利用RAPD技术鉴别玉米自交系

本文利用RAPD技术对我国28个玉米骨干自交系进行了分析,从300个引物中筛选出了40个多态性好的引物,结果发现：仅使用OPI₁₀一个引物扩增的DNA指纹图谱就能区别开15个自交系,增加引物OPB7可以区分开26个自交系,再增加OPC₁₉、OPG₆、OPA₇、OPI₁₁、OPG₁₄中的任何一个引物就可以将28个自交系完全区分开。研究还表明亲缘关系很近、利用同工酶方法无法区分的姊妹系材料如：478、488和3189,以及双105和双741都能够被明显的区分开,证明了利用RAPD技术进行玉米自交系鉴定完全可行而且是非常有效的。     

玉米叶片水分利用效率与叶绿素a荧光参数的关系

利用Handy PEA植物效率仪测定叶绿素a荧光参数,研究玉米自交系叶片水分利用效率(WUE)与叶绿素a荧光参数的关系。结果表明,玉米自交系叶片WUE与叶绿素a荧光参数呈极显著的正相关。其中,F_o与高水分利用效率(HWUE)玉米自交系WUE的相关系数大于低水分利用效率(LWUE)玉米自交系WUE的相关系数;最大荧光(Fm)、可变荧光(F_v)、PSⅡ原初光能转换效率(F_v/F_m)和PSⅡ潜在活性(F_v/F_o)与水分利用效率不同的玉米自交系叶片WUE的相关系数恰好相反,这是造成不同玉米自交系WUE存在差异的生理原因之一,同时也说明叶绿素a荧光参数可以作为选育HWUE玉米自交系的重要指标。     

低磷胁迫下不同基因型玉米内源激素的动态变化

用高效液相色谱法测定在低磷胁迫下不同基因型玉米生育进程中叶片和根系内源激素含量的动态变化。结果表明,不同基因型玉米叶片和根系内源激素含量除ABA含量为磷低效自交系>磷高效自交系>F₁外,ZT、GA₃和IAA含量均为F₁>磷高效自交系>磷低效自交系。低磷胁迫下,除ZT含量较正常供磷水平减少外,GA₃、IAA和ABA含量均较正常供磷水平增加。ZT和ABA的变幅表现为磷低效自交系大于磷高效自交系和F₁,GA₃和IAA的变幅表现为磷高效自交系和F₁大于磷低效自交系。此外,低磷胁迫下磷高效自交系与磷低效自交系间同一内源激素最值出现时期不同。说明低磷胁迫下不同磷利用效率自交系内源激素表现出规律性变化,因此可将内源激素作为鉴定和选育玉米磷高效基因型的参考指标。     

玉米自交系辐照效应的研究

用200Gy⁶⁰Co-γ射线辐照玉米自交系"黄早4”干种子,会引起自交系各性状的较大变异.M₁表现出明显的辐射生理损伤效应,M₂、M₃的质量性状未发现有明显的变异,但生育期、株高、穗位高、穗长等数量性状出现较高的突变频率;M₃开始出现黄、白化苗、矮生株等隐性突变和雄性不育株,同时在粒色上也产生了有明显变异的个体.再次证明异花授粉作物的辐射诱发突变导致M₂形成杂合的植株,而诱发突变大多为隐性的,需在M₃纯合后才表现出来,M₄代测交种试验结果表明,自交系经辐照后,有选择出高配合力个体的可能。     

转育玉米大斑病抗病单基因Ht的实用性初探

对玉米自交系Mo17转育抗病单基因Ht₂、Ht₃,培育出Mo17的6个近等基因系,通过温室及田间人工接种玉米大斑病菌鉴定及配合力测定.得出在利用多基因抗性的基础上同时转育单基因Ht₁、Ht₂、Ht₃、Ht_N,把单基因尽可能集中到一个自交系或杂交种上;形成“多质系”或“多系品种”,因而具有兼抗多个生理小种的作用,从而延长杂交种的使用寿命.”     

不同普×爆后代群体膨爆特性的分离特征研究

对5个普通玉米自交系与4个爆裂玉米自交系组配的20个普×爆组合F₂,BC₁,BC₂3个世代的膨爆特性分析结果表明:F₂代膨爆特性较差,难以采用常规系谱法从中选育出优良的膨爆玉米自交系;通过回交可以快速恢复其优良的膨爆特性,但不同组合及同一组合不同世代间的膨爆特性存在较大差异.因此,要提高后代的选育效果,首先要选配适宜的普×爆组合,其次是要确定具体的回交世代。     

低钾胁迫下玉米逆境反应机制初探

采用低钾和正常供钾的液培方式,研究耐低钾玉米自交系Y₈对低钾胁迫的适应性生理生化反应机制。结果表明：与不耐低钾玉米自交系J₁₃相比,低钾胁迫下耐低钾玉米自交系Y₈的SOD活性降低,CAT活性增加,Pro含量增加,MDA含量明显减少,POD活性和AsA含量基本稳定。     

8622×GY220 F2∶3家系植株性状的分离特征及相关分析

利用普通玉米自交系8622与高油玉米自交系GY220杂交构建的F_2∶3家系为材料,在春播环境条件下对8个植株性状进行了初步分析。结果表明：F₁各植株性状介于双亲之间或高于双亲;F_2∶3家系间各性状均存在极显著差异,并呈连续正态分布,存在明显双向超亲分离;株高与穗位高、顶高、穗上叶片数、雄穗长,穗位高与雄穗长,顶高与顶高/株高、穗上叶片数、雄穗长,穗上叶片数与雄穗分枝数间均呈显著或极显著的表型和遗传正相关;穗位高与顶高、顶高/株高、穗上叶片数间均呈显著或极显著的表型和遗传负相关。     

玉米自交系耐盐种质的筛选及耐盐性评价

在0+0、2.5+2.5、5+5和7.5+7.5 mmol/L（Na₂CO₃+NaHCO₃）盐浓度胁迫下,对118份玉米自交系芽期、苗期的耐盐性差异进行比较,以主要农艺性状综合表现为依据筛选耐盐种质。各指标受盐害影响程度大小顺序为株高>芽势>叶长>根长>地上含水量>地下含水量>叶宽>芽率>须根数>根冠比>茎粗>根粗;当盐胁迫溶液为7.5 mmol/LNa₂CO₃+7.5 mmol/L NaHCO₃时,对玉米自交系影响差异显著。综合各个指标的盐害率对118份玉米自交系进行评价和排序,5个耐盐性强的自交系品种为DL、A71、PHB1M、A92和WM33;对盐敏感的5个品种为06NY-25、Mo17、郑32、南引26和农M1。     

低温胁迫及恢复对玉米光合特性的影响

以玉米自交系掖478、合344、吉853为材料,在不同低温胁迫及恢复正常温度情况下比较幼苗光合作用及叶绿素荧光参数等指标的变化。结果表明,随着胁迫温度的下降和低温胁迫时间的延长,3个玉米自交系幼苗叶片初始荧光F_o呈上升趋势,F_v/F_o、F_v/F_m整体上均呈下降趋势。叶绿素荧光参数随着低温胁迫程度的加强变化较大,且相同温度下的变化幅度掖478<合344<吉853。3个玉米自交系在各温度胁迫后恢复到常温时的叶片初始荧光F_o下降,F_v/F_m、F_v/F_o整体上呈上升趋势。掖478恢复常温1～2 d后恢复到正常水平,抗冷性最强;吉853的PSⅡ系统受损较重,恢复常温3 d未达正常水平,抗冷性较弱。     

In vitro reproduction in the annual pasture legumes subterranean clover (Trifolium subterraneum L.) and French serradella (Ornithopus sativus Brot.)

Pasture legumes are important components of both mixed farming rotations and permanent pastures in temperate climates. Breeding of two widely sown pasture legumes, subterranean clover (Trifolium subterraneum L.) and French serradella (Ornithopus sativus Brot.), is constrained by the long generation cycle, typically enabling only one generation per year. We hypothesized manipulation of culture medium and conditions would enable the development of a laboratory‐based protocol for in vitro reproduction in subterranean clover and French serradella. In vitro flowering and viable seed set was induced from both species. For subterranean clover, the most effective treatment was culturing on modified MS medium with 1 μm kinetin and 0·1 m sucrose under a 100 μmol m^?2 s^?1 light intensity and continuous photoperiod. For French serradella, culture on a hormone‐free B5 medium with 5 mm NH₄Cl and 0·1 m sucrose under a 100 μmol m^?2 s^?1 light intensity and 20 h photoperiod was optimum. It is expected this technique will have application in accelerating generation turnover within breeding programs, for the study of factors influencing flowering in pasture legumes, and for the propagation of valuable yet enfeebled plants such as embryo‐rescued hybrids.     

Estimation of lucerne yield stability for enabling effective cultivar selection under rainfed conditions

Evaluation of crop and forage yield stability is of increasing relevance in the context of current and recent environmental changes but, in contrast to other field crops, there are no published systematic analyses among forage crops in Europe. A study of stability performance was conducted with 13 Czech cultivars of lucerne at four locations over a 2‐year period with the following aims: (a) to evaluate yield stability of varieties across different environments and (b) to calculate measurable benefits of variety selection in relation to the specific environment. The cultivar Vlasta was identified as the highest yielding cultivar (annual yield 16.0 t DM/ha), whereas the lowest yielding cv. Magda, Tereza and Oslava averaged around 14.9 t DM/ha. Effect of genotype × environment interaction (G × E) was two times higher than for genotype alone. Additive main effects and the multiplicative interaction (AMMI) model showed that the highest yielding cultivars may not be stable across environments. This study demonstrated further that significant yield improvement could be detected, even among a relatively homogenous group of domestic cultivars, and this was driven mainly by site productivity: the improvement was +10% in low‐yielding sites, compared with +3% in high‐yielding sites. Results highlight that advanced agronomy should also consider stability parameters such as AMMI stability value or superiority measures for forage crops in response to the challenges associated with climate change.     

稻文化的再思考3:稻与社稷——印度、泰国等东南亚、南亚主要国家

东南亚、南亚地区是世界上重要的稻米产区,稻米在民众饮食生活和国家社会政治中占有重要地位,民众生活中也保存了非常悠久和丰富的稻作文化习俗及稻谷起源神话传说。本文分析了水稻在东南亚、南亚主要国家印度、印度尼西亚、泰国、越南、菲律宾、孟加拉国、缅甸的作用、地位、生产、消费、文化等情况,并指出了印度、印度尼西亚稻文化的主要标志。     

Model of wheat yield response to application of diclofop-methyl to control ryegrass (Lolium rigidum)

A general model of crop yield response to herbicide application is proposed. The model includes three components: the effect of herbicide dosage on weed density, the effect of surviving weed density on crop yield and the effect of herbicide directly on the crop. The model is used to estimate the response of wheat yield to application of diclofop-methyl to control ryegrass (Lolium rigidum) in Australia. It is found that the competitiveness of ryegrass plants surviving treatment is reduced by the treatment and that the proportion of yield loss at a given ryegrass density is not independent of the absolute weed-free yield. The response function is used to calculate economic thresholds and optimal herbicide dosages.     

大豆对钼与氮、磷、钾的吸收分配动态及相互关系的初步研究

大豆植株中其叶片的钼、氮、磷含量均高于茎杆、叶柄、繁殖器官高于营养器官。钾在整个生育期中都保持较高的水平,只是叶片中的含量低于其它器官。种子中的钼、氮、磷、钾含量都较高。大豆吸收钼及氮、磷、钾的数量因品种及各生育阶段而有差异,吸收量以结荚至鼓粒期为最多,鼓粒期以后,安农75—59的植株中氮、磷、钾吸收量明显下降,唯有钼还在继续吸收,而安激一号对钼及氮、磷、钾仍在吸收。大豆对钼与氮、磷、钾的吸收呈极显著的直线相关,尤其是钼与氮相关最明显。安农75—59亩产189.5kg,需要N素16.05kg,P_2O_54.25kg,K_2O8.43kg,微量元素Mo357.32mg。安激一号亩产214.5kg.需要N素18.00kg、P_2O_55.01kg、K_2O8.85kg、微量元素Mo449.57mg。安激一号的种子除糖、脂肪含量较低外,而氮、磷、钾、钼、维生素C的含量均高于安农75 59。     

Blackgram fiber (Phaseolus mungo): Mechanism of hypoglycemic action

The effect of the administration of blackgram fiber (Phaseolusmungo) on the metabolism of carbohydrates was studied in rats fed 30%NDF (neutral detergent fiber) diet. The experimental group showed a significant increase in liverglycogen level and a significant decrease in blood glucose. Significantincreases in the activities of glycogen phosphorylase, hexokinase, fructose-1,6-diphosphatase, glucose-6-phosphate dehydrogenase and isocitratedehydrogenase were observed in the experimental group. The activities ofphosphoglucomutase and glucose-6-phosphatase were significantly lower inrats fed the fiber diet. The study showed that blackgram fiber exhibitssignificant hypoglycemic action in experimental animals.     

Carbohydrase systems of Saccharophagus degradans degrading marine complex polysaccharides

Saccharophagus degradans 2-40 is a γ-subgroup proteobacterium capable of using many of the complex polysaccharides found in the marine environment for growth. To utilize these complex polysaccharides, this bacterium produces a plethora of carbohydrases dedicated to the processing of a carbohydrate class. Aiding in the identification of the contributing genes and enzymes is the known genome sequence for this bacterium. This review catalogs the genes and enzymes of the S. degradans genome that are likely to function in the systems for the utilization of agar, alginate, α- and β-glucans, chitin, mannans, pectins, and xylans and discusses the cell biology and genetics of each system as it functions to transfer carbon back to the bacterium.     

基于颜色和形状的茶叶计算机识别研究

综合利用计算机视觉、图像处理技术,增加茶叶的形状参数,改进神经网络算法,实现了茶叶品质识别的自动化。研究中通过数码相机等直接得到茶叶图像,经过对图像格式进行转换和预处理,然后基于HSI模型提取的茶叶颜色特征参数和二值化后图像提取的茶叶形状特征参数,通过遗传神经网络,最后完成对茶叶的自动识别。实验结果表明此方法能取得更好的识别效果,计算机的检测结果与人工检测结果高度吻合。     

Grain number dominates grain weight in temperate cereal yield determination: Evidence based on 30 years of multi-location trials

Multi-location data collected over 30 years in Finland on major cereal crops (spring barley, oat and wheat, and winter wheat and rye) provide an opportunity to characterise variation, interrelation and relative importance of the grain yield determining components, grain number per square meter (GNO) and single grain weight (SGW). In addition to evaluating differences among cereal crops in yield determination, changes among different age groups (AG) were compared. Field experiments were carried out in 1970–2001 at 25 locations in Finland. Grain yield was recorded (at 15% moisture) and SGW (mg) and GNO (number m⁻²) determined. Frequencies of different GNO and SGW combinations were analysed for all crops and component means in different yield groups as well as among four AGs. In most cases GNO dominated SGW, representing the major yield component determining grain yield. GNO was highly responsive to favourable growth conditions. The change in GNO was especially high when recurrent, relatively low yield groups were compared, while at higher yields the role of SGW became increasingly important, but did not exceed that of GNO. The degree of GNO domination varied according to crop. Increased grain yield in spring oat and winter rye was associated with higher numbers of set grain, while spring barley and winter wheat responded to yield favouring conditions also through higher SGW. Despite GNO dominated SGW due to its responsiveness to growing conditions, its role in yield improvement was not obvious when the entries (n ≥ 30) were classified into four AGs. Improvements in grain yield derived from AG were associated with crop-specific GNO and/or SGW changes.     

The Challenge of Ecophysiological Biodiversity for Biotechnological Applications of Marine Microalgae

In this review, we aim to explore the potential of microalgal biodiversity and ecology for biotechnological use. A deeper exploration of the biodiversity richness and ecophysiological properties of microalgae is crucial for enhancing their use for applicative purposes. After describing the actual biotechnological use of microalgae, we consider the multiple faces of taxonomical, morphological, functional and ecophysiological biodiversity of these organisms, and investigate how these properties could better serve the biotechnological field. Lastly, we propose new approaches to enhancing microalgal growth, photosynthesis, and synthesis of valuable products used in biotechnological fields, mainly focusing on culture conditions, especially light manipulations and genetic modifications.