籼型水稻光、温敏核不育系配合力研究

选用 6个籼型光 (温 )敏核不育系 ,5个籼型父本 ,按 6× 5NCⅡ设计 ,共配 30个组合 ,对亲本一般配合力 (GCA)及杂种的特殊配合力 (SCA)进行了研究 ,结果如下 :(1)筛选了一批优良的两系亲本材料 ,不育系中籼型以X0 7S、3418S为好 ,父本中紫恢10 0、明恢 6 3、2 346配合力为好。 (2 )在本研究中播始历期和结实率SCA与GCA的关系是相对独立的 ,籼杂中株高、穗实粒 ,有一定的联系 ,高特殊配合力的组合 ,一般至少有一方亲本的一般配合力高。 (3)初步筛选了 3418S/2 346、3418S/明恢 6 3、X0 7S/2 346、X0 7S/紫恢 10 0等强优组合 ,在本试验中单株产量均显著超过汕优 6 3。文中对供试不育系和初步筛选的强优组合应用前景进行了讨论     

澳大利亚昆士兰州松树杂交育种和造林

经过４０多年的努力，澳大利亚昆士兰州在松树杂交育种方面取得了举世瞩目的成绩。选育的ＰＥＥ×ＰＣＨＦ１具有母本湿地松的树干通直圆满、抗风力强、分枝习性好、耐水渍和父本洪都拉斯加勒比松的速生、皮薄等优点，除适应性广、材质好外，大面积造林比其亲本的商品材积增加３０％。文内较详细地介绍了澳大利亚昆士兰州松树杂交育种及其造林的方法     

Provenance and progeny results for the tropical white pine, Pinus chiapensis, at five and eight years of age

Eleven provenances and 132 open-pollinated families of Pinus chiapensis were established at six locations in Brazil, Colombia, and South Africa and assessed for height, volume, and forking percent at five and eight years of age. Provenance × site and family × site interactions were examined in a subset of three trials with 38 open-pollinated families in common. Average volume production of P. chiapensis in Colombia and South Africa was 25 m³/ha/yr and 12 m³/ha/yr, respectively, at eight years of age. Provenance and family differences for height and volume were significant at the individual test sites at eight years of age. The La Trinidad (Chiapas) source was the most productive. Forking percent ranged from 3% in South Africa to 38% in San Jose, Colombia at eight years. Provenance × site interactions were significant for forking but not for height and volume. Family × site interactions were significant for height and volume but not for forking. Forty-six percent of the interaction variance between height and location was contributed by only six families. Height/diameter ratios for P. chiapensis were 0.29 and 0.39 in Colombia and South Africa, respectively, and significantly different.     

华北落叶松和白杄幼苗对光照和竞争响应的差异比较

选用3年生华北落叶松和白杆幼苗为试验材料,盆栽试验以自然光照为基础设置4个遮光率水平作为不同光照条件,设置5个密度水平,每个树种15个栽植组合方式(包括单独栽植和混合栽植),进行一个生长季节的试验和取样观测分析,以确定这2个树种在苗期对光照和栽植密度的生长和生理响应以及存活率等功能特性的差异.结果表明:华北落叶松幼苗的相对地径生长量在微光条件下显著提高,且其存活率在半光照和弱光照条件下也显著提高.白杆幼苗的高生长量及叶片叶绿素含量表现出随光照减弱而升高的趋势,但其存活率不受光照条件的影响;在不同的栽植密度下,华北落叶松幼苗的生长和生理指标均未表现出显著差异,但适中的栽植密度可显著提高其存活率;白杆幼苗高生长量及叶片叶绿素含量在与落叶松混栽时比单树种栽植时高,但其存活率没有任何变化.上述结果表明:适度遮荫和密植可以在一定程度上改善华北落叶松苗期生长并显著提高其存活率,从而有利于华北落叶松成功度过幼苗幼树期;同时,适度遮荫和混栽也有利于白杆幼苗幼树的生长.     

峨眉山常绿阔叶林常绿和落叶物种叶片C、N、P研究

采用常规方法对峨眉山常绿阔叶林的常绿和落叶物种植物C、N、P含量及其之间的相互关系进行了研究,结果表明:①峨眉山常绿阔叶林常绿物种叶片C、N、P平均含量分别为42.30%、1.46%、0.10%;落叶物种叶片C、N、P平均含量分别为41.078%、1.59%和 0.12%.常绿和落叶物种植物叶片N-P成极显著的乘幂关系,而C-N和C-P关系不显著;②峨眉山地区常绿阔叶林常绿物种叶片N/P比平均值为14.48,落叶物种的N/P比平均值为13.61,其对生态环境的适应性较低;③在峨眉山海拔700、1 100和1 500 m处,植物叶片N-P亦成显著的关系,而植物叶片C-N和C-P关系不显著.     

Relationships between soil and foliar nutrients in young densely planted mini-plots of Pinus radiata and Cupressus lusitanica

The long-term nature of forest crop rotations makes it difficult to determine impacts of forestry on soil nutrients that might be depleted by forest growth. We used small scale, highly stocked plots to compress the length of the rotation and rapidly induce nutrient depletion. In the study, two species (Pinus radiata D. Don and Cupressus lusitanica Miller) are compared under two disturbance regimes (soil undisturbed and compacted), and two fertiliser treatments (nil and plus fertiliser), applied in factorial combination at 33 sites, covering the range of climatic and edaphic variation found in plantation forests across New Zealand. To assess our ability to rapidly highlight important soil properties, foliar nutrient concentrations were determined 20 months after planting. It was hypothesised that the densely planted plots, even at a young age, would create sufficient pressure on nutrient resources to allow development of relationships between properties used as indicies of soil nutrient availability and foliar nutrient concentrations. For both species significant relationships between foliar nutrients and 0–10 cm layer soil properties from unfertilised plots were evident for N (total and mineralisable N) and P (total, acid extractable, organic, Bray-2 and Olsen P). With the exception of Ca in C. lusitanica, foliar K, Ca and Mg were correlated with their respective soil exchangeable cation measures. The results thus confirm the utility of the experimental approach and the relevance of the measured soil properties for forest productivity.

In unfertilised plots foliar N and P concentrations in P. radiata exceeded those in C. lusitanica, the differences being eliminated by fertiliser application. Foliar N/P ratios in P. radiata also exceeded those in C. lusitanica. In contrast to N and P, foliar K, Ca and Mg concentrations were all higher in C. lusitanica, the difference being particularly marked for Ca and Mg. P. radiata contained substantially higher concentrations of the metals Zn, Mn and Al than C. lusitanica, whereas the latter contained higher B concentrations. Possible reasons for differences between species in foliar nutrient concentrations are discussed.     

Dexmedetomidine attenuates acute alcoholic hepatic injury in mice

AIM: To investigate the effects of dexmedetomidine (DEX) on acute alcoholic hepatic injury in mice and to explore the possible mechanisms. METHODS: Kunming mice (n=50) were randomly divided into 5 groups (n=10): normal saline control (NS) group, acute alcoholic hepatic injury model (E) group, low-dose (10 μg/kg) DEX (E+L) group, medium-dose (50 μg/kg) DEX (E+M) group and high-dose (100 μg/kg) DEX (E+H) group. The animals were sacrificed at 6 h after gavage of alcohol or normal saline. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), malondialdehyde (MDA), glutathione (GSH) and superoxide dismutase (SOD) were measured. The livers were removed for evaluation of histological characteristics and determining the content of tumor necrosis factor-α (TNF-α) amd interleukin-1β (IL-1β) in the liver tissues by ELISA. The expression levels of cytochrome P450 2E1 (CYP2E1) and nuclear factor-κB (NF-κB) in the liver tissues were evaluated by Western blot. RESULTS: Compared with NS group, the levels of ALT, AST and TG were obviously increased in E group, which were obviously decreased in E+M and E+H groups. Compared with NS group, the levels of TNF-α, IL-1β and MDA were obviously increase in E group, which were obviously decreased in E+M and E+H groups. Compared with NS group, the activity of SOD and the content of GSH were obviously decreased in E group, which were obviously increased in E+M and E+H groups. Compared with NS group, the expression of CYP2E1 and NF-κB was obviously increase in E group, which was obviously decreased in E+M and E+H groups. Compared with NS group, ethanol induced marked liver histological injury, which was less pronounced in E+M and E+H groups. CONCLUSION: DEX has a protective effect on mouse liver with acute alcoholic injury by the involvement in the processes of antioxidation and antiinflammation, and its mechanism may be associated with the inhibition of CYP2E1 and NF-κB expression.     

Effect of soil pore size distribution on plant-available water and least limiting water range as soil physical quality indicators

Soil pore size distribution(SPSD) is one of the most important soil physical properties. This research investigated the relationships of location and shape parameters of the SPSD curves with plant-available water(PAW) and least limiting water range(LLWR) of the light-textured soils at the Torogh Agricultural Research Station in north-eastern Iran. Soil moisture release curve(SMRC), PAW and LLWR in matric heads of 100 and 330 h Pa for the field capacity and location and shape parameters of the SPSD curves of 30 soils with different texture and organic carbon contents were determined, and the variable relationships were statistically analyzed. The results showed that the median equivalent pore diameter(de), mean de, standard deviation(SD*), and skewness of the SPSD curves were significantly correlated with PAW(PAW330) and LLWR(LLWR330) measured in a matric head of 330 h Pa. Decrease in deand increase in the diversity of soil pore size(SD*) increased PAW330 and LLWR330. The SD* values of all the soil samples were lower than the optimal ranges suggested in literature. Neither PAW nor LLWR values were significantly different in the soils with the optimal modal deand those with non-optimal modal de. Optimal values of median and mean equivalent pore diameters and kurtosis of SPSD curves led to a significant improvement of PAW330 and LLWR330 as soil physical quality indicators. It was recommended to revise the optimal ranges for SD* and modal defor future studies.     

长期用生活污水处理厂排放的废水浇灌影响了糙米和土壤中重金属的含量

A pot experiment was conducted in a plastic film house to evaluate the translocation and uptake of heavy metals(Pb,Cd,Cu,and Zn) into brown rice(Oryza sativa L.) and the heavy metals residues in soils which had previously been irrigated with domestic wastewater for a long time(3 years).The range of Pb,Cd,Cu,and Zn was 5.10 ± 0.01,0.105 ± 0.017,5.76 ± 0.42,and 23.56 ± 1.40 mg kg-1,respectively in the domestic wastewater-irrigated soil,and 0.370 ± 0.006,0.011 ± 0.001,0.340 ± 0.04,and 2.05 ± 0.18 mg kg-1,respectively,in the domestic wastewater-irrigated brown rice.The results indicated that application of domestic wastewater to arable land slightly increased the levels of Pb,Cd,Cu,and Zn in soil and brown rice(P < 0.01).The concentrations of heavy metals in brown rice were lower than the recommended tolerable levels proposed by the Joint FAO/WHO Expert Committee on Food Additives.However,the continuous monitoring and pollution control of hazardous materials from domestic wastewater are needed in order to prevent excessive build-up of heavy metals in the food chain.