杉木不同种源叶养分变异的研究

研究表明,不同种源杉木的叶养分含量在树液流动期、芽膨期、旺盛生长期(6月,9月)和封顶期有明显的差异。在供试种源分布区范围内,树液流动期和6月旺盛生长期的叶P含量与纬度成显著负相关;N/P值与纬度成显著正相关。产地≥10℃积温与树液流动期的P,K含量,N/P值及6月旺盛生长期的N/P值都有显著负相关关系。产地日照时数仅与芽膨期的叶Mg,Ca,P养分的正偏相关关系明显(α=0.10).用统一的线性模式较难反映变异的规律。但经主成分(PCA)分析,揭示出南岭山地优良种源区种源叶养分(尤其是P,Mg)含量高于一般产地种源的趋势。     

Family Outcrossing Rates of Pinus caribaea Morelet var. caribaea in Seed Orchard and Natural Populations

Family outcrossing rates of Pinus caribaea var. caribaea populations that differed in origin and management were estimated by using isozyme markers. The family outcrossing rates were estimated by (1)fixing the probability of pollen gene frequency (p); (2) allowing pollen gene frequency to vary among families. The estimates of family outcrossing rates for all the populations varied widely among families (clones of the seed orchard), ranging from 0.39 to 2.0. The average family outcrossing rates of both methods were greater than the     

彩色棉的研究与产业化

彩色棉是一种纤维中含有色素类物质的特殊类型的棉花，原始种多来自美洲大陆和中美洲的短纤维野生彩色棉，栽培的彩色棉大多是利用与白色棉进行杂交选育而成的。用彩色棉加工成的纺织品无需漂白、印染、消毒等传统工艺处理，不产生化学污染，衣物中不含有害成分与任何化学物质残留，是典型的环保健康产品，备受消费者的欢迎。本文简述了国内外在彩色棉遗传特性、品种选育等方面的研究以及产业化的动态，分析了彩色棉生产中存在的问题并提出了相应的解决方案。     

小麦收获前种子发芽敏感性配合力的研究

选用5个收获前穗发芽敏感性不同的白皮小麦亲本品种,进行双列杂交,研究了发芽敏感性的配合力。结果表明:小麦收获前种子发芽敏感性同时受加性和非加性基因效应影响,而加性基因效应起主导作用;亲本品种发芽敏感性的一般配合力存在极显著差异,杂交组合的特殊配合力和反交效应方差则有时显著,有时不显著;白皮小麦杂交当代种子,以     

棉花黄萎病抗性的分子研究进展

本文综述了棉花黄萎病菌的分子鉴定，棉花黄萎病抗性的遗传基础，分子标记在棉花抗黄萎病方面的应用，棉花黄萎病抗性基因的克隆及转化等方面的研究进展。     

黄土旱塬农业生态系统土壤深层水分消耗与水分生态环境效应

研究了渭北旱塬不同土地利用方式下大田土壤深层剖面含水率的变化特征，并与长期田间定位试验结果进行比较。结果发现，不同土地利用方式能显著影响土壤深层含水率状况，各种方式对土壤深层水消耗能力的排序是15龄苹果园＞15龄人工苜蓿＞10龄苹果园＞刺槐幼林＞高产农田＞20年撂荒地＞5龄苹果园＞裸地。10龄苹果园剖面剩余含水率分布接近高产农田，而15龄苹果园土壤剩余含水率低于高产农田，说明10龄到15龄苹果树耗水量显著增大，超过高产农田作物消耗的水分，导致土壤深层水分进一步消耗。由于塬面大部分耕地是高产农田与苹果园，土壤深层含水率普遍处于较低水平。苹果树的大面积种植加快了土壤深层水分消耗，最终可能影响这一区域的陆地水循环。     

关于土壤系统分类中一些诊断层的鉴别

本文对中国土壤系统分类中的黏化层、雏形层、铁铝层和低活性富铁层的鉴别作进一步讨论。     

岷江上游23年生油松纯林下凋落物与土壤截留降水的效应

为了评价人工林下凋落物与土壤截留降水的能力,定位监测和分析了岷江上游23年生人工油松纯林下凋落物层和土壤层对65次降水事件的截留与分配过程。结果表明,65次林外降水总量为400.9 mm,其中208.726mm以穿透雨、33.388 mm以树干茎流进入林地,凋落物层、土壤层分别截留25.695,214.375 mm,截留率分别是6.41％,53.47％。但林外降水量<0.3 mm时,不产生林内降水,凋落物与土壤层不能截留降水。在0.3～10 mm降水范围内,土壤截留量随着降水增大呈增加趋势,而凋落物层截留率先增后减,但降水量>10 mm后,土壤截留率逐渐趋于稳定,呈较小波动(63.46％～73.58％),而凋落物截留率趋于稳定,并略有下降趋势;土壤截留量与林内外降水量、土壤截留量与茎流量均呈显著线性相关关系。综合分析表明,人工油松林凋落物层和土壤层对降水均有一定的拦蓄截留效应,其中:土壤层>凋落物层,土壤层的截留量达同期林外降水量的1/2以上。     

Effects of salinity and desalination on seed germination of six annual weed species

The effects of various salinities and desalination on seed germination of six annual glycophytes (Artemisia sieversiana, A. scoparia, Chloris virgata, Eragrostis pilosa, Chenopodium acuminatum and Chenopodium glaucum) were studied in Horqin Sandy Land, Inner Mongolia, China. NaCl solutions of five concentrations (0 mM, as the control, and 50, 100, 200 and 300 mM) were used for saline stress and desalination treatments. Increasing salinity significantly reduced germination percentages of A. sieversiana, A. scoparia, Ch.virgata and Ch. acuminatum, but had no effect on the germination percentages of E. pilosa. Lower salinity levels (50 mM) significantly increased germination percentage of Ch. glaucum. High salinity might be a precondition for germi- nation after desalination for five of the six species, excepting E. pilosa at NaCl concentration of 300 mM in comparison with non-primed seeds. Higher salinity (>200 mM) led to some specific ion toxicity and reduced seed viability of A. sieversiana. No specific ion toxicity but an osmotic effect limited the germination of other five species was observed The final germination percentages (salinity stress and desalination) of the six species showed three variations in comparison with the controls, namely, indiscrimination, stimulation, and reduction. Germination responses to salinity and desalination suggested that the six species were separated into three categories. Three species (A. sieversiana, Ch. virgata and Ch. acuminatum) showed similar germination responses to salinity with those of halophyte, but also showed a lower tolerance limit than most halophytes, although this was not always the case. A. scoparia and Ch. glaucum exhibited some ’salt stimulation’ in seed germination percentages after desalination, whereas E. pilosa did not show any obvious responseto salinity. Therefore, salinity usually induces dormancy of seeds with strong germination capacity in fresh water, but has few, or even positive, effects on seeds with strong innate dormancy.     

坤血安胶囊中芍药苷含量的测定

采用芍药苷为坤血安胶囊的质量控制指标,并应用高效液相色谱对制剂中芍药苷的含量测定方法进行了研究。