【作者】 张岩；

【导师】 边秀举；

【作者基本信息】 河北农业大学 ， 作物栽培学与耕作学， 2008， 硕士

【摘要】 狗牙根[Cynodon.Dactylon(L.)Pers.]是一种具有发达匍匐茎和根状茎的多年生暖季型草坪草,在世界各温暖潮湿和温暖半干旱地区均有分布。本试验以河北农业大学选育出的两个当地狗牙根新品系和美国近年来推出的两个狗牙根新品种为研究对象,对其在人工干旱处理和不同盐浓度处理下的植株形态特征变化、外观表现和生理生化指标等进行了观察和测定,对4个狗牙根材料的抗旱、耐盐性进行综合评价,试验结果如下:1.干旱缺水条件下,各狗牙根材料的绿叶率和相对含水量都随干旱的加剧而逐渐降低,但材料间下降幅度有所差异,下降幅度依次为:A3＞A5＞C1＞C3。MDA含量与质膜透性却逐渐升高,其中以A5变化最快,增幅最大,其次为A3和C1,C3变化幅度最小。2.干旱缺水条件下,叶绿素含量首先升高,于断水处理的第6天达到峰值后又逐渐下降,材料A5下降幅度最大,其次为C3,A3与C1降幅较小。脯氨酸含量在断水前期逐渐升高,各材料在处理第10天同时达到最大值后,随干旱时间延长和干旱程度增加又迅速下降,但各材料峰值的脯胺酸含量差异显著,峰值较大的是品种(系)C3与C1,分别为325.47μg/g和324.16μg/g,且两者差异不显著,但显著高于其它品种(系)(P＜0.05)。其次是A3,峰值为306.56μg/g,显著高于A5。A5的峰值最小,仅为277.19μg/g。3.在盐处理下,各狗牙根材料的相对含水量和叶绿素含量均随着盐处理浓度的增加及处理时间的延长而逐渐降低,丙二醛含量与质膜伤害率却逐渐变大。脯氨酸的含量在处理初期及低浓度处理下逐渐升高,在盐处理达到一定浓度和一定时间时脯氨酸含量达到一个极值,而后逐渐下降。4.干旱及盐分的逆境处理对叶片的叶绿素荧光参数的影响都较大,各材料的荧光值随着处理强度的加强而逐渐降低,并且方差分析结果差异显著或极显著。因此可以利用不同品种(系)叶绿素荧光参数对逆境胁迫的反应差异,筛选抗逆性强的种质。5.供试的4种狗牙根材料的两种抗逆性差异显著。在干旱缺水条件下,C3的抗旱性最强,抗旱级别值为30,其次为C1与A3,抗旱级别值分别为28和21,A5的抗旱性最差,抗旱级别值仅为8。盐分处理下,4种狗牙根材料的耐盐性强弱顺序为:A3＞C3＞C1＞A3。6.通过对4种狗牙根材料抗旱及耐盐生理生化的研究进行综合评价,材料C3与C1的抗旱综合评价级别相似,且两品种(系)的抗旱能力均较强,因此认为其在抗旱性育种及栽培中具有更好的开发利用价值。材料A3的抗盐综合评价级别值最高,其在抗盐育种与栽培中具有更大的发展潜力。材料C3的各种抗盐性能也较为稳定,因而也具有进一步研究利用的价值。而材料A5的抗旱耐盐性均极差,不宜直接用于干旱区及盐碱地的粗放管理草坪。更多还原

【Abstract】 Bermudagrass[Cynodon.Dactylon(L.)Pers.]is a kind of perennial warm season grass with developed stolons and rhizomes,widely distributed in warm semi-humid zone, warm wet zone in the world.By taking the two local Bermudagrass new strains selected by Agricultural university of Hebei and the two cultivars pushed out by the USA recently as the research objects,the change of morphology,appearance performance,the physiological and biochemical index of the plant under drought and salt stresses were observed and measured,the drought resistance and salt tolerance of the four Bermudagrass materials were comprehensively evaluated in the experiment.The results were as follows:1.During the drought,green leaf ratio and relative water content of the bermudagrass materials were declined with the intensification of stress degree.Decrease amplitude was different in the materials,the order was:A3＞A5＞C1＞C3.MDA contents and membrane permeability increased gradually,with the maximal increase slope of A5,the C land A3 second,and the C3 was the smallest.2.Under the drought stress,chlorophyll content increased to the peak after the 6 days’ stress,then declined gradually,with the A5 decreased first,the C3 second,the A3 and C1 last.Pro content of the materials increased to the peak at the 10th day,and quickly declined with the extend of stress time and increase of drought degree.The proline content was significantly different in the materials,with C3 and C1 first,325.47ug/g and 324.16μg/g,A3 second,306.56μg/g,and A5 the last,277.19μg/g.3.Under salt stress,the relative water content and the chlorophyll content of materials reduced gradually with the increase of salty stress concentration and the extension of time.The MDA content and the protoplasmic membrane injury rate gradually increased. The proline content elevated gradually in the early period and low concentration,till to the peak,and then gradually dropped.4.The effect of salt stress and drought stress on the chlorophyll fluorescence parameters of leaves was great,fluorescence value reduced gradually with the stress intensity,and the results were significantly different.So it was feasible to use the different responses of varieties to the stress to choose varieties with high stress-resistance.5.Significant difference exists in the four materials resistance.Under water stress,the drought-resistance of C3 was the strongest,its value of drought resistance was 30.C1 and A3 was second,their values of drought resistance were 28 and 21,the drought-resistance of A5 was the worst and its value of drought resistance was only 8. The order of the four materials salt tolerance was A3＞C3＞C1＞A5.6.Through studying on physiological and biochemical mechanism under drought stress and synthetical estimating on the drought resistance,the result of disquisition indicate: bermudagrass C3 and C1 possessed of the worth of exploiture because of its strong draught resistance abilities;and it was necessary to pursue roundly research on C3 for their better drought resistance;while A5 was unsuitable exploited directly for drought region because of its weak drought resistance.更多还原