不同光质对黄芪生长及药用成分积累的影响

为探讨适合黄芪(Astragalus membranaeus(Fisch.)Bge)生长及药用成分合成积累的光照条件,提高黄芪药材的产量与质量,运用植物逆境生理和次生代谢研究理论,研究了蓝光、黄光、红光、白光和自然光(对照)条件下,黄芪3种主要药用成分含量的动态变化。结果表明,蓝光和黄光可以促进黄芪根部干物质的积累,并可以有效提高药用成分含量,而红光则不利于黄芪干物质的积累;蓝光下黄芪黄酮的含量最高,比自然光下提高了51%,经济产量提高了56%;黄芪多糖和皂甙无论是含量还是经济产量都是在蓝光下最为理想,其中,黄芪多糖的含量比自然光提高了23.9%,经济产量提高了19.3%,黄芪皂甙的含量比自然光提高了106%,经济产量提高了105%。     

成为有效教师的新路径探析

随着课改的深入,有效教学成了讨论的焦点,然而只要存在教学,教师作为教学工作的中心地位就不能动摇。美国教育家鲍里奇提出的＂有效教师＂的概念无疑为开拓教学方法改革提供了新的思路。本文旨在通过分析教师教学行为的＂有效性＂,在教学准备上探索成为＂有效教师＂的新路径。     

证券期望收益率同值变动时有效边界平移分析

先证明证券市场所有证券同值变动时，证券有效边界将上下平行移动，然后引入无差异曲线来说明市场中证券期望收益率同方向变化且变化值相差不大时，不必改变证券组合。     

磷化铝间歇熏蒸对锈赤扁谷盗致死效果研究

本文采用磷化铝间歇熏蒸法，使粮堆内部各处PH3浓度在一定的时间内保持在有效浓度之上，无虫期超过12个月，有效地防治了锈赤扁谷盗。     

包装玉米长期安全储藏试验

在华南地区高温高湿环境下，在尚不具备机械通风设备的楼房仓内进行玉米包装大堆保管。采用合理的剂量和熏蒸方法，保持粮堆内较长时间的PH3有效浓度，抑制了玉米的呼吸强度和微生物、害虫的生长繁殖，确保了玉米长期安全储藏，保持了较好的储粮品质。     

东北地区主要食物维生素E含量的分析及其评价

采和高效液相色谱法分析了东北地区在一百四十多种食物中维生素E的容量，并对其结果进行分析、归纳和总结，从而为制定新的食物成分表提供了科学依据。     

钢筋混凝土约束梁斜向贴CFRP抗剪加固研究

通过对 1 2根承受集中荷载作用下破坏后补好的矩形截面钢筋混凝土约束梁斜向贴 CFRP抗剪加固试验结果的分析 ,提出了 CFRP有效应变的概念 ,得出了随角度变化 CFRP抗剪承载力计算公式     

湿地松种子园疏伐试验研究

根据子代测定结果和当代表现等因子对湿地松种子园进行疏伐，使种子园的结实量显著增加，结实株百分率其强度疏伐的为62%，中度疏伐的为39%，轻度疏伐的为28%，不疏伐的为22%；单株种子产量的比例为不疏伐；轻度伐；中度伐；强度伐=100：120：200：400，不疏伐的为22%；单株种子产量的比值为不疏伐；轻度伐：中度伐：强度伐=100：120：200：400；亩均种子产量的比例为不疏伐；轻度伐；中度伐；强度伐=100：119：208：411，当种子园进入结实盛期时，每亩保留8-10株是合理的，如果无性系的营养生长和生殖生长能力特别强，每亩保留6-8株即可。     

A procedure for combining a quantitative inheritance study with the first cycle of a breeding program

Summary The number of effective factors controlling the inheritance of a quantitative character can be estimated by analysis of F₃ lines where the parental lines are homozygous. The procedure is illustrated with data from a study of pod length inheritance in common bean (Phaseolus vulgaris L.). The mean pod length of Sprite, the parent with longer pods, was compared statistically with the means of F₃ progenies derived from F₂ plants obtained from the appropriate tail of the F₂ frequency distribution for pod length. The data indicate that analysis of F₃ progenies avoids much of the underestimation of the effective factor number which is characteristic of other procedures. The number of effective factors was estimated to be a minimum of 4 and the correlation between random F₂ parents and F₃ progeny means was r=0.82.Florida Agricultural Experiment Station Journal Series No. 406.     

Transgressive segregation in inter and intraspecific crosses of barley

Summary Six populations of F₂-derived lines of barley and their parents were evaluated for heading date, plant height, grain yield, bundle weight, and harvest index in a replicated experiment in the field. These data were used to estimate the minimum number of effective factor pairs segregating for each trait, the number of favorable factors contributed by each parent in a cross, and the frequencies and magnitudes of transgressive segregates.Heading date, plant height, and harvest index were controlled by three to four effective factor pairs, whereas grain yield and bundle weight were controlled by five or more.All three H. spontaneum strains used in our study contributed one or more useful genes for each of the traits, grain yield, heading date, plant height, bundle weight, and harvest index. Therefore, it seems that H. spontaneum can be a useful source of favorable genes for quantitative traits, especially for grain yield, which could be incorporated into barley varieties readily by backcrossing. Transgressive segregates for grain yield in the interspecific crosses may provide the basic materials for improving the productivity of cultivated barley varieties.Journal Paper No. J-9760 of the Iowa Agric. and Home Econ. Exp. Stn., Ames, IA 50011. Project 2227. Supported in part by a grant from the Science and Education Administration-Cooperative Research, United States Department of Agriculture.