超滤技术制备乳铁蛋白制品工艺的研究

本文通过超滤技术从牛初乳中分离乳铁蛋白，然后对浓缩液进行干燥制成乳铁蛋白制品。文中对分离工艺，膜的组件优选及操作参数的影响作了全面论述。     

2个小麦AL型细胞质雄性不育系的异交特性分析

提高不育系的异交结实率是杂交小麦制种产量取得突破的重要途径。为明确小麦AL型雄性不育系的异交结实特性，连续3年测定了2个小麦AL型不育系36A和3235A的柱头活力、柱头外露率、颖间距和自然异交结实率。结果表明，36A和3235A的平均自然异交结实率分别为113.02%和44.65%，柱头活力分别为104.96%和76.7%，差异均达到显著水平；二者的柱头外露率和颖间距无显著差异。相关分析表明，授粉天数与柱头活力呈显著负相关，柱头活力随授粉天数的延长而降低；柱头活力与柱头外露率和颖间距、柱头外露率与颖间距间均呈显著正相关。随授粉进程推移，柱头活力、柱头外露率和颖间距均呈先增后减趋势，36A的3个指标均高于3235A，综合表现为异交结实率高。花后第4～11天套袋饱和授粉异交结实率最高，授粉后第6～12天，柱头外露率和颖间距均达到最大。因此，小麦AL型不育系的恢复系扬花始期比不育系推迟2～3 d，小花陆续开放、柱头活力也较强，并持续开颖，可保持较高结实率，为最佳授粉时间。     

不同株行距配置对机采棉成铃特性及纤维品质的影响

以新疆生产建设兵团第七师地区推荐棉花品种“Z1112”和“中棉641”为试验材料,设置一膜六行（10cm+66cm+10cm+66cm+10cm）、一膜四行（76cm+10cm+76cm）和一膜三行（76cm+76cm）3种株行距配置模式,研究不同株行距配置模式对棉花成铃特性和纤维品质的影响。结果表明：同一棉花品种下,一膜三行和一膜四行配置模式的伏前桃多于一膜六行,而伏桃与内围铃则表现为一膜六行多于一膜四行和一膜三行。3种株行距配置模式下均表现为下部铃>中部铃>上部铃,中部铃和下部铃表现为一膜六行的单位面积铃数显著高于一膜三行,但与一膜四行间差异不显著。一膜三行株行距配置模式较其他两种配置模式更有利于棉花脱叶和吐絮,但不同行距配置模式对棉花产量、纤维长度、整齐度指数、马克隆值和伸长率均无显著影响,对断裂比强度和短纤维指数有一定影响。综合比较来看,一膜三行配置模式具有充足的行距空间,可充分发挥个体与群体的生产潜能,显著提高棉花单株结铃数和单铃重,同时具有较优的脱叶吐絮效果和棉纤维品质,因此,一膜三行株行距配置模式适宜在该地区推广。     

Improving the Productivity of Bread Wheat by Good Management Practices under Terminal Drought

Drought‐induced damages in crop plants are ranked at top amid all losses instigated by diverse abiotic stresses. Terminal drought (drought at reproductive phase) has emerged as a severe threat to the productivity of wheat crop. Different seed enhancement techniques, genotypes and distribution of crop plants in different spacings have been explored individually to mitigate these losses; however, their interaction has rarely been tested in improving drought resistance in wheat. This study was conducted to evaluate the potential role of different seed enhancement techniques and row spacings in mitigating the adversities of terminal drought in two wheat cultivars during two consecutive growing seasons of 2010–2011 and 2011–2012. Seeds of wheat cultivars Lasani‐2008 (medium statured) and Triple Dwarf‐1 (dwarf height) soaked in water (hydropriming) or CaCl₂ (osmopriming) were sown in 20‐, 25‐ and 30‐cm spaced rows; just before heading, the soil moisture was maintained at 100 % field capacity (well watered) or 50 % field capacity (terminal drought) till maturity. Terminal drought significantly reduced the yield and related traits compared with well‐watered crop; however, osmopriming improved the crop performance under terminal drought. Among different row spacings, wheat sown in 20‐cm spaced rows performed better during both years of study. Wheat cultivar Lasani‐2008 performed better than cultivar Triple Dwarf‐1 under both well‐watered and stress conditions. Maximum net returns and benefit–cost ratio were recorded from osmoprimed seeds of cultivar Lasani‐2008 sown in 20‐cm spaced rows under well‐watered condition. Nonetheless, osmoprimed seeds of cultivar Lasani‐2008 sown in 20‐cm spaced rows were better able to produce good yield under terminal drought.     

杨树造林宽行窄距试验研究

合理利用土地,充分发挥林地的经济效益,是林业可持续发展的一项重要举措,杨树造林采用行距大株距小的栽植格式,是增加林地经济效益一项新技术,是很有研究价值的一项重要内容。     

Temporal development of crown condition of beech and oak as a response variable for integrated evaluations

The evaluation uses the longest available time series for beech and oak defoliation in Germany. The data from Hesse, starting from 1984, show a typical pattern: for the first 12 years, a continuous increase in defoliation was observed ranging from an average value of 14% in 1984 to a peak value of 30%. This was followed by a subsequent decrease in the loss of foliage accompanied by a high variability, until the last monitoring in 2003, where an average value of 25% defoliation was observed. For both tree species, the years of trend reversal were identical. The same pattern was observed in the German federal states: Rhineland-Palatinate, North Rhine-Westphalia, and Bavaria. The year of trend reversal was identical in Hesse and Rhineland-Palatinate. In North Rhine-Westphalia, it occurred 1 year earlier and in Bavaria 3 years earlier. Whereas defoliation trends were clearly demonstrated, tree mortality did not appear on a large scale. The sample trees were grouped into four discrete clusters according to their annual defoliation values from 1984 to 2003. In 1996, the clusters represent 15, 25, 35, and 50% defoliation values. Regarding beech in Hesse, there was no overlap in the defoliation curves observed among the different clusters. These four clusters having different degrees of defoliation over the whole time span of 20 years were used for a further detailed statistical analysis. For discrete variables like crown spacing and—in the case of beech—fruit bearing, mosaic plots were applied in order to visualize relations of low dimensional contingency tables, with defoliation trends being used as the response variable. The data show for beech a very clear relation between defoliation and age, relative crown spacing, stand composition, and fruit bearing. Regarding oak, besides age and relative crown spacing, the years with significant appearance of biotic stress factors—leaf eating insects—show a clear relation to trends of defoliation. The statistical model used in this study—logistic regression—allows applying a multinomial response variable and a number of continuous or categorical explanatory variables. With this approach, an iterative optimized selection of effect variables was used to test the relevance of different variables on the defoliation pattern of the same four clusters mentioned above. For this, the variables were grouped in an iterative process with five steps, starting with a few basic variables of tree and site information, and ending with a total of more than 20 variables in the fifth step. The process selects first the variables which are of significance on the defoliation, and calculates the possible errors in the grouping of the different trees to the four clusters. In this analysis of beech, the basic tree and stand variables: age, relative crown spacing, stand composition and fruit bearing proved to be the most relevant group of parameters, with the other variables explaining the variation of defoliation only to a minor extent. More complex model levels do not change any basic selected variables; however, Cation Exchange Capacity (CEC), C/N-ratio, Al- and Ca-proportion of CEC are additionally selected and give a hint of the relevance of soil conditions. Regarding beech, the errors of the statistical model are lower compared to oak.     

Influence of different Taxodium ascendens stands on the open ranges and system performance in Jiangsu Province, China

This paper reveals the results of an eight-year experiment set up to identify the effects of four tree spacing configurations (1.5 × 4 m, 1.2 × 5 m, 2 × 3 m and 1.5 × 2 × 6 m) on open ranges and the relationship between open ranges and species coexistence in Taxodium ascendens-intercrop systems. Relative interrow open ranges and relative interplant open ranges were significantly different among four tree spacings. All relative open ranges (relative interrow open ranges, relative interplant open ranges, relative canopy open ranges and relative space-volumed open ranges) decreased with increasing age. The wider interrow or interplant spacings of trees offered wider (relative) interrow or interplant open ranges for intercrops. All of the tree spacings, except spacing 2 × 3 m, had negative relative interplant open ranges in nine-year-old stands, suggesting that the canopies between a plant and its neighbouring plant were in direct competition, and no interplant open range existed between two individual trees. Up to age nine, spacing 1.5 × 2 × 6 m showed no marked disadvantage in growth performance as compared to the other three spacings, but provided wider interrow open ranges for intercrops. Starting with tree stands of age four years, the yields of interplanted wheat (Triticum aestivum), soybean (Glyciae max) and rape (Brassica napus) decreased significantly as a result of the decrease of open ranges in tree stands. The yields of wheat, soybean and rape were lower in tree spacing 2 × 3 m than in other spacings. There was a positive correlation between wheat yields and canopy open ranges. This revised version was published online in June 2006 with corrections to the Cover Date.     

Modelling species and spacing effects on root zone water dynamics using Hydrus-2D in an Amazonian agroforestry system

Modelling the root zone water dynamics in a tree crop agroforestry system is a useful approach to understanding small-scale effects in tree crop systems and may be helpful for optimizing tree spacing in agroforestry system planning. The agroforestry system in this study consists of the species Theobroma grandiflorum (Willd ex Spreng) Schum (Cupuaçu), Bactris gasipaes H.B.K. (peach palm) and the cover crop Pueraria phaseoloides (Roxb.) Benth (Pueraria). The soiltype is an oxisol. Calibration was conducted for each of the three species separately. Calibration results show good conformity between simulated and measured data. Simulated scenarios examine the influence of different spacing between trees on root water uptake, evaporation and drainage. Mean interception and crop factors of the whole flow region vary with spacing or are held constant to examine below-ground effects only. Also a fictitious scenario of an older agroforestry system with deeper roots is calculated. In order to overcome restrictions of the computer program Hydrus-2D, correction factors in the root zone were introduced and a calculation scheme for root water uptake of a flow subregion was developped. Below-ground effects of spacing between trees are not or almost not present, but the depth of the tree roots has a significant influence on root water uptake, evaporation and drainage. When mean interception and crop factor vary, drainage increases and root water uptake decreases slightly with spacing. The modelling approach has been found promising for optimizing agroforestry systems although it can only be seen as a first beginning. In an agroforestry systems under drier conditions differences in results will probably be larger.     

杂交稻制种带宽和行比与产量的关系研究

杂交水稻制种采用不同的行带宽度和行比，对产量有一定影响。试验结果表明：在一定的行带宽度内，单行父本比大双行父本增产，差异极显著；小双行父本比单行父本增产，差异不显著；单行父本在行带宽度为２．４７５８ｍ、行比为１（父）：１５￣１６（母）时产量最高；小双行父本在行带宽度为２．３２７６ｍ、行比为２（父）：１３￣１４（母）时产量最高；产量最高时的颖花比为１（父）：３．５０７（母）。应用这一研究结果并采取相