不同研究方式和方法对小麦根系活力及根质量测量准确度的影响

为增强不同研究方式和方法条件下小麦根系研究的可比性,以郑麦9023和矮抗58为材料,于2010-2011年度研究了不同研究方式和方法对根系生理活性及根质量测量值的影响。结果表明,其他条件相同时,盆栽条件下的根系活力(以鲜质量计)显著高于大田,不同生育期分别为24.607～334.839,29.362～298.834μg/(g.h)。室内培养时,不同培养基质条件下的根系活力大小顺序是水培>珍珠岩培>沙培>蛭石培>土培,不同处理间的差异达显著水平。大田和盆栽条件下,直接冲根与筛网包裹冲根处理的单株根量损失率分别为45.57%～70.25%,15.79%～34.28%,差异达极显著水平。研究认为,盆栽条件下的根系活力测定值仅可作为大田栽培条件下的一个参考;室内培养条件下,为使根系活力测定值更具有可比性,应注明培养基质种类;研究中,建议采用筛网包裹冲洗的方法以获得准确的根质量测量值。     

玉米根系活力与耐铝性的关系

铝胁迫可提高耐铝自交系根系还原力，而铝敏感自交系TTC还原强度则显著下降,表明自交系根系TTC相对还原强度与耐铝性具有很好的一致性。耐铝自交系根系活跃吸收面积，尤其是根系活跃吸收面积占总吸收面积的比例相对较高。铝胁迫可维持或略提高铝自交系根系氧化力，而敏感自交系根系氧化力则有所下降，说明耐铝自交系在铝胁迫下仍可维持较高的呼吸代谢活性。铝胁迫可造成玉米自交系伤流量减少，且敏感自交系降幅较大。     

利用种子醇溶蛋白选育玉米姊妹系和姊妹种的研究

不同分离世代产生的姊妹系配制的早晚代姊妹种在农艺性状、产量和种子蛋白图谱上存在很大的差别。大多数早代姊妹种种子蛋白谱带具有双亲的互补带，并表现出较强的优势，晚代姊妹种的种子蛋白图谱基本上与亲本相同，优势不及早代姊妹种明显。     

Research on treatment efficiency of deep sequence constructed wetlands

According to the problems that traditional constructed wetlands have low nitrogen removal performance and large areas, deep sequence constructed wetlands(DSCW) is proposed and the influences of depth of wetland, filler particle size and operational states of DSCW on treatment efficiency are investigated. The experimental results show that when the depth of wetland is increased from 0.5 m to 2 m, it has no significant influent on its treatment efficiency. The running condition has influence on its treatment efficiency. When the water temperature is 20~25 ℃ and operating condition of DSCW is inlet water 8 min-reaction 12 h-outlet water 8 min-idle 12 h, the removal rate of COD, NH+4-N, TN, PO3-4-P is 83.8%, 54.1%, 48.1%and 63.9% respectively by DSCW with the depth of 2 m. The area load for COD, TN, PO3-4-P is 128, 17.6, 1.49 g/(m2·d) respectively, raised 2.4 times, 2 times and 1.71 times respectively compared with traditional constructed wetlands. Land occupation for processing 1 m3 wastewater is 1.87 m2, decreasing 3~5 times commendably. Compared to DSCW system of particle size of gravel of 20~30 mm, the removal rate of COD, NH+4-N, TN and PO3-4-P of DSCW system of 5~10 mm is increased by 3.8%, 7.9%, 3.8% and 7% respectively. The filler particle size exhibits some influences on DSCW efficiency.     

Error analysis of worm grinding wheel precise dressing by diamond roller with straight profile

In worm grinding wheel dressing with diamond roller, using straight line instead of theoretical curve of roller will result in dressing error. Method of the precise dressing is studied, while the mathematical model is presented. Theoretical curve of diamond roller is calculated based on the space meshing theory and helicoid equation of worm grinding wheel. The fitting error between the theoretical curve and approximate straight line which is obtained by the theoretical curve is calculated. The dressing error on normal section of worm grinding wheel is analyzed. The case study of a kind of worm grinding wheel with single head shows that the dressing error increases with diameter decreasing of worm grinding wheel and diamond roller, while the variation of diamond roller’s diameter makes little contribution. The validity of worm grinding wheel dressing using straight line diamond roller is proved, and the algorithm can be used as guidance in practice.     

红树内生细菌AmS2防治香蕉采后炭疽病的研究

采用平板对峙结合生长速率法测定分析了红树内生细菌AmS2菌株及其甲醇粗提液对香蕉炭疽病菌的抑制活性,并对其甲醇粗提液的防病效果进行了研究。结果表明,红树内生细菌AmS2菌株及其甲醇粗提液对香蕉炭疽病菌的抑菌带宽分别为12.0 mm和11.5 mm;毒力测定结果表明,AmS2甲醇粗提液对香蕉炭疽病菌的菌丝生长和孢子萌发均有较强的抑制作用,EC50分别为1.007 6 mg/mL和1.902 8 mg/mL;AmS2菌株的甲醇粗提液对香蕉炭疽病具有较好的防治效果,且随着提取液浓度的加大,防治效果不断提高,当AmS2甲醇粗提液使用浓度为4.0 mg/mL时,对接种香蕉炭疽病菌10 d后的防治效果为79.83%。     

超高茬麦套稻的产量及低碳效应分析

通过对超高茬麦田套稻稻作方式的机理进行了介绍,分析了其低碳优势和高产原因,为现代农业生产提供参考。     

平塘县玉米地膜覆盖栽培技术要点及成效

平塘县属典型的喀斯特山区,土地破碎,水源条件较差,实施玉米半膜覆盖保墒技术项目能增温保墒,弥补温、光、水资源的不足,从而提高玉米产量。在农村劳动力少、常年干旱情况下,实行玉米地膜覆盖栽培,既减少劳动力投入又起到增收目的。对平塘县2012年实施玉米地膜覆盖主要栽培技术及应用效果进行分析总结,可供贵州山区实施地膜覆盖提供参考。     

白菜型冬油菜抗坏血酸过氧化物酶(APX)基因的克隆、表达及其活性分析

抗坏血酸过氧化物酶(APX)是一种在逆境条件下清除细胞内氧自由基、增强植物抗逆性的关键酶。本研究根据已发表植物抗坏血酸过氧化物酶基因APX的同源保守序列设计引物, 采用RT-PCR扩增超强抗寒白菜型冬油菜陇油7号的DNA, 获得APX基因开放阅读框, 长度为753 bp, 编码250个氨基酸残基, 推导的氨基酸序列具有APX蛋白的典型特征。生物信息学分析显示, 与已报道的大白菜的APX氨基酸序列同源性达到99%, 该酶蛋白具有高度的进化保守性, 其保守序列属于植物的POD超家族, APX相对分子质量和理论等电点依次为27.7 kD和5.58;APX基因无信号肽, 是一个亲水性蛋白, 可推测其定位于细胞质中;二级结构预测表明陇油7号的APX是由不规则卷曲和α-螺旋组成的稳定蛋白。实时荧光定量PCR和酶活性分析显示, 该基因表达和酶活性受低温胁迫诱导, 表明该基因在白菜型冬油菜陇油7号适应低温胁迫过程中发挥重要作用。