早熟禾族3种基因型草坪草的染色体核型分析

通过对禾本科早熟禾族(Poeae)匍匐翦股颖(帕特putter)和多年生黑麦草(首相premier、焦点focus)3种草坪草染色体核型进行分析,结果显示,3种基因型材料的染色体均以中部着丝点和近中部着丝点染色体为主,都具有随体。匍匐翦股颖帕特体细胞染色体数目为30条,核型公式是2n=30=22m(2SAT)+2sm,核型不对称系数(AS.K%)55.2%,分类标准属于“2C”型;多年生黑麦草2个品种草坪草体细胞染色体数目均为14条,其中首相核型公式是2n=14=12m(2SAT)+2st,核型不对称系数58.0%,核型分类标准属于“2C”型;焦点核型公式是2n=14=6m(2SAT)+8sm,核型不对称系数63.05%,属于“2B”型。     

Impact of frost and plant age on compensatory growth in timothy and perennial ryegrass during winter

Two cultivars of each of two contrasting grass species, timothy ( Phleum pratense L.) and perennial ryegrass ( Lolium perenne L.), sown either in May or July, were sampled for dry matter (DM) weight of roots and herbage in late October (end of main growing season) and examined for regrowth when exposed to a frost treatment (−8 to −10°C in darkness for 48 h) in late January, early March and late April. The frost treatment caused compensatory root and herbage growth, and regrowth of roots in March and April was greater than regrowth of herbage. Early-sown plants had higher DM weights of roots and herbage than late-sown plants in October but had the lowest survival rate when exposed to the frost treatment in April. Compensatory growth of root and herbage in response to moderate frosts occurred in January and March in all cultivars, and in the most frost-resistant timothy cultivar in April. Concentration of total carbohydrates increased from October to March with the greatest increase in the most winter-hardy cultivar of each species, and then decreased in April. An indirect correlation between concentration of total carbohydrates and tolerance to moderate frost was indicated, and plant survival and ability for compensatory growth were also associated with differences in adaptation related to winter survival in the cultivars tested.     

Influence of different forage grasses on nitrate capture and leaching loss from a pumice soil

Nitrogen (N) uptake and loss in leachate from a pulse of ¹⁵N-labelled synthetic cow urine applied to a pumice soil were compared in a glasshouse lysimeter experiment among the grass species, Agrostis capillaris , Dactylis glomerata , Phalaris aquatica , Lolium multiflorum , L . perenne and a L . multiflorum/A. capillaris mixture. In addition, four L. perenne treatments investigated the effect of infection by Neotyphodium lolii strains. Leachate volumes and leachate nitrate concentrations were measured. At final harvest 24 weeks after sowing, dry matter (DM) mass of shoots and roots, plant N and ¹⁵N contents, soil residual mineral N, and root diameters and lengths were measured. Endophyte had no effect on plant or nitrate variables. Lysimeters planted with L . perenne (pooled endophyte treatments) leached 48 mg of NO₃-N compared with <3 mg N for the other grasses. Recovery of ¹⁵N was highest in A. capillaris (0·99), followed by D. glomerata and P. aquatica (0·89), the L . multiflorum / A. capillaris mixture (0·87), L . multiflorum (0·60) and L . perenne (0·44). Low ¹⁵N recoveries and high leaching losses from L . perenne were associated with low plant and root masses of DM and low rooting depth. High aerial mass of DM, root systems extending below 20 cm and high root masses of DM in lysimeters with A. capillaris , P. aquatica and D. glomerata contributed to a high rate of nitrate interception by these species and low leachate losses. The L . multifloru m/ A. capillaris mixture was intermediate between the two species for most of the variables measured.     

2个黑麦草品种SPAD值和叶绿素及粗蛋白含量的相关性研究

通过测定黑麦草(Loliumperenne)"长江2号"和"蓝天堂"2个品种间叶片的SPAD值、叶绿素含量和粗蛋白质含量,比较分析了这2个品种的SPAD值、叶绿素含量、粗蛋白质含量的差异以及三者之间的关系。研究结果表明,"长江2号"无论是SPAD值、叶绿素含量还是蛋白质含量都比"蓝天堂"高;这2个黑麦草品种的第1叶SPAD值、叶绿素含量和粗蛋白质含量都高于第2叶,但这2个品种的这3个性状差异不显著;"蓝天堂"和"长江2号"的SPAD值与叶绿素含量、粗蛋白质含量均呈显著正相关。     

6个多年生黑麦草品种酯酶和过氧化物同功酶比较研究

选取6个多年生黑麦草品种,利用聚丙烯酰胺凝胶电泳技术对它们的根和茎叶的酯酶及过氧化物同功酶进行了测定,将酶谱数量化,应用SPSS统计软件求出各品种间的遗传相异度,并进行了聚类分析。结果表明:(1)本研究中的4个同功酶图谱皆有多态性,可以鉴别供试的6个品种;(2)供试品种之间的Jaccard相异系数在0.3到0.9091之间。若以Jaccard相异系数0.50为阈值,可以将供试品种分为3群:雅晴和匹克为一群,凯琳特、顶峰和明星为一群,首相单独为一群;(3)Jac-card相异系数最低的为雅晴和匹克两个品种以及顶峰和明星两个品种,均为0.30,亲缘关系最近。而首相与其它品种亲缘关系最远。     

NaCl胁迫对黑麦草几种抗逆生理指标的影响

采用1%NaCl胁迫处理黑麦草,以未经NaCl胁迫的、在同样环境条件下生长的黑麦草为对照（蒸馏水处理）,分析检测处理5d内黑麦草几种抗逆生理指标的变化规律。结果表明：NaCl胁迫5d内黑麦草叶片MDA含量呈现先升高后降低的趋势;Pro大量积累;叶绿素含量于胁迫后第2d极显著升高,3d后呈下降趋势;SOD活性呈现先下降后升高的趋势;CAT和POD活性于胁迫后第2d显著增加后呈下降趋势;细胞膜透性急剧增加。结论：黑麦草能够对盐渍环境做出必要的响应,以维持正常的生理活动,从而表现出较强的耐盐能力。     

多花黑麦草不同品种草产量研究

本课题的总体目标是以区域试验和示范带动我国草种子的产业化生产,大幅度提高我国单位面积牧草及生态草种子的产量和质量,促进草种产业的起步与发展。对14个多花黑麦草品种进行品种比较试验,通过对参试品种物候期的观测、不同品种黑麦草鲜干草产量的测定及各品种不同时期刈割产量比较的研究,发现参试的十四个品种在本地区差异较为明显,从测定的各品种的各个数据来看,其中钻石T、海湾、特高表现较为突出,在生长势和产草量方面优于其它品种。故最适宜我区种植的多花黑麦草品种为钻石T、海湾、特高。     

建植第1年刈割对黑麦草+白三叶草地杂草空间格局的影响

栽培草地稳定性是近年来草地建植与管理的核心问题之一,其中草地抗杂草入侵是其稳定性的重要表现形式。本研究应用地统计学分析方法,分析了刈割处理下多年生黑麦草(Lolium perenne)+白三叶（Trifolium repens）混播草地杂草生物量空间分布的异质性。结果表明,不同刈割强度下,多年生黑麦草+白三叶混播草地入侵杂草地上生物量空间格局异质化程度及其相关范围变化比较明显。变异函数的基台值(C0+C)在不同刈割强度下的变化表明,在重度刈割条件下,杂草地上生物量空间分布异质性最高(12.530),对照条件下次之(4.751),轻度刈割条件下较低(4.557),中度刈割条件下最低(3.149)。变异函数的相关范围(A0)表明,在重度刈割条件下空间相关范围最大(1 004.1 cm),中度刈割条件下最小(122.1 cm),轻度刈割 (161.9 cm)和对照(219.1 cm)条件下居中。空间变异比分析表明,由空间自相关因素引起的空间异质性占主要部分(50.3%～93.5%)。空间分布格局图(Kriging map)分析进一步显示,不同刈割强度下多年生黑麦草+白三叶混播草地杂草地上生物量格局变化显著。     

Impact of effective microorganisms and other biofertilizers on soil microbial characteristics,organic‐matter decomposition,and plant growth

Incubation and pot experiments were conducted to investigate the impact of commercially distributed biofertilizers (effective microorganisms [EM], BIOSTIMULATOR, BACTOFIL‐A, and BACTOFIL‐B) on soil microbial‐biomass content and activity, net N mineralization in soil, and growth of Lolium perenne. According to the manufacturers, the products tested are based on microbial inoculants or organic growth stimulants, and are supposed to influence soil microbial properties and improve soil conditions, organic‐matter decomposition, and plant growth. In the incubation experiment (40 d, 20.6°C, 50% maximum water‐holding capacity), EM was repeatedly applied to soil together with different organic amendments (nonamended, chopped straw, and lupine seed meal). Under the experimental conditions of this study, no or only marginal effects of EM on organic C, total N, and mineral N in soil could be observed. In soil treatments without any organic amendment, EM suspension slightly enhanced microbial activity measured as soil CO₂ evolution. In soil with easily degradable plant residues (lupine seed meal), EM suspension had a suppressive effect on microbial biomass. However, comparisons with sterilized EM and molasses as the main additive in EM suspension showed that any effect of EM could be explained as a pure substrate effect without the influence of added living organisms. In the pot experiment with Lolium perenne (air‐conditioned greenhouse cabin, 87 d, 16.8°C, 130 klxh d^–1 light quantity), the products EM, BIOSTIMULATOR, BACTOFIL‐A, and BACTOFIL‐B were tested in soil with growing plants. The products were repeatedly applied for a period of 42 d. Within this study, no effects of the different biofertilizers on mineral N in soil were detectable. There were clear suppressive effects of all tested biofertilizers on microbial‐biomass content and activity. Comparisons with sterilized suspensions showed that the effects were not due to living microorganisms in the suspensions, but could be traced back to substrate‐induced processes.     

多年生黑麦草抗逆性研究进展

多年生黑麦草是一种优良的冷季型草坪草。介绍了近几年来黑麦草抗逆性的研究进展,概括了干旱、高温、低温、盐碱、重金属等对黑麦草的危害及植物体的抗逆性应答反应,列举了提高黑麦草抗逆性的措施。同时袁总结了黑麦草抗逆性研究中存在的问题,为进一步研究提供思路。