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1.
差异显示法分离水稻耐淹涝相关的基因   总被引：3，自引：0，他引：3  
摘 要：应用mRNA差异显示技术(DDRT—PCR)对耐淹材料FR13A和敏感材料IR39595-503-2-1-2在淹涝胁迫下的基因差异表达进行分析。结果显示：从40对引物中共扩增出1428条片段，筛选到102条在耐淹涝材料和敏感材料间差异明显的基因片段，差异率为7.1% 。其中有42条差异片段来自耐淹涝材料，有7个差异片段已通过Northern杂交验证在耐淹涝材料FR13A中表达，进一步克隆测序并进行数据库比对分析表明：有4个与受到水分胁迫时产生的应答反应和生理生化变化有关，其中一个与ATP结合蛋白的高度同源，3个与异柠檬酸酶脱氢酶，NADH2脱氢酶和乙醛酸转移酶部分序列高度同源。其余3个为新的cDNA片段。  相似文献   

2.
Abstract

Poor productivity of rice in rainfed lowlands is due to complete submergence as it is a major abiotic stress of these regions. For enhancing the rice productivity of these areas, better nutrient management options are required and results may even better when combined with stress tolerant cultivars, even when tested under natural conditions of farmers’ field. For supporting the above statement, the effect of nitrogen and phosphorus in graded doses was evaluated for submergence tolerance in controlled conditions and the results obtained were tested and validated at farmers’ field in Cuttack, Odisha, India. Shoot elongation, leaf senescence and lodging were lowest with the application of higher phosphorus (60?kg ha?1). Highest dose i.e. 100-60-40 NPK kg ha?1 resulted in higher plant survival of all the varieties by 90–170% over no nutrient application, it was also reflected in the higher growth after recovery, leaf greenness, leaf and stem growth, chlorophyll and carbohydrate concentrations and ultimately higher grain yield. At farmers’ field, application of basal P, K and post-flood N management practice resulted in overall better performance of Swarna and Swarna-Sub1 showing higher yield attributes leading to 65.7 and 37.9% higher grain yield, over conventional practices followed by farmers. Apart from that results were more positive if post-flood nitrogen was applied as urea foliar spray might be due to quick absorption of N by plant leaves and also spraying helps in removing the silt of flood water sticking to the leaf surface and facilitated the plants to photosynthesize and survive after desubmergence. These cost-effective management options may enhance the productivity and profitability of rice in the flood-prone areas where farmers hesitate to apply nutrients.  相似文献   

3.
利用差异显示法研究水稻耐淹涝相关基因   总被引：7，自引：0，他引：7  
应用mRNA差异显示法对耐淹材料籼稻(Oryzasativassp.indica)FR13A和敏感籼稻(O.sativassp.indica)IR39595-503-2-1-2在淹涝胁迫下的基因差异表达进行了分析。结果显示,从40对引物中共扩增出1428条片段,筛选到102条在耐淹涝材料和敏感材料间差异明显的基因片段,差异率为7.1%。其中有42条差异带来自耐淹涝材料,有7个差异片段已通过Northern杂交验证在耐淹涝材料FR13A中表达。进一步克隆测序并进行数据库比对分析表明,有4个与水分胁迫产生的应答反应和生理生化变化有关,其中一个与ATP结合蛋白高度同源,另3个与异柠檬酸酶脱氢酶、NADH脱氢酶和乙醛酸转移酶部分序列高度同源,其余3个为新的cDNA片段。  相似文献   

4.
A rapid and simple nutrient addition technique was used for evaluating Al tolerance of six local upland rice (Oryza sativa L.) cultivars (BG35, BR21, DA25, DA26, DA14, and DA22) from Bangladesh and three IRRI rice, IR46, IR97, and IR45, cultivars from the Philippines. The plants were grown for 21 days with Al (0 μM, 140 μM, 280 μM or 560 μM) at pH 4.1. The roots were more affected by Al than the shoots. In rating cultivars for Al sensitivity, relative shoot weight (RSW) was found to be the best parameter due to the severe damage of the roots, irrespective of Al sensitivity. The cultivars were rated as Al tolerant (BG35, BR21, DA25, and DA26), mid‐tolerant (DA14, DA22, and IR46) and sensitive (IR97 and IR45) . More Al was retained in the roots of tolerant cultivars than in the mid‐tolerant or sensitive cultivars. In shoots, the Al concentration of tolerant cultivars was less than in the mid‐tolerant or in the sensitive cultivars and the inhibition of growth was proportional to Al concentration irrespective of Al tolerance. Therefore, the variation among cultivars in Al sensitivity could be related to the capacity of roots to retain Al from transport to the shoots.  相似文献   

5.
西藏东南部山洪灾害过程水文动力模拟和临界雨量   总被引：2，自引：1，他引：1  
[目的]研究西藏山洪致灾临界雨量确定方法,为西藏地区水文气象预警提供基础数据资料,以服务于高原山洪灾害防御工作。[方法]采用水文动力模式Floodarea模型对西藏东南部的一次山洪过程进行模拟研究,并利用气象资料逐时降水量进行了淹没高度计算,得到了山洪致灾临界雨量。通过实地考察获取西藏自治区林芝市巴宜区2015年8月一次山洪灾害的基本参数资料,与模型模拟研究结果进行对比分析和模型验证。[结果](1)Floodarea对暴雨诱发山洪过程的模拟结果较好,结合多源降水数据能更准确地模拟西藏山区山洪暴发的过程;(2)通过调整雨量情景设定可推算山洪不同淹没水深的临界雨量,得到较为准确的洪水淹没范围和降雨量—淹没深度关系;(3)应用降雨量—淹没深度关系计算得到巴宜区永久河山洪沟的4个淹没深度灾害山洪等级(0.1,0.6,1.2,1.8m)的6h累计临界雨量分别为33,55.7,75.4,91.9mm。[结论]研究结果表明Floodarea软件适用于西藏高原水文观测资料匮乏的复杂地形山区,能较准确地重现山洪灾害过程和确定山洪临界雨量,可为复杂地形山区山洪防治和预警提供参考。  相似文献   

6.
研究了外源Ca2 对盐胁迫下耐盐性不同的两个水稻品种(武育粳3号和IR36)几种抗氧化酶活性及膜脂过氧化的影响。结果表明:适量的Ca2 供应能有效提高水稻叶片超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)以及抗坏血酸过氧化物酶(APX)的活性,使之维持在较高的水平上,并降低了丙二醛(MDA)含量和细胞膜透性。此外,外源Ca2 还增加了抗坏血酸(AsA)的含量,增强了水稻幼苗的根系活力。这表明适量的外源Ca2 供应提高水稻耐盐性的原因之一,在于其增强了植株的活性氧清除能力以及对细胞膜的稳定作用。  相似文献   

7.
 针对甘肃舟曲"8.7"特大山洪泥石流灾害,结合北京山区荒溪分类与危险区制图工作经验,认为防治山洪泥石流灾害,要重视采用综合措施,并提出关于加强山洪泥石流防治工作的7点建议。  相似文献   

8.
The flash release (FR) process, consisting of rapidly heating the grapes and then applying strong vacuum, has been proposed to increase the polyphenol content of red wines. Its impact on polyphenol extraction kinetics and on the polyphenol composition of red juice and wines was studied over two seasons on different grape varieties (Grenache, Mourvedre, Carignan). The FR process allows fast extraction of all phenolic compounds (hydroxycinnamic acids, flavonols, anthocyanins, catechins, proanthocyanidins) and can be used to produce polyphenol-enriched grape juices. However, the concentration of all polyphenols dramatically decreased throughout fermentation when pressing was achieved immediately after FR. The FR wines made with pomace maceration were also enriched in polyphenols compared to the corresponding control wines. Increasing the duration of high-temperature exposure in the FR treatment further increased extraction of phenolic compounds but also accelerated their conversion to derived species. The tannin-to-anthocyanin ratio was particularly low in the wine fermented in the liquid phase, higher after FR than in the control, and even higher after longer heating. FR resulted in an increased tannin-to-anthocyanin ratio and an increased conversion of anthocyanins to tannin-anthocyanin adducts showing the same color properties as anthocyanins. The tannin-to-anthocyanin ratio was particularly low in the wine fermented in the liquid phase that also contained larger amounts of orange sulfite bleaching-resistant pigments.  相似文献   

9.
为了探讨分蘖期干旱胁迫对寒地粳稻产量形成的影响机理及其耐旱机制,以东农425(耐旱型)和松粳6号(干旱敏感型)为试验材料,通过盆栽方式于分蘖期控制土壤水势至0 k Pa(对照)、-10 k Pa(轻度干旱)、-25 k Pa(中度干旱)、-40 k Pa(重度干旱),依次记为A0、A1、A2、A3。处理21 d后复水,研究分蘖期不同程度干旱胁迫对寒地粳稻叶面积、光合特性、叶绿素总含量、产量及产量构成因素的影响。结果表明,分蘖期干旱胁迫导致叶面积减小、功能叶片净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和胞间CO2浓度(Ci)均随土壤水势降低而下降。同时,干旱处理期间寒地粳稻功能叶片叶绿素总含量、叶绿素a/b值均随干旱胁迫程度增加而下降,但类胡萝卜素含量的变化却与其相反。干旱胁迫下寒地粳稻产量显著下降,且下降幅度随土壤水势降低而逐渐增大。有效穗数和穗粒数大量降低造成产量显著下降,说明分蘖期干旱胁迫造成减产的主要原因是低土壤水势造成了寒地粳稻库容量或单位面积颖花量的大量降低。与A0(对照)相比,A1、A2和A3下松粳6号产量降幅分别为13.87%、20.87%和32.51%;而东农425分别为10.58%、15.21%和25.52%,均显著低于松粳6号,且耐旱型品种东农425始终保持较高光合生长能力。本研究结果为寒地粳稻抗旱节水栽培技术措施的制定提供了理论依据。  相似文献   

10.

Treatment of seeds of two rice (Oryza sativa L.) cultivars (Ratna and IR36) separately with 10-5and 10-4M PbCl2and HgCl2decreased germination percentage, germination index (GI), shoot and root length, tolerance index (TI), vigour index (VI) and dry mass of shoot and root but increased percentage difference from control (% DFC) of germination and percentage phytotoxicity in both the cultivars. It was observed from these indices that the phytotoxic effect of mercury was greater than lead at identical concentrations and that IR36 appeared more tolerant than Ratna to these metals. Among the monitoring indices examined, TI, VI, and % phytotoxicity seemed to serve as good biological monitoring methods for evaluating the relative toxicity of lead and mercury to rice cultivars.

  相似文献   

11.
Cultivars with submergence tolerant quantitative trait locus (SUB1) greatly enhance submergence tolerance at vegetative stage. Whether such cultivar is better off or not at reproductive stage submergence is not known. Due to uncertainties in rainfall pattern and delayed monsoon, flooding at later stages corresponding to reproductive stage is very much common now. Therefore, the main goal of the present investigation is to work out the effect of submergence at reproductive stage on yield and yield attributes in three rice cultivars namely Swarna, Swarna-Sub1, and Baliadhan (a traditional rice cultivar showed similar reaction to SUB1). The present study envisages that submergence at reproductive stage greatly decreased the grain yield even though there was no mortality of plants. Yield reduction was greater at flowering stage followed by booting and panicle initiation stage. Swarna-Sub1 performed significantly better compared to Swarna when submergence was given at panicle initiation stage. Swarna-Sub1 and Baliadhan both maintained greater quantities of carbohydrate and total dehydrogenase activity yet the yield reduction was greater in Swarna-Sub1 compared to Baliadhan due to greater chalf formation in the former. The cultivar with SUB1 is quite better off at reproductive stage submergence. Baliadhan is superior to Swarna-Sub1.  相似文献   

12.
除草剂对不同耐寒性水稻幼苗的氧化胁迫效应   总被引：3，自引：2，他引：1  
通过分析比较百草枯和丙酯草醚处理以及零上低温处理对水稻幼苗的生长、膜脂过氧化及抗氧化剂水平的效应,研究了新型除草剂丙酯草醚对不同耐寒性水稻品种（耐寒性品种圣稻13和冷敏感性品种IR50）的氧化胁迫特征。100 nmol/L丙酯草醚处理显著抑制圣稻13和IR50幼苗的生长,但50 nmol/L百草枯仅对IR50幼苗生长有显著抑制。百草枯处理使2个水稻品种的丙二醛（MDA）有大幅度的提升,这与百草枯通过产生氧自由基的杀草机理相符,而圣稻13对百草枯一定程度的抗性可能与其谷胱甘肽和抗坏血酸的上升响应有关。丙酯草醚处理虽然引起圣稻13中MDA的上升,但对IR50的MDA含量没有显著影响,表明丙酯草醚处理对圣稻13造成了氧化胁迫伤害,而对IR50的生长抑制可能与氧化胁迫没有密切关系。  相似文献   

13.
ABSTRACT

Common abiotic stresses in rain-fed rice areas like drought can occur at any phase of crop growth and may occur periodically. Variation in intensity and severity of drought requires the use of different rice varieties and different nutrient management strategies. This study evaluated the morphological and physiological response of contrasting rice cultivars (Rajalaxmi, IR64, and Sahbhagidhan) to various nutrient combinations under water sufficience and scarce conditions. Drought stress at vegetative stage significantly reduced tiller formation, dry matter remobilization, and photosynthesis, leading to around 41.6% yield reduction. The effect of drought stress was more evident in Rajalaxmi and IR64 by a yield reduction of 57.4% and 43.2% as against only 24.3% in Sahbhagidhan. The combined application of nutrients resulted in higher proline accumulation, chlorophyll and carbohydrate concentrations, and photosynthesis and antioxidant enzymes, ultimately better tolerance to drought. This is reflected in higher values of tolerance indices and low scores of leaf drying and leaf rolling, especially for Sahbhagidhan. The combined application of P, K, Ca, Zn, and Fe resulted in 52.9, 53.3, 48.9% higher yield over P or K application. Rice drought tolerance can be managed by combining breeding of drought-tolerant high yielding varieties with the proper application of fertilizer nutrients.  相似文献   

14.
In this study, two rice cultivars including a drought tolerant (Q8) and a drought susceptible (Q2) were foliar applied with exogenous vanillic acid (VA) and p-hydroxybenzoic acid (PHBA) to examine their effectiveness on drought-tolerant levels and induction of pigments, antioxidants, phenolics, flavonoids, and phytoalexin momilactones A (MA) and B (MB). Generally, the tolerant level of Q2 was more accelerated than those of Q8. Total contents of phenolics, flavonoids, pigments, and antioxidant activity were positively promoted, although the difference between Q8 and Q2 was negligible. In the quantitative induction of phenolic acids, VA, PHBA, and VA+PHBA showed dose-dependent variable effects, of which Q2 was more influenced than Q8. In all treatments, PHBA appeared to have a more significant role toward drought tolerance than VA. Although MB was found only in non-treated Q8, treatments of VA+PHBA caused formation of both MA and MB, however the induced quantities of MA and MB varied among applied doses and rice cultivars. This research is the first to show that, besides increasing antioxidant activity and total pigments, phenolics, and flavonoids, application of VA and PHBA induced phytoalexins MA and MB to enhance rice drought tolerance, of which MB may play a greater role than MA.  相似文献   

15.
A hydroponic experiment with two rice cultivars differing in cadmium (Cd) tolerance was conducted to investigate the alleviating effect of zinc (Zn) on growth inhibition and oxidative stress caused by Cd. Treatments consisted of all combinations of two Zn concentrations (0.2 and 1 μM), three Cd concentrations (0, 1, and 5 μM), and two rice cultivars (Bing 97252, Cd‐tolerant; Xiushui 63, Cd‐sensitive). Cd toxicity caused a dramatic reduction in plant height and biomass, chlorophyll concentration and photosynthetic rate, and an increase in Cd concentration in both roots and shoots, malondialdehyde (MDA) concentration, and superoxide dismutase (SOD) and peroxidase (POD) activities in shoots. The response of all these parameters was much larger for Xiushui 63 than for Bing 97252. Addition of Zn to the medium solution alleviated Cd toxicity, which was reflected in a significant increase in plant height, biomass, chlorophyll concentration, and photosynthetic rate, and a marked decrease in MDA concentration and activity of anti‐oxidative enzymes. However, it was noted that Zn increased shoot Cd concentration at higher Cd supply, probably due to the enhancement of Cd translocation from roots to shoots. Therefore, further studies are necessary to determine the effect of Zn supply on Cd translocation from vegetative organs to grains or grain Cd accumulation before Zn fertilizer is applied to Cd‐contaminated soils to alleviate Cd toxicity in rice.  相似文献   

16.
对不同品种水稻分蘖期耐淹能力及不同淹涝强度对一些农艺性状的影响进行了研究,结果表明:(1)淹后叶片相对成活率和茎蘖耐淹能力评分可作为评价水稻分蘖期耐淹能力的指标,供试品种可划分为耐淹、中性、敏感3种类型;(2)随着淹涝强度的增加,淹后株高一般表现出“矮-高-矮”的变化,始穗期推迟时间为:敏感品种>中性品种>耐淹品种,产量性状受影响程度为:敏感品种>中性品种>耐淹品种。  相似文献   

17.
以1934～2006年育成,在我国南方广泛种植的16个代表性早籼稻品种为材料,参照生产实践及品种演变阶段,按育成时间将供试品种划分为高秆品种、矮秆品种、矮抗品种、优超品种4种类型,采用常规栽培方法研究其群体质量的演变特征。结果表明,早籼稻品种改良进程中,花后群体光合生产能力增强,干物质积累增加,齐穗期总颖花量增加,高效叶面积率与颖花根流量略有下降,有效叶面积率与成穗率变化不大,单茎茎鞘重呈先下降后略有上升的趋势。早籼稻群体进一步改良的有效途径是增强根系活力,促进根系水分与矿物质的吸收及根系物质向籽粒的转运;提高高效叶面积率,增加花后光合产物积累和总颖花量,进而提高粒叶比,达到源库协调。  相似文献   

18.
Reports on varietal diversity of upland rice in relation to relatively low aluminium (Al) levels are limited. Therefore, effects were examined of 35, 70, and 140 μM Al on plant growth and uptake of macro‐ and micro‐nutrients (K, P, Ca, Mg, Fe, Zn, Cu, and Mn) and their distribution in three upland rice (Oryza saliva L.) cultivars (BG35, DA14, and IR45) with different Al sensitivity. After an initial growth period of 5 days without Al, the plants were grown for 21 days in nutrient solutions containing Al at pH 4.1. Cultivar BG35 showed the highest and IR45 the lowest tolerance to Al when fresh weights of shoots or roots were considered. Except for IR45 at 140 μM Al, total dry weight was unaffected by Al, and the cultivars could not be clearly distinguished with respect to Al tolerance. Net Al uptake rate was higher in Al tolerant BG35 than in DA14 or IR45. Conversely, in IR45 the absorbed Al was rapidly transported to the shoots and accumulated there. In BG35, net P and Ca uptake rates in Al‐treated plants were high enough to maintain the P and Ca status of the shoots at all Al levels. Irrespective of Al sensitivity, there was a general depression of internal Mg concentration in Al‐reated plants. The Fe, Zn, Cu, and Mn concentrations of the plants were not negatively affected by Al in any of the cultivars.  相似文献   

19.
Rice can yellow during storage if moisture levels and temperatures are allowed to increase. This postharvest yellowed (PHY), or stackburn, rice is reduced in value but no study has investigated the inherent potential within rice germplasm for limiting PHY. To screen a large number of cultivars for propensity to PHY, a laboratory method for PHY using a small amount of rice was used. Ninety‐eight popular southern U.S. rice cultivars were yellowed under laboratory conditions. Additional samples of the low‐yellowing and high‐yellowing cultivars were retested after two and three years of storage as rough rice using higher amounts and larger containers. All cultivars showed greater color change with the higher amounts of rice and when yellowed as milled rather than as rough rice. Length of time of storage and storage temperature did not affect the degree of PHY. The low‐ and high‐yellowing groups remained distinguishable but the overall high level of coloring in southern U.S. rice cultivars indicates that a more diverse germplasm should be investigated to increase the likelihood of identifying low‐PHY cultivars.  相似文献   

20.
《Cereal Chemistry》2017,94(2):251-261
The objective for this study was to investigate the effectiveness of scaled‐up infrared (IR) heating followed by tempering steps to dry freshly harvested rough rice. An industrial‐type, pilot‐scale, IR heating system designed to dry rough rice was used in this study. The heating zone of the equipment had catalytic IR emitters that provided heat energy to the sample as it was conveyed on a vibrating belt. The sample comprised freshly harvested rough rice of long‐grain pureline (Cheniere), long‐grain hybrid (6XP 756), and medium‐grain (CL 271) cultivars at initial moisture contents of 23, 23.5, and 24% wb, respectively. Samples at a loading rate of 1.61 kg/m2 were heated with IR of radiation intensity 5.55 kW/m2 for 30, 50, 90, and 180 s followed by tempering at 60°C for 4 h, at a product‐to‐emitter‐gap size of 450 mm, in one‐ and two‐pass drying operations. Control samples were gently natural air dried in an equilibrium moisture content chamber set at relative humidity of 65% and temperature of 26°C to moisture content of 12.5% wb. The effects of IR treatments followed by tempering on percentage points of moisture removed, head rice yield, energy use, rice color, and pasting characteristics were evaluated. For all cultivars, percentage point moisture removed increased with increase in IR drying duration. For all rice cultivars, one‐pass IR treatments for 180 s resulted in head rice yield significantly lower than that of rice dried with natural air in the controlled‐environment conditions (P < 0.05). Energy required to dry rice increased with increase in drying duration. Viscosity values of all the experimental samples were significantly greater (P value < 0.05) than that of the control samples for all the cultivars, except those treated with IR for 180 s. There was a significant difference (P < 0.05) in the color index (ΔE ) of treated milled samples and the controls. In conclusion, the study provided information crucial to understanding the effects of scaled‐up radiant heating and tempering of rough rice on drying rates and rice quality for long‐grain pureline, long‐grain hybrid, and medium‐grain rice cultivars.  相似文献   

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