophytes Catapodium rigidum and Hordeum maritimum in response to potassium availability were assessed under natural conditions. Plants were cultivated in the greenhouse of the experimental station of the Biotechnology Centre of Borj Cédria (a Mediterranean coastal area) 30 km south-east of Tunis for four months from the autumn to winter of 2007–2008. H. maritimum biomass production was not significantly affected by the K+ concentration, but C. rigidum growth was increased significantly with increasing K+ concentration in the medium. Root/shoot dry weight ratio remained constant in C. rigidum, but decreased significantly at 1000 and 3000 µM K+ in H. maritimum. KAE increased but KUE decreased significantly with increasing K+ concentration in the medium in both species. However, KAE was higher in H. maritimum than in C. rigidum showing a contrasting response to K+ concentration between the two species. Overall, the maintenance of a cationic balance may be explained by cation antagonism. The lower K+ requirement of H. maritimum to express its optimal growth can be attributed to its higher efficiency to acquire and transfer K+ to shoots.  相似文献   

2.
《Plant Production Science》2013,16(2):107-116
Abstract

To clarify the genotypic variation of nitrogen (N) response in the AA genome Oryza species, we investigated dry matter production, N uptake, N and water use efficiencies (NUE and WUE), bleeding sap rate (BR), and root morphological traits at vegetative stage in 6 cultivars and 4 strains of 6 species (O. sativa, O. glaberrima, O. barthii, O. nivara, O. meridionalis, and O. rufipogon) grown under standard N (SN) and low N (LN) conditions. Some wild Oryza strains and O. glaberrima showed high dry matter production under both N conditions. In most plants, total dry weight decreased and root dry weight increased under the LN condition, resulting in decreased top-root ratio. In japonica cultivars of O. sativa, however, these traits were unaffected by the N condition. There were no significant differences in WUE with plant species or N conditions. In all plants, however, NUE was higher in the LN than SN condition, and was conspicuously high in most wild Oryza species and O. glaberrima. Some of them showed increased capacity of nitrate-N (NO3-N) uptake under the LN condition. In cultivars and strains with a high NUE, root dry weight, root surface area, and BR were also higher under the LN condition. These results suggest that a high NUE is associated with the development of a root system, increased BR, and probably increased capacity of NO3-N uptake. This study revealed the presence of superior wild Oryza strains for growth under LN that may be a promising genetic resource for low N-input agriculture.  相似文献   

3.
《Plant Production Science》2013,16(4):335-341
Abstract

The contribution of cell wall components and nonstructural carbohydrate (NSC) to grain filling in rice (Oryza sativa L.) was clarified by investigating the differences in the dynamics of hemicellulose, sugar composition of hemicellulose, β-(1→3),(1→4)-glucan, and NSC among cultivars with different grain filling capacities. This investigation was performed using the stems of standard, high yield and low harvest index (HI) cultivars. Hemicellulose concentration in stems tended to decrease slightly during the grain filling stage. This decrease was attributed to a decrease in β-(1→3),(1→4)-glucan concentration, which was detected as a decrease in glucose composition of hemicellulose in the stems during the grain filling stage. The rate of decrease and decrease in the amount of β-(1→3),(1→4)-glucan in the stems differed among the cultivars. These were higher in high yield and high HI cultivars than in relatively low yield and low HI cultivars. Moreover, a positive correlation was observed between the rate of decrease in β-(1→3),(1→4)-glucan and NSC, indicating similarities in the dynamics of β-(1→3),(1→4)-glucan and NSC among the cultivars. When the top half of panicle was removed, β-(1→3),(1→4)-glucan and NSC concentrations in the culm and leaf sheath did not decrease during the grain filling stage. Therefore, the β-(1→3),(1→4)-glucan in stems might be one of the sources that supply substrate to panicle as well as NSC.  相似文献   

4.
Abstract

In Japan, soybean is usually cultivated in fields that have been converted from rice paddies, and poor seedling establishment due to pre-emergence seedling damping-off is often observed during the rainy season. In this study, the factors that cause the damping-off in flooded soil were investigated under high soil moisture conditions in a greenhouse and in agricultural fields. In sterilized soil sampled from a soybean field, seedlings emerged well under 48-hr flooded conditions. In unsterilized soil, soybean seeds treated with the fungicide, mancozeb+metalaxyl exhibited much higher emergence rates even under 48-hr flooded conditions than the seeds treated with oxytetracycline +streptomycin, benomyl, or flutolanil. Pythium, Phytophthora, Mucorales, Trichoderma, Geotrichum-like microorganisms, and some fungi producing conidia in a false head, were isolated from decayed seedlings. Of the isolated microorganisms, oomycete microorganisms, Pythium helicoides, other Pythium sp., and Phytophthora sp. were pathogenic to soybeans under flooded conditions. As the length of the flooding period increased, pre-emergence seedling rot also increased. However, the pathogenic oomycetes rarely caused pre-emergence seedling rot under conditions without flooding. Furthermore, under flooded conditions, the damage caused by these pathogens was reduced by treating the seeds with mancozeb+metalaxyl. These results indicate that oomycete microorganisms are involved in pre-emergence seedling damping-off under flooded soil conditions.  相似文献   

5.
《Plant Production Science》2013,16(2):128-134
Abstract

Aqueous methanol extracts of a traditional Bangladeshi rice cultivar (Oryza sativa L. cv. Kartikshail) inhibited root and shoot growth of cress (Lepidium sativum), lettuce (Lactuca sativa), alfalfa (Medicago sativa), timothy (Phleum pratense), crabgrass (Digitaria sanguinalis), Italian ryegrass (Lolium multiflorum), barnyardgrass (Echinochloa crus-galli) and jungle rice (Echinochloa colonum). The inhibition was increased with increasing the extract concentration, which suggests that cv. Kartikshail may have growth inhibitory substances and allelopathic potential. The aqueous methanol extract of cv. Kartikshail was purified and two main inhibitory substances were isolated and identified by spectral data as 3-hydroxy-β-ionone and 9-hydroxy-4-megastigmen-3-one. The concentrations required for 50% growth inhibition on cress roots and shoots, respectively, were 4.9 and 9.5 μM for 3-hydroxy-β-ionone, and 0.54 and 0.72 μM for 9-hydroxy-4-megastigmen-3-one. The concentrations required for 50% growth inhibition on barnyardgrass roots and shoots, respectively, were 160 and 310 μM for 3-hydroxy-β-ionone, and 53 and 140 μM for 9-hydroxy-4-megastigmen-3-one. The inhibitory activity of a mixture of the two compounds was much higher than that of the sum of the two compounds, suggesting that the two compounds may act synergistically to inhibit the growth of cress and barnyardgrass. The present research suggests that 3-hydroxy- β-ionone and 9-hydroxy-4-megastigmen-3-one may be responsible for the growth inhibitory effect of cv. Kartikshail and may play important roles in the allelopathy of cv. Kartikshail. The traditional Bangladeshi rice cultivar Kartikshail may be potentially useful for weed management as a weed suppressing agent when this rice cultivar is incorporated into the soil or included in rice-based cropping systems.  相似文献   

6.
Abstract

To evaluate the effect of inclination angle of the leaf on the leaf injury of rice by O3, we examined the effect of a 5-hr exposure to 0, 0.1, 0.3 cm3 m-3 O3, abbreviated as O0, O0.1 and O0.3, respectively, of the flag leaf using natural-light gas-exposure chambers. The middle portion of the flag leaf was set horizontally using lead weights (H plant) and it was compared with a non-treated, erect leaf (E plant). Gas exchange and chlorophyll fluorescence were measured immediately before, immediately after, and 1 and 3 d after the start of the exposure. The net photosynthetic rate, stomatal conductance and operating quantum efficiency of photosystem II (Fq’/Fm’) were decreased by the exposure to O3. Furthermore, the inhibitory effects of O0.1 and O0.3 on the H plants were severer than those on the E plants. The maximum quantum efficiency of photosystem II (Fv/Fm) in the leaf of H plants decreased immediately after exposure to O3. These results indicate that the weaker inhibitory effect of O3 on the erect leaf depends on the lower light intensity at the leaf surface, rather than the horizontal leaf position.

Key words: Ascorbic acid, Chlorophyll fluorescence, Gas exchange, Leaf inclination angle, Oryza sativa, O3, Quantum efficiency.  相似文献   

7.
Abstract

Chilling is a major constraint in rice production in cool climates. In rice (Oryza sativa L.) plants, both the air temperature and the water (soil) temperature affect various growth processes independently, and low root zone temperature (thus, root temperature) can inhibit rice growth and yield. In this study, we investigated the effect of low root temperature on rice growth in relation to dry matter production and root water uptake. Plants were grown in hydroponic solutions at two temperatures, one equivalent to air temperature and the other 14ºC for 15 d starting 11 d after germination. Low temperature of the solution (low root temperature) inhibited dry matter production of rice plants by decreasing leaf area rather than photosynthetic rate. The response of leaf area was affected by changes in plant water status, that is relative water content (RWC) of stem was decreased by low root temperature resulting in reduced leaf area. The decrease in RWC caused by low root temperature was related to that in root hydraulic conductance (Kr). The responses of transpiration (E) and Kr to the low root temperature depended more on root surface area than on changes in hydraulic conductance per unit root surface area (Lpr). These results suggest that dry matter production under the low root temperature condition is controlled mainly by quantitative growth parameters such as leaf area and root surface area.  相似文献   

8.
Abstract

Excess phosphorus (P) has accumulated in Japanese paddy soils, due to fertilizer P inputs over crop requirement for several decades, and improvement of the excess of P is necessary in view of environmental conservation. This study aimed to evaluate the input/output balance of P related to soil P status in paddy rice systems, and to obtain a practical indication. Irrigated rice (Oryza sative L.) was cultivated on a gley soil from 1997 to 2006. Six field plots fertilized with commercial fertilizer, animal waste composts, green manure and none were included. Phosphorus input varied among plots from 0 to 73 kg ha-1 yr-1. Rice P uptake was approximately 20 kg ha-1, indicating no response to the P input. This was attributed to a large amount of plant-available Bray- and Truog-P in our soils. In our fields, paddy rice could be cultivated with no P-containing fertilizer or amendment. As a result, increase in the P input led to an increase in partial P balance (PPB). Cumulative increase in PPB resulted in the increase in soil total P, whereas cumulative decrease of PPB tended to decrease it. Excess accumulation of the soil P results in a loss of P into the environment. We concluded that P fertilization should be restricted to 20 kg ha-1 yr-1 (corresponding to 46 kg ha-1 yr-1 as P2O5), based on evenly balanced P input with the rice P uptake. It is also important to include all of the P-containing fertilizers and amendments when determining the amount of application.  相似文献   

9.
《Plant Production Science》2013,16(3):205-216
Abstract

Enhanced aerenchyma development in rice under transient drought-to-waterlogged (TD-W) stress promotes root system development by promoting lateral root production. This study analyzed the quantitative trait loci (QTLs) associated with the plasticity in aerenchyma development under TD-W stress. A mapping population of 60 F2 genotypes of chromosome segment substituted lines (CSSL) derived from CSSL47 and Nipponbare crosses were grown in rootboxes and evaluated for shoot and root growth, and aerenchyma development (expressed as root porosity). The TD-W stress was imposed starting with water saturated soil condition at sowing and then to progressive drought from 0 to 21 days after sowing (DAS) prior to exposure to sudden waterlogging for another 17 days (21 to 38 DAS). We performed simple and composite interval mapping to identify QTLs for aerenchyma development. QTL associated with aerenchyma development was mapped on the short-arm of chromosome 12 and designated as qAER-12. The effect of qAER-12 on the plasticity in aerenchyma development under TD-W was significantly associated with the increase in lateral root elongation and branching. This resulted in greater root system development as expressed in total root length and consequently contributed to higher dry matter production. This qAER-12 is probably the first reported QTL associated with aerenchyma development in rice under TD-W and is a useful trait for the improvement of the adaptive capability under fluctuating soil moisture conditions.  相似文献   

10.
《Plant Production Science》2013,16(4):295-304
Abstract

The genotypic variation of oxidative damage under oxidative and drought stresses was evaluated for a total of 67 rice cultivars consisting of 61 from the rice diversity research set of germplasm and 6 high-yielding varieties. The maximum quantum yield of photosystem II (Fv/Fm) and the membrane stability index (MSI) were measured to assess the oxidative damage induced by methyl viologen (MV) for oxidative stress and polyethylene glycol (PEG) for drought stress. Considerable variations in Fv/Fm and MSI among the cultivars in MV treatment indicated the existence of genotypic diversity in the susceptibility to oxidative damage. The weak relationships of Fv/Fm and MSI between MV and PEG treatment suggested that mechanisms other than oxidative stress tolerance affected the genotypic diversity of oxidative damage in PEG treatment. We used principal component analysis to quantify the cross-tolerance to oxidative damage under MV and PEG treatments: cross-tolerance was higher in cultivars in the japonica group than in the indica groups and higher in the improved cultivars than in the landraces. These results suggest that genotypic diversity of cross-tolerance is related to adaptation to the ecosystem where the genotypes originated and that the characteristics responsible for the tolerance to oxidative damage have been selected during breeding for improved grain yield.  相似文献   

11.
《Plant Production Science》2013,16(3):215-218
Abstract

Distribution of Na+ along the root axis under salinity stress was analyzed in two rice (Oryza sativa L.) cultivars with different salt resistance (salt-sensitive IR 24 and salt-resistant Pokkali). Rice plants were grown hydroponically and NaCl was applied with nutrient solution at concentrations of 0, 25 and 50 mM for 7 d after germination. The distribution of Na+ in roots under salinity was analyzed by the cryo time-of-flight secondary ion mass spectrometry (cryo TOF-SIMS). The Na+ content in the root was higher in salt-sensitive IR 24 than in salt-resistant Pokkali under NaCl stress. The content was highest at the root tip and was decreased basipetally along the root axis. The difference in Na+ content between the cultivars was apparent in all regions from the root tip.  相似文献   

12.
《Plant Production Science》2013,16(4):325-330
Abstract

The root and coleoptile growth of aerobically germinated rice (Oryza sativa L.) seedlings was suppressed by anoxic stress, but the suppression was more conspicuous in roots than in coleoptiles. In this study, the physiological and metabolic responses of roots to anoxia were compared with those of coleoptiles in aerobically germinated rice seedlings. ATP concentration in the coleoptiles was higher than that in the roots under anoxia. Alcohol dehydrogenase activity and ethanol concentration in the coleoptiles were also higher than in the roots under anoxia, which suggest that ethanolic fermentation may be more active in the coleoptiles than in the roots where glycolysis and ethanolic fermentation are the main source of ATP production. Activity of α-amylase, which mobilized reserved starch in the seeds, was not detected in the roots and coleoptiles of rice seedlings either under aerobic or anoxic conditions. However, α-amylase activity was found in endosperms of the rice seedlings even under anoxia. The α-amylase activity in anoxic endosperms was 64% of that in aerobic endosperms. Sugar concentration in the anoxic coleoptiles was higher than that in the anoxic roots. ATP and ethanol concentrations in the roots and coleoptiles of rice seedlings were correlated well with sugar concentrations in the roots and coleoptiles, which also showed a good correlation with anoxia tolerance of roots and coleoptiles with respect to elongation. These results suggest that the sugar level may be important for the anoxia tolerance of the roots and coleoptiles since the availability of sugar is essential for the operation of ethanolic fermentation leading to ATP production under anoxia, and it may serve to distinguish the anoxia tolerance of the roots and coleoptiles of the rice seedlings.  相似文献   

13.
《Plant Production Science》2013,16(2):193-198
Abstract

Molecular Cloning of Oxygen-Evolving Enhancer Genes Induced by Salt Treatment in a Halophyte, Salicornia europaea L.

Abstract : To understand the function of oxygen-evolving enhancer proteins (OEEs) in PSII, we cloned the complete nucleotide sequence of three OEE genes from Salicornia europaea cultured in a 3% NaCl solution and determined the effect of salt treatment on the expression levels of the OEE genes. The three OEE proteins were 89-74% identical to those of spinach. The expression of OEE1 gene was increased by NaCl treatment but not changed in OEE2 and OEE3. Therefore, the increases in the expression levels of Salicornia OEE1 gene may be important in maintaining the PSII activity in the presence of NaCl.  相似文献   

14.
《Plant Production Science》2013,16(4):318-324
  相似文献   

15.
《Plant Production Science》2013,16(3):260-269
Abstract

We grew 1005 mutated scented japonica rice lines to the seventh steady genetic generation, and treated the seedlings with six true leaves with 300 mM NaCl for three days. Only the salt-tolerant line, SM61, survived. We obtained F1, F2 and F3 populations from the cross between SM61 and a salt-susceptible indica variety, TCS17. After culture with 200 mM NaCl for five days, SM61 and F1 (SM61×TCS17; TCS17×SM61) plants survived (R) while TCS17 plants did not (S). The R to S ratio in 513 F2 plants showed a good fit to the Mendelian 3 : 1 segregation ratio by a Chi-square test indicating that the salt-tolerance of SM61 was governed by a single dominant gene. The mutated salt-tolerance gene explained close to 100% of the total phenotypic variation, and was tightly linked to RM223 (marker) located on chromosome 8, which was different from the results of previous studies investigating the relationship of QTLs with salt tolerance. This is the first report of mapping tightly linked markers of a single dominant mutated salt-tolerance gene.  相似文献   

16.
《Plant Production Science》2013,16(3):249-253
Abstract

NH3 emission from leaves of three rice (Oryza sativa L.) cultivars, Akenohoshi, Shirobeniya and Kasalath, was examined using a simple open chamber system.　In the three cultivars, NH3 emission rate (AER) and NH4+ content of leaves decreased with decreasing NH4+ concentration in the root medium, but these values differed significantly with the cultivar. In the daytime, AER, NH4+ content and glutamine synthetase (GS) activity in leaves changed similarly with maximum values around midday. Akenohoshi showed significantly lower AER and NH4+ content but higher GS activity than Kasalath. The difference in AER among the rice cultivars may be related to the activity of GS involved in photorespiratory NH3 recycling. Akenohoshi can be a breeding material useful for improving N recycling.  相似文献   

17.
《Plant Production Science》2013,16(3):254-259
Abstract

We investigated responses of wet climate (CY17) and dry climate (XN889) Trititcum aestivum L cultivars under 85, 55 and 25% field water capacity (FC). Less decrease in grain yield, relative water content, growth, gas exchange and chlorophyll fluorescence parameters indicated that XN889 was more drought-tolerant than CY17. At 55%FC, CY17 showed a lower net photosynthetic rate (Pn) than XN889 mainly due to stomatal closure. Stomatal closure was also observed in XN889, but its Pn was higher at 55%FC than at 85%FC. The higher Pn in XN889 may be associated with a higher chlorophyll content and resulting increase in photochemical quenching (qP), apparent electron transport rate, and effective quantum yield of photosystem II (PSII). Both cultivars showed photodamage at 25%FC, but XN889 showed less photodamage in terms of maximal PSII photochemical efficiency. XN889 showed higher qP and non-photochemical quenching than CY17, further demonstrating its superior drought tolerance.  相似文献   

18.
Background:Glioblastoma multiforme is the most invasive and lethal form of brain cancer with unclear etiology. Our study aimed to investigate the molecular prevalence of HCMV and EBV infections in patients with GBM. Methods:This case-control study was conducted on 42 FFPE brain tumor samples from GBM patients and 42 brain autopsies from subjects without neurological disorders. The presence of EBV and HCMV DNA was determined, using PCR and nested-PCR assays, respectively. Results:HCMV DNA was detected in 3 out of 42 (7.1%) of GBM samples and was absent from the control group (p = 0.07). Importantly, EBV DNA was detected in 9 out of 42 (21.4%) brain tissue specimens of GBM subjects, but again in none of the control group (p = 0.001). Conclusion:Our findings indicate that infection with EBV is associated with GBM. Key Words: Brain tumor, Epstein-Barr virus, Glioblastoma, Human cytomegalovirus  相似文献   

19.
Background:Premature ovarian failure is a heterogeneous disorder, leading to early menopause. Several genes have been identified as the cause of non-syndromic POF. Our aim was to explore the genetic defects in Iranian patients with POF. Methods:We studied a family with three females exhibiting non-syndromic POF. WES was performed for one of the affected individuals after ruling out the presence of CGG repeat expansion at FMR1 gene in the family. Sanger sequencing was used to confirm the candidate sequence variants in the proband, and screening of the detected mutation was performed for the other affected and unaffected members of the family. Results:A homozygous frameshift mutation, c.349delC, was identified in FCN3 gene in the proband and two other patients. The parents and two healthy brothers were heterozygous for the mutation, and an unaffected sister was homozygous for wild type. Conclusion:This is the first report of a mutation in FCN3 gene in a family with POF. Our findings can lead to the enhancement of genetic databases of patients with POF, specifically for families with high-risk background. Key Words: Ficolin-3, Premature ovarian failure, Whole exome sequencing  相似文献   

20.
《Plant Production Science》2013,16(2):118-127
Abstract

The whole-leaf photosynthetic rate in rice plants is controlled by various physiological processes. In a high-yielding indica rice variety, Habataki, the leaf photosynthetic rate (LPR) of the uppermost fully expanded leaves was approximately 130 to 140% of that in a japonica variety, Sasanishiki, from booting to the early ripening stage. We characterized the difference in the LPR between Habataki and Sasanishiki. Leaves of Habataki contained higher levels of nitrogen and, as a consequence, of Rubisco, and had higher stomatal conductance that was associated with higher hydraulic conductance from roots to leaves than those of Sasanishiki. These features were responsible for the higher LPR of Habataki. An analysis of chromosome segment substitution lines (CSSLs) in which chromosome segments from Habataki were substituted into the genetic background of Sasanishiki showed that three genetic regions on chromosomes 4, 5 and 11 were responsible for the increase in the LPR. Each of these regions was estimated to increase the LPR by 15 to 30%, and we showed that they were associated with higher activity of mesophyll photosynthesis due to higher leaf nitrogen content and greater stomatal conductance. Leaf nitrogen content and stomatal conductance may be useful parameters for further quantitative trait locus analysis of efficient photosynthesis in leaves.  相似文献   

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