小麦农杆菌介导转基因植株的稳定获得和检测

 以预培养 4 d的小麦幼胚愈伤组织为受体 ,L B培养基上激活培养 3 d或 AB培养基上激活培养 4 d,并在WCC培养基中重悬的 C5 8c1农杆菌菌系为供体 ,将含有目的基因、标记基因的 p PTN2 4 9、p PTN 2 5 4、p PTN2 70、p SIS-GFP等重组 DNA质粒转入了小麦 ,经在含 10～ 5 0 mg/ L geneticin( G4 18)、5 0 mg/ L cefotaxime、5 0 m g/ L vancomycin、5 0 m g/ L ticillicin选择培养基上多次选择 ,移栽前利用 npt EL ISA检测 ,移栽后利用叶片离体退绿、PCR和 South-ern blot 4种方法综合检测 ,共获得了 2 9株转基因植株 ,转化频率平均为 0 .82 %。在所获得的转基因植株中 ,单拷贝整合植株占 65 .5 2 %。研究结果还表明 ,不同基因型的转化效率显著不同 ,除了 Bobwhite外 ,笔者也从扬麦 10号获得了转基因植株 ;EL ISA测定值的高低与外源 DNA整合的拷贝数有一定关系 ;初步建立了农杆菌介导稳定转化小麦的技术体系。     

How do grassroot NGOs in rural Myanmar express their visions for the food system? Food security and food sovereignty as entangled narratives within NGO struggles and strategies

Recent research has promoted the idea that political struggles over food systems can be understood through the concepts of food security (the right to access food) and food sovereignty (the right to exercise control over food systems). These concepts emphasise different political priorities in the social relations of food: for the former, the promotion of decent work and the strengthening of the social safety net to enhance people's abilities to put food on their plates; for the latter, the defence of land, water and resource rights, to underpin capabilities for food own‐provisioning. The question we pose in this paper is how these priorities are articulated by grassroots non‐government organisations working at the frontline of global food poverty? Interviews with 22 representatives of food‐related non‐government organisations in Myanmar were used to elicit narratives about how they understood their challenges. The paper finds that narratives did not cohere exclusively to either the food security or food sovereignty concept, but blended ideas associated with the political priorities of both in complex and contradictory ways. These insights lend important firsthand evidence to the argument that supports a multi‐dimensional framing of the politics of food that is inclusive of the diverse struggles highlighted by food security and food sovereignty concepts.     

Inter-tree competition analysis in undebarked cork oak plantations as a support tool for management in Portugal

New Forests - Scheduling the first thinning in young cork oak stands is an important decision in management that is usually subjectively defined by each manager. An analysis of competition in cork...     

Cytological and genetical studies on hybrids between sorghum almum parodi (2n=40) and some diploid (2n=20) species of sorghum

Hybridization between S. almum (2n=40) and diploid (2n=20) species of Sorghum resulted in plants with 2n=40 and 2n=30 chromosomes. As segregation for many characters occurred in the offspring of those with 2n=40, hybrids of this type provide a means of transferring genes from the diploid to the tetraploid species of Eu-sorghum. Segregations for some genes in the progeny of these hybrids revealed heterozygosity in S. almum which may indicate that one of the ancestors of S. almum was a variety of S. vulgare very similar to the commercial grain sorghum.The triploids were only slightly fertile and the chromosome numbers of plants resulting from backcrossing to S. almum ranged from 30 to 46. Some of the plants with the higher chromosome numbers were self-fertile and segregation for genes which were present in the original diploid and tetraploid parents were observed in their off-spring. Backcrossing the triploid to the diploid parent produced fertile plants with 2n=20 and it is possible that the triploids could be used to transfer genes from the tetraploid to the diploid species of Eu-sorghum.The chromosome pairing in the triploids was similar to that expected in an autotriploid, but some non-homologous pairing was detected which may be the result of duplication of some chromosomes or chromosome segments within the genome (n=10) of S. vulgare.     

Decarboxylation of organic anions to alleviate acidification of red soils from urea application

Purpose

Decarboxylation of organic anions in crop straw is recognized as one of the mechanisms for increasing pH in acidified soils. However, the effectiveness of specific compounds in alleviating soil acidification from nitrification has not been well determined. This study examined three organic anions commonly found in crop straws and their effect on soil acidity and N transformation processes following urea application to a red soil (Ferralic Cambisol).

Materials and methods

A 35-day incubation experiment was conducted using soil after receiving 26 years of two different nutrient treatments: (1) chemical nitrogen, phosphorus, and potassium fertilization (NPK, pH 4.30) and (2) NPK plus swine manure (NPKM, pH 5.88). Treatments included three rates (0.25, 0.5, and 1.0 g C kg^?1) of calcium citrate, 0.5 g C kg^?1 calcium oxalate, 0.5 g C kg^?1 calcium malate, urea-only (control) soil, and a non-treated soil as a reference. Soil acidity, mineral N species, decarboxylation, and their correlations were determined.

Results and discussion

All three organic anions significantly increased pH in both soils and the effectiveness was positively correlated with application rate. The change in total exchangeable soil acidity was dominated by aluminum concentration in the NPK soil, but by proton concentration in the NPKM soil. At ≥?0.5 g C kg^?1, the anions decreased soil exchangeable acidity by 25–68% in NPK soil and by 63–88% in NPKM soil as compared with control. Oxalate was the most effective in increasing soil pH by 0.70 and 1.31 units and reducing exchangeable acidity by 3.79 and 0.33 cmol₍₊₎ kg^?1 in NPK and NPKM soils, respectively, and also resulted in the highest CO₂ production rate. Addition of organic anions led to a lower nitrification rate in NPKM soil relative to the NPK soil.

Conclusions

These results imply that crop straws rich in organic anions, especially oxalate, would have a higher potential to alleviate soil acidification.

     

Identification of botanical biomarkers in Argentinean Diplotaxis honeys: flavonoids and glucosinolates

To select and establish floral biomarkers of the botanical origin of Diplotaxis tenuifolia honeys, the flavonoids and glucosinolates present in bee-deposited nectar collected from hive combs (unripe honey) and mature honey from the same hives fron which the unripe honey samples were collected were analyzed by LC-UV-PAD-ESI-MS(n). Glycosidic conjugates of the flavonols quercetin, kaempferol, and isorhamnetin were detected and characterized in unripe honey. D. tenuifolia mature honeys contained the aglycones kaempferol, quercetin, and isorhamnetin. The differences between the phenolic profiles of mature honey and freshly deposited honey could be due to hydrolytic enzymatic activities. Aliphatic and indole glucososinolates were analyzed in unripe and mature honeys, this being the first report of the detection and characterization of glucosinolates as honey constituents. Moreover, these honey samples contained different amounts of propolis-derived flavonoid aglycones (1765-3171 μg/100 g) and hydroxycinnamic acid derivatives (29-1514 μg/100 g). Propolis flavonoids were already present in the freshly deposited nectar, showing that the incorporation of these compounds to honey occurs at the early steps of honey production. The flavonoids quercetin, kaempferol, and isorhamnetin and the glucosinolates detected in the samples could be used as complementary biomarkers for the determination of the floral origin of Argentinean Diplotaxis honeys.     

黄土高原多沙粗沙区植被适宜性空间分析与制图

 以黄土高原多沙粗沙区为研究区,以植物自然分布为基础,利用DEM地形分析方法,对降雨、温度等因素的空间变化进行分析,并结合物种的生态环境需求,利用GIS空间分析功能,对该区38个物种适宜性的空间变化进行分析,并以此为基础,评价立地对植物生长型的适宜性。结果表明:利用DEM地形分析与GIS空间分析,可以很好地将物种适宜性的空间变化表现出来;利用VB编程,结合GIS,将物种适宜性与立地适宜性的空间变化予以图形显示。随着数据的积累和数据采集手段的改进,所采用的方法对于区域植被空间适宜性评价可提供积极的借鉴作用。     

Reservoir to river: Quantifying fine-scale fish movements after translocation

Translocation of individuals is a widely used tool in the conservation of threatened species. The movement behaviours of translocated individuals in their new environment are a key factor that can influence translocation success (i.e. survival and reproduction). In this study, eel-tailed catfish (Tandanus tandanus) and Murray cod (Maccullochella peelii) movements were monitored using fine-scale acoustic telemetry over a 5-month period in two lowland rivers in eastern Australia. Fine-scale movement and habitat selection were compared among translocated lacustrine and resident riverine T. tandanus and between species. We found no difference in fine-scale movement behaviours between translocated and resident T. tandanus; however, there was some variation in movement response to environmental variation between species. In contrast, habitat selection varied not only between the two species, but also between resident and translocated T. tandanus individuals. Notably, activity was significantly lower in the first day after release compared to the remainder of the study period. Although T. tandanus translocated from a reservoir had never experienced the environmental fluctuations of a riverine system, individuals still responded in the same way as resident riverine fish, suggesting an innate behavioural response. However, this was not the case for habitat selection, where translocated individuals preferred habitats more common in their source population's lacustrine environment. The findings of this study are important in guiding future conservation efforts involving the translocation of wild-caught fish, primarily the importance of the suitable habitat at the release site to ensure the success and persistence of translocated populations.     

Direct effect of fertilization on microbial carbon transformation in grassland soils in dependence on the substrate quality

Response of microbial metabolism (growth, substrate utilization, energetic metabolism) to fertilization by N and P and resulting changes in soil‐organic‐matter (SOM) decomposition (priming effect) were studied in grassland soils with relatively high organic‐matter content. Treatments with and without glucose addition were studied to simulate difference between rhizosphere and bulk soil. Our expectation was that fertilization would decrease soil respiration in both treatments due to an increased efficiency of microbial metabolism. At first, fertilization activated microbial metabolism in both treatments. In glucose‐nonamended soils, this was connected with a short‐term apparent priming effect but if glucose was available, the higher energetic demand was covered by its mineralization in preference against SOM, causing significant SOM savings as compared to unfertilized soils. After a relatively short period of 1–3 d, however, the phase of deprived microbial metabolism occurred in both treatments, which was characterized by lower soil respiration in fertilized than in unfertilized soils. Fertilization further decreased net microbial growth following glucose addition, shortened turnover time of microbial biomass and changed the partitioning of assimilated glucose within microbial biomass (decreased accumulation of storage compounds and increased the proportion of mineralized glucose). As a result, fertilization reduced soil respiration mainly due to a deprivation of microbial metabolism. The rate and range of microbial response to fertilization and also the amount of saved soil C were larger in the soil with higher SOM content, likely driven by the higher content of microbial biomass.