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1.
几种化学物质和温度处理对高羊茅种子发芽的影响 总被引:7,自引:0,他引:7
用高羊茅(Festuca arundinacea)种子为试验材料,置入光照培养箱培养,研究化学物质和温度处理对其发芽的影响.结果表明:0.2%的次氯酸钠(NaClO)处理促进高羊茅种子的发芽,浓度梯度设置在0.5%~1.5%时均抑制其发芽,且浓度与发芽率和发芽势均成负相关.不同浓度的硝酸钾(KNO3)处理均促进其发芽,且浓度为2.0%时,发芽率最高,发芽势是先降低后升高.高羊茅最适播种温度为20℃,高于或低于20℃,对种子的发芽均有不同程度的抑制作用. 相似文献
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A crop rotation experiment was conducted on two adjacent tracts of land differing in long-term croppin history (30 year in tall fescue pasture or 3 year in sorghum-sudangrass hybrid (SSGH).. Short-term crops were 2 years in tobacco or low-endophyte (Acremonium coenophialum Morgan-Jones & Gams) tall fescue. Tobacco was grown on all plots in Year 3, and data relating mycorrhizal stunt disease of tobacco and populations of the stunt pathogen, Glomus macrocarpum Tul. & Tul., and of other members of the mycorrhizal fungal community, were taken. Disease incidence was highest with SSGH-tobacco and lowest with fescue-fescue, the other two combinations being intermediate. Mycorrhizal colonization was related to disease occurence. At the beginning of the season, populations of G. macrocarpum were equally high in land with a long-term history of SSGH, regardless of its short-term history; but at the end of the season, populations of G. macrocarpum among the four treatments were proportional to the incidence of disease. Populations of four mycorrhizal fungal species which were high in land with a short-term history of fescue were depressed by production of tobacco. Monocropping of tobacco appeared to narrow the diversity of the mycorrhizal fungal community and increased the proportion which is pathogenic, the overall result being lower productivity of soil for tobacco. Crop rotation of tobacco with fescue decreased the proportion of the mycorrhizal fungal community which is pathogenic and maintained productivity of soil for tobacco. 相似文献
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Gary W. Webb Susan Demster Kelsie Minton Susan P. Webb Elizabeth L. Walker Benjamin Onyango 《Journal of Equine Veterinary Science》2012
Ten horses were paired by body weight, age, and skill level, and one of each pair was assigned to one of two groups. Horses were fed alfalfa hay and a mixture of commercial sweet feed and pellets. Horses in group A were fed fescue seed that contained both ergovaline and ergotamine (E+), whereas those in the other group were fed seed that was free from ergot alkaloids (E−). After the first 35 days, horses were switched to the opposite seed treatment. Seed was fed at 8.2% of the diet, resulting in 406 ppb of ergotamine plus ergovaline in the E+ diet. During weeks 3, 5, 7, and 10, horses were subjected to two separate standardized exercise tests (SETs). The aerobic test consisted of walking, trotting, and loping and was designed to maintain horse's heart rate (HR) to less than 150 beats per minute (bpm). The anaerobic test consisted of 40 turns in less than 4 minutes in response to the movements of a mechanical cow and was designed to increase the horse's HR to more than 150 bpm. There were no treatment effects on water consumption or sweat production. There were also no treatment effects on rectal temperature at rest or during recovery from the anaerobic SET. However, rectal temperatures were higher (P < .05) 1 and 30 minutes after the aerobic SET for horses consuming E+ seed. When horses were on the E+ treatment, HRs were lower (P < .05), both at rest and during the SET. HRs were also lower (P < .05) for the E+ treatment at 1 minute after the aerobic test and 5 and 10 minutes after the anaerobic test. Respiration rates were higher (P < .05) 30 minutes after the aerobic SET and 30 and 60 minutes after the anaerobic SET for the E+ treatment. Horses may have increased respiration rates to compensate for a reduction in the efficiency of evaporative cooling, which resulted from vasoconstriction of peripheral blood vessels. 相似文献
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Feed with ergot alkaloids ingested by horses has a deleterious clinical and economic impact on the industry. The clinical manifestation of the effects in mares is early embryonic mortality, abortions, prolonged gestation, dystocia, thickened (edematous) or retained placental membranes, agalactia, and increased rates of newborn mortality. For the stallion, very little is known, although ergot alkaloids decrease the ejaculate volume. However, a large number of breeding stallions graze endophyte infected (E+) pastures. This is especially true in the southeastern United States, and clinically we do not perceive that any stallions have any defined problems that could be attributed to ergot alkaloids. However, the number of spermatozoa produced by any stallion might mask the effects. The effects on fertility may be more subtle and only evident with sperm cell manipulation such as chilling or freezing. A preliminary study was performed on six breeding stallions fed feed containing infected fescue seed. We were not able to determine any significant (P < .05) detrimental effects on sperm motility, number morphology, and sperm morphology when compared with controls. 相似文献
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[目的]探索苇状羊茅在安康地区适应性。[方法]试验按海拔高度在川道、低山、中山区设立3个试验点,观察物候期,测定植株高度、产草量及耐热性。[结果]苇状羊茅以秋季播种为宜,5月上中旬抽穗扬花,植株平均高度103.4cm,产草量可达56415kg/hm2。苇状羊茅适应性强,即使在冬季也能始终保持青绿,在夏季38℃的高温下生长良好。[结论]苇状羊茅具有耐热、耐旱、生长快、绿期长、易管理等特点,适于在安康地区栽培,是生态建设、发展绿色产业的优良草种。 相似文献
6.
叶面喷施铁制剂对高羊茅养分因子的影响(简报) 总被引:5,自引:1,他引:4
铁是植物正常生理代谢所必需的微量营养元素之一,虽然在植物体内的含量甚微,但它作为多种酶的重要组成成份参与氧化还原反应,在植物生长发育中起着非常重要的作用;此外,铁的供应水平和绿色植物叶绿素含量之间常常有良好的相关性[1]。引起草坪草缺铁的条件是多样的。冷凉和潮湿的土壤,尤其在春季当生长速度加快时,会导致铁的不足[2],土壤pH值高、磷含量非常高均会导致缺铁,过量施氮或其他金属离子会使缺铁加剧[3]。施铁肥是目前改善草坪草缺铁症最普遍、最有效的方法[4,5]。有研究表明,用铁和氮的混合物在低氮率时就可有效地改善草坪色泽,因此,施铁作为部分氮的替代物及对无明显缺铁症状时施用铁肥的研究逐步受到研究人员的重视[3,6]。 相似文献
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以光敏感度不同的两个高羊茅品种(.Aftd3和Houndog5)为实验材料,研究外源脱落酸(ABA)在遮荫胁迫下对其生理生化的影响。研究结果表明:在遮荫条件下(LL),Arid3和Houndog5的膜透性与对照相比较,差异达到显著水平(P〈0.05);而在遮荫与脱落酸处理(LL+ABA)后的Arid3和Houndog5膜透性与对照相比较,差异也达到显著水平(P〈0.05),但Arid3增幅大于Houndog5。在LL+ABA处理条件下的Arid3的叶绿素a的含量比对照减少了40.94%,叶绿素b含量比对照减少了35.6%,而Houndog5的叶绿素a的含量比对照减少了38.21%。然而,在LL+ABA处理条件下的Arid3和Houndog5的叶绿素含量均有所减少,且与对照差异没有达到显著水平(P〉0.05)。同时,Arid3和Houndog5在LL+ABA处理下,脯氨酸和可溶性蛋白含量均显著增加(P〈0.05),其中脯氨酸含量变化为:u+ABA〉LL〉cK,Arid3的可溶性蛋白含量变化为:LL〉LL+ABA〉CK;Houndog5则表现为:LL+ABA〉LL〉CK。因此,Arid3和Houndog5都具有较好的耐荫性,且Houndog5耐荫性优于Arid3。同时,脱落酸可以提高高羊茅对弱光逆境的抗逆性。 相似文献
10.
Kathleen?DelateEmail author Eric?Holzmueller DeAnn Davis?Frederick Carl?Mize Charles?Brummer 《Agroforestry Systems》2005,65(1):43-52
The integration of forage crops in an alley-cropped system was examined as a method of encouraging tree planting to increase
farm income, improve soil quality, and enhance biodiversity on Midwestern U.S. farms. Crop and tree performance were evaluated
in an alley-cropped system using four forage intercrops grown in tree alleyways to simulate a potential hay crop – oat (Avena sativa L.) and red clover (Trifolium pratense L.); oat, red clover, and red fescue (Festuca rubra L.); oat, red clover, and orchardgrass (Dactylis glomerata L.); and oat and hairy vetch (Vicia villosa Roth) – compared to a herbicide, mowing and control (no management) treatment. Five tree species, divided into fast-growing
hardwoods of two poplar (Populus spp.) clones [Crandon (P. alba L. × P. grandidentata Michx.) and Eugenei (P. deltoids Bartr. × P. nigra L.)], and silver maple (Acer saccharinum L.) were compared with two high-value, slow-growing hardwoods planted from seed and as seedlings: red oak (Quercus rubra L.) and black walnut (Juglans nigra L.). Tree survival in the first year was greater for the fast-growing species, and by the fourth year, tree height among
the four forage treatments was equivalent for all upland locations. The oat/hairy vetch ground cover was associated with the
shortest trees in the bottomland site. Herbicide-treated trees were taller than the average of the four forage treatments
for all four planting conditions. Tree height in the mowing and the control treatments was not significantly different for
all four planting conditions. The nutritive value of the forage crop was excellent in the second year of tree establishment,
with crude protein content and digestibility at 17 and 71%, respectively, in the oat/red clover/red fescue treatment, suggesting
the viability of forage crops as alternatives to herbicides in alley-cropped systems. 相似文献