High-yield spore production from <Emphasis Type="Italic">Bacillus licheniformis</Emphasis> by solid state fermentation

Bacillus licheniformis was grown for 48 h at 37°C in solid state fermentation; a maximum of 1.7 × 10¹¹ spores/g dry substrate were obtained using rice straw powder (300 g/kg) and wheat bran (700 g/kg) supplemented with glucose (40 g/kg), peptone (20 g/kg), yeast extract (20 g/kg), KH₂PO₄ (10 g/kg) and CaO (5 g/kg) with an initial moisture content of 65%.     

Intraspecific responses of <Emphasis Type="Italic">Fagopyrum esculentum</Emphasis> to enhanced ultraviolet B radiation

The effects of supplemental UV-B radiation on crop growth, morphology, reproduction and physiology were studied in three cultivars of Fagopyrum esculentum Moench (buckwheat) originating from high elevation (Qinghai-Tibet plateau) and lower altitudes (The Sichuan Basin). Our results showed that common buckwheat was sensitive to UV-B stress. Plant growth, development, and reproduction were inhibited by elevated UV-B radiation. Plant lipid oxidation and polyphenol oxidase (PPO) activity increased with increasing UV-B radiation, along with the concentration of phenylpropanoid compounds, superoxide dismutase (SOD) activity and ascorbic acid (Asa) concentration were also enhanced at the lowest level of supplemental UV-B radiation but decreased at the higher level of enhanced UV-B. While, a cultivar originating from elevated locations had lower dry matter accumulation and was more tolerant to UV-B radiation than cultivars originating from lower elevations. The effects on leaf thickness and increased antioxidant capacity could be linked with the improved performance of cultivar originating from high elevation when exposed to enhanced UV-B radiation. We conclude that UV-B tolerance should be considered prior to introducing or breeding common buckwheat cultivars from lowland cultivation to regions at high elevation such as the Qinghai-Tibet plateau.     

普通荞麦资源的耐铝性研究

利用小容器溶液培养法对耐铝性鉴定条件和52份普通荞麦栽培品种资源的耐铝性进行了研究。结果发现普通荞麦耐铝性鉴定的适宜条件为发芽种子于500μmol/LAlCl3溶液(pH4.5)处理3d,以发芽种子在这三天内的根伸长量衡量耐铝性程度。在该处理条件下,普通荞麦不同品种间的耐铝性有显著差异。其中,陕西大红花甜荞品种、日本大粒荞、织金红花甜荞的耐铝毒胁迫能力最强,值得在荞麦耐铝性育种和耐铝机制研究中利用。     

苦荞麦麸皮的化学成分研究

从苦荞麦麸皮浸膏中分离得到7个化合物,经波谱分析确定结构分别为：β—谷甾醇(1)、过氧化麦角甾醇(2)、大黄素(3)、胡萝卜甙(4)、山奈酚(5)、异山奈酚(6)和槲皮素(7)。化合物1—6为首次从苦荞麦麸皮中分离得到。     

Buckwheat (Fagopyrum esculentum Moench) has high capacity to take up phosphorus (P) from a calcium (Ca)-bound Source

Two experiments were carried out in a growth chamber to investigate the phosphorus (P)-uptake efficiency of Fagopyrum esculentum Moench (buckwheat) and Triticum aestivum (spring wheat) from a Ca-bound form. The first experiment was based on a sand-culture system with either rock phosphate (RP) or CaHPO₄ (CaHP) as the P source and nitrate or ammonium nitrate as nitrogen source. A highly calcareous soil was used in the second experiment. Buckwheat was shown to be highly efficient in taking up Ca-bound P compared to spring wheat. When plants were supplied with nitrate, the total P uptake by buckwheat from RP was nearly 10-fold higher than that of spring wheat (20.1 compared with 2.1 mg P pot^–1). Changing nitrogen source from nitrate only to ammonium nitrate increased P uptake by spring wheat substantially, but not buckwheat. High P-uptake efficiency of buckwheat was also demonstrated using the field soil, but to a lesser extent, which may be related to the difference in Zn supply between sand culture and field soil. It is suggested that buckwheat may be included in intercropping or crop rotation systems to activate P sources in calcareous soils. The principal mechanism of P uptake efficiency of buckwheat may be its ability to acidify the rhizosphere; however, further study is needed to unravel the regulation of root excretion of H⁺ and its molecular basis in order to exploit buckwheat's genetic capability to utilise sparingly soluble P from soil.     

六个不同类型荞麦花花粉粒形态的电镜观察比较研究

对二倍体甜荞长花柱类型 (ES2 s)、二倍体甜荞短花柱类型 (ES2 S)、四倍体甜荞长花柱类型 (ES4s)、四倍体甜荞短花柱类型 (ES4S)、四倍体有翅细野荞 (GR4HI)、四倍体无翅细野荞 (GR4HO)等 6个不同荞麦类型花的花粉形态学进行了电镜观察。结果表明 :这些荞麦类型的花粉粒都是椭圆形 ,都有网状纹饰、3孔沟等特征。二倍体甜荞染色体加倍后形成的四倍体甜荞 ,相对于二倍体甜荞而言 ,花粉粒显著增大和明显变圆。无论二倍体还是四倍体甜荞 ,其长花柱型花的花粉粒都比其对应短花柱型花的花粉粒要小。尽管四倍体甜荞和四倍体细野荞在染色体数目和倍性上一样 ,但是它们在花粉粒的大小上有显著差异。四倍体细野荞有翅类型和无翅类型的花粉粒大小和形态差异不显著     

重庆部分地区的种质资源调查荞麦篇

"第三次全国农作物种质资源调查与收集"重庆项目组,于2015年10月至11月初在重庆市巫山县、奉节县和石柱县3个县开展了农业生物资源的系统调查,通过深入村社和农户,调查了解作物种类与品种多样性情况,收集和挖掘古老、特有和稀少种质资源。本次调查共收集到农作物地方品种和野生近缘植物种质资源341份,其中粮油作物136份、蔬菜86份、果树57份、茶树5份、烟草22份、牧草30份、麻类5份。本文重点介绍在粮油作物中的荞麦种质资源调查和资源收集情况,在收集到的19份荞麦资源中,既有珍稀、古老的地方品种,也包括特有野生资源。荞麦承载了彝族等少数民族的文化内涵,随着现代农业的发展,荞麦的古老、珍稀和特有种质资源正在流失,建议相关部门因地制宜,在发展现代农业生产的同时,采取必要的经济措施,对古老、珍稀和特有的荞麦种质资源,进行农户或原生境保护,为进一步开发利用提供种质资源基础。     

两个荞麦品种的核型分析

本文对南方两个荞麦品种高荞3号和溪荞5号的根尖细胞有丝分裂染色体进行核型分析。结果表明,高荞3号和溪荞5号的核型都为2A,高荞3号和溪荞5号的核型公式分别为2n=2x=16=10m(2SAT)+4sm+2st和2n=2x=16=8m+6sm(2SAT)+2st。     

Probing the cell wall heterogeneity of micro-dissected wheat caryopsis using both active and inactive forms of a GH11 xylanase

The external envelope of wheat grain (Triticum aestivum L. cv. Isengrain) is a natural composite whose tissular and cellular heterogeneity constitute a significant barrier for enzymatic cell wall disassembly. To better understand the way in which the cell wall network and tissular organization hamper enzyme penetration, we have devised a strategy based on in situ visualization of an active and an inactive form of a xylanase in whole-wheat bran and in three micro-dissected layers (the outer bran, the inner bran and the aleurone layer). The main aims of this study were to (1) evaluate the role of cuticular layers as obstacles to enzyme diffusion, (2) assess the impact of the cell wall network on xylanase penetration, (3) highlight wall heterogeneity. To conduct this study, we created by in vitro mutagenesis a hydrolytically inactive xylanase that displayed full substrate binding ability, as demonstrated by the calculation of dissociation constants (K_d) using fluorescence titration. To examine enzyme penetration and action, immunocytochemical localization of the xylanases and of feebly substituted arabinoxylans (AXs) was performed following incubation of the bran layers, or whole bran with active and inactive isoforms of the enzyme for different time periods. The data obtained showed that the micro-dissected layers provided an increased accessible surface for the xylanase and that the enzyme-targeted cell walls were penetrated more quickly than those in intact bran. Examination of immunolabelling of xylanase indicated that the cuticle layers constitute a barrier for enzyme penetration in bran. Moreover, our data indicated that the cell wall network by itself physically restricts enzyme penetration. Inactive xylanase penetration was much lower than that of the active form, whose penetration was facilitated by the concomitant depletion of AXs in enzyme-sensitive cell walls.     

Hyperactive α-amylase production by Aspergillus oryzae IFO 30103 in a new bioreactor

Aims: To improve the α‐amylase production in solid‐state fermentation (SSF) condition utilizing a new bioreactor (NB) system. Methods and Results: In NB system, 20 g of wheat bran moistened with liquid medium in 1 : 1 ratio (w/v) was taken on the tray present inside the upper vessel and an additional 80 ml medium was supplemented into the lower vessel. Oxygen uptake rate was improved by supplying compressed air that lifted the liquid medium into the upper vessel and touched the substrate bed. This condition probably facilitated the heat transfer to liquid medium, reduce water loss and catabolite repression. With 1% glucose supplementation, maximum α‐amylase activity of 22 317 Ugds^?1 was produced by Aspergillus oryzae IFO 30103 within a very short incubation period (48 h) at 2‐cm bed height with air flow rate of 0·1 l min^?1 g^?1 wheat bran at 32°C and initial medium pH of 6. Conclusions: Within a short incubation period, significantly high α‐amylase activity was obtained and it is higher than those reported to date at bioreactor scale operating with a fungal strain. Significance and Impact of the Study: The reactor is novel and can overcome some of the major problems associated with SSF process. A. oryzae IFO 30103 is reported as the best fungal source for α‐amylase production.