扁穗雀麦种子休眠机理的初步研究

扁穗雀麦种子形态成熟后15 d对其进行质量评定,结果表明,其千粒重为11.6 g,在常温(25～30℃)下种子发芽率为15.5％。3个月后,通过几种不同的处理,测定其处理后的发芽率,结果表明对照发芽率为35％,较15 d试验种子发芽率明显提高,说明其休眠和种子收获后的贮存时间相关,随着贮存时间的延长其休眠程度下降。KNO_3处理种子发芽率提高了6％,土床培养提高了23％,灭菌片+KNO_3处理提高了25％;H_2SO_4、灭菌片和H_2O_2均不同程度地抑制了扁穗雀麦种子的发芽,分别降低了31.25％、10％和30％。这说明种子的休眠和种子内抑制物的存在具有密切关系,但具体抑制物的种类和存在部位有待进一步研究。     

A plant ideotype for Bromus inermis Leyss. in Western Canada

Summary This study relates the yield of two harvests of Bromus inermis Leyss. to tiller type and morphology. Tillers were classified as being nonelongated, elongated and headed. At four times during the growing season, observations were made of tiller density; individual tiller weight; leaf number, area and weight; stem length, area and weight; leaf to stem ratio; specific leaf weight; head area and weight.Results showed that there was a pattern of tiller control over yield which was different for each of the two harvests. Stem characters contribute more to yield than leaves. Growth, early in the season, had a prominent effect on yield of the first harvest and also influenced the second harvest. Height at the time of each harvest was highly predictive of yield of the respective harvests. A morphological ideotype for bromegrass harvested twice in a season was described.     

Estimating the genetic relationship of hybrid bromegrass to smooth bromegrass and meadow bromegrass using RAPD markers

The two most widely grown bromegrass species in North America are smooth bromegrass, a hay type grass, and meadow bromegrass, a pasture type grass. Hybrid populations between these two species have been developed through hybridization and recurrent selection. The objective of this study was to determine the genetic relatedness of the hybrid bromegrass population S‐9073M to its parental populations using random amplified polymorphic DNA (RAPD) markers and to determine genetic variation within and between populations. Individuals from each of the three populations were genotyped at 43 polymorphic RAPD loci. One of the RAPD fragments was meadow bromegrass‐specific. Cluster analysis showed three groups representing the two parental populations and the hybrid population. An analysis of molecular variance (AMOVA), showed that the hybrid population had the highest within‐population variation, followed by meadow bromegrass and smooth bromegrass. The interpopulation genetic distance (phi‐statistic =Φ_st) was highest between meadow and smooth bromegrass and lowest between smooth and hybrid bromegrass. The hybrid population was genetically intermediate to smooth bromegrass and meadow bromegrass, but closer to smooth bromegrass, possibly reflecting the selection criteria used in the development of this hybrid.     

无芒雀麦叶组织物质周转规律及其与草地管理的关系

对无芒雀麦叶组织物质周进行了研究，结果表明，在生长期无芒雀麦净叶数和净叶伸长生长符合抛物线变动规律，叶累积死亡和累积枯萎长度按直线规律增长，根据植物种群生态学生物统计分析原理，还探讨了叶组织周转规律与草地合理利用的关系。     

无芒雀麦-污泥系统中泥/土不同比例对PAHs修复效果的影响

城市污水处理厂污泥中含有较高浓度的有毒有害物质多环芳烃(PAHs),且污泥产量大,如果不经过处理直接农业利用或堆放会导致土壤和作物的污染。本研究利用污泥和土壤不同配比组合(W0%,泥土比0∶1;W25%,泥土比1∶3;W50%,泥土比1∶1;W75%,泥土比3∶1;W100%,泥土比1∶0)的盆栽试验,探讨无芒雀麦-污泥系统对污泥多环芳烃的修复效果。研究结果表明,随污泥含量增加对无芒雀麦株高的影响差异不明显,而生物量却呈现出明显的上升趋势。无芒雀麦对污泥的耐受性表现良好;无芒雀麦对泥/土组合14种PAHs的吸收总量以W100%处理最高,且对3环、4环多环芳烃的吸收量比其他环数优势明显;在不同泥/土组合处理下,无芒雀麦-污泥系统对泥/土14种PAHs总量的去除率在W50%、W75%、W100%处理间没有明显差异,以W75%组合去除率为最高,达85.4%。且含有污泥的所有组合对高环芳烃Pyr、Chry、BaA、BbF、BkF、BaP、InP单体的去除优势表现非常突出,均达到80%或90%以上。综合考虑无芒雀麦的生长状况、吸收量及去除率认为,将耐抗性和去除率高的无芒雀麦作为优选植物资源直接用于城市污泥PAHs的修复是可行的,且以泥土比3∶1为最佳修复组合。     

混播比例对苜蓿青贮品质的影响

[目的]研究不同比例的无芒雀麦与紫花苜蓿混播对青贮效果的影响。[方法]试验设5个处理,即紫花苜蓿单播、无芒雀麦单播、紫花苜蓿＋无芒雀麦以50％＋50％、60％＋40％和70％＋30％比例混播,分析各处理青贮材料的pH值、CP、NDF、ADF、乙酸、丁酸、乳酸和总酸的变化,研究无芒雀麦与紫花苜蓿不同比例混播对青贮品质的影响。[结果]与单播苜蓿相比,混播可以显著降低青材料的pH值（P〈0．01）、NH3．N／TN值（P〈0．01）和丁酸含量（P〈0．01）,有利于保存青贮物的营养成分。混播还可提高青贮产物中乙酸、乳酸和总酸的含量（P〈0．01）,从而提高苜蓿青贮品质。[结论]以混播处理A（苜蓿50％＋无芒雀麦50％）效果最好,pH值,NH3-N/TN的含量最低,乳酸含量和综合评分最高。     

无机磷溶解菌的分离筛选及其对扁穗雀麦生长的影响

对扁穗雀麦根际溶磷微生物进行分离筛选,测定其溶磷、分泌IAA能力及对扁穗雀麦的促生效果。结果表明,不同菌株对不同无机磷底物具有选择性,以磷酸钙为磷源时,筛选的溶磷菌株都有溶磷活性,其中Br17的溶磷活性最高;以磷酸铝为磷源时,只有Br1、Br7与Br8具有溶磷活性,其中Br7溶磷活性最高。IAA测定结果显示Br4、Br8、Br17与Br24具有较强IAA分泌能力,添加生长素前体物质色氨酸时菌株分泌IAA能力增强。对培养基pH分析发现,筛选的8株溶磷菌株都为产酸型微生物。将纯化后的溶磷菌接种到扁穗雀麦无菌苗,对根长、根数、株高以及生物产量等性状考察发现接种Br8、Br13、Br17与Br24菌株对扁穗雀麦的根系影响较大,主要表现为主根变短,根数变多。接种Br7、Br8、Br13与Br24菌株促进扁穗雀麦株高增高、产量增加。综合分析,Br24在贵州地区的应用潜力最大。     

雀麦发生与防治的媒体摄制技术

多媒体是加大宣传与推广雀麦防治技术的一项重要措施。本文结合近3年来的试验、示范和多年媒体的摄制经验,就雀麦的发生与防治的多媒体摄制技术进行了介绍。     

云南地区扁穗雀麦繁殖对策研究

对云南野生种牧草扁穗雀麦的繁殖对策进行了初步研究,结果表明:有性繁殖和营养繁殖效果都很好,种子产量可以达到270.00 g/m2,且种子发芽率在无任何处理的情况下也能达到80%以上,总繁殖效力平均为34.24%。扁穗雀麦有性繁殖苗期生长缓慢,生长速率为0.361 cm/d,但分蘖以后生长速率加大,抽穗开花期达最大;扁穗雀麦营养繁殖成活率较高,为89.7%,生长速度比有性繁殖快,并且随植株长大,生长速率呈下降趋势;种子产量随地上生物量的增加而增加。     

奇台无芒雀麦穗肿病防治

无芒雀麦穗肿病以无芒雀麦瘤瘿螨为病原，侵食小穗所致，对种籽生产威胁大。良种繁育体系、早春重复放牧、早春火烧茬地、早春和晚秋灌水、轮作倒茬、深翻、浸种和药剂防治，均得到显著效果。