水稻PFP基因的克隆及其遗传转化

采用RT–PCR方法,成功克隆到1个与水稻苗期耐热相关的基因PFP,构建了该基因的超表达载体,通过基因枪法转化水稻品种中花17,获得9个转基因阳性植株,与对照相比,T1代转基因植株的苗期耐热性明显增强。33个代表性地方水稻品种的耐热表型与PFP基因型的相关性分析结果表明,PFP基因的基因型与品种的耐热表型存在显著的相关性。本研究中还分析了该基因在盐、4℃低温、PEG和ABA胁迫处理下的基因表达情况。     

Possible involvement of fructose 1,6-bisphosphatase in cold-induced sweetening of potato tubers

Summary In measuring fructose 1,6-bisphosphatase (EC 3.1.3.11; FBPase) in potato tubers, we used anti PFP antibodies to ensure that the assay was specific for FBPase and that PPi:fructose 6-phosphate 1-phosphotransferase (EC 2.7.1.90: PFP) did not contribute to the production of fructose 6-phosphate (Fru-6-P). The involvement of cytosolic FBPase in cold sweetening was determined by monitoring enzyme activity during storage ofSolanum tuberosum cv. Erntestolz tubers at 2 or 8°C. In contrast to the rapid increase in sucrose and reducing sugars, the specific activity of FBPase showed no change and PFP rose slightly during storage at 2°C. Sugar concentrations and enzyme activities remained virtually unchanged during storage at 8°C. These data allow the interconversion of fructose 1.6-bisphosphate (Fru-1,6-P₂) to Fru-6-P and vice versa by FBPase and PFP, respectively, in potato tubers, but do not support a causal relationship between coarse metabolic control of FBPase and cold-induced sweetening.     

水稻测土配方施肥试验的肥料效应研究

为提高水稻施肥效益,定制合理的肥料施用配方,进行了测土配方施肥与常规施肥试验。结果表明测土配方施肥能够提高肥料农学效率,单位施肥量对于产量的贡献明显提高。其中尿素、重过磷酸钙、氯化钾、NPK的肥料农学效率值分别提高28．1％,82．4％,44．7％,48．8％;肥料偏生产力值提高37．0％;测土配方完全施肥区较常规施肥区产量增加785kg／hm2,提高9．9％。     

Molecular approaches for enhancing sweetness in fruits and vegetables

The quality of fruits and vegetables is mainly dependant on the sweetness determined by the level of soluble sugars such as glucose, fructose and sucrose. Other fruit quality parameters include Brix content, acidity, aroma, color, size and shape. Total sugar content in fruits and vegetables is a function of genetic, nutritional, environmental and developmental factors. Understanding the factors controlling sweetness is important to design strategies for enhancing quality of fruits and vegetables. Modifying the activity of enzymes in carbohydrate metabolism such as sucrose synthase (SuSy), acid invertase, ADP-glucose pyrophosphorylase (AGPase), sucrose phosphate synthase (SPS) and sucrose transporters were found to influence carbohydrate partitioning and sucrose accumulation in sink tissues of several food crops. Plant based taste-modifying sweet proteins such as brazzein, cucurmin, mabinlin, monellin, miraculin, neoculin and thaumatin have potential application for developing transgenic plants to improve the sweetness and quality of fruits and vegetables. The present review envisages various cultural, breeding and molecular approaches used for enhancing sugar content and sweetness in fruits and vegetables.     

河北夏玉米产量潜力、产量差与氮肥效率差分析

利用2011~2014年河北省"测土配方施肥"数据库数据对河北省夏玉米产量差和氮肥效率差进行分析。结果发现,河北省夏玉米一般农户产量、高产农户产量、配方施肥产量和高产纪录产量分别为7 911、10 097、8 411、11 093 kg/hm~2,所对应的产量差分别为2 186、500、3 182 kg/hm~2。邯郸地区的产量潜力和产量差最大,廊坊和沧州的产量潜力最小,产量差以石家庄和衡水最小。一般农户、高产农户、配方施肥和高产纪录的氮肥偏生产力分别为39.5、47.3、42.7、50.3 kg/kg,所对应的氮肥偏生产力差分别为7.8、3.2、10.8 kg/kg,存在较大的效率差。不同地区玉米氮肥偏生产力效率差以邯郸最大,邢台最小。     

有机-无机配施对盐渍土壤水稻生长及养分利用的影响

针对滨海盐渍化土壤水稻种植过程中根系生长受盐碱胁迫,导致养分利用率低的问题。采用田间试验研究了有机肥与磷肥配施对滨海盐渍化土壤水稻不同生育期根系生长、水稻产量及养分利用率的影响。试验采用双因素设计,3个碳水平:(1)C0,无碳;(2)C1:低碳,450 kg/hm~2;(3)C2:高碳,900 kg/hm~2;3个磷水平:(1)P0:无磷;(2)P1:低磷,P_2O_5 64 kg/hm~2;(3)P2:高磷,P_2O_5 128 kg/hm~2。结果表明,在水稻成熟期,低碳低磷(T5)处理时根系总表面积显著高于高碳低磷(T7)和高碳高磷(T8)处理,分别增加25.2%和30.2%;低碳处理(T5、T6)时根系总体积显著高于高碳处理。T5处理时水稻产量、生物量显著高于其他处理,分别为10 245,9 550 kg/hm~2。结实率较高是低碳低磷(T5)处理水稻产量最高的原因。低碳低磷(T5)处理时糙米P积累量最高,显著高于T6、T7、T8处理,分别高出13.9%,27.8%,31.2%。T5处理的磷肥贡献率和农学效率显著高于其他施磷肥处理。磷肥偏生产力表现为低磷投入显著高于高磷投入。综上所述,与单独施用无机肥相比,有机肥与磷肥配施能够显著促进滨海盐渍化土壤水稻根系生长,提高水稻产量及磷肥农学效率,其中低碳低磷(T5,C 450 kg/hm~2+P_2O_5 64 kg/hm~2)处理最有利于盐渍化土壤水稻根系生长。     

Phosphorus fractions in preferential flow pathways and soil matrix in hillslope soils in the Thuringian Forest (Central Germany)

Phosphorus (P) is primarily transported in soil through preferential flow pathways (PFP), which can rapidly move water and matter bypassing large portions of the soil. This study investigated the composition of P forms in PFPs and soil matrix in two profiles at a forested hillslope in the Thuringian Forest (Central Germany), in order to evaluate (1) the effect of PFPs on the distribution of P fractions in forest soils, and (2) how hillslope position influences P fractions and other chemical parameters. To characterize water and mass fluxes in the profiles, flow pathways were visualized using dye tracer experiments. Stained and unstained soil material was sampled to assess differences of chemical parameters in the PFPs and soil matrix, and tested for correlations between chemical parameters to determine the factors influencing P fractions in soils. The results revealed significantly higher P contents (total P and most P fractions) in the upslope profile compared to the downslope profile. This accumulation effect in the upper profile was also observed for C, N, Fe, and Mn. The distribution of flow patterns also differed between the two profiles with stronger vertical infiltration into mineral soil and more preferential flow along stones and roots in the upslope profile compared to the downslope profile. However, the observed difference could not be addressed to hillslope effects as both test plots were located in mid‐slope position, but were strongly influenced by spatial heterogeneity (e.g ., micro‐relief). Furthermore, no statistically significant accumulation effect of P or other elements in PFPs compared to soil matrix was found. At the test site, the combination of high stone content with low potential for P sorption, and predominance of near‐surface lateral flow, appears to have hampered the development of gradients in chemical parameters between PFPs and soil matrix.     

氮肥后移对江汉平原小麦籽粒产量及氮肥偏生产力的影响

以中筋小麦品种郑麦9023为试验材料,研究了氮肥后移对小麦籽粒产量、收获指数及氮肥偏生产力的影响。结果表明,底追比例为7：3,追肥时期由起身期后移至拔节期,籽粒产量及氮肥偏生产力均显著提高;底追比例为5：5,追肥时期由拔节期后移至旗叶露尖期,籽粒产量及氮肥偏生产力均显著降低,表明拔节期是追施氮肥的适宜时期。追肥时期同为拔节期,底追比例由3：7 调整至5：5,由5：5则调整至7：3,籽粒产量、收获指数、氮肥偏生产力均显著升高。总之,在本试验条件下,总施氮量为180kg•hm-2,底追比例为3：7、拔节期追肥的处理,成熟期籽粒产量最高,收获指数和氮肥偏生产力亦显著大于其他处理,是氮肥运筹的最优处理。     

东北西部地区春玉米施肥现状分析

对吉林西部6个乡镇和通辽市5个旗县共170份玉米养分调查数据进行分析和评价.结果 表明,吉林西部玉米平均单产8782 kg/hm2,氮、磷、钾养分平均投入量分别为199、96、94 kg/hm2,偏生产力分别为50、97、101 kg/kg;内蒙古通辽平均单产10200 kg/hm2,氮、磷、钾养分平均投入量分别为27...     

宁南山区春玉米施肥现状及减施潜力

在宁南山区的固原市原州区和彭阳县调查65个春玉米种植户的产量、施肥量及肥料种类等.结果 表明,该区域春玉米平均产量为9.4 t/hm2,80％的调查农户春玉米产量处在适中及偏低以下水平(＜10.5 t/hm2).春玉米生产中N、P2O5、K2O养分的平均用量分别为353、253、370 kg/hm2,其中,化肥N、P2...