施用有机肥对春玉米生育后期叶片酶活性的影响

为了防止春玉米早衰,探讨施用有机肥对春玉米生育后期叶片酶活性的影响。我们采用盆栽方法,测定春玉米灌浆期和蜡熟期穗位叶超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性、丙二醛（MDA）和可溶性蛋白质含量。结果表明：随着有机肥（鸡粪）施用量的增加丙二醛的含量随之降低,超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性和可溶性蛋白质含量则随之提高。施用有机肥（鸡粪）26.7 g/kg土的处理,春玉米穗位叶的过氧化物酶（POD）活性和可溶性蛋白质含量下降。玉米灌浆期的穗位叶超氧化物歧化酶（SOD）活性普遍高于蜡熟期的。适量的施用有机肥可以提高春玉米生育后期叶片保护酶活性,防止或延缓春玉米的衰老。     

Structural Analysis of a Heteropolysaccharide from Saccharina japonica by Electrospray Mass Spectrometry in Tandem with Collision-Induced Dissociation Tandem Mass Spectrometry (ESI-CID-MS/MS)

A fucoidan extracted from Saccharina japonica was fractionated by anion exchange chromatography. The most complex fraction F0.5 was degraded by dilute sulphuric acid and then separated by use of an activated carbon column. Fraction Y1 was fractionated by anion exchange and gel filtration chromatography while Fraction Y2 was fractionated by gel filtration chromatography. The fractions were determined by ESI-MS and analyzed by ESI-CID-MS/MS. It was concluded that F0.5 had a backbone of alternating 4-linked GlcA and 2-linked Man with the first Man residue from the nonreducing end accidentally sulfated at C6. In addition, F0.5 had a 3-linked glucuronan, in accordance with a previous report by NMR. Some other structural characteristics included GlcA 1→3 Man 1→4 GlcA, Man 1→3 GlcA 1→4 GlcA, Fuc 1→4 GlcA and Fuc 1→3 Fuc. Finally, it was shown that fucose was sulfated at C2 or C4 while galactose was sulfated at C2, C4 or C6.     

Evaluation in pot and field trials of resistance of potato cultivars and breeding lines to common scab caused byStreptomyces scabies

Summary The resistance to common scab of nine cultivars and eight advanced breeding lines of potatoes, fiveSolanum andigenum Juz. et Buk. clones, and three potato breeding lines selected for resistance to common scab, was investigated in a field and a pot trial. In the pot trial potaroes were planted in inoculated coarse river sand in plastic pots (150 mm in diameter) placed on irrigated subsoil in a glassfibre house. In a field trial potatoes were planted in an artificially infested field. The harvested tubers were scored individually for scab incidence according to two scales, viz. a 1–5 point scale for percentage surface covered with scab and a 1–3 point scale for lesion type. A scab index value was calculated for each tuber. A significant correlation coefficient of 0.82 was obtained for the results of the two tests.     

Response and resistance of cereal crops to pathogens

正The special topic of the two papers is the systemic acquired resistance (SAR) and pathogenesis-related protein genes(PR). SAR is an enhanced resistance against further potential parasite beyond the initial infection site, which can be induced by either pathogen infection or exogenous inducer, including synthetic chemicals and natural products. As awhole-plantresistance defense, SAR confers     

广西大明山土壤微生物数量及酶活性研究

[目的]探明土壤微生物数量及酶活性与土壤肥力的关系,为合理开发利用广西大明山土壤提供参考.[方法]按土壤发生分类法采集9种典型土壤类型的剖面样品,测定其微生物数量和酶活性,并与土壤性质进行相关性分析.[结果]土壤三大菌的数量为:细菌>放线菌>真菌;土壤微生物总数量总体以粗骨土最多,为88.53×105 CFU/g,以草旬土最低,为8.87×105 CFU/g;随土壤剖面深度的加深而呈下降趋势;土壤三大菌数量与土壤有机质、全N、全P、碱解氮、速效钾呈显著或极显著正相关,与土壤pH值、土壤全K呈显著或极显著负相关.土壤脲酶与蔗糖酶活性表聚现象明显,其活性随土壤剖面深度的加深而呈降低趋势;土壤脲酶、蔗糖酶与有机质、全N、全P、碱解氮和速效钾呈极显著正相关,与pH值、全K呈极显著负相关.土壤过氧化氢酶除了与全K呈显著负相关外,与其他土壤性质不存在显著相关性.[结论]土壤微生物数量、土壤脲酶和蔗糖酶活性均可作为评价大明山土壤性质指标.     

野生蔬菜—地笋根状茎膨大动态及其数学模型的研究

在地笋根状茎膨大期间,对地笋根状茎的鲜质量、干质量、茎粗(最大直径)、茎长、体积、节数、节间长以及库活性等进行测定,并对膨大的主要指标构建数学模型,推断其生长规律。研究结果表明,在地笋根状茎膨大过程中,鲜质量和干质量的增加速率均表现为慢—快—慢,呈"S"形曲线,鲜质量与干质量呈极显著正相关;茎粗(最大直径)表现为前期迅速增加,后期缓慢增加,茎长表现为先缓慢增加后迅速增加接着又缓慢增加,膨大早期以增粗为主,膨大后期以增长为主;地笋根状茎的体积变化表现为前期缓慢增加,后期迅速增加,生长速率快速增加的初始时间较鲜质量快速增加的初始时间晚15d,说明地笋根状茎的膨大早期以质量增加为主,后期以体积增加为主;地笋根状茎节数随膨大时间的延长持续增加,增加速率为慢—快—慢,平均节间长则表现为持续变短;地笋根状茎的库活性在膨大前期迅速增强,维持一段时间度后呈现下降趋势。对地笋的鲜质量、干质量、根状茎长、根状茎粗、体积进行回归建模,均拟合良好,运行数学模型,得出的变化规律与实际测量值的变化规律基本吻合。     

洛阳市农业科技扶贫的现状与对策

总结了洛阳市“九五”科技扶贫的成效,找出了存在的问题,并提出了今后搞好科技扶贫工作的对策:增强科技扶贫意识,加大科技投入力度,加速科技成果的转化和应用,围绕公路沿线发展新的经济增长点或增长带,培育农产品加工企业和名牌产品,走具有山区特色的扶贫开发之路。     

水稻低纤维突变体LCM527-1性状鉴定、遗传分析与基因定位

水稻茎秆机械强度是抗倒伏能力强弱的一项重要指标。为了深入研究水稻茎秆机械强度和抗倒伏特性的内在生理、生化、遗传和分子等方面机制,经400Gy 60Coγ射线诱变和筛选,获得了一个特异性低纤维突变体LCM527-1。经考查,该突变体与野生型品种527(WT)相比,除整个生长期间表现出茎秆、叶片、叶鞘、穗颈和枝梗均脆性及极易折断外,还伴随有生长势偏弱、植株变矮、穗数减少、剑叶和穗变短等形态特性。抗倒伏指数、茎秆单位长度的鲜质量和干质量以及倒一节和倒二节抗折断力均明显降低,茎秆中Ca、Si、K等重要组成元素显著减少,茎秆纤维素含量显著下降,半纤维素含量增高。遗传分析表明,该低纤维突变性状受单隐性核基因控制(暂名为lcm527-1),利用SSR分子标记将lcm527-1基因定位于2号染色体的RM3774和RM1092之间,遗传距离分别为10.6cM和5.1cM。这些结果将为今后研究低纤维突变及其精细定位提供依据,也为深入研究水稻抗倒伏机制提供分子生物学支持。     

猫绦虫病防治初报

本文经过对保定市家猫粪便抽查统计,表明猫绦虫感染率为33.33%。就诊的绦虫病猫约为猫就诊病例总数的9.13%。用绦灵散驱治88例次,效果良好。在送检29侧次中,13例次为肥颈带绦虫,15例次为犬复孔绦虫,1例为肥颈带绦虫与犬复孔绦虫双重感染。犬复孔绦虫最大感染强度为541条,平均49.38条。肥颈带绦虫最大感染强度为12条,平均4.93条。     

主要城市绿化树种苗木耗水特性研究

利用Licor-6400便携式光合作用测定系统,对18种盆栽城市绿化苗木的蒸腾耗水特性进行了测定.结果表明,针叶树种耗水速率低于阔叶树种.针叶树种中日最大耗水速率以油松(Pinus tabulaeformis)最大(35.83g/h),侧柏(Platycladus orientalis)最小(17.15g/h);阔叶树种中,火炬树(Ehus typhina)、刺槐(Robina pseudoacacia)、元宝枫(Acer mono)、紫穗槐(Amorpha fruticcosa)耗水速率的最大值分别达5