棉籽中敌草隆及其代谢产物残留量的测定方法

为解决传统方法检测棉籽中敌草隆及其代谢物残留量时存在受杂质干扰强烈的弊病,采取将敌草隆及其代谢物全部转化为3,4-DCA后,用气谱法进行测定。结果表明,这个方法可准确测得敌草隆及其代谢物的残留量,精密度高,重现性好,杂质干扰极好。     

自然极度干旱条件下胡麻品种不同播种期的二次生长表现

在自然极度干旱条件下,胡麻不同品种、不同播种期均可发生二次生长,但发生程度有很大差异。播种期与胡麻二次生长率及二次生长指数存在较高的相关性,随播种期提前,胡麻不同品种的二次生长率及二次生长指数均呈规律性递增。品种之间的二次生长也有很大差异,其中坝选三号对干旱反应敏感,二次生长率及二次生长指数最高,坝亚七号次之,坝亚十二号最低。同一品种随播种期的提前,单株二次生长经济性状(二次分枝数、二次蒴果数、二次果粒数、单株二次粒重)表现越高,说明胡麻提前播种比晚播种单株二次生长发育充分,不同品种有着一致的规律。     

Fallow to forest: Applying indigenous and scientific knowledge of swidden cultivation to tropical forest restoration

Rotational swidden cultivation systems, with fallow periods long enough for the regeneration of secondary forests are capable of maintaining forest cover and plant diversity in a dynamic balance in swidden cultivation landscapes. Regeneration of secondary forests through several successional stages and by a combination of coppicing and seedling development is still poorly understood, especially the influence of different swiddening practices and the role of animals as seed dispersers. Swidden cultivators possess a vast knowledge of plants growing in swidden fallows and of fallow dynamics as well. Forest restoration in Thailand has been carried out mainly on the basis of experimental research on the potential of indigenous tree species to promote natural forest regeneration and biodiversity recovery; the so-called framework species. Another viable source of knowledge for forest restoration can be the study of the semi-natural revegetation processes in fallows and the indigenous knowledge of swiddeners of these processes. The research presented here was carried out to attain a better understanding of forest regeneration on fallow swiddens under different swiddening regimes and how it may be applied to practical forest restoration, We investigated the vegetation characteristics of from various stages of secondary succession in fallow swiddens of the Karen and Lawa ethnic groups in the Mae Chaem watershed, Chiang Mai province, northern Thailand. Indigenous knowledge on the use of species and traditional ecological processes in swiddening was recorded by questioning key informants. The data were analyzed and discussed with respect to their application in forest restoration and participatory forest management.     

蜜环菌原种品种及配方筛选试验

比较了蜜环菌原种不同品种及配方的菌丝(索)生长速度,结果表明蜜环菌AM6、密A9、宁强A9-1三个菌株的菌丝(索)生长速度最快,分别为2.86 mm.d-1、2.80 mm.d-1、2.71 mm.d-1,与其他品种相比差异极显著;原种配方以配方2(木屑50%、玉米芯25%、麦麸12%、玉米粉10%、葡萄糖1%、石膏1%、石灰0.5%、磷酸二氢钾0.3%、硫酸镁0.2%、VB1 10 mg)最好,平均生长速度达2.18 mm.d-1,与其他配方差异极显著。因此,该研究筛选出的优良品种及配方可以在生产上推广应用。     

夹竹桃内生真菌J14次生代谢产物的分离和抑菌活性

为进一步开发、利用和保护夹竹桃植物资源,对从秦岭山区夹竹桃茎中分离得到活性较高的内生真菌J14进行鉴定,并对其次生代谢产物的化学成分进行研究。采用形态学特征和ITS序列分析对菌株J14进行鉴定,利用硅胶柱色谱、Sephadex LH-20柱色谱、重结晶等方法对该菌株的发酵产物进行分离、纯化,根据化合物的理化性质和1 H-NMR、13C-NMR数据鉴定其结构,利用金黄色葡萄球菌、乳酸链球菌、大肠杆菌、绿脓杆菌以及小麦赤霉病菌、番茄灰霉病菌、烟草枯萎病菌、白菜黑斑病菌对所得化合物进行抑菌活性测试。结果表明:经形态学特征和ITS序列分析,鉴定菌株J14为链格孢霉(Alternariasp.SPS-04)。从其发酵产物中分离得到8个化合物,分别鉴定为交链孢甲醚(1)、交链孢酚(2)、malformin A1(3)、胸腺嘧啶(4)、尿嘧啶(5)、黄嘌呤(6)、赤藓醇(7)和甘露醇(8)。化合物3、4、5、6、7首次从链格孢属真菌发酵产物中得到。化合物1对金黄色葡萄球菌的最小抑菌浓度为1.95μg/mL,对番茄灰霉病菌的最小抑菌浓度为3.91μg/mL。     

Isolation,production and in vitro effects of the major secondary metabolite produced by Trichoderma species used for the control of grapevine trunk diseases

Antibiosis has been shown to be an important mode of action by Trichoderma species used in the protection of grapevine pruning wounds from infection by trunk pathogens. The major active compound from Trichoderma isolates known to protect grapevine pruning wounds from trunk pathogen infection was isolated and identified. The compound, a 6‐pentyl‐α‐pyrone (6PP), was found to be the major secondary metabolite, by quantity, which accumulated in the culture filtrate of T. harzianum isolate T77 and the two T. atroviride isolates UST1 and UST2. Benzimidazole resistant mutants generated from these isolates also produced 6PP as their main secondary metabolite, except for a mutant of T77 that had lost its ability to produce 6PP. The isolates UST1 and UST2 were co‐cultured with the grapevine trunk pathogens Eutypa lata and Neofusicoccum parvum in a minimal defined medium and a grapevine cane‐based medium (GCBM). Co‐culturing UST1 with N. parvum induced 6PP production in the minimal defined medium and the GCBM. The production of 6PP by UST2 was induced in the GCBM, while co‐culturing with the two trunk pathogens either reduced or had no effect on 6PP production. Mycelial growth and ascospore/conidia germination of E. lata, N. australe, N. parvum and Phaeomoniella chlamydospora were inhibited by 6PP in a concentration‐dependent manner. The results show that the presence of N. parvum and grapevine wood elicits the production of 6PP, suggesting that this metabolite is involved in Trichoderma–pathogen interactions on grapevine pruning wounds.     

Rangeland Monitoring and Invasive Weeds

One of the serious biological obstacles that must be addressed in any comprehensive revision of rangeland ecological condition assessment is what to do with sites dominated by exotic self-invasive species. In certain cases such species have truncated succession so that with a bare minimum of disturbance, the sites will never return to dominance by native perennial species. Are such sites destined to remain always in what is defined as "poor" ecological condition. Many communities dominated by exotic annuals are closed to the recruitment of seedlings of native perennial species. At the same time the communities are open to invasion by other introduced species. Should susceptibility to future invasions be a criteria in assessing the ecological condition of rangeland communities. The sustainability of communities dominated by exotic invasive species is assessing the ecological condition of such communities. Deviation from the plant community concepts of range condition and trend judgement involves setting new benchmark standards. This is an endeavor fraught with many perils.     

Biochemical and histological effects of gibberellic acid on Locusta migratoria migratoria fifth instar larvae

Experiments were conducted to assess the effect of gibberellic acid (GA₃), a plant growth regulator, on Locusta migratoria migratoria fifth instar larvae. Newly emerged larvae were exposed to various concentrations of GA₃ administered by topical application or by forced ingestion. Results showed that treated insects exhibited toxic symptoms with a dose-dependent mortality. GA₃ toxicity was also demonstrated by perturbation of the moult processes. In fact, we noted that treated insects present exuviations difficulties due to the impossibility to reject the old integuments causing mortality in the 5th instar larvae. Histological study of proventriculus revealed alterations in the epithelial cells and absence of apolysis phenomenon. Data also showed that GA₃ induced significant quantitative variation of haemolymph metabolites. These changes result in a significant decrease in the total concentration of proteins and carbohydrates and an increase in the total concentration of haemolymph lipids.     

论当代中华民族传统体育文化的共时形态

中华民族传统体育文化在经过千百年新旧文明残存与复兴、退化与新生共存的动态传承和演变,形 成了多形态、多层次和多元价值并存的动态文化有机体。其过程体现出个性鲜明,常变常新的原生文化形 态;经过适应和整合形成以原生文化为主体,以现代文明的新生文化为辅的次生文化形态;并在不断变革 和创新中孕育而生的,无论从外部特征还是内在规律都体现超稳因素的变异文化形态。当代这三种表现方 式不同的文化形态具有既能够符合区域和民族的价值选择,同时也能够适应现代社会文化交流和发展趋势 的共时形态特征。