Regrowth Rates of Timothy and Meadow Fescue as Related to the Content of Remaining Water-soluble Carbohydrates and Non-elongated Tillers

The relationship between regrowth rates and the content of water-soluble carbohydrates in stubble (WSC) and percentage of non-elongated tillers (PNT) was studied in timothy (Phleum pratense L.) and meadow fescue (Festuca pratensis Huds.) cut at different phenological stages. Single plants were grown in pots and cut outdoors and then regrown under controlled climatic conditions. The data for the dry matter production during the following 3 weeks were fitted to an expolinear growth equation to determine an initial maximum relative regrowth rate (R _m) and a daily maximum regrowth rate (C _m). C _m appeared to be positively correlated to PNT in both species, whereas R _m was increased with increasing WSC. For regrowth after later cuts of meadow fescue there was a positive contribution to R _m by PNT.     

能源草生态风险评价体系的构建

为构建一套专门用来评估能源草生态风险等级的体系,本研究通过文献法与专家咨询法确立分布特征、扩散特征、繁殖特征、遗传特征、适应特征、危害特征和被控制特征7个方面共计33个与能源草生态风险评价相关的指标。然后通过yaahp10.1软件利用层次分析法对各指标进行权重赋值,进而构建相应的生态风险评价体系。最后选取10种已知生态风险等级的高大禾草对该体系进行检验,并依据检验结果对评价体系的生态风险等级层次进行划分。结果表明所构建的体系可以有效地辨别出不同物种的生态风险等级,并将风险等级层次划分为高危生态风险(系统评分74.5),一定生态风险(系统评分在54.5～74.5)和基本无生态风险(系统评分54.5)。     

基于VR技术的旋耕埋草机功率检测研究

为了提高旋耕埋草机的功率检测准确性和效率,实现旋耕埋草机的结构优化,将VR虚拟现实技术引入到了埋草机的功率测算过程中,并采用Lab VIEW软件设计了功率检测虚拟平台,从而实现了旋耕埋草机的功率数据采集、处理和仿真模拟。为了验证方案的可行性,以一台简单的旋耕埋草机为例,在农田里展开了试验。首先,对其作业性能进行了测试,在保证其能正常作业的情况下采用虚拟仪器对功率进行了测算,并将其和实际功率仪器上的采集功率进行了对比。结果表明:采用虚拟仪器得到的功率和实际功率相吻合。由此验证了方案的可行性,为旋耕埋草机的优化设计提供了数据支持,为农机智能检测仪器和嵌入式系统的开发提供了较有价值的参考。     

基于转录组测序的牧草分子标记开发研究进展

转录组测序是一种获得生物组织或细胞几乎所有转录本的高通量测序技术,测序所得的基因编码序列可用于研究植物在不同条件下的基因表达、调控方式及后续的功能基因发掘与遗传进化分析。随着分子标记技术的快速发展,转录组测序数据也可作为标记开发的重要来源,为牧草开展种质资源遗传多样性评价、遗传变异分析、居群结构研究和育种提供有效工具。本文综述了基于转录组测序的牧草分子标记如EST-SSR和SNP的开发及应用现状,以期为牧草分子标记开发提供重要参考。     

小麦族10种禾草叶片可消化性及矿物质含量的差异

利用扫描电镜及能量分散型荧光X射线新技术分析小麦族10种多年生禾草叶片的可消化性和矿物质含量.结果表明,供试草种叶片可消化性的高低顺次是:老芒麦>野大麦>航道冰草=加拿大披碱草>蒙农杂种冰草>诺丹冰草>肥披碱草≥新麦草=披碱草>蒙古冰草.叶片中7种矿物元素含量变幅为:Mg 0.21%～0.57%、Si 0.90%～3.31%、P 0.27%～0.3%、S 0.3%～0.0%、Cl 0.21%～0.52%、K1.44%～3.0%、Ca 0.42%～0.98%,草种间差异显著.     

Anther Culture Response in Perennial Ryegrass (Lolium perenne L.)

20 diploid clones from 7 varieties, and 10 tetraploid clones from 3 varieties of Lolium perenne were tested in replicated anther culture experiments. Embryos or calluses, were obtained from all clones, and plants were regenerated from all clones except one. The total yield of plants (albino and green plants) ranged from 0 to 61 plants per 100 cultured anthers among genotypes, and there was a general tendency for tetraploic genotypes to be more responsive. Viable green plants were obtained from 5 diploid and 7 tetraploid clones representing 2 and 3 varieties, respectively. Their origin from reduced pollen was confirmed by a haploid chromosome number in some regenerants and by homozygosity for isozyme loci in spontaneously chromosome doubled plants produced from heterozygous diploid donor plants. A large number of the plants were successfully established in the soil. For most donor genotypes, green plants were rare exceptions, but two diploic clones consistently produced 2.3 and 3.8 green plants per 100 cultured anthers, respectively. Estimates of variance components from replicates with greenhouse and field-grown donor plants showed that genotypes accounted for about 73 per cent of the total variation in yield of embryos/calluses, while only 14—15 per cent of the total variation was due to replicates. Hence at present, emphasis should be placed on die selection of high-response genotypes in material of high agronomic potential.     

Mild Drought Stress‐Induced Changes in Yield,Physiological Processes and Chemical Composition in Festuca,Lolium and Festulolium

The impact of mild drought stress (3 weeks at 40 % field water capacity) on yield, physiological processes, accumulation of proline and phenolic compounds and forage quality parameters in forage grasses was evaluated in pot experiments. During four different growing periods, the effects of water deficit were assessed in nine varieties from five species (Lolium perenne, Lolium multiflorum, Festuca pratensis, Festuca arundinacea and Festulolium braunii). All measured parameters were affected by drought stress in the different cuts. Photosynthesis, transpiration rate, stomatal conductance and dry matter yield were significantly lower in drought stress than under well‐watered conditions in all varieties. Higher water‐use efficiency was only observed during the first and fourth drought period, while this was not the case in the second and third. Mild drought stress significantly increased the content of proline, phenolic acid, flavonoids, water‐soluble carbohydrates and protein. All tested grasses showed also an increase of organic matter digestibility and cell wall digestibility under drought stress conditions.     

牦牛放牧率对江河源区混播禾草地上初级生产量及种间竞争力的影响

在江河源区2龄混播禾草草地(垂穗披碱草 星星草)上牦牛放牧试验结果表明: 随着放牧率的增加,在生长期内不同功能群地上净初级生产量和总地上初级生产量均出现了单峰曲线变化,即“S”型变化趋势; 总的地上净初级生产量和垂穗披碱草地上净初级生产量对放牧率的变化很敏感, 且随着放牧率的增加, 峰值出现日期提前; 其它禾草和星星草的峰值对放牧率的变化不很敏感;莎草类和杂草类对放牧率的变化比较敏感。随放牧率的增加, 地上现存量和总地上初级生产量的峰值下降, 且达到峰值的时间提前。在整个放牧期(植物生长期),重度放牧的RYT值均小于1,表明重度放牧使垂穗披碱草和星星草一直处于拮抗状态,其它各处理组在生长中后期也处于拮抗状态; 不同放牧率(包括对照)下垂穗披碱草的竞争力强于星星草, 垂穗披碱草因其高度和发达而较深的根系成为竞争的优胜者。     

24份加拿大牧草品种引种试验

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。     

5种冷季型草坪草的耐热性研究

通过生化培养箱模拟北京地区的高温高湿环境,对高羊茅（Festuca arundinacea）、多年生黑麦草(Lolium perenne)、匍匐剪股颖（Agrostis stolonifera）、草地早熟禾（Poa pratensis）和粗茎早熟禾(P.trivialis)这5种冷季型草坪草在热胁迫过程中的外观质量指标每株绿叶数、生长高度和生理生化指标叶片相对含水量、叶片相对电导率、叶绿素含量、超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性、过氧化物酶(POD)活性进行分析。结果表明,在昼夜35 ℃/30 ℃的高温下,随着胁迫时间的延长,5种草坪草叶片相对含水量下降,叶片相对电导率上升。叶片叶绿素含量在高温环境中变化趋势不一致,高羊茅、多年生黑麦草、草地早熟禾的叶绿素含量呈先上升后下降的趋势,而匍匐剪股颖和粗茎早熟禾则呈现出持续下降的趋势。随着高温胁迫时间的延长,5种草坪草的SOD、POD活性呈先上升后下降的变化趋势。CAT活性下降,且随着时间的延长,POD和CAT活性下降的幅度增大。在高温胁迫过程中,5种草坪草每株绿叶数和植株生长高度降低。 通过聚类分析可将5种草坪草大致聚为3个耐热级别：1级（相对耐热）高羊茅;2级（中等耐热）草地早熟禾、多年生黑麦草、匍匐剪股颖;3级（相对敏感）粗茎早熟禾。