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1.
我国北方地区玉米根寄生线虫的种类鉴定研究 总被引：3，自引：1，他引：3
1992～1995年对采自辽宁、吉林、黑龙江、内蒙古、河北、山东和江苏等省的玉米根寄生线虫进行分类鉴定研究，共鉴定出14属的36种线虫。即：丝尾垫刃线虫属Filenchus1个种；短体线虫属Pratylenchus10个种；拟短体线虫属Pratylenchoides1个种；矮化线虫属TylenchorhyNchus3个种；纽带线虫属Hoplolaimus3个种；螺旋线虫属Helicolylenchus4个种；盘旋线虫属相似文献
2.
耕作方式对连作大豆生长发育及产量的影响 总被引：2，自引：0，他引：2
采用秋旋耕起垄、秋深松旋耕起垄、春旋耕起垄和春顶浆打垄4种土壤耕作方式,进行田间大区试验,以探讨土壤耕作方式对连作大豆生长发育及产量的影响。试验结果表明,秋旋耕起垄和秋深松旋耕起垄出苗率高于春旋耕起垄和春顶浆打垄,出苗率均达85%以上,秋整地大豆生育期间干重、根瘤重和叶面积指数均高于春整地,秋旋耕起垄大豆根际微生物总数最多,细菌和放线菌数量明显高于春顶浆打垄。秋季整地地下害虫——蛴螬（Holotrichia diomphalia Bates）危害率比春季整地低10%左右,春顶浆打垄危害率高达34.3%。秋整地大豆的灰斑病发生程度、籽粒紫斑粒率和虫食率均低于春整地,秋整地产量较春整地增产16%以上,从本试验可以看出黑龙江省黑土平原区秋整地对连作大豆效果更好。 相似文献
3.
《Plant Production Science》2013,16(1):13-19
AbstractMorphological changes and function of calcium oxalate crystals in eddo roots in hydroponic solution containing calcium at various concentrations were investigated. Bundles of needle-shaped crystals in crystal idioblasts were tubularly arranged in the peripheral part of cortex in the apical zone of primary roots. Under scanning electron microscopy and optical microscopy, crystals in the idioblasts of roots cultured in 1 mM calcium nitrate solution were larger than those in 0 mM calcium solution but smaller than those in the solutions containing either 15 mM calcium nitrate or 15 mM calcium chloride. The number and area of crystal bundles in the sections of the apical zone in 1 mM calcium nitrate solution were significantly larger than those in 0 mM calcium solution and smaller than those in the solutions containing 15 mM calcium. The calcium mapping image obtained by energy dispersive X-ray spectrometry showed that the amount of calcium in crystal idioblasts was increased with increasing calcium concentration in the solutions. However, the weight percentage of calcium per cortex parenchyma cell in root apical zone did not vary significantly with the concentration of calcium in the solutions. In the root zone apart from the root apex having no crystals, the weight percentage of calcium per cortex parenchyma cell in the solutions containing 15 mM calcium was significantly higher than that in either 0 mM calcium or 1 mM calcium nitrate solution. These results suggested that the crystals in the tubular arrangement participated in the regulation of calcium levels in the apical zone of primary roots. 相似文献
4.
Watermelon yield loss due to Fusarium wilt is increasing in the U.S., due in part to the emergence of the virulent race 2 of Fusarium oxysporum f. sp. niveum, and to the shift in production to triploid cultivars, which generally have less host resistance than previously grown diploid cultivars. One potential management strategy is the use of soil-applied fungicides to reduce Fusarium wilt. The U.S. national program, interregional project 4 (IR-4) supported multistate trials of soil-applied chemicals to manage Fusarium wilt of watermelon. Greenhouse trials were conducted in Maryland, Indiana and Georgia to test the efficacy of 14 chemicals on Fusarium wilt. Based on the performance of these chemicals in the greenhouse, six in Maryland and Delaware and eight in Indiana were selected for subsequent field evaluations. These chemicals were applied once, as a drench at planting, in field trials in Maryland, Indiana, and Delaware in 2008. The fungicides prothioconazole, acibenzolar-S-methyl, and thiophanate-methyl resulted in the greatest reduction in Fusarium wilt, and caused no phytotoxicity. In Maryland and Indiana in 2009, these chemicals were applied through the drip irrigation line alone and in combination, at 0, 2 and 4 weeks after planting. The experiment was repeated in 2010 in Maryland. Prothioconazole alone and in combination with acibenzolar-S-methyl or/and thiophanate-methyl resulted in the greatest decrease in the area under the disease progress curve (AUDPC) of Fusarium wilt of watermelon in Maryland in 2009. The same trend was observed in 2010 in Maryland where three of the prothioconazole treatments ranked the lowest of all treatments and prothioconazole in combination with thiophanate-methyl had significantly lower Fusarium wilt AUDPC compared to the non-treated control. All chemical applications except for acibenzolar-S-methyl in combination with prothioconazole reduced Fusarium wilt AUDPC in Indiana in 2009. Prothioconazole alone and prothioconazole in combination with thiophanate-methyl ranked lowest in Fusarium wilt AUDPC, although not significantly lower than most other treatments. These studies are the first to demonstrate that the soil-applied fungicides prothioconazole and thiophanate-methyl may provide an additional field management option for Fusarium wilt of watermelon. 相似文献
5.
以籽粒蛋白质含量有显著差异的杂交后代及亲本为材料,分析了灌浆成熟过程中叶片蛋白水解酶和籽粒谷氨酰胺合成酶活性以及籽粒可溶性蛋白质含量的变化动态。结果表明,在籽粒蛋白质含量相近的亲本衍生的杂交后代中,通过籽粒蛋白质含量的连续定向选择不仅可以获得籽粒蛋白质含量和叶片蛋白水解酶活性及籽粒谷氨酰胺合成酶活性明显变高或变低的杂种后代,而且可获得蛋白质含量和酶活性超亲的后代;稻米蛋白质含量与灌浆过程中的叶片蛋白水解酶活性呈正相关, 籽粒可溶性蛋白质含量与籽粒谷氨酰胺合成酶活性呈显著负相关。 相似文献
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采用水培技术研究不同钾水平对 RRIM600 无性系种子实生幼苗各器官 MDA 含量和保护酶活性的影 响。结果表明： 在低钾胁迫下, 除叶部的 K0、 K1、 K10 处理、 根中的 K10、 K50 处理外, 缺钾降低了巴西橡胶树幼苗各器官中 MDA 含量, 但各器官中各处理间 MDA 含量差异不显著; 除叶部的 K0 处理、 茎部的皮和根中 K50处理外, 缺钾降低了各器官中 SOD 酶活性, 且在叶部 SOD 酶活性显著降低; 除叶部的 K1、 K10、 K50 处理、 根中的 K1 处理外, 缺钾降低了各器官中 POD 酶活性, 但各器官中各处理间 POD 酶活性差异不显著; 缺钾极显著提高了巴西橡胶树幼苗叶片 CAT 酶活性。 因此, 在巴西橡胶树幼苗各器官中抵御低钾胁迫主要靠各种保护酶相互协调来完成。 相似文献
8.
R. G. THOMAS 《Grass and Forage Science》1981,36(2):121-125
Flowering behaviour of plants of six cultivars of Trifolium repens (Kent Wild White, Grasslands Huia, S100, Blanca, Olwen and Milkanova) growing in field plots at the Grassland Research Institute, Hurley, was recorded in mid-July. Half of each plot had been defoliated in early May, the other half in mid-June. In all cultivars defoliated in May, inflorescence initiation had stopped even though the natural photoperiod at that time was well above the critical daylength for initiation Defoliation in mid-June had led to a renewal of inflorescence initiation in all cultivars.
The results confirm that the stimulatory effect of defoliation on inflorescence initiation in plants that have stopped initiation in long days, which has previously been observed in Grasslands Huia in controlled environments, also occurs in the field and in other cultivars. 相似文献
The results confirm that the stimulatory effect of defoliation on inflorescence initiation in plants that have stopped initiation in long days, which has previously been observed in Grasslands Huia in controlled environments, also occurs in the field and in other cultivars. 相似文献
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10.
野生大豆植株中酰脲分布和嘌呤降解酶活性 总被引：2，自引：0，他引：2
野生大豆植株中,合成酰脲的三种关键酶中的黄嘌呤脱氢酶,尿酸酶只存在于根瘤中,而尿囊素酶存在于所有器官。茎和荚皮中的尿囊素和尿囊酸含量较高,茎尿囊素和尿囊酸含量高峰在结荚后期,荚皮尿囊素和尿囊酸含量在结荚初期最高,以后迅速下降,根瘤尿囊素酶活性较其它器官高,在整个生育期中以结荚后期最高。荚皮中尿囊素和尿囊酸含量明显高于籽粒,而籽粒中尿囊素酶活性是荚皮1—3倍。 相似文献
11.
对福建省三明各县（市）1961—2008年汛期（5、6月份）的降水资料进行统计分析，揭示汛期雨量特多、特涝和异常偏涝年份的时间、地域分布特征和周期演变规律；用500hPa月平均高度场资料分析了2005年汛期异常偏涝的环流特征，并就2005年汛期异常偏涝与历史上特涝年的环流形势进行了对比分析。结果表明：5、6月份由于东亚大槽明显偏东，副高面积大、强度强，脊线明显偏南，印缅槽强度偏强，导致西风槽非常活跃，不断东移、南压，这是造成2005年三明各县（市）汛期异常偏涝的主要原因；5、6月份由于逐日副高脊线位置适中、稳定，导致三明各县（市）汛期开始早、结束迟、持续时间长，这是造成2005年汛期异常偏涝的原因之一。 相似文献
12.
茉莉3品种叶肉细胞超微结构的季节变化研究 总被引：2，自引：0，他引：2
应用透射电镜对地栽3茉莉品种叶肉细胞超微结构的季节变化进行详细观察和比较研究。结果显示,3茉莉品种春季和秋季叶肉细胞的超微结构完整,但夏季和冬季3茉莉品种叶肉细胞超微结构变化明显且品种间的变化有差异。茉莉遭受高温（夏季）或低温（冬季）胁迫时,叶肉细胞超微结构的变化具有适应意义,但随着胁迫时间的延长,细胞亚显微结构会受伤害。比较研究结果表明,双瓣茉莉比单、多瓣茉莉抗低温和高温能力更强,有细胞超微结构基础,在高温和低温胁迫下,双瓣茉莉细胞超微结构更稳定。 相似文献
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单双液相下不同多酚氧化酶源对酶性合成茶黄素的影响 总被引：9，自引：3，他引：6
比较了单双液相条件下不同来源的多酚氧化酶对酶性合成茶黄素效率的影响。结果表明,在本试验体系下单双液相试验中,以不同的酶源合成茶黄素的试验效果不同,就茶鲜叶酶源而言,双液相明显比单液相的效果要显著,在单液相系统中总乙酸乙酯层茶黄素总含量达33.74%,合成率为14.245%,而在双液相系统中,其总含量达39.74%,合成率为31.792%;而就梨酶源处理而言,单液相的效果要比双液相稍好,在单液相系统中总乙酸乙酯层茶黄素总含量达45.73%,合成率为18.799%;而在双液相系统中,其总含量达40.20%,合成率为22.11%;就苹果酶源而言,单液相比双液相的效果要好些,在单液相系统中总乙酸乙酯层茶黄素总含量达18.22%,合成率为13.34%;而在双液相系统中,其总含量达11.56%,合成率为6.935%。 相似文献
15.
茶叶中稀土元素的组成及存在状态 总被引：13，自引：0，他引：13
用ＩＣＰ ＭＳ分析了安徽省郎溪茶场的茶叶及茶园土壤中的稀土元素含量、组成及存在状态。结果表明：茶叶中含有其栽培土壤中所有的１５种稀土元素，其中以Ｌａ、Ｃｅ、Ｎｄ、Ｐｒ和Ｙ为主，这５种元素含量之和占稀土总量的９２％。茶叶中和土壤中的稀土元素在组成和分布模式上基本相同，只是茶叶对Ｌａ吸收相对较多，而对Ｃｅ、Ｙｂ吸收相对较少而已。茶叶中的稀土元素四分之三以上是不溶于热水而残存在茶渣中，其中又有１６％是与α 纤维素结合在一起的，因此，人们喝茶时摄入的稀土元素不足茶叶中稀土含量的四分之一（约０４８ｍｇ／ｋｇ，远低于≤２０ｍｇ／ｋｇ的国家允许标准）。茶叶中存在有稀土多糖复合物，茶汤中约有８％的稀土是以这种状态存在的。在稀土多糖中以Ｌａ、Ｃｅ、Ｎｄ为主，其含量约占８０％以上。 相似文献
16.
P. N. Satwadhar S. S. Kadam D. K. Salunkhe 《Plant foods for human nutrition (Dordrecht, Netherlands)》1981,31(1):71-76
Changes in polyphenols and in vitro protein digestibility due to germination and cooking were studied in horse gram and moth bean. Horse gram had higher amounts of polyphenols than moth bean. Polyphenol content in horse gram decreased from 1.6% to 1.1% at 48h germination, but in moth bean there was a reduction in polyphenol content from 1.3% to 1.0% at 24 h germination with a significant increase from 1.0% to 1.7% at 36 h germination. Seeds germinated for 48 h also exhibited higher amounts of polyphenols than in raw moth bean. The germination had no effect on total protein content, but a progressive increase in free amino acid content was observed in both legumes. In the ungerminated form, horse gram protein was more digestible than moth bean protein. The in vitro protein digestibility of both the legumes increased during germination. Cooking decreased the protein digestibility of horse gram either in ungerminated or germinated form, but such a decrease was noticed in moth bean at only 36 h germination. Moth bean either in raw form or germinated for 24 h did not exhibit a decrease in in vitro protein digestibility after cooking. Cooking decreased polyphenol content by 20%–50%. The apparent decrease in polyphenols in moth bean and horse gram due to cooking has been attributed to a decrease in assayable polyphenols. 相似文献
17.
发展专用品种提高玉米效益 总被引：6，自引：5，他引：6
根据当前及未来农业生产发展对玉米生产的需要，分析了黑龙江省专用玉米品种的应用现状及前景，对育种及相关方面存在的问题及解决办法进行了阐述，提出切合实际的育种发展战略。 相似文献
18.
The effects of fungicides used to control Rhynchosporium secalis in winter barley were investigated in five field trials in Co. Down, Northern Ireland. Benzimidazole resistance was present in the R. secalis population of each site. Fungicide performance was evaluated in terms of disease control, maintenance of green leaf area, grain yield and grain quality. Samples of R. secalis isolates taken before and after treatment in each field were assessed for sensitivity to carbendazim in the laboratory. Carbendazim contributed little to disease control, the maintenance of green leaf area, grain yield or grain quality. Carbendazim was associated with a significant increase in disease severity in some plots. Treatments containing carbendazim, either alone or in mixture, caused an increase in the proportion of carbendazim-resistant isolates within R. secalis populations. Propiconazole-containing treatments performed well in terms of disease control, maintenance of green leaf area and grain quality. They caused no change in carbendazim resistance frequency. 相似文献
19.
Summary Potato crops in subtropical climates are often subjected to water stress, resulting in low yields and poor tuber quality.
The yield response of potato genotypes to water supply was investigated in six trials, three each in spring and autumn plantings.
Trials were conducted under automated rain shelters, using an irrigation boom to impose five soil water regimes.
The negative effect of water stress on tuber yield was more detrimental in spring than in autumn, because of higher atmospheric
evaporative demand and higher temperatures in spring. An average yield reduction of 68% was recorded for the most severely
stressed regime in spring plantings, while the mean reduction for the same treatment in autumn was only 42%. Genotypic differences
in yield response to drought were clearly illustrated in spring, but not in autumn. This suggests that the choice of genotypes
is only influenced by the availability of water in spring, when more drought tolerant genotypes should be used. 相似文献