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为探明盐胁迫对羽衣甘蓝种子萌发特性的影响,明确种子萌发期对盐胁迫的耐受能力,本试验以羽衣甘蓝种子为试验材料,研究不同浓度的NaCL(0、40、80、120、160、200mmol/l)和NaHCO(3 0、20、30、40、50、60mmol/l)对种子萌发胁迫的作用。结果表明:1、2 种盐胁迫处理下,羽衣甘蓝种子的发芽率、发芽势、发芽指数和活力指数等指标均随着盐浓度的升高逐渐降低;2、高浓度的NaHCO3盐溶液对羽衣甘蓝种子的胚根、胚芽的生长抑制较NaCL 盐溶液显著;3、2 种盐 相似文献
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1986年我们从加拿大碧青种子公司引进牧草种子24份,其中豆科7份,禾本科17份,于当年秋播。从3年试种结果看,Glory苜蓿、Minto苜蓿、Algonquin苜蓿在北京种植,无论是产草量、种子产量、草质还是适应性均表现良好。Leo百脉根在北京可安全越冬,其特点是夏季生长繁茂,草质好,耐牧,耐践踏。Orbit长穗冰草、Chief 中间冰草、阿尔泰野麦草表现为抗寒耐旱,产草量高,但要适时利用,否则会降低饲用价值。俄罗斯野麦草、Nordan沙生冰草、草地看麦娘、猫尾草产草量一般,但草质好,春季返青早,枯黄期晚,可在京郊西部山区种植。无芒雀麦(2份)、鸭茅、牛尾草、(艹鹝)草(3份)均表现为适应性好,草质优,产草量高,是较好的禾本科牧草。白三叶、草地早熟禾可做为地被植物和草坪草。 相似文献
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Sugarcane yields have been severely reduced by white leaf and grassy shoot phytoplasma diseases in many parts of Asia. Australian sugarcane crops are not known to be affected by these diseases, but plant pathogenic phytoplasmas found in other introduced and native grasses in northern Australia could pose a serious threat to the Australian sugarcane industry. To further evaluate this threat, leaves from plants of 20 grass species, with and without symptoms, were collected during field surveys in northern Australia and tested to determine whether phytoplasmas were present and whether symptoms were reliable indicators of phytoplasma presence. Molecular tools were used to detect and characterize phytoplasmas. Four different phytoplasmas were found in seven grass species known to grow near healthy sugarcane crops. All the phytoplasmas were closely related to sugarcane white leaf phytoplasma (SCWL), one of the phytoplasmas that causes disease in sugarcane in Asia. Four of the host plant species and two of the phytoplasmas were new records. The relationship between symptoms and phytoplasma presence was poor. Because some plants with symptoms tested negative for phytoplasmas, a series of surveys was carried out in which flowers, leaves, roots and stems of two known host plant species, Whiteochloa cymbiformis and Sorghum stipoideum, were tested separately on nine occasions during two wet seasons. This was done to investigate the distribution of phytoplasmas within plants over time. Results showed that spatial and temporal variation of phytoplasmas occurred in these two host plant species. Hence, evaluation of disease distribution within a region requires repeated testing of all plant parts from plants without symptoms, as well as those with symptoms. To date, there is no report of a vector capable of transmitting to Australian sugarcane the phytoplasmas found in grasses in this study. If one is present, or occurs in the future, then native and introduced grasses could constitute a large reservoir of phytoplasma for vectors to draw on. This work provides an early warning for the sugarcane industry that the potential for infection exists. 相似文献
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Karin Themann Sabine Werres R. Lüttmann H.-A. Diener 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(4):337-343
Samples of water and sediment were taken from drains, reservoirs and wells from four commercial hardy ornamental nurseries with water recirculation systems. The samples were taken on seven different dates throughout a single year from August 1994 to July 1995. The samples were screened for Phytophthora species using five different methods: direct plating, three bait tests (using lupin seedlings, apples and Rhododendron leaves) and a DAS-ELISA (double-antibody sandwich enzyme-linked immunosorbent-assay) with two antisera. In the nurseries with old water recirculation systems, Phytophthora species were detected in the drains and in the reservoirs. In the nursery with a new recirculation system, the pathogens were only present in the drains. None of the water samples from wells in any of the nurseries were contaminated. Phytophthora species were present in the water as well as in the sediment samples from drains and reservoirs. They were detected in the water recirculation systems irrespective of the season. The number of isolates increased about sevenfold between late summer and spring. At least 12 different Phytophthora species were identified: some isolates were previously unrecorded species. The epidemiology of the pathogens in outdoor water recirculation systems as well as the importance of the results for commercial nurseries is discussed. 相似文献
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江河源区披碱草和星星草混播草地土壤物理性状对牦牛放牧强度的响应 总被引:5,自引:1,他引:5
在江河源区披碱草Elymus natans 星星草Puccinellia tenuflora混播人工草地上研究了牦牛放牧强度对土壤物理性状的影响,2年的试验结果表明:随着放牧强度的增加,不同土壤层含水量均呈降低趋势,土壤容重、土壤坚实度呈增大趋势.相关分析表明, 放牧强度与不同土壤层含水量呈极显著的负相关(P<0.01), 与土壤容重和坚实度呈极显著的正相关(P<0.01),而且土壤容重和坚实度均具有累积效应. 相似文献
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通过野外调查和查阅文献资料,得出石门国家森林公园共有野生观赏植物122科267属377种,其中蕨类植物19科23属28种,裸子植物4科5属7种,被子植物99科239属342种。分析了石门国家森林公园野生观赏植物资源的基本特征和用途,并探讨其保护和开发利用。 相似文献
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香花植物在园林景观中满足了人们视觉感官与嗅觉感官的双重要求,有着独特的应用价值。本文对海口市5所大型综合性公园的香花植物进行调查,为推动其在海口市园林景观中的应用提供参考。研究发现,所调查的公园有香花植物45种(含1变种,2栽培品种),隶属于29科39属,以乡土植物为主,木本植物居多;多集中于夏季开花,花色以白色为主;花香从微香型到浓香型,以芳香型为主;主要有闻香主景式、点缀配景式两种配置形式。另外,香花植物种类偏少、种植面积小、花色单调等问题突出,针对以上问题提出相应对策。 相似文献