羊草和大针茅群落光合速率的比较研究

本研究用同化箱法,在野外条件下测定了羊草群落和大针茅群落的光合速率日进程和季节变化。得到如下结果：1;在整个生长期中,测得羊草和大针茅两群落光合速率的日进程都属双峰型,上、下午,各有一个高峰,但一般以上午峰值较高。2．羊草和大针茅两群落日净光合量的季节变化趋势是相似的。自返青后迅速的提高,到7月上旬达最大值,羊草和大针茅两群落的日净光合量分别为31.68和11.5 gCO2／m2d,随后逐渐降低。3.两群落光合能力的大小,峰值的高低和出现的早晚、中午光合降低的幅度以及季节变化的特点等都与植物生长发育阶段和环境条件有密切的关系。 4．羊草群落各阶段的瞬时光合、日净光合,LAI和生物量等都高于相近时期的大针茅群落。但在环境条件较差(干旱)时,羊草群落光合增加的幅度要比环境条件好时小。5．大针茅群落要比羊草群落耐旱,对不良环境的适应能力强,但在条件较好时增产幅度小。     

典型草原地区退化草原的改良及提高生产力途径的研究

作者在内蒙古典型草原地区进行了围栏封育、轻耙松土、耕翻撩荒、播种羊草和羊草混播旱生豆科植物,经过5年的试验,显示出这些措施都能不同程度地提高产草量;由于这些改良措施均在七月雨季进行,翻耕后的植物当年即可覆盖土表,所以也不会导致沙化。     

A New triterpenoid in the fruits of Phellodendron chinense Schneid

A new triterpenoid, phellochin, C31H52O4 (HRMS 488.3747), mp. 173–175℃, [α]25D -84.8 (C=0.10, methanol), was isolated from the fruits of Phellodendron chinense Schneid, and its structure was established by spectroscopic methods (IR, MS, NMR and COSY).     

Studies on the Characteristics of K,Na Content in Aneurolepidium chinense Grassland of Northeast China

The characteristics of K, Na contents of the pasture-for-cutting of Aneurolepidiurn chinense grassland of Northeast China were studied. Results showed that: K concentration of every organ of the aboveground part of A. ch inense was highest in early growing season, then decreased gradually as plant continues to grow. The variation of Na concentration was more or less similar to that of K, but there was a sudden increase in August. The concentrations of K, Na in the aboveground part of the community were higher than those in the underground part..The variations of K, Na accumulations of the aboveground part of ,A. chinense in the growing season were of the single-peak type, the peaks of K and Na appeared in July and August respectively. The variations of K, Na accumulations of the aboveground parts of Carex duriuscula and Heleocharis acicularis were similar to those of the biomass, which were of the double-peak type. The accumulations of K and Na in the underground part of community were significantly higher than those in the aboveground part; the accumulations of K, Na in leaf and stem were very close to each other. The K, Na accumulations in the community were accounted for 0.25% and 0.71% of the total reserves of the soil, 2.31% and 0.93% of the soluble plus exchangeable reserves of the soil respectively.     

Studies on Seed Development and Embryogenesis in Liriodendron chinense (Hemsl.) Sarg

Embryogenesis, seed formation and the relationship between pollination and seeding rate were investigated by means of artificial pollination, X-ray analysis, routine paraffin-embedded sectioning technique and fluorescence assay. Pollen germinated two hours after artificial pollination and the peak germination rate reached by six hours. The stigma vitality lasted about thirty hr. The pollen tube grew into the stigma canal through the secretion between the stigma hairs, then passed the style canal, obturator and nucellar cap and finally reached the embryo sac where porogamy was conducted. Two weeks after artificial pollination, ab initio cellular endosperm was formed first as a narrow tissue of two to three cells in thickness, but six weeks later it filled the entire embryo sac, along with the disappearance of the nucellus. The spherical or cordate-like embryo appeared during the seventh to the eighth week. The cotyledon was formed during the fourteenth to the sixteenth week. By the twenty-second weeks the seed became matured, containing abundant endosperm, the seeding rate of an individual plant with natural pollination was less than 1%; after artificial pollination, however the highest seeding rate of an individual fruit could reach 39%, the average rate of nine fruits being 17.7%.     

羊草草原土壤动物特征的研究

对东北羊草草原土壤动物特征的研究表明i,土壤动物共有4门6纲14目。其水平分布规律是杂类草群落>羊草群落>拂子茅群落>榆树疏林>碱茅群落>碱蓬群落。土壤动物的数量和生物量的季节变化趋势相似,最大值均出现在8月份。随着土层的加深其数量逐渐减少,0-10cm上层中土壤动物数量约占总数的50%以上。     

中国辣椒热胁迫转录因子的全基因组鉴定及热胁迫响应的初步分析

采用生物信息学方法,从中国辣椒(Capsicum chinense Jacq.)全基因组序列中鉴定得到28个热胁迫转录因子(HSF)候选基因,并对这些候选基因的染色体分布、基因结构及编码蛋白的3D结构特征进行了分析。结果显示:28个候选基因的编码蛋白长度为128~526 aa;系统发育分析结果表明,HSF可分为A、B、C 3个亚家族。进一步对热胁迫处理后的中国辣椒种质进行转录组分析,共检测到27个HSF转录本,与对照组相比,实验组中有25个基因对热胁迫有不同程度的响应。     

鹅掌楸人工林生长最优模型选择研究

选取鹅掌楸(Liriodendron chinense)标准木进行树干解析，采用Logistic、Webull、二次曲线等13个有代表性的数学模型对鹅掌楸胸径、树高和材积生长进行方程拟合。经筛选和验证，得出鹅掌楸胸径生长的最佳模型为：D= 75.6887{1-e–[(T+2.3354)/19.5656]^3.1489}；树高生长的最佳模型为：H=(55.5498+34.2298T1.9310)/(119.6386+T1.9310)；材积生长的最佳模型为：V=2.5736{1-e–[(T–2.2455)/16.3381]^3.8741}。这三个模型的决定系数均为0.9999，拟合精度分别为99.7258%、99.8827%、99.7930%，且平均偏差、平均绝对偏差、平均相对偏差、平均相对偏差绝对值较小。各林龄段的生长预测值和实测值比较，数据吻合度高，残差总体偏小，趋势线表现一致。各模型可用于指导预测福建省闽北地区鹅掌楸人工林中幼林的生长情况。     

红檵木的3′端延长随机引物扩增DNA(3′-ERPAD)标记

为了对116个10－mer随机引物的RAPD分子标记进行深入了解，探讨分子标记与园艺性状的关系，筛出多态性明显、重复性好、亮度大、分子量也较大（1031bp以上）的10－mer随机引物，在其3'端添加一任意碱基，对14个红木材料和2个来源不同的生态型木材料进行3'-ERPAD标记分析。发现在S2和S35的延伸引物中能够得到最佳扩增结果的引物对是S2－G＋S2－C和S35－A＋S35－C，它们的扩增结果都含有与各自基本引物相同的差异扩增带，这些差异带分别是S21500、S21031和S353000、S35900、S35560。通过与园艺性状比较，发现S21500片段可能与控制叶色的基因有关。