香根草叶片水提液对重金属胁迫下两种草坪草种子萌发的影响

为改善重金属胁迫下草坪草种子的萌发,采用室内水分发芽床试验,研究香根草叶片水提液对单一不同浓度重金属(锌、铜、镉)胁迫下高羊茅和多年生黑麦草种子萌发和幼苗生长的影响。结果表明,香根草叶片水提液对高羊茅和多年生黑麦草种子萌发无显著化感作用,但香根草叶片水提液相较对照(蒸馏水)显著提高了Cd²⁺(200mg/L)胁迫下多年生黑麦草种子的发芽率,Cu²⁺(100、200mg/L)、Cd²⁺(100、200mg/L)和Zn²⁺(200mg/L)胁迫下高羊茅种子的发芽率。香根草叶片水提液显著增加了的Zn²⁺(600mg/L)、Cu²⁺(50、100 mg/L)以及Cd²⁺(50、100、200 mg/L)胁迫下多年生黑麦草的苗长,显著增加了Zn²⁺(200、400 mg/L)、Cu²⁺(50 mg/L)以及Cd²⁺(100、200 mg/L)胁迫下多年生黑麦草的根长和最长根。另外,香根草叶片水提液显著增加了Cd²⁺(50、200 mg/L)胁迫下高羊茅的苗长,增加了Zn²⁺(200、400 mg/L)、Cd²⁺(50、200 mg/L)胁迫下高羊茅的根长和最长根。试验结果为香根草叶片水提液提高高羊茅和多年生黑麦草种子在Cu²⁺和Cd²⁺胁迫下的萌发特性提供科学依据,也为香根草更广泛的利用方式提供基础资料。     

苇状羊茅生长动态的研究

大量试验证明,苇状羊茅在当地土壤及气候条件不栽培,分蘖能力强,生长迅速,地上生物量及株高的增长动态均符合logistic曲线,而生物量的衰减动态符合y=a blnx曲线,峰值在7月,绿期长达250d左右,鲜草产量为37500kg/hm~2.     

磷肥和行距对两种草坪草种子产量和品质的影响

本试验运用二因素二次饮和Ｄ－最优设计，研究了磷肥和行距及其组合对草坪草多年生黑麦草和高羊茅种子产量和品质的影响。试验结果表明：磷肥和行距及其组合不但可以提高草坪草种子产量，而且可以改善草坪草种子品质，提高种子的发芽率、生长热和活力指数、磷肥和行距及其处理还可提高草坪草的每穗籽粒数、结实率和千粒重。     

虉草适应湿地环境的解剖结构和组织化学特征研究

为研究虉草适应湿地环境的结构特征,探讨了该植物不定根、根状茎、直立茎和叶的解剖结构、组织化学及其质外体屏障结构的通透性生理。利用光学显微镜和荧光显微镜对虉草进行了解剖学和组织化学研究。结果表明:1)虉草不定根解剖结构由外而内分别为表皮、外皮层、皮层、内皮层、中央为木质部和厚壁组织;茎结构由外而内分别为角质层、表皮、周缘厚壁机械组织层、皮层、具维管束厚壁机械组织层和髓腔。2)不定根具栓质化和木质化内皮层和外皮层组成的屏障结构;茎具角质层、栓质化和木质化周缘厚壁组织层和厚壁组织层;根状茎具内、外皮层,直立茎仅具外皮层。3)虉草体内气腔包括不定根中通气组织,茎皮层气腔和髓腔,及叶鞘气腔。虉草的机械组织结构、屏障结构和气腔是其适应湿地环境的重要结构特征,该研究为今后选择湿地生态修复的植物物种提供依据。     

都市屋顶绿化草坪草保水剂施用技术及经济效益分析

选取了北方地区常用草坪草高羊茅为研究对象,探究了保水剂在屋顶绿化草坪草栽培应用中的最优施用制度及经济效益。结果表明：在50%～70%FC水分控制下高羊茅生长所需的耗水量比70%～90%FC水分控制下的耗水量要小,且任意水分控制条件下,施用保水剂处理组的总耗水量均比对照组的总耗水量要小;当保水剂施用浓度为0.5%,施入层...     

Electron probe microanalysis of silicon in grass leaves

Abstract

Silicon is a major constituent of grasses, therefore, research was initiated to evaluate the use of the paraffin technique for electron probe microanalysis of Si in grass leaf tissue. Mature healthy leaves of a tropical grass, Wilmington bahiagrass (Paspalum notatum Flügge), and a cool season grass, tall fescuegrass (Festuca arundinacea Schred), were selected for study. Paradermal sections (10 μ) of paraffin impregnated leaf tissue were placed on sheet carbon that had been attached with Haupt's adhesive to 2.5 cm glass discs. The grass sections were fixed to the sheet carbon with Haupt's adhesive and the paraffin removed with xylene prior to microanalysis. Silicon was found to be highly concentrated in the epidermis of fescuegrass and bahiagrass. Short cells, many containing opal bodies, had the highest contents of Si of the epidermal cells. Large quantities of Si was also present in guard cells but long cells contained relatively small amounts.     

高羊茅赤霉素2-氧化酶编码基因的克隆及功能验证

赤霉素(GA)是一类重要的植物激素,在植物的生长发育过程中发挥着重要作用。许多赤霉素代谢途径关键酶的编码基因已经被克隆和研究,但在高羊茅(Festuca arundinacea)中尚未见报道,利用RACE技术获得了高羊茅赤霉素2-氧化酶基因(FaGA2ox)。结果表明:FaGA2oxcDNA全长1566bp,包含1026bp开放阅读框,编码一个由341个氨基酸组成的蛋白质。FaGA2ox转基因烟草(Nicotiana tabocum)表现出赤霉素缺陷的表型,叶片面积明显变小,且叶片褶皱,叶片颜色暗绿,节间长度明显变短。综上所述,FaGA2ox在烟草中的过量表达可以导致植株矮化,为进一步利用该基因转化高羊茅培育矮化植株奠定基础。     

不同温度对高羊茅种子发芽的影响

高羊茅种子在不同温度下的发芽实验结果表明：高羊茅最适宜播种的温度为20—25℃，温度高至30℃，发芽率显著下降，不宜播种；温度低至10℃，平均发芽速度显著减小，发芽率有所下降。     

The morphology and development of Lotus uliginosus and Trifolium subterraneum under Pinus radiata canopy in southern Chile

A split-plot experiment was conducted in southern Chile to study the effects of tree cover and level of fertilizer application at establishment on the morphology and development of the legumes Lotus uliginosus and Trifolium subterraneum, when sown in conjunction with Festuca arundinacea as the companion grass. Trees were 13-year-old Pinus radiata, spaced at 4 × 12.5 m intervals and with a mean canopy diameter of 4.8 m. At 150 days after sowing the total area of Lotus leaves and length of Lotus stems/plant were not affected by tree cover. Individual plants had fewer stems but they were longer. For Trifolium, despite large increases in individual petiole length and leaf area, total petiole length and leaf area/plant were reduced by tree cover because of a reduced number of petioles/plant. At 275 days after sowing, the number and weight of Lotus components/ha was not affected by tree cover, although companion grass development was reduced. By 640 days the number and weight of Lotus components/ha was reduced but only to the same degree as the companion grass. Trifolium plant development, and in particular seed yield, was affected by tree cover at 275 and 640 days and to a greater extent than Lotus or the companion grass. A high level of fertilizer application at establishment induced a greater development of both legumes at 275 days, but by 640 days the effects were much reduced. It is concluded that both Lotus uliginosus and Trifolium subterraneum respond to tree cover by increasing stem length and leaf area, but that in situations with low soil fertility, the development of Lotus is less affected by tree cover than Trifolium. This revised version was published online in June 2006 with corrections to the Cover Date.     

盐胁迫对醉马草和高羊茅种子萌发及幼苗生长的影响

采用质量分数分别为0.1％、0.3％、0.5％、0.7％和0.9％的盐溶液处理带内生真菌醉马草(Achnatherum inebrians)、不带内生真菌醉马草、高羊茅(Festuca arundinacea)品种'侠客岛'(Island)和'猎狗6号'(Hound 6)种子,测定发芽率、发芽势、活力指数、苗高、胚根长等指标,并建立相关函数方程确定4份种质材料对NaCl的耐受值,探讨单盐NaCl对4份种质材料种子萌发和幼苗生长的特性,明确种子萌发阶段及幼苗生长阶段对单盐NaCl胁迫的耐受程度并进行综合耐盐性评价.结果表明,与对照组相比,高羊茅品种'侠客岛'和'猎狗6号'的发芽率、发芽势、发芽指数、活力指数、苗高、胚根长随着盐浓度的升高而降低,根冠比则与之相反.轻度盐胁迫(0.1％和0.3％)对于两种醉马草种子萌发和幼苗生长等有促进作用(P<0.05).种子萌发阶段的带菌醉马草、不带菌醉马草、'侠客岛'和'猎狗6号'的耐盐适宜浓度分别为0.70％、0.60％、0.37％和0.49％;耐盐半致死浓度分别为0.98％、0.72％、0.46％和0.61％;耐盐极限浓度分别为1.02％、0.91％、0.61％和0.87％.幼苗阶段的带菌醉马草、不带菌醉马草、'侠客岛'和'猎狗6号'的耐盐阈值分别为1.23％、1.01％、0.44％和1.09％.综合耐盐性为带菌醉马草>高羊茅'猎狗6号'>不带菌醉马草>高羊茅'侠客岛'.