甘薯组织培养中不定根的高频诱导和优化

在甘薯组织培养中获得了不定根的高频诱导，诱导率达95.2%。用正交试验法对影响不定根分化的各种因子进行了研究和优化。结果表明，甘薯不定根诱导和分化的最佳培养基为MS 1.0mg/lANN；不定根生长的最适培养基为MS 0.1mg/lNAA；茎段是甘薯不定根诱导及生长的最适外植堆栈 ；外植体类型对不定根分化的影响最大，其次是NAA，而BA影响最弱。     

稀土对茶园增产及品质影响的分析

本文通过常规分析方法、 生物痕量分析技术及酶活性检测等手段对茶园喷施稀土后的一些 生理生化指标进行了分析。 结果表明， 喷施稀土可明显提高叶绿素的含量， 有利于光合 作用； 增强了谷氨酸脱氢酶(GDH)、 过氧化氢酶(CAT)、 过氧化物酶(POD)及肽酶(PTD)等 酶活性； 提高了茶叶水浸出物含量， 品质得分高于对照； 有利于     

试论档案价值鉴定工作的几个"误区"

由于我国档案价值鉴定理论和观念的长期滞后，导致人们在认识上存在许多“误区”。一、对“丰富馆藏”的理解片面，效益观念淡漠；二、忽略了对永久、长期档案的价值鉴定；三、档案价值鉴定是否重要是由档案数量的多少来决定的；四、鉴定难，销毁更难。文章详细探讨了产生这些“误区”的原因，以及由此带来的负面效应，并提出了正确的认识和今后努力的方向。     

多花黑麦草幼穗分化进程对种子生产性状的影响

两年分期播种试验结果表明，多花黑麦草幼穗分化进程对穗部性状和种子产量有显著影响。幼穗分化的天数与每穗种子粒数呈极显著正相关。播种愈早，幼穗分化天数愈多，种子产量愈高。南京地区留种的多花草麦草的最佳播期为８月２０日至９月１０日。二棱期是多花黑麦草通过春化阶段的形态标志，也是幼穗能否分化完全的转折点。单棱至护颖分化期是影响种子粒数最关键的时期。     

Determination of growth-stage-specific crop coefficients (Kc) of cotton and wheat

Development of crop coefficient (Kc), the ratio of crop evapotranspiration (ETc) to reference evapotranspiration (ETo), can enhance ETc estimates in relation to specific crop phenological development. This research was conducted to determine growth-stage-specific Kc and crop water use for cotton (Gossypium hirsutum) and wheat (Triticum aestivum) at the Texas AgriLife Research field at Uvalde, TX, USA from 2005 to 2008. Weighing lysimeters were used to measure crop water use and local weather data were used to determine the reference evapotranspiration (ETo). Seven lysimeters, weighing about 14 Mg, consisted of undisturbed 1.5 m × 2.0 m × 2.2 m deep soil monoliths. Six lysimeters were located in the center of a 1-ha field beneath a linear-move sprinkler system equipped with low energy precision application (LEPA) and a seventh lysimeter was established to measure reference grass ETo. Crop water requirements, Kc determination, and comparison to existing FAO Kc values were determined over a 2-year period on cotton and a 3-year period on wheat. Seasonal total amounts of crop water use ranged from 689 to 830 mm for cotton and from 483 to 505 mm for wheat. The Kc values determined over the growing seasons varied from 0.2 to 1.5 for cotton and 0.1 to 1.7 for wheat. Some of the values corresponded and some did not correspond to those from FAO-56 and from the Texas High Plains and elsewhere in other states. We assume that the development of regionally based and growth-stage-specific Kc helps in irrigation management and provides precise water applications for this region.     

Regeneration of adventitious shoots from mature stored cotyledons of Japanese plum (Prunus salicina Lind1)

Adventitious shoot regeneration from mature stored cotyledons of Japanese plum (Prunus salicina Lind1) was achieved in vitro. The influences of the presence and absence of the light, different concentrations of thidiazuron (TDZ) and benzyladenine (BA) in the culture media, TDZ pretreatments and different basal salts on shoot regeneration were evaluated. TDZ was more effective in inducing shoot regeneration from mature stored cotyledons than BA. Dark incubation significantly increased the regeneration frequencies. Quoirin/Lepoivre (QL) basal salts stimulated shoot regeneration more than woody plant (WPM) or B5 salts did. The frequency of adventitious shoot formation varied among the varieties and the regeneration ability appeared to be genotype depended. The frequency of regeneration under the optimum tested conditions for ‘Bruce’, ‘Shiro’, ‘Redheart’, ‘Gladstone’ and ‘Early Golden’ cotyledons were 66.7%, 46.7%, 43.3%, 26.7% and 6.7%, respectively.     

Does root-sourced ABA play a role for regulation of stomata under drought in quinoa (Chenopodium quinoa Willd.)

The Andean seed crop quinoa (Chenopodium quinoa Willd.) is traditionally grown under drought and other adverse conditions that constrain crop production in the Andes, and it is regarded as having considerable tolerance to soil drying. The objective of this research was to study how chemical and hydraulic signalling from the root system controlled gas exchange in a drying soil in quinoa. It was observed that during soil drying, relative g_s and photosynthesis A_max (drought stressed/fully watered plants) equalled 1, until the fraction of transpirable soil water (FTSW) decreased to 0.82 ± 0.152 and 0.33 ± 0.061, respectively, at bud formation, indicating that photosynthesis was maintained after stomata closure. The relationship between relative g_s and relative A_max at bud formation was represented by a logarithmic function (r² = 0.79), which resulted in a photosynthetic water use efficiency WUE_Amax_/gs$\text{WU}{\text{E}}_{A_{\text{max}}/g_{\text{s}}}$ of 1 when FTSW > 0.8, and increased by 50% with soil drying to FTSW 0.7–0.4. Mild soil drying slightly increased ABA in the xylem. It is concluded that during soil drying, quinoa plants have a sensitive stomatal closure, by which the plants are able to maintain leaf water potential (ψ_l) and A_max, resulting in an increase of WUE. Root originated ABA plays a role in stomata performance during soil drying. ABA regulation seems to be one of the mechanisms utilised by quinoa when facing drought inducing decrease of turgor of stomata guard cells.     

地中海弧菌Vibrio mediterranei 117-T6的溶藻活性

很多藻类致病菌具有广谱溶藻活性。本研究发现紫菜黄斑病致病菌地中海弧菌Vibrio mediterranei 117-T6（Vm 117-T6）对赤潮异湾藻、颗石藻、叉编金藻和东海原甲藻等微藻也具有较强的溶藻活性，可使其叶绿素含量显著降低，是一株广谱性溶藻细菌。Vm 117-T6能在40 min内使赤潮异弯藻的活动能力下降，光合作用受抑，感染120 min即可导致藻体裂解并产生白色絮状沉淀。Vm 117-T6能降解卡拉胶，不能降解果胶、纤维素和几丁质。菌体、胞内及胞外提取物均具有较强的溶藻活性，其胞外溶藻物质易溶于水、不溶于石油醚和乙酸乙酯，具较强极性；耐高温、不易被活性炭吸附、乙醇处理会降低溶藻活性。Vm 117-T6在常规与易感条件下的关键差异蛋白包括大量的ABC转运蛋白、外膜蛋白、鞭毛蛋白及少量Toxin。这些研究结果提示Vm 117-T6毒力效应物中含有极性非蛋白质类物质，且与毒力因子转运、分泌以及细胞黏附相关的蛋白可能在其毒力作用中发挥重要作用。上述研究结果表明：多种溶藻机制参与了Vm 117-T6的溶藻过程。