共查询到20条相似文献,搜索用时 209 毫秒
1.
对河口低热河谷区辣木林四季杂草种类、群落组成进行调查。结果表明,该辣木林有杂草73种,隶属22科65属,其中外来入侵种19种,占杂草总数的26.0%。通过分析四季主要杂草的优势度得出,春、夏、秋季优势杂草主要是菊科的鬼针草(Bidens pilosa),禾本科的马唐(Digitaria sanguinalis)、十字马唐(Digitaria cruciata)、光头稗(Echinochloa colona)、牛筋草(Eleusine indica)等组成;冬季优势杂草主要有菊科的鬼针草、小飞蓬(Conyza canadensis)、鼠麴草(Gnaphalium affine)、野茼蒿(Gnaphalium affine)组成。其中,鬼针草为常年优势杂草,在四季杂草组成中外来入侵杂草优势明显。 相似文献
2.
3.
通过对海南昌江和白沙县4种菊科外来入侵杂草的调查发现,飞机草、假臭草和蟛蜞菊分布广泛、危害严重;从4种外来杂草上共分离获得7种病原真菌,分别为:侵染假臭草的链隔孢(Alternaria sp.)、飞机草的炭疽菌(Colletotrichum sp.)、飞机草的泽兰尾孢(Cerospora eupatorii Peck.)、飞机草的链格孢(Alternaria sp.)、胜红蓟的弯孢(Curvularia sp.)、蟛蜞菊的链隔孢(Alternaria sp.)和蟛蜞菊的炭疽菌(Colletotrichum sp.),这些病原菌的生防潜力有待进一步研究。 相似文献
4.
江苏金坛水稻田杂草发生危害调查研究 总被引:1,自引:0,他引:1
为揭示江苏金坛稻麦轮作制水稻田杂草组成、发生等危害特点,于2014年10月调查不同区域、不同管理措施的90块水稻田。结果显示:金坛地区水稻田有12科21属23种杂草,其中外来入侵杂草2种;优势杂草种为鸭舌草(Monochoria vaginalis)、水苋菜(Ammannia baccifera)、稗草(Echinochloa crusgalli)、千金子(Leptochloa chinensis)、陌上菜(Lindernia procumbens)、多花水苋(Ammannia multiflora)。 相似文献
5.
福建省鼓浪屿于2017年获准列入世界文化遗产名录。为保护鼓浪屿岛上117栋重点历史建筑及其植物资源,本文通过实地走访、标本收集与鉴定,针对建筑周边(围墙、墙体和院子)的植物资源及岛上的外来入侵植物进行了调查分析。结果表明:建筑周边植物有97科292种,资源总数比较丰富,但以常见的绿化苗木居多。其中,出现频次高的科依次是桑科、凤尾蕨科、菊科、酢浆草科、大戟科、紫葳科、荨麻科、茄科、禾本科、无患子科。出现频次最高的种是小叶榕(Ficus microcarpa L.f.),分布在90栋建筑,占建筑总数的76.92%。出现在50%以上建筑内的植物还有蜈蚣凤尾蕨(Pteris vittata L.)、酢浆草(Oxalis corniculata L.)、猫爪藤[Macfadyena unguis-cati (L.) A. Gentry]、冷水花(Pilea notata C. H. Wright)等。周边植物最丰富的是黄荣远堂(39科59种),其次为褚家园(35科48种)。岛上主要入侵植物有25科42种,其中,菊科种类最多,占16.67%,原产美洲的种数量达29种,属于有意引入的外来入侵植物31种,占73.81%。外来入侵植物优势种有猫爪藤[Macfadyena unguis-cati (L.) A. Gentry]、红瓜[Coccinia grandis (L.) Voigt]、鸡矢藤(Paederia foetida L.)、爬山虎[Parthenocissus tricuspidata (Sieb. et Zucc.) Planch]、五爪金龙(Ipomoea cairica Hand.-Mazz.)等5种。小叶榕及几种外来入侵植物优势种对建筑的墙体、围墙甚至全岛具有入侵蔓延趋势。 相似文献
6.
《中国麻业》2021,(3)
为准确评价农田杂草的危害程度,为亚麻杂草综合防控提供依据,采用倒置"W"9点取样法调查甘肃省亚麻主产区亚麻田杂草种类、株数、株高和盖度。依据调查结果分析提出相对优势度RA的计算公式:RA=RD(相对密度)+RF(相对频度)+RU(相对均度)+RH(相对高度)+RC(相对盖度)。该计算方法与国内外文献报道的不同,属于计算方法的改进,适用于倒置"W"9点取样法在不调查杂草鲜重条件下(快速调查)对相对优势度的全面评价。依据杂草相对优势度并结合杂草具体发生情况提出了评价亚麻田杂草危害程度的4级分级标准。依据分级标准评价,4级杂草种类有藜等8种,占杂草种类的4.91%;3级杂草种类有蔓首乌等6种,占杂草种类的3.68%;2级杂草种类有黄花蒿等22种,占杂草种类的13.50%;1级杂草种类有节节草等127种,占杂草种类的77.91%。该分级标准能够准确评价农田杂草的危害程度,对杂草综合防控具有重要指导意义。 相似文献
7.
剑麻是我国重要的热带经济作物,杂草危害给剑麻生产带来严重障碍和损失。为了掌握我国广东、广西和海南剑麻园杂草情况,从而进行科学防控。本研究采取踏查和定块系统调查相结合,全面调查了我国剑麻园杂草种类、分布与危害。结果表明,剑麻园共有杂草49科144属200种,其中禾本科40种,菊科24种,豆科20种,茜草科和莎草科各10种;一年生杂草79种,二年生杂草1种,多年生杂草100种,其它生活周期20种;种子繁殖杂草143种,种子、茎和根茎等繁殖杂草57种;外来杂草68种,本地杂草132种;5级危害的杂草3种(大白茅、铺地黍和香附子),4级危害的杂草7种(牛筋草、短颖马唐、假臭草、阔叶丰花草、加拿大蓬、鬼针草、薇甘菊)。在剑麻园杂草防控方面,提出了"生态优先,以草治草"策略和"不生草的剑麻园不可能是生态剑麻园,只有生良草的剑麻园才可能是生态园"的新观点,并采取剑麻园种草控草、养地、养麻、养畜和驱虫防病的生态化管理技术措施,达到减肥减药、生态安全的可持续发展目标。 相似文献
8.
9.
本文调查研究了州内亚麻种植地区的田块杂草种类、分布和发生规律.查清杂草共有101种,隶属25科,发生危害重的有7科26种,占25.74%;双子叶杂草77种,占76.23%,单子叶杂草22种,占21.78%,蕨类杂草2种,占1.98%.一年生杂草42种,占42.58%,越年或一年生杂草29种,占28.71%,多年生杂草30种,占29.71%.杂草随亚麻的播种而生长,至枞形期达最高峰,88-1231株/m2.防治上在亚麻枞形期(株高5-10cm)、杂草2-3叶期选择50%敌草隆+5%精喹禾灵或50%敌草隆+56%二甲四氯钠盐,兑水喷雾,防除效果达90%以上. 相似文献
10.
11.
12.
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. 相似文献
13.
Quynh-Hoa Pham Xuan-An Tran Thi-Nha-Trang Nguyen Thi-Thuy-Anh Tran Hai-Yen Hoang Thi-Hong-Van Nguyen Thi-Hanh Tang Thi-Phuc Do 《水稻科学》2016,23(6):334
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. 相似文献
14.
15.
17.
为科学地制定除草体系,在比较详尽地查实历史资料的基础上,将本县80a来的稻田除草方法划分为5个除草阶段,阐述了每个阶段的除草特点和除草效果,提出了今后稻田化学除草的发展方向。 相似文献
18.
试验以5个生产用马铃薯品种脱毒试管苗为材料,采用组织培养的方法,初步研究了茎切段在正常磷及低磷培养基中生长30 d时幼苗的磷营养效率差异,为筛选出适宜于生产用的磷高效马铃薯品种奠定了基础。试验结果表明,5个马铃薯品种幼苗在正常磷和低磷胁迫下对磷素的吸收和利用能力均存在明显的基因型差异。利用各品种幼苗的磷效率指标(植株干重、鲜重、吸磷量、磷利用效率)的相对指标(低磷处理的结果/正常磷处理的结果×100)进行聚类分析(类平均法)的结果表明,大白和I-1035属于磷高效基因型品种,中农Ⅷ是磷低效基因型品种,凉薯97和疫不加则属于中间类型品种。 相似文献
19.