杂交玉米制种质量问题分析及解决措施

玉米是我国第二大宗粮食作物。玉米杂交种质量对玉米产量有着重要影响。亲本纯度低、制种质量差是造成玉米杂交种子质量低劣的两大根本原因。提纯亲本、加强隔离、严格去杂、严格去雄、割除父本以及做好收、脱、晒、藏等后期工作是确保玉米杂交种子质量提高的有效措施。     

杂交水稻亲本纯度与种子纯度的相关性分析

为研究杂交水稻制种中,亲本纯度与种子纯度之间的关系,用6家公司提供的水稻亲本和制种后代进行田间鉴定.结果表明,在杂交种子生产中没有采取去杂等手段时,两者具有正相关性;当种子生产中去杂、隔离措施到位时,则无相关性.因此,种子企业需要加强保纯意识,促进种子生产的质量保障.     

两系粳杂70优04高产制种技术

通过对两系杂交粳稻 70优 0 4制种实施“父本栽插苗数”、“父母本栽插行比”、“生物激素使用”和“父本偏施氮肥”四项试验 ,明确了该组合制种父本适宜栽插苗数为穴栽 2粒种子苗 ,行比以 2∶1 2为宜 ,九二○最佳用量为 2 40 g/hm2 。分析了父本适当偏施氮肥应注意的问题     

特优627优质高产制种技术

通过杂交中晚稻新组合特优627的父母本、龙特甫A与亚恢627特征性的观察及分期播种试验.结合2005、2006两年特优627小面积制种试验,提出了特优627在福安市溪柄等制种基地制种的最佳播插期,培育丰产苗架,合理使用“920”、人工辅助授粉和确保种子纯度等优质高产制种技术措施.     

不同化学试剂浸种对银杏种子萌发和幼苗生长的影响

银杏是集食用、药用与观赏价值于一体的我国特有的裸子植物。种子繁殖是银杏繁殖的主要方法,优质种苗的繁育成为银杏产业发展的关键。本研究以银杏种子为试材,采用不同浓度的硝酸钾、氯化钙和赤霉素(GA_3)三种化学试剂对银杏种子进行浸种处理,研究不同化学试剂浸种对银杏种子发芽特性和幼苗生长的影响。结果表明0.8M硝酸钾是最适宜银杏种子浸种的浓度,40mM和80mM氯化钙是较为适宜银杏种子浸种的浓度,尤其以40mM为较优浓度,250mg/L的GA_3浸种能够促进银杏种子的萌发和幼苗生长,而较高浓度的GA_3浸种对银杏种子的萌发和幼苗生长具有明显的抑制作用。研究结果能够为银杏种子繁殖提供一定的科学依据与参考。     

水稻光温敏核不育系育性选择方法的探讨

针对光温敏核不育水稻的制种安全性和繁殖丰产性 ,根据宜春近 2 0年气温资料和光温敏核不育水稻育性遗传变异特点 ,提出将光温敏核不育水稻的不育起点温度降至 2 1℃、自身繁殖产量高的育性选育目标 ,阐述了有利于目标性状选择的自然低温环境以及实现育种目标的选育方法 ,介绍了已取得的选育进展 .     

灵宝杜鹃种子特性及赤霉素对其萌发的影响

以灵宝杜鹃种子为材料,对灵宝杜鹃种子形态特征、吸水性以及赤霉素处理对种子发芽的影响进行了研究.结果表明,灵宝杜鹃种子呈锥状,为小型种子;吸水过程中,0～2 h种子吸水速度最快,随后吸水速度迅速降低,至18 h达到饱和状态. GA₃浸泡处理能提高种子发芽率和发芽势,提高了种子的发芽速度和整齐度,但浸种时间影响不大;灭菌处理影响种子发芽,采取先用8%NaClO灭菌后用GA₃处理的方法可以显著提高发芽率.     

2000年晚熟尖椒生产建议

１ .选用中熟品种 :如羊角型的８６１和牛角型的中熟品种。２ .选用景尖椒一号晚熟品种时 ,一定要购买成盒种子 ,购买的种子纯度高 ,后期抗病力及增产能力都能得以发挥。杜绝私自从生产田采集种子自留。３ .提早育苗 ,加长炼苗时间 ,提高栽植后的抗病力。４ .选用景尖椒一号晚熟品种时 ,要采取移苗措施 ,以保证秧苗的营养面积。５ .增施粪肥 ,多施羊粪、鸡粪（要注意充分拌土腐熟 ,以防栽后烧根、毁苗） ,搭配二铵（每亩１０公斤） ,并注意后期的叶面喷肥。６ .选用超薄地膜 ,全部扣膜移栽（彻底根据市场需要打破晚熟尖椒扣膜易红的旧习惯）…     

杂交晚籼新组合"Ⅰ特优3381"的选育与应用

Ⅰ特优3381是福建省龙岩市农业科学研究所用不育系Ⅰ龙特甫A作母本,新恢复系龙恢3381作父本杂交配组育成的杂交晚籼新组合.该组合具有米质较优,高产,稳产,生育期适中,适应性广等特点.2003-2004年经福建省晚稻新品种区域试验,2a平均产量471.89kg/667m2,比对照汕优63增产6.03%,达到显著水平.全生育期129d.2006年1月通过福建省农作物品种审定委员会审定.介绍了其选育过程、特征特性、栽培及制种技术要求.     

黄毛耳草中乌索酸的分离制备及定量分析

目的:采用“醇提凝析法”分离制备黄毛耳草中的乌索酸,建立其含量的测定方法 方法:IR、MS、1HNMR、13CNMR鉴定乌索酸结构,反相高效液相色谱法测定其含量,色谱柱为SymmetryShieldRP1 8柱(3 . 9×1 5 0mm ,5 μm) ;流动相为甲醇∶水(88∶1 2 ,V/V) ;流速为1 0mL/min ;二极管阵列检测器检测,检测波长2 1 0nm ;柱温2 5℃;结果:确证化合物为乌索酸 HPLC法线性范围:4 . 5～2 2 . 5 μg ;线性回归系数大于0 . 9998 乌索酸纯度为99 . 82 %,得率3 . 6 5‰ 结论:制备方法实用可行,乌索酸纯度高,安全性好 HPLC法快速简便、精密度高、重现性好、线性范围宽,可用于控制乌索酸产品质量     

汉字倒说

汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

钱生钱!

我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了     

Inequalities for inscribed simplexes

The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex.     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

微薄的薪水,高尚的情操

现在,我们可以没有面包,没有钱,没有房子,没有车子……但我们唯独不能丢失的是高尚的情操,笃定的信念,还有,满满的希望!     

Virtual reality approach for 3D large model browsing on web site

Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator＇s Garden. Translating building data to the Virtual Reality Modeling Language （VRML） is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-ofdetail switching.