Uptake Rate of Tracer MetalIons by a?Lycium barbaruma?Somatic Embryogenesis

The callus of medical plant Lycium barbarum L. in Ningxia was used as the materials for inducing somatic embryogenesis, and multitracer technique and γ-ray energy spectrum analysis were used for studying the rates of uptake of several tracer metal ions during embryogenesis. The results were: 1) Of 23 radionuclides, only 16 (Mn-52, Zn-65, Co-56, Co-60, As-74, Se-75, mTc-95, Rh-99, V-48, Rb-83, Rb-84, Sr-85, Y-87, Y-88, Zr-88 and Zr-89) were selectively absorbed, the other 7 (Be-7, Tc-96, Ru-97, mRh-101, Sc-46, Ga-67 and Cr-51) were not absorbed. 2) The rates of absorption of different metal ions were different at the same developmental stage. In 10 day culture, the rates of uptake of most metal ions were 5%/g, but that of Se-75, Ab-83, Sr-85 and Zr-89 were 10%-30%/g. The rates of absorption of the same metal ion were different at the same developmental stage, e.g. the rates of uptake of Se-75 were increasing in the course of development, two peaks of absorption appeared in the 5-7th and 15-20th days, being 14%/g and 20%/g. But, around 10th, the uptake rate decreased somewhat. The maximum uptake rate was 20%/g in 20th days. The uptake rates of some metal ions were with the somtimes keeping pace differentiation of embryonic cells. But sometimes not and division. The tendencies of the uptake rates of Se-75, Rb-83, Sr-85, Co-56 and V-48 were similar, indicating that the metal ions were accumulated in the callus during somatic embryogenesis. The uptake rate of Mn-52 was not only similar to other elements, but the variation was like normal distribution.     

高海拔地区烟草光合作用的日变化

在高海拔地区(昆明)对5个品种(系)烟草光合作用日变化的研究结果表明,所有供试材料的净光合速率表现为不显著的"双峰型"曲线。其主要原因可能是较高的空气湿度、相对适宜的温度和强光的综合影响;一定范围内的温度和CO₂浓度变化对光合作用的日变化未能产生明显的影响。     

用ISSR标记研究高卢蜜环菌系统发生学的尝试

用ISSR(Inter-Simple Sequence Repeat)标记对黑龙江省牡丹江地区高卢蜜环菌的系统发生学进行了研究,用6个引物对35个菌株的DNA模板进行扩增。结果表明该地区的35个菌株分属3个不同的发育系,并且3个发育系在地理分布上是交错在一起的。同时表明ISSR标记是研究蜜环菌系统发育关系的理想的分子标记手段。     

绥农14及其系谱亲本的遗传多样性及重组分析

以绥农14及其系谱中的亲本品种为实验材料, 对14个农艺性状及分布在20个大豆连锁群上139对SSR引物进行分析, 揭示品种间遗传多样性和遗传重组关系, 为大豆新品种选育提供理论依据。聚类分析结果与品种间的亲缘关系相似, 每个SSR位点Shannon-Weaver指数的分布范围为0~1.677; 品种间的相似系数平均值为0.6380, 变化范围为0.5380~0.7990。筛选出区分这些品种的最少SSR位点数为3个; 如Satt543、Sat_130、Satt218。研究发现, 连锁群中间区段重组率与两个末端区段重组率无显著性差异, 说明连锁群上各区段的遗传重组是随机分布的。在139对引物中有39对引物在绥农14及其8个亲本间没有多态性, 表明这些位点可能对品种改良具有重要作用; 位于B2连锁群的Satt168是从祖先亲本紫花4号保留给绥农14的唯一的多态性位点, 可见, 经过5个世代的杂交重组和遗传改良, 绥农14的遗传组成与紫花4号相比已经发生了很大的变化。     

土壤中乙草胺的微生物降解及其对防除稗草持效性的影响

采用气相色谱法和生物测定法,研究了土壤中乙草胺的微生物降解及其对防除稗草持效性的影响.结果表明,在同样的湿度和温度条件下,当添加到土壤中的乙草胺浓度为125、25和5.0 mg·kg^-1时,相同浓度的乙草胺在非灭菌土壤中的半衰期显著短于灭菌土壤,说明土壤微生物对乙草胺有明显的降解作用.三大主要菌群分离培养物降解实验与上述结果一致.生物测定结果表明,乙草胺在非灭菌土壤中防除稗草的持效期显著短于灭菌土壤,微生物的存在缩短了乙草胺在土壤中的滞留时间,从而降低了乙草胺防除稗草的持效性.     

Tissue Culture and Plant Regeneration of Jatropha curcas (Euphorbiaceae)

In this paper , plumules, cotyledons, hypocotyls, blades, petioles and stalks of physic nut ( Jatropha curcas L. ) were used as explants, and callus induction and plant regeneration were studied on MS medium contained different concentrations of 6-BA and NAA. The results showed that the MS medium with 5.0 mg/L BA and 1.0 mg/L NAA was the best for callus induction, and with 5.0mg/L BA and 0.1mg/L NAA, for formation of adventitious bud, and with 1.0mg/L BA and 1.0 mg/L NAA, for bud growth, and that 1􊄯2 MS medium with 1.0 mg/L NAA was the best for formation and growth of adventitious root .     

二化螟大发生原因及控制对策

二化螟是水稻的三大主要害虫之一。近50年来,其种群在我省几起几落,近年来大发生频率明显增加,为害损失有逐年加重之势。2002-2003年大暴发,仅南昌县成灾面积就达6.67×103余hm2,许多田地晚稻颗粒无收,是新中国成立以来受害损失最重的年份。本文探讨的是近年来二化螟在我省大发生的原因及控制对策。1我省二化螟群落演变情况1956年水稻改制前,稻螟以二化螟为主,1956年以后,单季改双季、间作改连作、中稻改早稻,高秆改矮秆后,三化螟迅速上升为主要害虫,二化螟种群随之凋落。1978年以后,由于大面积推广杂交晚稻,早稻以早中熟品种为主,6月20日以…     

Late Pliocene vegetation and climate of Zhangcun region,Shanxi, North China

To understand the Neogene climatic changes in eastern Asia and evaluate the intercontinental climatic differences, we have quantitatively reconstructed the vegetation successions and climatic changes in the late Pliocene Zhangcun area based on the palynological data and explored the regional climatic differences between central Europe and eastern Asia. The late Pliocene palynological assemblage of Zhangcun, Shanxi was composed of 63 palynomorphs, belonging to 50 families, covering angiosperms (90.2%), gymnosperms (9.7%), ferns (0.09%), and other elements (0.02%). Four periods of vegetation succession over time were recognized. In period 1, a needle‐ and broad‐leaved mixed forest prevailed with a cool and dry climate. Period 2 was characterized by an expansion of forest with a warmer and wetter climate. The number of conifers increased and that of herbs decreased in period 3, and the climate became cool and dry. In period 4, the forest was dominated by conifers and reflecting a cooler climate. The data of seven climatic parameters in general and four periods estimated by the Coexistence Approach suggested that (1) The late Pliocene temperatures and precipitations were higher than today. (2) The Neogene climate of both Central Europe and North China exhibited a general cooling and drying trend although the mean annual temperature dropped by ca. 1 °C in North China, vs. ca. 7 °C in Central Europe from the middle Miocene to the late Pliocene. (3) The decline of the mean maximum monthly precipitation might signal a weakening of the summer monsoon. (4) The decline of both the mean coldest monthly temperature and the mean minimum monthly precipitation might be linked to the strengthening of the winter monsoon in eastern Asia. (5) The rapid uplift of the Tibetan Plateau strengthened the climatic cooling and drying during the late Pliocene of the Zhangcun region.     

344对性伴侣生殖器念珠菌感染的菌型分析

<正>生殖器念珠菌病包括外阴阴道念珠菌病和念珠菌性包皮龟头炎。念珠菌是条件致病性真菌,一般健康妇女阴道可携带而无临床症状,孕妇带菌者     

A Critical Role of the mTOR/eIF2α Pathway in Hypoxia-Induced Pulmonary Hypertension

Enhanced proliferation of pulmonary arterial vascular smooth muscle cells (PASMCs) is a key pathological component of vascular remodeling in hypoxia-induced pulmonary hypertension (HPH). Mammalian targeting of rapamycin (mTOR) signaling has been shown to play a role in protein translation and participate in the progression of pulmonary hypertension. Eukaryotic translation initiation factor-2α (eIF2α) is a key factor in regulation of cell growth and cell cycle, but its role in mTOR signaling and PASMCs proliferation remains unknown. Pulmonary hypertension (PH) rat model was established by hypoxia. Rapamycin was used to treat rats as an mTOR inhibitor. Proliferation of primarily cultured rat PASMCs was induced by hypoxia, rapamycin and siRNA of mTOR and eIF2α were used in loss-of-function studies. The expression and activation of eIF2α, mTOR and c-myc were analyzed. Results showed that mTOR/eIF2α signaling was significantly activated in pulmonary arteries from hypoxia exposed rats and PASMCs cultured under hypoxia condition. Treatment with mTOR inhibitor for 21 days attenuated vascular remodeling, suppressed mTOR and eIF2α activation, inhibited c-myc expression in HPH rats. In hypoxia-induced PASMCs, rapamycin and knockdown of mTOR and eIF2α by siRNA significantly abolished proliferation and increased c-myc expression. These results suggest a critical role of the mTOR/eIF2αpathway in hypoxic vascular remodeling and PASMCs proliferation of HPH.