Evaluation of performance of sorghum varieties grown in Tokyo for sugar accumulation and its correlation with vacuolar invertase genes SbInv1 and SbInv2

ABSTRACT

The sugar-accumulating potential of global and local sweet and grain sorghum varieties were tested under the local conditions. The basis for this study was the dependency of sugar accumulation on temperature and photoperiod. Thus, the efficacy of cultivars as a bioenergy source would need to be determined based on their performance under the local environmental conditions. A strong correlation of sucrose content with brix was observed, enabling large-scale screening of varieties for high sucrose content. The morphological characteristics inherent in sweet sorghum, such as tall stems, greater number of leaves and a longer vegetative period, were found to correlate with the total stem sugar content. Assessment of sugars along the stem revealed maximum sugar accumulation in the upper intermediate to upper internodes in most of the varieties tested. The maximum theoretical ethanol yield (MTEY), a function of brix and juice yield, was determined as a better indicator of testing the performance of a variety as a potential source of bioethanol, mainly due to a negative correlation of stem juiciness and sucrose content in the varieties tested. Further, the relative expression of vacuolar invertase genes, SbINV1 and SbINV2, was studied, and a strong negative correlation of SbINV2 to stem sucrose content was observed. This reveals a possibility of involvement of vacuolar invertase gene, SbINV2, in sugar accumulation in sweet sorghum stems, and as a key candidate for molecular breeding studies for higher stem sugar content.     

赤霉素对‘粉红朱砂’和‘虎丘晚粉’开花的影响

该文研究了不同时间、不同浓度的赤霉素处理对‘粉红朱砂’和‘虎丘晚粉’两种露地栽培梅花的花期、展叶期和落蕾率的影响。结果表明 :2 0 0 0mg L的赤霉素在 10月底至 11月处理可使‘粉红朱砂’的花期提前约 1个月 ,展叶期提前 30～ 4 1d ,但同时出现明显的落蕾效应 ;而 1月处理使‘虎丘晚粉’始花期、末花期均延迟 ,同时开花量增加 ,且观赏期延长。研究还探讨了温度作为梅花开花的主导因子对试验研究的影响。     

Influence of carbon substrates and moisture regime on nitrogen fixation in paddy soils

The influence of several carbon sources on heterotrophic N₂ fixation in four paddy soils under flooded and nonflooded conditions was investigated by ¹⁵N-tracer technique. Greater N₂ fixation occurred in submerged soils amended with cellulose and rice straw, the former being superior. Addition of sucrose, glucose and malate in that order stimulated N₂ fixation in submerged alluvial soil, while sucrose alone enhanced N₃ fixation in laterite soil. In submerged acid soils none of these C sources stimulated N₂ fixation. Nonflooded conditions favoured N₂ fixation in alluvial and acid saline soils amended with cellulose, sucrose and glucose.     

Heterochromatic silencing and HP1 localization in Drosophila are dependent on the RNAi machinery

Genes normally resident in euchromatic domains are silenced when packaged into heterochromatin, as exemplified in Drosophila melanogaster by position effect variegation (PEV). Loss-of-function mutations resulting in suppression of PEV have identified critical components of heterochromatin, including proteins HP1, HP2, and histone H3 lysine 9 methyltransferase. Here, we demonstrate that this silencing is dependent on the RNA interference machinery, using tandem mini-white arrays and white transgenes in heterochromatin to show loss of silencing as a result of mutations in piwi, aubergine, or spindle-E (homeless), which encode RNAi components. These mutations result in reduction of H3 Lys9 methylation and delocalization of HP1 and HP2, most dramatically in spindle-E mutants.     

海南兰花病毒病调查及病原检测

2007-2008年,对海南主要兰花种植基地进行病毒病危害情况调查。结果表明,海南兰花病毒病症状复杂,以斑驳花叶型和坏死型最为普遍。凋查还发现,兰花的病毒病发病率与龄期呈正相关,文心兰、石斛兰的发病率显著高于蝴蝶兰。病原血清学检测表明,海南兰花病原病毒主要为建兰花叶病毒、齿兰环斑病毒,以及二者复合感染,检出率分别为29．5％、2．3％、15．9％。其中文心兰和蝴蝶兰带毒率较高,石斛兰带毒率最低,石斛兰上未检出齿兰环斑病毒。     

RAPD and ISSR fingerprinting in cultivated chickpea (<Emphasis Type="Italic">Cicer arietinum</Emphasis> L.) and its wild progenitor <Emphasis Type="Italic">Cicer reticulatum</Emphasis> Ladizinsky

Detection of genetic relationships between 19 chickpea cultivars and five accessions of its wild progenitor Cicer reticulatum Ladizinsky were investigated by using RAPD and ISSR markers. On an average, six bands per primer were observed in RAPD analysis and 11 bands per primer in ISSR analysis. In RAPD, the wild accessions shared 77.8% polymorphic bands with chickpea cultivars, whereas they shared 79.6% polymorphic bands in ISSR analysis. In RAPD analysis 51.7% and 50.5% polymorphic bands were observed among wild accessions and chickpea cultivars, respectively. Similarly, 65.63% and 56.25% polymorphic bands were found in ISSR analysis. The dendrogram developed by pooling the data of RAPD and ISSR analysis revealed that the wild accessions and the ICCV lines showed similar pattern with the dendrogram of RAPD analysis. The ISSR analysis clearly indicated that even with six polymorphic primers, reliable estimation of genetic diversity could be obtained, while nearly 30 primers are required for RAPD. Moreover, RAPD can cause genotyping errors due to competition in the amplification of all RAPD fragments. The markers generated by ISSR and RAPD assays can provide practical information for the management of genetic resources. For the selection of good parental material in breeding programs the genetic data produced through ISSR can be used to correlate with the relationship measures based on pedigree data and morphological traits to minimize the individual inaccuracies in chickpea.     

黔油18号高产综合农艺措施数学模型研究

【目的】为明确影响高原生态区黔油18号油菜产量的关键因子及实现高产高效优化栽培的综合农艺措施。【方法】运用四因素二次回归最优组合设计试验方法,在海拔950￣1200m的高原生态区对优良杂交油菜新品种黔油18号的主要栽培措施施氮量、施磷量、施钾量与油菜产量的量化关系进行系统研究,通过建立数学模型的优化与解析,【结果】结果表明,在4因素中,对黔油18号的影响为氮肥>密度>磷肥>钾肥;【结论】要获得≥2493.46kg/hm2的产量,其最佳栽培措施组合是:保持密度13.60￣14.50万株/hm2,氮肥291.35￣330.00kg/hm2,磷肥92.28￣102.2746kg/hm2,钾肥119.20￣129.20kg/hm2。     

Perchlorate Depositional History as Recorded in North American Ice Cores from the Eclipse Icefield, Canada, and the Upper Fremont Glacier, USA

Temporal depositional rates are important in order to understand the production and occurrence of perchlorate (ClO₄⁻) as limited information exists regarding the impact of anthropogenic production or atmospheric pollution on ClO₄⁻ deposition. Perchlorate concentrations in discrete ice core samples from the Eclipse Icefield (Yukon Territory, Canada) and Upper Fremont Glacier (Wyoming, USA) were analyzed using ion chromatography tandem mass spectrometry to evaluate temporal changes in the deposition of ClO₄ ⁻ in North America. The ice core samples cover a time period from 1726 to 1993 and 1970 to 2002 for the Upper Fremont Glacier (UFG) and Eclipse ice cores, respectively. The average ClO₄ ⁻ concentration in the Eclipse ice core for the time period from 1970 to 1973 was 0.6 ± 0.3 ng L⁻¹, with higher values of 2.3 ± 1.7 and 2.2 ± 2.0 ng L⁻¹ for the periods 1982–1986 and 1999–2002, respectively. All pre-1980 ice core samples from the UFG had ClO₄ ⁻ concentrations <0.2 ng L⁻¹, and the post-1980 samples ranged from <0.2 ng L⁻¹ to a maximum of 2.6 ng L⁻¹ for the year 1992. A significant positive correlation (R = 0.75, N = 15, p < 0.001) of ClO₄⁻ with SO₄²⁻ was found for the annual UFG ice core layers and of ClO₄ ⁻ with SO₄²⁻ and NO₃⁻ in sub-annual Eclipse ice samples (R > 0.3, N = 121, p < 0.002). The estimated yearly ClO₄⁻ depositional flux for the Eclipse ice core ranged from 0.6 (1970) to 4.7 μg m⁻² year⁻¹ (1982) and the UFG from <0.1 (pre-1980) to 1.4 μg m⁻² year⁻¹ (1992). There was no consistent seasonal variation in the ClO₄⁻ depositional flux for the Eclipse ice core, in contrast to a previous study on the Arctic region. The presence of ClO₄⁻ in these ice cores might correspond to an intermittent source such as volcanic eruptions and/or any anthropogenic forcing that may directly or indirectly aid in atmospheric ClO₄⁻ formation.     

多花木兰人工生态恢复植物群落种群竞争及其生态位研究

为了掌握常吉高速公路边坡多花木兰人工生态恢复植物群落的种间竞争和生态位等生长状况,运用Hegyi的单木竞争指数模型、Shannon-Wiener公式和Shoener公式对多花木兰人工植物群落的种内与种间竞争强度、生态位宽度与生态位重叠进行研究。结果表明：多花木兰种内竞争能力与个体的地径径级成正比,多花木兰竞争能力大于刺槐、小叶女贞,原有配置的马尾松等植物已经死亡;群落各种群生态位宽度的大小顺序为：多花木兰>刺槐>小叶女贞,分别为2.271、2.147、2.088;群落各种群的生态位重叠值较大,多花木兰和刺槐的生态位重叠值最大,为0.793,多花木兰和小叶女贞生态位重叠值最小,为0.632。多花木兰能够很好地适应高速公路边坡环境,群落中已经被淘汰的其他竞争力太弱的树种不适合与多花木兰混植。