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1.
水杨酸和热锻炼诱导的高羊茅幼苗的耐热性与抗氧化的关系   总被引:49,自引:0,他引:49  
研究了水杨酸(SA)处理和热锻炼(HH)对高羊茅(Festuca arundinacea Schred.)幼苗耐热性的影响和在耐热性诱导过程中植物体内可溶性蛋白含量与超氧化物歧化酶(SOD),过氧化的酶(POD)和过氧化氢酶(CAT)等3种抗氧化酶的活性变化。结果表明:0.5mmol/L男SA预处理能显著提高高羊茅幼苗在42℃热胁迫(HS)后转至常温下恢复生长18d时的苗高,绿叶数和绿叶指数;在常温下SA提高高羊茅幼苗的CAT活性,降低POD活性,而对SOD的影响不显著;SA和HH均能降低高羊茅幼苗在HS下细胞外渗液电导率,提高可溶性蛋白的含量和SOD、CAT活性,但不能显著提高POD活性。因此,推测SA与HH提高耐热性上具有相似的机理。  相似文献
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施肥对高羊茅草坪越夏的影响   总被引:15,自引:1,他引:14  
施用N、K、Ca和杀真菌剂对高羊茅(Festuca arundineces Schreb.cv.Pixie)越夏影响的研究结果表明,施氮肥可以打破高羊茅的夏季休眼,促进植株生长,促进植株对N、K的吸收,增加植株叶绿素含量,提高草坪质量,而不会明显降低草坪草的抗热性。但施氮肥后褐斑病等病害加重,通过喷洒杀真菌剂可控制病害的发生。  相似文献
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Xylem maturation in elongating leaf blades of tall fescue ( Festuca arundinacea ) was studied using staining and microcasting. Three distinctive regions were identified in the blade: (1) a basal region, in which elongation was occurring and protoxylem (PX) vessels were functioning throughout; (2) a maturation region, in which elongation had stopped and narrow (NMX) and large (LMX) metaxylem vessels were beginning to function; (3) a distal, mature region in which most of the longitudinal water movements occurred in the LMX. The axial hydraulic conductivity ( K h) was measured in leaf sections from all these regions and compared with the theoretical axial hydraulic conductivity ( K t) computed from the diameter of individual inner vessels. K t was proportional to K h throughout the leaf, but K t was about three times K h. The changes in K h and K t along the leaf reflected the different stages of xylem maturation. In the basal 60 mm region, K h was about 0.30±0.07 mmol s−1 mm MPa−1. Beyond that region, K h rapidly increased with metaxylem element maturation to a maximum value of 5.0±0.3 mmol s−1 mm MPa−1, 105 mm from the leaf base. It then decreased to 3.5±0.2 mmol s−1 mm MPa−1 near the leaf tip. The basal expanding region was observed to restrict longitudinal water movement. There was a close relationship between the water deposition rate in the elongation zone and the sum of the perimeters of PX vessels. The implications of this longitudinal vasculature on the partitioning of water between growth and transpiration is discussed.  相似文献
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高羊茅和其他羊茅植株再生与遗传转化研究进展   总被引:10,自引:0,他引:10  
高羊茅、紫羊茅和草地羊茅均为很重要的多年生冷季型牧草与草坪草,生物技术在其品种改良中具有很大的应用潜力.30年来,三种羊茅的组织培养、胚性培养物的长期保存以及遗传转化等研究取得了较大进展,已建立起多种植株再生体系和遗传转化技术,但作为单子叶植物,这些草种的组织培养和转基因遗传改良也还存在一些问题.本文就以上几方面的内容进行了综述.  相似文献
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Spatial distribution of cell turgor pressure, cell osmotic pressure and relative elemental growth rate were measured in growing tall fescue leaves ( Festuca arundinacea ). Cell turgor pressure (measured with a pressure probe) was c . 0.55 MPa in expanding cells but increased steeply (+0.3 MPa) in cells where elongation had stopped. However, cell osmotic pressure (measured with a picolitre osmometer) was almost constant at 0.85 MPa throughout the leaf. The water potential difference between the growth zone and the mature zone (0.3 MPa) was interpreted as a growth-induced water potential gradient. This and further implications for the mechanism of growth control are discussed.  相似文献
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Summary Three legume species (alfalfa, red clover, and birdsfoot trefoil) in combination with five grass species (timothy, bromegrass, red fescue, tall fescue, and orchardgrass) were used to study N transfer in mixtures, using the 15N dilution technique. The advantage of grass-legume mixtures was apparent. Total herbage and protein yields of grasses in mixtures were higher than those alone, especially at the later cuts. This benefit of mixed cropping is mainly due to N transfer from legumes to associated grasses. N2-fixation and N transfer by alfalfa rated highest, red clover intermediate, and birdsfoot trefoil lowest. The importance of each pathway of N transfer from legumes appeared to differ between species. Alfalfa and red clover excreted more N than trefoil, while the latter contributed more N from decomposition of dead nodule and root tissue. The greatest advantage from a grass-legume mixture, with respect to the utilization of N released from the legume, varied with early maturing tall fescue (Kentucky 31), orchardgrass (Juno), and bromegrass (Tempo), to intermediate timothy (Climax), and least with late maturing red fescue (Carlawn). Contribution no. 817 of the Ottawa Research Station.  相似文献
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Neotyphodium coenophialum (Morgan-Jones and Gams) Glenn, Bacon and Hanlin, a fungal endophyte found primarily in shoots of tall fescue (Festuca arundinacea Shreb.), can modify rhizosphere activity in response to phosphorus (P) deficiency. In a controlled environment experiment, two cloned tall fescue genotypes (DN2 and DN4) free (E-) and infected (E+) with their naturally occurring endophyte strains were grown in nutrient solutions at low P (3.1 ppm) or high P (31 ppm) concentrations for 21 d. Endophyte infection increased root dry matter (DM) of DN4 by 21% but did not affect root DM of DN2. Under P deficiency, shoot and total DM were not affected by endophyte but relative growth rate was greater in E+ than E- plants. In high P nutrient solution, E+ plants produced 13% less (DN2) or 29% more (DN4) shoot DM than E- plants. Endophyte affected mineral concentrations in roots more than in shoots. Regardless of P concentration in nutrient solution, E+ DN2 accumulated more P, Ca, Zn and Cu but less K in roots than E- plants. When grown in high P nutrient solution, concentrations of Fe and B in roots of E+ DN2 plants were reduced compared with those of E- plants. Concentrations of P, Ca and Cu in roots of DN4 were less, but K was greater in E+ than E- plants. In shoots, E+ DN2 had greater concentrations of Fe and Cu than E- DN2, regardless of P concentration in nutrient solution. Genotype DN4 responded to endophyte infection by reducing B concentration in shoots. Nutrient uptake rates were affected by endophyte infection in plants grown in low P nutrient solution. A greater uptake rate of most nutrients and their transport to shoots was observed in DN2, but responses of DN4 were not consistent. Results suggest that endophyte may elicit different modes of tall fescue adaptation to P deficiency. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献
10.
高羊茅组织培养再生体系及GUS基因瞬间表达研究   总被引:5,自引:0,他引:5  
以成熟种子为外值体,对高羊茅纰织培养和植株再生体系进行了优化,分析了不同浓度2.4-D、6-BA和激动素对高羊茅愈伤组织诱导和愈伤组织分化成苗的影响.结果表明:9.0mg/L 2.4-L)对愈伤组织的诱导效果最佳.0.2mg/L激动素是愈伤组织分化成苗的最适浓度.二者的诱导率和分化率分别达到68.08%和45.83%。在愈伤组织继代培养基中附加1.0mg/L 2.4-D、0.5mg/L 6-BA和1.25mg/L CuSO4;有利于胚性愈伤组织的形成,可以明显促进愈伤组织分化。同时.采用基因枪法将GUS基因导入高羊茅愈伤组织中,通过组织化学染色检测到了GUS瞬间表达活性;并对影响CUS基因瞬间表达的因素进行了分析.以期为提高基因枪法遗传转化效率提供参考。  相似文献
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