Comparative Biomass Production of Six Oat Varieties in a Saline Soil Ecology

Oat is widely used as a food source in human and animal diets. In China, supplementary cultivation of oat has recently been extended into marginal saline soils, due to its extensive use. The goal of the present study was to explore and compare the agronomic characteristics, biomass production, and distribution of oat in coastal saline soil. A single-factor randomized block design experiment with six naked and husked oat varieties [Bayou-1 (BU-1), Baiyan-2 (BY-2), Baiyan-7 (BY-7), Huawan-6 (HW-6), Huazao-2 (HZ-2), and Pin-16 (P-16)] as treatments was conducted in the Hebei Province of China. The growth period (77 to 88 days) of the six oat varieties were shorter in saline soil than their original breeding region. Moreover, the plant was shorter, with a lower grain number per plant and seed setting. Grain weight increased and no change was observed in the floret number in coastal saline soil relative to the original habitats. The BY-7 variety produced the highest biomass value of 7.0 t ha^?1 compared to the other five varieties. Compared with two active growth points, most varieties in the present study showed just one growth activity point between elongation and heading. Two fast growth periods for the six oat varieties were due to the high total leaf biomass growth rate (BGR) from elongation to heading and panicle BGR from heading to maturity. The biomass growth ratio (BGO) during elongation to heading was the largest among the four growth stages of the oat varieties. The number of kernels per spike decreased at the research site, but grain weight increased. Substantial differences were observed for growth periods, biomass, BGR, BGO, and other agronomic characters in the coastal saline soil of North China, but the BY-7 variety was the most suitable variety for the study site.     

The Use of a GUS Transformant of Trichoderma Harzianum, Strain T3a, to Study Metabolic Activity in the Spermosphere and Rhizosphere Related to Biocontrol of Pythium Damping-off And Root Rot

The activity of Trichoderma harzianum in the spermosphere and rhizosphere of different plant species was studied by use of a beta-glucuronidase (GUS) transformant (strain T3a). Hereby, direct observation of micro-habitats supporting metabolic activity of T. harzianum is reported. Germination of conidia and mycelial growth were not supported by exudates from healthy roots of various ages. Instead, growth and activity of T. harzianum depended on access to dead organic substrates such as seed coats, decaying roots, and wounds, including those caused by infecting pathogens. A correlation between the GUS activity of T. harzianum and the biomass of Pythium ultimum in infected roots was established. On the basis of our observations, we suggest that the biocontrol ability of T. harzianum involves competition with the pathogen for substrates including the seed coat, and wounded or infected root tissue.     

碱茅草地上生物量的分布和利用评价

碱茅草能降低盐渍化土壤表层的含盐量,营养价值高。通过对它地上生物量的测定,证实碱茅草不仅具有耐牧性,也是一种较好的刈草场种类。     

青藏高原几种嵩草的生物量及其幼苗生长发育的初步研究

研究了青藏高原４种嵩草属植物的枝条发育状况，生物量积累特征以及３种嵩草幼苗的生长发良规律。结果表明；各嵩草营养枝条的季节变化有两个高峰期，而线叶蒿草的生殖枝有一个明显的高峰期，其它嵩草无高期峰。     

红豆草草地地上生物量动态规律的研究

１９８８年，利用红豆草改良长芒草草地，建设人工割草场，显著提高了草地生产能力，经对１９８８－１９１年该草地地上生物量试验资料进行统计分析，建立了地上生物量动态模型。为管理，保护，合理利用同类草地，发展畜牧业提供了科学依据。     

厚朴播种育苗密度

本文分析了厚朴苗木留苗密度与地径，苗高，根系生叶面积等苗木主要生长因子的相关关系，认为厚朴播种育苗的最佳留苗密度为２５．７％万株／ｈｍ＾２。     

辽东半岛结缕草无性系种群构件生物量相关模型及形成规律

按生物构件的理论,分析了辽东半岛结缕草无性系种群叶片、叶鞘、分株、匍匐茎各构件生物量以及总生物量间的相关模型和构件生物量的分配、形成规律,探讨了其不同生物量基于种群大小(密度)的形成规律。结果表明,辽东半岛结缕草无性系种群的总生物量及各构件生物量均随着种群密度的增大而以线性函数增加,各构件生物量与总生物量以及各构件生物量间亦均以线性函数增加,生物量增加比率均表现为:分株>匍匐茎,叶鞘>叶片,总生物量增量的27.2%分配给叶片,29.2%分配给叶鞘,43.6%分配给匍匐茎,叶片,叶鞘和匍匐茎构件生物量的积累是按1∶1.1∶1.6比例形成。     

论股权分置改革中的分类表决制度

分类表决制度是我国证券市场的一大制度革新。随着我国股权分置改革的全面推进，分类表决制度也发挥着越来越重要的作用，它赋予流通股股东更多自我保护的权益，对股权分置改革起到有力的推动作用；同时，它也存在着不容忽视的局限性。文中通过具体分析，提出一些建议以供参考。     

翻耙补播对科尔沁碱化草地土壤理化性质和生物活性的影响

对科尔沁地区碱化草甸草地翻耙补播沙打旺后的土壤理化性质和土壤生物活性的变化进行了研究.结果表明,翻耙补播改良后草地综合生产性能得到明显改善,土壤容重、pH、含盐量和碱化度降低,土壤含水量和孔隙度增加,土壤有机质和N、P、K等养分含量增加;同时,土壤微生物C、N的含量以及土壤酶的活性也得到较大幅度提高.