N离子注入对陆地棉发芽率和出苗率的影响

在3千电子伏(Kev)能量和四种不同的注入时间下,用N离子注入四个陆地棉品种干种子内,以估计不同品种承受能力和不同剂量对棉花出苗率和发芽率的影响。结果表明:PD系统的品种有较好的承受能力,而同一品种在四种剂量下的发芽率无显著的差异。     

利用花药培养加速离子束介导转基因水稻后代的纯合速度

利用花培加速玉米稻分离后代的纯化。从 1996年开始 ,对转基因玉米稻经多代选择仍“疯狂”分离的后代 ,进行花药培养 ,经两年的繁育种植 ,已获得株型较理想、性状稳定遗传的玉米稻花培株系 ,表明将花药培养方法与转基因技术相结合 ,对加速玉米稻分离后代的纯化是有效的     

A review of phosphorus homeostasis and the impact of different types and amounts of dietary phosphate on metabolism and renal health in cats

Elevated concentrations of serum phosphate are linked with progression and increased case fatality rate in animals and humans with chronic kidney disease. Elevated concentrations of serum phosphate can be a risk factor for development of renal and cardiovascular diseases or osteoporosis in previously healthy people. In rodents, an excess intake of dietary phosphorus combined with an inverse dietary calcium : phosphorus ratio (<1 : 1) contributes to renal calcification. Renal injury also has occured in cats fed experimental diets supplemented with highly soluble phosphate salts, especially in diets with inverse calcium : phosphorus ratios. However, not all phosphorus sources contribute similarly to this effect. This review, which focuses on cats, summarizes the published evidence regarding phosphorus metabolism and homeostasis, including the relative impact of different dietary phosphorus sources, and their impact on the kidneys. No data currently shows that commercial cat foods induce renal injury. However, some diets contain high amounts of phosphorus relative to recommendations and some have inverse Ca : P ratios and so could increase the risk for development of kidney disease. While limiting the use of highly soluble phosphates appears to be important, there are insufficient data to support a specific upper limit for phosphate intake. This review also proposes areas where additional research is needed in order to strengthen conclusions and recommendations regarding dietary phosphorus for cats.     

离子注入引起银杏种子M1代染色体畸变的研究

本文报道了离子注入引起银杏Ｍ１代染色体畸变的结果。研究表明,Ｎ＋离子辐照银杏种子后,胚根细胞中出现了核异常和染色体畸变,显微观察发现有多核、染色体桥、游离染色体和落后染色体,畸变频率在０．８～ｌｌ．２％。随着辐照剂量的提高,畸变频率增大,畸变类型增多。发芽试验结果与染色体损伤结果相符。     

离子注入在棉花育种中的诱变功效

分析了在棉花离子注入育种中出现的各种有用变异,包括早熟性、株型、主茎高度和粗细,以及陆地棉与海岛棉种间杂种出现的性状稳定加快现象。     

外源葡萄糖对盐胁迫下黄瓜幼苗光合作用和离子分布的影响

[目的]为了探讨外源葡萄糖缓解盐胁迫下黄瓜幼苗生理伤害的作用机制。[方法]采用营养液水培法,以盐敏感型黄瓜品种‘津春2号’为材料,研究外源葡萄糖对盐胁迫下黄瓜幼苗生长、叶绿素含量、光合作用以及体内离子分布的影响。[结果]盐胁迫(65mmol/L Na Cl)显著降低了黄瓜幼苗叶片的叶绿素含量、净光合速率(Pn)、气孔导度(Gs)和胞间CO2浓度(Ci),限制了黄瓜幼苗植株的生长,而根施2 mmol/L葡萄糖缓解了盐胁迫诱导的光合速率和生长下降;在盐胁迫下,黄瓜幼苗叶片、茎和根中Na+和Cl-含量显著增加,而K+和Mg2+含量明显降低,外源葡萄糖处理逆转盐胁迫诱导黄瓜植株体内离子含量的变化。[结论]外源葡萄糖通过抑制根中Na+和Cl-向地上部的运输,减轻叶片中Na+和Cl-积累诱导的离子毒害,从而缓解盐胁迫对光合作用的抑制,进而促进盐胁迫下黄瓜幼苗的生长。     

离子色谱-电导检测法测定农田灌溉水中阴离子的研究

[目的]建立了一种离子色谱法同时测定农田灌溉水中F-、Cl-的新方法。[方法]分析柱采用容量高的Dionex IonPac AG19阴离子交换柱,自动在线产生KOH淋洗液,等浓度泵作等度淋洗。[结果]阴离子检出限为F-3.0μg/L,Cl-5.0μg/L,测定结果相对标准偏差均小于5%,回收率为95.5%~104.8%,线性范围宽,相关性好(r0.999 8),精密度高(RSD2.01%),准确度好。[结论]该方法简便、快速、准确度高、前处理简单,能够满足环境水样中阴离子的分析要求。     

FPA 98型树脂对肝素钠的吸附特性研究

[目的]筛选适宜的离子交换树脂,并优化提取工艺条件。[方法]通过比较4种阴离子交换树脂对肝素钠的吸附效果,研究吸附时间、温度、溶液pH、盐浓度对FPA 98型树脂对肝素钠的吸附率的影响。[结果]FPA 98型大孔树脂对肝素钠的吸附效率最高。在吸附温度60℃、pH为8.8、盐浓度3%的条件下吸附7.0 h,FPA 98树脂对肝素钠的吸附率达92%。[结论]FPA 98型树脂对肝素钠的吸附特性研究为肝素钠的生产提供了参考。     

园林植物高新技术育种研究综述和展望

随着我国园林绿化市场的持续升温,园林植物育种领域的研究不断得到重视,在传统育种技术的基础上,以现代生物技术、航天和离子注入诱变育种为核心的高新技术育种得到较大程度的发展。本文阐述了基因工程和细胞工程技术在园林植物株型和花型、花色和香味、生长发育、延缓衰老、抗病虫、抗逆境等方面的研究现状;综述了航天育种和离子注入育种等高新技术的研究基础,及其在园林植物种质创新领域的研究进展;并介绍了国内有关研究单位的一些相关研究情况。分析了园林植物育种技术的发展趋势,并重点对园林植物现代生物技术、航天和离子注入育种作了展望。     

Differential Sensitivity of Rice Cultivars to Salinity and Its Relation to Ion Accumulation and Root Tip Structure

Abstract

Effects of NaCl on the growth, ion content, root cap structure and Casparian band development were examined in four rice (Oryza sativa L.) cultivars with different salt resistance (salt-sensitive indica-type IR 24 and japonica-type Nipponbare and salt-resistant indica-type Nona Bokra and Pokkali). Experiments were conducted to find the differences in salinity resistance during early seedling and developed seedling stages among the cultivars. For salinity treatment, sodium chloride (NaCl) was added to nutrient solution at concentrations of 0, 25 and 50 mM for 7 days from germination to the 7th day (early seedling stage) or from the 7th day to 14th day (developed seedling stage). Growth inhibition by salinity was more prominent in the early seedling stage than in the developed seedling stage. Based on the growth, the order of the sensitivity was IR24 > Nipponbare > Nona Bokra > Pokkali. The growth of NaCl-treated rice cultivars relative to control was significantly and negatively correlated with the Na⁺ content and Na⁺/K⁺ ratio in roots and shoots in both stages. Scanning electron microscopic observation revealed that the root cap tissues proliferated and extended to the basal part of the root tip by salinity. The length of root cap was, however, reduced by 50 mM NaCl in sensitive cultivars due to peeling off. An endodermal Casparian band was formed in the basal region of the root tip. Development of the Casparian band was more prominent in sensitive cultivars than in tolerant cultivars. Root cap proliferation might be related to NaCl resistance in rice seedlings, but the Casparian band may not function efficiently in Na⁺ exclusion. Essentially the present results suggest that exclusion of Na⁺ from roots plays a critical role in expression of Na⁺ resistance in rice seedlings and the root cap is important for Na⁺ exclusion.