安徽省沿江棉区移栽棉田杂草发生及其化学防除研究

通过2009年的调查,明确了安徽省沿江棉区移栽棉田杂草种类、发生规律及对棉花的危害,同时研究了4种棉田常用除草剂对移栽棉田杂草的防除效果,明确了其对棉花的安全性。     

安徽省沿江植棉区油棉连作棉田杂草多样性调查

 对安徽省东至县油菜-棉花连作棉田杂草群落进行调查,利用Shanon Weiner指数、Simpson指数、物种丰富度指数、生态优势度和均匀度指数分析了杂草群落结构及杂草种群优势度。结果表明,油菜-棉花连作棉田杂草有15科30种,其中早熟禾、通泉草、马齿苋、千金子和婆婆纳为优势种;双子叶杂草在种类和数量上均超过单子叶杂草,成为杂草群落的优势种群;该棉田杂草群落参数中Shanon Weiner指数和Simpson指数均偏低,表明群落结构不稳定。     

安徽省东至县油菜-棉花连作棉田杂草发生规律的研究

安徽省沿江植棉区以油菜-棉花连作为主。为进一步了解该种植模式下杂草群落结构及多样性变化,2013年对安徽省东至县棉田杂草发生情况进行了调查。结果表明阔叶杂草种类和数量均大于禾本科杂草,千金子、铁苋菜和婆婆纳已上升为优势种;前期不除草,到8月上中旬杂草在种类和数量达到最高,对棉花产量影响较大。     

永康市稻田杂草群落演替及康因分析

水稻是浙江省永康市主栽作物,常年栽培面积3万hm2,远远超过其它作物。我市曾在1986年对稻田杂草分布及危害程度进行系统调查。14年来,由于耕作制度、栽培水平和杂草治理技术不断发展,尤其是90年代以来,水稻田化学除草迅速发展、种植业结构调整加快,轻型栽培技术推广,我市稻田杂草群落的组成、分布及发生规律均有了较大的变化,种群演替加速,尤其是杂草优势种的演替分布和危害程度发生了很大变化。为掌握目前我市水稻田杂草发生情况,有的放矢的推广稻田草害综合治理技术,有效控制杂草危害,确保水稻丰收,于1999～2000年开展了水稻田杂草调查。     

永康市稻田杂草群落演替及原因分析

水稻是浙江省永康市主栽作物 ,常年栽培面积３万ｈｍ２,远远超过其它作物。我市曾在１９８６年对稻田杂草分布及危害程度进行系统调查。１４年来 ,由于耕作制度、栽培水平和杂草治理技术不断发展 ,尤其是９０年代以来 ,水稻田化学除草迅速发展、种植业结构调整加快 ,轻型栽培技术推广 ,我市稻田杂草群落的组成、分布及发生规律均有了较大的变化 ,种群演替加速 ,尤其是杂草优势种的演替分布和危害程度发生了很大变化。为掌握目前我市水稻田杂草发生情况 ,有的放矢的推广稻田草害综合治理技术 ,有效控制杂草危害 ,确保水稻丰收 ,于１９９９～…     

新疆团场棉田杂草的为害与防治

棉田杂草是棉花生产的一大灾害 ,成为高产、优质、低耗、增效的一个制约因素。在棉花生产中防除杂草不少团场每年都要投入大量的人力和物力 ,人工除草不仅效率低 ,而且劳动强度大 ,十分辛苦。１棉田杂草种群结构及消长规律１ １棉田杂草种群变化。新疆属于典型的大陆性气候 ,昼夜温差大 ,冬季气温低 ,夏季气候炎热 ,而且降雨量少 ,蒸发量大 ,属灌溉农业区。杂草群落一般由耐旱、耐盐的杂草如扁秆蔗草、芦苇、田旋花、灰绿藜、刺儿菜、稗草、灰绿碱蓬、苍耳、荆三棱、反枝苋等组成。这些杂草种类和群落随着耕作制度 ,轮作倒茬 ,种植方式以及…     

盐城棉区抗虫棉棉田杂草的种类及危害

通过对盐城农区大丰、东台等县市区不同耕作制度下,转基因抗虫棉田间杂草发生种类的调查,明确了盐城棉区转基因抗虫棉棉田杂草的群落组成及数量特征.并通过在盐都区的田间试验,测定了杂草对转基因抗虫棉的为害损失.     

赣北植棉区板地直播棉田的杂草轻简防除技术

为了棉花轻简化高效益栽培杂草的科学防除,通过在赣北植棉区开展油菜接茬板地或冬闲地精量直播种植模式杂草防除的实践。结果表明:比棉田常规除草防效高、持效期长,可节省用工数12个/hm2。同时介绍了赣北植棉区圩区洲地棉田杂草群落、板地直播棉田冬闲露地直播春棉杂草发生特点和油菜接茬直播棉田杂草发生特点,推荐了用于防治板地直播棉田杂草的几种常用化学除草剂品种,总结了通过实践得出的冬闲直播棉田除草和油菜接茬直播棉田除草的高效方法。     

覆膜棉田杂草的危害及其化学防除

棉田覆膜后,杂草比裸地棉田提早7～10天出苗,20天左右即可达到生长盛期。影响了覆膜效果和棉苗的生长发育。为了清除棉田杂草,选择适宜的化学除草剂,必须摸清棉田杂草的种类和生长发育规律,根据朝阳县木头城子乡万亩棉田的调查结果,棉田杂草有15科,25种。其中单子叶杂草有马唐、毛马唐、虎尾草、稗草、狗尾草等5     

淮北沿海棉区杂草发生情况及化除配套技术

淮北沿海棉区 ,气候温暖湿润 ,温光资源丰富适宜棉花生长 ,该地区常年种植棉花 1 0万公顷。近年来 ,由于地膜覆盖技术的广泛应用 ,杂草的发生期相应提前 ,密度加重 ,加之人均承包面积大 ,劳力紧张 ,杂草危害严重 ,已成为影响该地区棉花生产的主要障碍因素。为了解决生产中的实际问题 ,我们对棉田化学除草技术进行了研究 ,初步摸清了棉田杂草的消长规律 ,形成了较为完善的棉田杂草化除配套体系 ,并在生产上得到大面积推广应用 ,取得了良好的社会效益。1主要杂草种类及优势种该区棉田主要杂草隶属 1 3科 2 5种 ,其中禾本科占 72 .7% ,阔叶草占…     

兜兰离体快繁技术研究进展

由于生境破坏和人工过度采挖及繁殖的障碍,兜兰已是世界上最濒危的植物物种之一,所有野生种均被列入《濒危野生动植物种国际贸易公约》附录I而被禁止交易。突破其种苗繁殖技术瓶颈有利于兜兰种质资源的保护和可持续利用。本文对兜兰属植物无菌播种、共生萌发和组织培养技术等离体快繁技术的进展进行综述,并提出了目前存在的问题和解决方法,以期为兜兰属植物离体繁殖技术的深入研究和优质种苗的规模化生产提供参考。     

High variation in frequency of infection by endophytes in cultivars of meadow fescue in Finland

Systemic and asymptomatic Neotyphodium fungal endophytes infect numerous species of the Poaceae. The frequencies of Neotyphodium endophyte infection in Finland were investigated among and within seven Nordic cultivars of meadow fescue, Schedonorus pratensis (Huds.) P. Beauv., which is a widely grown pasture and forage grass species in Scandinavia. The cultivars were Kasper, Salten, Antti, Fure, Ilmari, Inkeri and Kalevi. Frequencies of infection of cultivars varied from endophyte-free cultivar Fure to highly infected cultivar Inkeri [mean (standard deviation of mean) of 0·95 (0·023)]. Mean frequencies of infection of three cultivars remained lower than 0·10, and two of the cultivars, Kasper and Salten, were intermediately infected. In most of the cultivars, frequencies of infection varied only slightly among seed lots. In cultivar Kasper, however, the frequency of endophyte infection was highly variable (0–0·96) among the 45 seed lots examined. The relative importance of cultivar, seed lot and infection by Neotyphodium endophyte to the aphid Rhopalosiphum padi L. was studied experimentally, using both endophyte-free and endophyte-infected plants of four seed lots of the two intermediately infected cultivars. Endophyte infection increased plant resistance to R. padi , overriding the influences of seed lot and cultivar. It is proposed that variation caused by endophyte infections in cultivars of meadow fescue should be taken into account in assessing plant breeding programmes in Europe.     

Investigation of Polymorphisms in Coding Region of OsHKT1 in Relation to Salinity in Rice

Rice(Oryza sativa) is sensitive to salinity, but the salt tolerance level differs among cultivars, which might result from natural variations in the genes that are responsible for salt tolerance. High-affinity potassium transporter(HKTs) has been proven to be involved in salt tolerance in plants. Therefore, we screened for natural nucleotide polymorphism in the coding sequence of Os HKT1, which encodes the HKT protein in eight Vietnamese rice cultivars differing in salt tolerance level. In total, seven nucleotide substitutions in coding sequence of Os HKT1 were found, including two non-synonymous and five synonymous substitutions. Further analysis revealed that these two non-synonymous nucleotide substitutions(G50T and T1209A) caused changes in amino acids(Gly17Val and Asp403Glu) at signal peptide and the loop of the sixth transmembrane domain, respectively. To assess the potential effect of these substitutions on the protein function, the 3D structure of HKT protein variants was modelled by using PHYRE2 webserver. The results showed that no difference was observed when compared those predicted 3D structure of HKT protein variants with each other. In addition, the codon bias of synonymous substitutions cannot clearly show correlation with salt tolerance level. It might be interesting to further investigate the functional roles of detected non-synonymous substitutions as it might correlate to salt tolerance in rice.     

马铃薯试管苗组织培养及微型薯诱导技术的研究

通过加入不同浓度的BA、NAA和KT,以探讨外源激素对马铃薯试管苗生理性状的影响,发现低浓度的外源激素较适合用来进行试管苗的增殖。本试验利用香豆素进行微型薯的诱导,结果表明低浓度的香豆素对提高薯重和大薯率有利,而高浓度有利于提高微型薯的结薯数量。     

Role of invertase in the accumulation of sugars in cold-stored potatoes

Freshly harvested potatoes contain low levels of total invertase and high levels of invertase inhibitor. Total invertase increases sharply when potatoes are placed in cold storage, but the inhibitor is not depleted in all varieties. The absence of basal invertase activity in Norchip tubers indicates that an excess of invertase is not required for reducing sugar formation. Analyses of 37 varieties and seedlings after 3 months cold storage revealed that the reducing sugar content is not proportional to the invertase activity. High sugar contents are associated with low inhibitor levels, but low sugars are not necessarily associated with high inhibitor levels. The results indicate that invertase participates in reducing sugar formation, but other factors are responsible for the regulation of starch-sugar conversion in potatoes during cold storage.     

Quantitative assessment of metals in local brands of tea in Pakistan

In present study, Mn, Fe, Zn, Cu, Co, Pb, Cr, Ni and Cd were analyzed by FAAS in green and black tea samples of locally available in the Pakistani market. Na and K were also determined by Flame Photometer. Tea leaves can be the source of mineral components and trace elements, as well as some undesirable substances due to exposure to the environment. Among the metals tested, K was the most abundant one followed by Na, Mn and Fe. Fortunately, toxic heavy metals, Pb and Cd, had the lowest contents in tea samples and also in tea aqueous extracts. Concentration of heavy metals in tea aqueous extract was markedly lower than their total contents except that of K. The solubility of studied metals in tea aqueous extract varied widely and ranged from 0.0-95%. The lowest ranges of solubility were listed for toxic heavy metals Pb and Cd. The possible uptake of metals by the human body from tea aqueous extract has also been determined. The amounts of metals that one may take up through consumption of tea aqueous extract were found to match the acceptable daily intake even taking into account exposure from air, food and drinking water.     

我国发展能源油料作物的策略分析

分析了国内外植物油脂的供需形势、我国耕地和边际地利用潜力、油脂植物资源的种属分布特点等,提出发展我国能源油料作物和生物柴油产业的3点建议：加大对边际地、油脂植物资源的调查等基础平台性研究,为政府决策和产业服务;加强产学研结合,形成研究、推广、产业的良性循环;制定能源植物推广应用优惠政策、推动能源油料作物生产发展。     

玉米耐盐性研究进展

综述了玉米耐盐生理机制和耐盐育种的研究进展。