冰核活性细菌的分子生物学及防霜技术的研究进展

 从冰核活性细菌的分子生物学基础上,研究冰核细菌的基因遗传背景。并提出了冰核细菌的研究方法,防霜新技术的开发应用及冰核细菌在不同领域的应用等方面阐述冰核活性细菌的研究进展。     

玉米苗期冻害对生育期和产量影响分析

气候变暖背景下气温异常及变化对农业生产影响显著。针对2013年5月承德围场出现的低温冻害,通过对苗期受冻玉米进行跟踪调查和测定,分析了本次玉米冻害发生时的温度条件及影响。结果表明：玉米苗期气温骤降,日最低气温达-3.3℃,低于0℃的持续时间达4小时,玉米叶片受冻显著,但其生长点尚未冻死,后期可以缓慢恢复生长,但发育期推迟;苗期冻害,直接影响中后期玉米的营养生长,严重影响个体产量性状。在气候变暖情况下,须加强低温对农业生产不利影响的防范。     

北京园林树木遭受倒春寒冻害的春季温度特征分析

[目的]探讨北京市园林树木遭受倒春寒冻害的春季温度特征。[方法]根据温带倒春寒天气特征,对北京市的春季温度进行分析,并根据建成区公园树种组成分析倒春寒冻害的潜在威胁。[结果]倒春寒在40°N附近温带地区的发生规律是在4月份正常春季物候开始之前气温提前回暖并持续5 d以上后,最低气温立刻骤降至0℃以下所发生的冻害。2011—2016年北京市频繁发生倒春寒迹象,但是与2011—2013年相比,2013—2016年倒春寒天气迹象中的低温天数有所减少。[结论]北京市的多数落叶乔木都曾有遭受倒春寒冻害的记录,而常绿树种的受害比例较低。建议在未来北京城市绿化中多采用常绿树种代替落叶树种,以降低树木遭受倒春寒冻害的风险。     

Floral initiation in field-grown forage peas is delayed to a greater extent by short photoperiods, than in other types of European varieties

Frost is one of the main climatic stresses which has to be overcome by a winter pea crop. Some forage lines show a delayed floral initiation, which helps them to escape the main winter freezing periods, as a higher susceptibility to frost is observed after floral initiation commences. Frost tolerant forage peas have been used in all winter pea breeding programs in France and our main purpose was to evaluate to what extent those lines and the current winter varieties are variable for the date of floral initiation in field conditions. A field experiment was carried out during two years at the INRA experimental station of Mons (northern France). Different genotypes (9 in 1995–1996 and 12 in 1996–1997) were sown at approximately monthly intervals between September and June to provide a range of photothermal conditions. The date of floral initiation was determined by destructive sampling. We observed variability for the date of floral initiation among the different genotypes and sowing dates. Our data particularly highlighted the different reactions to photoperiod. Three varieties had no detectable reaction. Six varieties exhibited a quantitative response, with varied intensities. Lastly, the three forage varieties showed a qualitative, high response to photoperiod, which indicated the presence of the Hr allele, already described in Pisum. This revised version was published online in July 2006 with corrections to the Cover Date.     

使用壮早丰避霜剂对棉花生长发育的影响

经过3年田间试验与示范，研制出棉花促早避霜剂—壮早丰(配方编号97BS8)。棉花系统喷施壮早丰后，棉株株高降低9．89％～22．58％，主茎节间和果枝节间缩短，棉花株型紧凑，协调了营养生长与生殖生长关系，内围铃增多，单株铃数和铃重增加，生育进程加快，吐絮期提早2～4d，皮棉比对照增产5．4％～17．93％，对棉花纤维品质无不良影响。     

混凝土外加剂对混凝土的影响

介绍混凝土外加剂的概念和作用,针对目前传统混凝土、水泥砂浆在使用过程中常因塑性及干缩等原因产生开裂现象,提出在混凝土施工过程中适当加入混凝土外加剂有助于提高混凝土的强度和密实性,改善混凝土拌合物和易性,节约水泥,防止混凝土受冻破坏。     

低温胁迫对柑桔离体叶片质膜透性和MDA及V—C含量的影响

以兴津、Ｐｅｎｇ柑、朋娜脐橙、安江香柚４个品种的离体春叶为试材，测定了经不同时间（２，４，６，８ｄ）低温（－５Ｃ）胁迫和同一时间（２ｄ）不同低温（０，－５，－８，－１０Ｃ）胁迫后质膜透性和膜脂过氧化产物丙二醛（ＭＤＡ）及抗坏血酸（Ｖ－Ｃ）的含量，结果表明，柑桔抗寒性与电解质外渗量和ＭＤＡ含量呈负相关；与Ｖ－Ｃ含量呈正相关。这些还原性物质的浓度差异在抵抗低温伤害中具有重要意义，可作为柑桔各品种抗寒的     

Effect of common bunt on the frost resistance and winter hardiness of wheat (Triticum aestivum L.) lines containing Bt genes

In order to determine the effects of bunt inoculation on frost resistance and winter hardiness in lines containing resistance genes, the bunt [Tilletia foetida (Wallroth) Liro, T. caries (DC.) Tulasne] susceptibility of wheat lines containing bunt resistance genesBt1 to Bt10 and the effect of the year on the degree of infection were studied over six years from 1991 to 1997 in an artificial inoculation nursery. Uninoculated and artificially inoculated wheat plants were tested for frost resistance in the phytotron in 1995 and in the field in boxes in three years from 1994/95 to 1996/97. The line withBt10 was very resistant, lines with Bt5, Bt6, Bt8 and Bt9 were resistant, the line with Bt4 was moderately resistant, those with Bt2 and Bt3 were moderately susceptible, the line with Bt1 was susceptible and the line with Bt7 was very susceptible to the local bunt population in Hungary. Bunt incidence also varied over years. The frost resistance of the Bt lines was generally lower after bunt inoculation than that of uninoculated plants. The increased frost kill in inoculated plants was not correlated with the extent of varietal susceptibility to bunt. Some lines with resistance, namely those with Bt5 (1.6% infection), Bt8 (0.6%) and Bt10 (0.0%), suffered significantly greater frost kill in the young plant stage as the result of bunt inoculation. By contrast, the Bt7line had excellent frost resistance and winter hardiness but suffered the greatest extent of bunt infection, whereas the Bt6 line had good frost resistance and good bunt resistance. This revised version was published online in July 2006 with corrections to the Cover Date.     

基于多元统计分析的小麦低温冻害评价及水分效应差异研究

[目的]明确不同水分条件下低温胁迫引起的小麦冻害程度,筛选冻害鉴定指标并建立冻害定量评估模型,为小麦生产科学防控低温冻害提供理论支撑.[方法]以弱春性品种偃展4110、兰考198和半冬性品种郑麦366、丰德存麦21为试验材料,在模拟冻害发生前一周进行灌水(W)和不灌水(D)处理,于雌雄蕊分化期将盆栽小麦移到低温模拟室进...     

近50年宁夏酿酒葡萄晚霜冻日数及变化趋势分析

利用1961—2010年宁夏16个气象站的逐日最低气温资料,根据酿酒葡萄霜冻气候指标统计了终霜日、霜冻日数等。采用统计和气候诊断分析方法,研究了宁夏酿酒葡萄的晚霜冻日数和变化趋势。结果表明:近50 a全区酿酒葡萄晚霜冻平均日数为1.8 d/a;近50 a全区酿酒葡萄霜冻日数呈现减少趋势,引黄灌区霜冻日数的线性倾向率与全区接近;全区轻、中、重霜冻日数与50年平均相比,在20世纪70年代偏多,60和80年代基本持平,90年代及以后偏少;气候突变检验结果表明霜冻日数的突变年为1984年。