玉米深层根系对地上部营养生长和产量的影响

采用切断土柱根系方法,研究了在玉米拔节期和抽雄期时土表20 cm和40 cm以下根系对玉米杂交种四密21和掖单19地上部营养生长和产量及其构成因子的影响.结果表明,与不断根相比,在抽雄期切断20 cm深处根系,使四密21和掖单19株高分别降低37.1 cm和32.1 cm,叶绿素总量降低20.0%和37.0%,光合速率降低21.6%和19.6%,百粒重降低12.1%和9.0%,穗粒数减少18.8%和17.5%,产量降低26.2%和20.0%.切断土层40 cm深处根系,株高分别下降23.5 cm和23.6 cm,百粒重下降10.1%和5.2%,穗粒数减少13.1%和12.0%,产量降低21.5%和18.6%.拔节期断根使叶绿素含量显著降低,切断20 cm深处根系使四密21和掖单19叶绿素降低13.6%和25.2%,切断40 cm深处根系使叶绿素下降10.4%和14.2%.切断根系对玉米产量的影响,为抽雄期大于拔节期。     

不同耕作方式对松嫩平原半干旱区玉米生长和产量的影响

耕作方式影响玉米的生长和产量。设置旋耕垄作(RT)、旋耕垄作深松(RTS)、免耕(NT)、免耕深松(NTS)、旋耕平作(FT)、旋耕平作深松(FTS)6个处理,分析不同耕作方式对玉米苗期根系生长、干物质积累、净光合速率和产量构成,研究不同耕作方式对半干旱区玉米生长和产量的影响。结果表明,免耕处理显著降低了玉米苗期根系的鲜重、干重和体积。旋耕垄作、旋耕平作和免耕结合深松处理干物质积累量较未深松处理增加3.17%～15.08%,旋耕平作结合深松处理提高了玉米有效穗数、玉米净光合速率,进一步提高玉米产量。     

Influence of Moisture Content,Variety and Parboiling on Milling Quality of Rice Grains

The effects of moisture content （8%, 10%and 12%）, variety （Tarom and Fajr） and parboiling on milling quality of rice as a function of milling recovery （MR）, head rice yield （HRY）, degree of milling （DOM） and whiteness were investigated. The parboiled grains was prepared with three soaking temperatures of 25 oC, 50 oC and 75 oC and three steaming times of 10, 15 and 20 min. As a result of parboiling, the increasing rates of MR and HRY values were 7.8%and 14.3%for Tarom and 9.8%and 10.0%for Fajr, respectively, and the decreasing rates for DOM and whiteness were 6.6%and 10.8%for Tarom and 6.8% and 10.5% for Fajr, respectively. Moreover, decreasing moisture content to 8%maximized MR （75.8% for Tarom and 74.3% for Fajr） and HRY （65.8% for Tarom and 57.0% for Fajr） while increasing that to 12%revealed maximum values of DOM （6.1%for Tarom and 6.2%for Fajr） and whiteness （24.8%for Tarom and 28.2%for Fajr）.     

氮肥对水稻节间和叶鞘非结构性碳水化合物积累转运特征的影响

以两优培九和扬稻6号为材料进行盆栽试验,研究低氮(N1)和高氮(N2)处理下水稻主茎上部3个节间和叶鞘非结构性碳水化合物(NSC)的积累转运特征及对氮肥用量的响应。结果表明:1)与N2处理相比,N1处理总体上显著促进灌浆早期两优培九倒2、倒3节间和叶鞘NSC的转运,对扬稻6号的影响差异不明显;N1处理显著增加了扬稻6号上部3个节间及叶鞘和两优培九倒3节间及叶鞘NSC表观转运量,也增加了两品种上部3个节间及叶鞘的NSC(总)表观贡献率。2)两个氮肥处理下,供试品种的叶鞘(两优培九倒3叶鞘除外)NSC转运量和表观贡献率大于节间。3)两优培九倒2、倒3节间及叶鞘NSC表观转运量和贡献率、上部3节间及叶鞘的NSC总转运量与总表观贡献率在两个氮肥处理下均高于扬稻6号。4)N1处理下,两优培九和扬稻6号倒2、倒3节间及叶鞘的转运量分别占总转运量的92%和75%,贡献率分别占91%和76%;而N2处理下两优培九倒2、倒3节间及叶鞘的转运量占90%,扬稻6号倒2、倒3节间则无输出。本研究表明水稻上部3个节间和叶鞘的NSC(总)转运量品种间存在差异,并受施氮量和节/叶位的影响。在水稻高产和减氮栽培中,通过选用适宜品种和优化氮肥管理,增加花前茎鞘NSC积累和花后NSC再分配,对提高水稻产量潜力和氮效率,特别是对花后逆境和减氮条件下产量稳定具有重要意义。     

Lime and phosphorus influence Kennebec potato yield and chemical composition

An experiment conducted in 1970 and 1971 with Kennebec potatoes on a Typic Cryothod near Willow Creek in Alaska compared the effects of seven P rates, with and without lime, on yields and chemical content of foliage and tubers. Each P increment increased plant vigor, foliage and tuber yields, P percentage in both foliage and tubers, K, Ca, and Sr concentration in the foliage and tubers, K, Ca, and Sr concentration in the foliage, and N, P, K, Ca, and Mg uptake by both foliage and tubers. The higher P rates depressed the A1 and Fe concentration in the foliage and the Ba in the tubers. Additions of high rates of P also tended to increase available P in the soil. Lime application decreased soil acidity, increased plant vigor, practically eliminated physiological leaf necrosis, and increased Ca and depressed Mn and Zn concentrations of both foliage and tubers. Lime further depressed the concentrations of A1, Ba, B, Cu, Fe, and Sr in the foliage and the Ba of the tubers. The uptake of N, P, K, Ca, Mg, and Na were also increased with lime applications because yields were greatly increased. Comparison of Ca/Mn and Mn/Fe ratios with those of another researcher (5) suggested a possible Mn toxicity. The concentrations of N and Cr in both foliage and tubers, and the amount of P, K, Na, A1, B, Cu, Fe, and Sr in the tubers were not influenced significantly by lime.     

种植密度对不同夏玉米品种饲用和青贮品质的影响

以登海605(DH605)、京农科728(JNK728)和山农饲玉2号(SY2)为试验材料,设置3个种植密度60 000株/hm²、75 000株/hm²和90 000株/hm²(记作D6、D7.5和D9),研究种植密度对不同夏玉米品种不同收获期及不同器官饲用和青贮品质的影响。研究结果表明,随着种植密度增加,DH605的鲜物质和干物质产量显著提高,D9密度下的鲜物质和干物质较D6分别增加17.32%和23.19%,较D7.5分别增加6.26%和7.13%;JNK728和SY2的鲜物质和干物质产量呈现先增加后降低的趋势。蜡熟期进行收获和青贮,玉米的饲用价值最高,以D7.5密度为例,DH605蜡熟期玉米粗饲料分级指数分别较乳熟期和完熟期增加8.31%和27.80%,JNK728分别增加12.55%和75.52%,SY2分别增加7.13%和58.10%;同时瘤胃降解率最高,各品种趋势一致。果穗青贮的饲用品质较秸秆青贮显著提高。本试验研究结果,DH605的最佳种植密度为90 000株/hm²,JNK728和...     

大豆品种(系)耐低钾性的筛选与评价

从国内外收集到不同来源大豆56份在低钾土壤上种植，发现不同品种（系）大豆对低钾的耐性上存在着较大的差异性。通过研究耐性与产量的关系。将这些品种（系）分为高产敏感型，高产不敏感型，低产敏感型和低产不敏感型4种类型。其中高产不敏感型与低产不敏感型具有钾高效基因。可作为基因材料应用于栽培和遗传育种的研究上。     

高校院系学生会工作企业化运作模式初探

高校院系学生会工作是高校院系思想政治教育工作的重要载体，为大学生提供了锻炼自我和素质拓展的平台，学生会工作的模式直接影响到其工作效率和高校思想政治教育工作的效果。现结合自身工作经验，对高校院系学生会同企业进行比较和分析，从资金来源、人事任免、工作制度、组织活动等方面阐述院系学生会工作企业化运作的利与弊，并为改进工作提出探索意见。     

玉米花生带状间作对植株氮吸收和土壤微生物群落的影响

为探明玉米花生带状间作模式下植株氮吸收利用和土壤微生物群落特征,设置玉米单作（SM）、花生单作（SP）和玉米花生间作（IMP）三种种植模式,系统分析了不同种植模式下氮素吸收利用规律,并采用16S/ITS测序技术明确玉米花生带状间作系统下根际土壤细菌/真菌群落结构变化。结果表明,间作玉米边行优势明显,地下和地上部干物质积累量和氮积累量显著高于单作玉米和间作玉米中间行。间作玉米和间作交互区根际土壤细菌和真菌多样性和丰富度降低,而间作花生根际真菌多样性和丰富度增加,其中变形菌门、担子菌门、子囊菌门等有益菌最为显著富集。土壤中细菌和真菌存在复杂的相关性,变形菌门与子囊菌门正相关。间作丰富了物种功能多样性,参与氨基酸运输、代谢和碳水化合物代谢的细菌和腐生营养型真菌的显著富集,改善了植物养分吸收,促进了植株生长发育。可见,玉米花生间作可通过优化土壤微生物的群落结构,促进植株对氮素的吸收和利用,本研究为玉米花生带状间作氮营养互促吸收提供了科学依据。     

不同裸燕麦品种抗倒能力及产量差异分析

为筛选抗倒伏能力强的高产裸燕麦品种,对16个裸燕麦品种的抗倒伏能力和产量进行比较,利用主成分分析和通径分析对与抗倒伏相关的7个性状进行分析。结果表明,裸燕麦品种间地上部生物量构成、主要农艺性状、茎秆基部第二节间形态及倒伏指数、产量及其构成因素均存在差异。通过主成分分析和通径分析,株高和穗位高是评价裸燕麦抗倒伏能力的关键。产量较高的白燕2号、白燕18号、花早2号的株高、穗位高较低,倒伏指数较小且田间未发现倒伏;坝莜14号、晋燕17号虽具有较高产量,但其株高、穗位高较高,倒伏指数较大,且田间分别表现为7级易倒伏和5级中抗倒伏。白燕2号、白燕18号、花早2号抗倒伏综合表现良好,产量高,适宜在内蒙古乌兰察布地区及类似地区推广种植。     

灌溉和施氮对小麦产量形成及土壤肥力影响的研究进展

水分和氮肥是小麦生长发育和产量形成中最重要的两个因子,二者存在相互制约或相互促进等互作关系。近年来,由于灌溉大量用水和氮肥的过量施用,造成了农业水资源匮乏和环境污染加重等一系列问题,合理灌溉和施氮以提高水氮利用效率越来越受到广泛的重视。为全面概括灌溉和施氮处理的作用,本文从小麦植株和土壤两个方面入手,对近年来国内外学者在灌溉和施氮对小麦产量形成和土壤肥力影响方面的研究进展进行了综述,为评估长期灌溉和施氮处理对小麦生产和土壤肥力的影响、制定灌溉和施氮技术措施提供依据。     

Effect of home processing on total and extractable calcium and zinc content of spinach (Spinach oleracia) and amaranth (Amaranthus tricolor) leaves

Spinach (Spinacia oleracia) and amaranth (Amaranthus tricolor) leaves were stored in polyethylene bags and without packing for 24 and 48 hours in a refrigerator at 5 and 30 °C in polyethylene bags. The fresh leaves were also dried (oven and sun); blanched (5, 10 and 15 min) and cooked in an open pan and a pressure cooker. The processed leaves were analysed for total and extractable calcium and zinc content. The Ca and Zn content of these leaves varied from 1320 to 2120 and 11.70 to 12.60 mg/100 g DM and the percentage HCl-extractability was 77.82 to 81.92 and 85.16 to 86.15, respectively. No significant effects of drying and storage were observed on total Ca and Zn content and HCl-extractability while blanching and cooking resulted in significant improvement of HCl-extractibility of these two minerals. Thus, cooking and blanching are good ways to improve the HCl-extractibility of Ca and Zn.     

Changes in Enzyme Activities Involved in Starch Synthesis and Hormone Concentrations in Superior and Inferior Spikelets and Their Association with Grain Filling of Super Rice

The changes in activities of key enzymes involved in sucrose-to-starch conversion and concentrations of hormones in superior and inferior spikelets of super rice were investigated and their association with grain filling was analyzed.Four super rice cultivars,Liangyoupeijiu,IIyou 084,Huaidao 9 and Wujing 15,and two high-yielding and elite check cultivars,Shanyou 63 and Yangfujing 8,were used.The activities of sucrose synthase (SuSase),adenosine diphosphoglucose pyrophosphorylase (AGPase),starch synthase (StSase) and starch branching enzyme (SBE),and the concentrations of zeatin + zeatin riboside (Z + ZR),indole-3-acetic acid (IAA) and abscisic acid (ABA) in superior and inferior spikelets were determined during the grain filling period and their relationships with grain filling rate were analyzed.Maximum grain filling rate,the time reaching the maximum grain-filling rate,mean grain filling rate and brown rice weight for superior spikelets showed a slight difference between the super and check rice cultivars,but were significantly lower in the super rice than in the check rice for inferior spikelets.Changes of enzyme activities and hormone concentrations in grains exhibited single peak curves during the grain filling period.The peak values and the mean activities of SuSase,AGPase,StSase and SBE were lower in inferior spikelets than in superior ones,as well as the peak values and the mean concentrations of Z + ZR and IAA.However,the peak value and the mean concentration of ABA were significantly higher in inferior spikelets than in superior ones and greater in the super rice than in the check rice.The grain filling rate was positively and significantly correlated with the activities of SuSase,AGPase and StSase and the concentrations of Z + ZR and IAA.The results suggested that the low activities of SuSase,AGPase and StSase and the low concentrations of Z + ZR and IAA might be important physiological reasons for the slow grain filling rate and light grain weight of inferior spikelets in super rice.     

Chemical characterization of barks from Picea abies and Pinus sylvestris after fractioning into different particle sizes

The composition of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) barks was studied after grinding and fractioning into different particles sizes.Both barks fractionated well and with similar fraction yield profile. The yield of fines was low and the major fractions were larger particles, i.e. 2.4% and 3.1% of particles under 0.425 mm and 66.0% and 50.3% of particles over 2 mm, respectively for spruce and pine bark.The chemical composition of spruce and pine barks, as a mass weighed average of all granulometric fractions was, respectively: ash 3.3 and 4.6%; total extractives 21.6 and 18.8% (hydrophilic extractives were dominant), lignin 27.9 and 33.7% and holocellulose 42.7 and 37.6%. Suberin accounted for 1.3% and 1.6% of spruce and pine bark, respectively. The non-cellulosic monosaccharides showed in both barks predominance of arabinose followed by xylose and mannose.Ash elemental composition showed that N represented about 35% of the total inorganics, Ca 35% and K 17%. Zn, Cu, Ni, Cr and Pb were present in both barks at levels under 1% of the total inorganics. Spruce bark had in average higher contents compared to pine bark, except for Pb and Cr.Size reduction of spruce and pine bark did not apply randomly to the different components and instead resulted into partial separation of the inorganic and organic matter into different size particles. Fine particles concentrated higher amounts of inorganic material and of extractives.     

胶园间作研究的现状、存在的问题及未来研究方向

目前，胶园间作研究多集中在幼龄胶园，而对成龄胶园研究不多，多局限在生产力、生态、水分、化感作用、营养元素的生物循环与能量流动及经济效益上，而很少把它作为一个完整的复合生态系统来研究橡胶树与间作作物之间养分竞争、水分竞争，而养分、水分资源协同高效利用的研究则更是少见。未来胶园间作的研究应着眼于成龄胶园，解决成龄胶园各组分之间的养分、水分竞争问题，着重探讨成龄胶园根系及其分泌物对养分、水分竞争的影响作用，阐明养分、水分竞争的机制，提高间作系统养分、水分利用率，为成龄胶园间作中资源高效利用提供理论依据和技术支持。     

秸秆覆盖深松对夏玉米花后穗位叶衰老和产量的影响

采用4种保护性耕作模式(深松覆盖、深松不覆盖、免耕覆盖、免耕不覆盖)在河南西平进行了3年田间试验,研究不同处理对玉米花后不同时期穗位叶超氧化物歧化酶(SOD)和过氧化物酶(POD)活性、丙二醛(MDA)含量的影响。结果表明,与其他3种处理相比,深松覆盖处理下玉米穗位叶一直保持着较高SOD、POD活性,在花后15d、30d显著高于其他处理;深松覆盖花后一直保持着较低的MDA含量,并且显著低于其他处理;深松覆盖处理产量比深松不覆盖、免耕覆盖、免耕不覆盖处理分别高2.17%、6.06%、14.13%,差异达到显著水平。研究表明,深松覆盖在降水较多的豫南雨养区能取得良好的增产效果。     

普洱市小粒咖啡病虫害种类调查分析

对云南省普洱市小粒咖啡主要栽种区病虫害及荫蔽树种类、杂草和荫蔽树与咖啡病虫害的关系进行调查研究。结果发现普洱市小粒咖啡害虫有13种,病害有7种,常用荫蔽树有17种。文中还分析杂草和荫蔽树与咖啡病虫害关系,就普洱市咖农的管理技术提出建议。     

雷公藤叶部病虫害的发生现状、成因及对策

随着栽培面积、规模的扩大和病虫害管理水平的滞后,地道性中药材雷公藤目前正遭受病虫害的严重危害。2009、2010年对福建省泰宁县雷公藤病虫害进行调查表明,雷公藤叶部病虫害主要表现为危害种类不断增加,复合危害现象普遍,不同藤龄、不同生境的雷公藤上发生水平也各不相同。防治观念淡薄,生产措施不当,管理水平偏低,病虫害的危害潜能较大以及气候异常等是导致叶部病虫害成灾的主要因素。因此,应在边防治边研究的基础上,逐步建立健全预测预报体系,采取有效的无公害病虫害防治技术,确保雷公藤产业的健康发展。     

不同耕作方式对玉米田土壤物理性质及产量的影响

通过对土壤容重、总孔隙度、含水量、田间持水量及玉米产量的测定和分析,研究一次性施肥条件下深松-旋耕、深松-免耕、常规旋耕和免耕不同耕作方式对土壤物理性状及玉米产量的影响。结果表明,不同耕作方式对土壤容重和土壤含水量的影响效果为深松-旋耕深松-免耕常规旋耕免耕;对土壤持水量的影响效果为深松-免耕常规旋耕深松-旋耕免耕;对玉米产量的影响效果为深松-免耕免耕常规旋耕深松-旋耕,深松-免耕和免耕分别与深松旋耕和常规旋耕的产量差异达极显著水平,深松-免耕较常规旋耕增产15.68%,产量高达6 829.73 kg/hm2。     

花生中两个硬脂酰-ACP去饱和酶基因的克隆与序列分析

脂肪酸去饱和酶是不饱和脂肪酸合成途径的关键酶,催化脂肪酸链特定位置上脱氢形成双键.本研究通过构建花生种子全长cDNA文库,结合大规模EST测序和RACE克隆等方法,从花生中克隆得到了两个FAB2基因,分别命名为AhFAB2-2和AhFAB2-3.其中AhFAB2-2全长为1387bp,ORF为1158bp,理论分子量为43.7 kD,理论等电点为5.69;AhFAB2-3全长为1452bp,ORF为1188bp,理论分子量为44.9 kD,理论等电点为6.37.它们推导的氨基酸序列与拟南芥的相似性依次为60.8％和57.2％;与大豆的相似性分别是62.3％和59.3％.这两个基因在GenBank上的登录号分别为KF358459和KF358460.