杀菌剂敌磺钠及植物生长调节剂对茭白孕茭的影响

以‘龙茭二号’为研究对象,通过在茭白植株不同生长发育阶段分别喷施杀菌剂敌磺钠和植物生长调节剂,比较分析其对茭白结茭的促进效果。对6个不同处理组合及对照材料的株高、内源激素含量变化及结茭情况的统计分析发现：喷施一定浓度的敌磺钠对茭白结茭具有明显的促进作用,以敌磺钠（标准浓度）＋营养液和敌磺钠（标准浓度）对茭白结茭产量的提高最为明显。植物生长调节剂处理能明显促进茭白早期植株生长,但对最终株高影响不大。采用间接酶联免疫法对茭白茎部3种激素（IAA、ABA和GA3）含量进行的比较分析表明：敌磺钠处理能够明显降低ABA含量,但对IAA和GA3含量没有明显影响;茭白结茭前ABA含量的降低可能有助于茭白结茭。     

内蒙古鄂尔多斯黄土丘陵沟壑区茭蒿种群结构及群落特征

对内蒙古鄂尔多斯黄土丘陵区不同生境中茭蒿种群结构和群落特征进行了研究。结果表明:茭蒿在条件恶劣的阳坡形成单优群落,种群稳定,在条件相对较好的阴坡与硬质早熟禾、假苇拂子茅共建形成群落,是一个增长型种群,而在条件优越的梁顶则是一个群落的伴生种;茭蒿在阴坡具有最大扩散范围的同时,其种群内个体间也产生了密度效应,阳坡种群扩散较阴坡差一些,梁顶植株基本呈现独立分布状态;表明茭蒿对资源重新分配后的黄土丘陵沟谷生境具有独特适应性,使得茭蒿成为黄土丘陵沟谷的专性"沟谷植物"。     

中国茭白在美国华盛顿地区的引种栽培研究

茭白是一种多年生水生植物,也是一种优良的中国特产蔬菜。介绍了将茭白引种到美国华盛顿地区后的生长、发育、产量和品质等方面的情况。同时将引种栽培过程中出现的优良性状也进行了报道：（1）此品种在该区域几乎不产生灰茭;（2）它在该地产茭期长达4－5个月;（3）表现出很强的孕茭性能;（4）这种植物能很好地适应华盛顿地区的气候条件。     

内蒙古鄂尔多斯黄土丘陵沟壑区茭蒿群落种间关系

对内蒙古鄂尔多斯黄土丘陵沟壑区不同群落中茭蒿种群格局及茭蒿生态位宽度和生态位重叠进行研究,结果表明:茭蒿种群在梁顶生境中随着撂荒恢复演替的进行,分布格局由随机分布转向小尺度聚集分布再转变为较大尺度聚集分布,与此同时种群空斑面积显著增加,种群领地减小;在沟谷生境中茭蒿种群则呈现典型的随机分布,种群空斑面积显著低于梁顶各群落,种群领地显著高于梁顶各群落.梁顶-沟谷生境梯度上,茭蒿的生态位宽度最大,表明其具有较强的资源利用能力,对环境的适应能力较强,可以广泛分布在梁顶和沟谷各种生境中;生态位重叠分析表明,茭蒿属于一个演替前期物种.     

诗意江湖茭草鲜

正"诗意江湖茭草鲜,集采雕胡忆先贤。秋风骤起菰羹好,乡味朝闻一梦牵。"这是笔者在家乡古淮河边,看到河中菰叶飘飘、紫穗轻垂的美景时而咏的一首小诗。家乡的水生蔬菜中,笔者最喜欢吃的,就是由菰变态发育而成的茭白。菰(Zizania latifolia(Griseb.)Turcz.ex Stapf)是禾本科(Gramineae)菰属(Zizania L.)的一种植物。分布于我国南北各地,主要产区在淮河流域及其以南地     

茭白籽粒的新贡献

茭白和茭笋,与水稻同属稻族,但隶属于菰属或茭白属(Zizania),美洲常把菰属植物称之为“野稻”或“水生稻”。在菰属植物中,大家最熟悉的是原产于东亚的落花茭白(Z.caduciflora),其因真菌寄生而膨大的嫩茎可供蔬食,我国各地均有栽培或野生。北美水茭白(Z.aquatica,=宽叶茭白Z.latifolia)和得克     

茭草和芦苇叶片光合与荧光特性对土壤持续干旱的响应

对茭草Zizania latifolia和芦苇Phragmites australi进行自然持续干旱处理,测定植物叶片光合作用特征参数和叶绿素荧光参数及相应的土壤水分含量,探讨茭草、芦苇叶片对土壤持续干旱胁迫的光合生理响应。随着土壤水分逐渐减少,茭草叶片净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)均先增大后减小,芦苇叶片的Pn、Tr、Gs均逐渐减小;茭草和芦苇叶片的胞间二氧化碳浓度(Ci)、光化学最大量子效率(Fv/Fm)、非光化学猝灭系数(NPQ)、水分利用率(WUE)、有效荧光产量(Yield)、电子传递速率(ETR)、光化学猝灭系数(qP)变化趋势一致,其中Ci逐渐增大,Fv/Fm、NPQ、WUE先增大后减小,Yield、ETR、qP逐渐减小。分析表明,当茭草和芦苇遭遇较严重干旱时,叶片Pn下降主要是非气孔限制因素导致;当生长基质(沙土)的田间持水量为19%,速效氮、磷、钾分别为28.14、2.25、25.76 mg·kg-1,pH 7.2时,茭草的干旱胁迫阈值在土壤含水量(2.17 ± 0.18)%和(1.66 ± 0.23)%之间,芦苇的干旱胁迫阈值在土壤含水量(1.84 ± 0.17)%和(0.25 ± 0.07)%之间。     

茭草叶饲养草鱼效果

茭草又称野菰(Zizania latifolia),广泛分布于我国内陆水体,在湖北省洪湖中,茭草是沿岸呈环带状分布的优势挺水植物。由于该湖年平均水深仅1.35米,底泥肥沃,适于茭草生长繁殖,群落面积已达22.7万亩,占该湖总面积的42％。每年生产茎叶干物质达15万吨以上,但绝大部分废弃分解还湖,未被充分利用。根据洪湖大水面水体生物生产力综合开发利用研究计划,我们对茭草不同器官化学成分分析的结果证明,茭草乃优质饲料,茭草叶含粗蛋白16.8—18.7％,其必需氨基酸组成比例与草鱼肌     

不同茭白品种中菰黑粉菌的鉴定及ISSR多态性分析

菰黑粉菌是茭白的内生真菌,对茭白孕茭具有重要作用。本文分离获得了13个不同茭白品种和孕茭表型的菰黑粉菌菌株(M‐T型和T型),ITS序列鉴定分析发现:13个菌株都属于菰黑粉菌,它们的ITS序列仅在ITS1序列区间存在3个碱基位点的变异;基于ISSR技术比较分析了菰黑粉菌菌株间的遗传多态性,聚类分析表明,菰黑粉菌菌株的遗传多态性与茭白栽培特点及孕茭表型密切相关,本研究有助于茭白种质资源的鉴定及保护,并为茭白田间栽培管理提供了技术支持和理论依据。     

茭白膨大期间游离氨基酸含量的变化

本试验测定了两熟茭白(Zizania latifolia )品种“广益”茭秋茭膨大期间肉质茎中游离氨基酸含量的动态变化。从“孕茭”始期开始,每4天取20株膨大肉质茎混匀。共测定6次。游离氨基酸用4％磺基水杨酸提取,然后用Waters-244型高压液相色谱仪分析。主要结果如下:1.茭白膨大过程中,所测得的18种游离氨基酸以天门冬氨酸、丝氨酸、丙氨酸、酪氨酸和组氨酸含量较高,而蛋氨酸和甘氨酸的含量相对较低,其它氨基酸含量中等。天门冬氨酸、苏氨酸(包括天门冬酰胺和谷酰胺)一直呈增加趋势。而丝氨酸谷氨酸甘氨酸丙氨酸缬氨酸酪氨酸和精氢酸在前期提高.后期下降:蛋     

Digitaria sanguinalis seedling development pattern: Relationship with seed origin

In the context of a long-term study of the pathosystem Digitaria sanguinalis–Ustilago syntherismae, seeds were collected over several years from a naturally infested field. Two different patterns of germination were found depending on the embryonic organ that first emerges: radicle or coleoptile. The mean frequencies of each pattern of germination were obtained in sets of seeds from non-smutted field plants of five consecutive years, and in a set of seeds belonging to the offspring of partially smutted field plants. The percentage of seeds showing radicular germination ranged from 54% to 69% in the field-collected lots, but it was only 1% in the offspring of partially smutted plants. Furthermore, while seeds with a radicular pattern reached 63% germination 43.5 hours after imbibition, the seeds with a coleoptilar pattern needed 101.5 hours to reach the same percentage. The effect of the amount of water during the imbibition period was also tested in two sets of seeds of different origin. There were no significant differences attributable to this factor, even in the levels of the factor that simulate flooding. We discuss the importance of the different germination behaviour observed in relation to the U. syntherismae infection process.     

Modification of seedling growth of triticale and barley by seed-applied chlormequat

Seeds of triticale and barley were soaked in a range of dilutions of chlormequat. Germination was monitored and the growth of seedlings assessed for up to five weeks. Some concentrations of chlormequat produced seedlings with significantly more leaves on the main stem, more primary tillers, a greater leaf lamina area and a higher shoot dry weight. It is argued that these modifications could lead to an increased yield potential.     

内蒙古高原四种针茅种群年龄与株丛结构的研究

用样带法调查了内蒙古高原4种针茅(StipaL.)的年龄结构,并将其年龄划分为5个阶段:幼苗、幼龄、成年、老龄前期和老龄期。结果表明:幼苗对种群年龄结构和动态有较大的影响,针茅幼苗的存活率通常很低,而成年株丛的存活率较高,株丛的实际寿命很长,老龄株丛在种群中占有较大的比例。4种针茅中大针茅(S.grandisP.Smirn.)和克氏针茅(S.kryloviiRoshev.)的幼苗比例较高,从贝加尔针茅(S.baicalensisRoshev.)群落到小针茅(S.klemenziiRoshev.)群落种群中幼龄和成年株丛比例呈下降的趋势,而老龄株丛比例呈增加的趋势;针茅属植物在株丛水平上的动态主要表现为株丛的破碎与枝条自疏过程,以及株丛生殖枝数量和营养枝生物量的波动,幂函数模型Y=aXb可以对株丛的枝条自疏过程进行定量描述     

Study on Age and Bunch Structure of Four Stipa Species in Inner Mongolia Plateau

The age status of four Stipa L. species, S. baicalensis Roshev., S. grandis P. Smim., S. krylovii Roshev., and S. klemenzii Roshev. in Inner Mongolia plateau was analyzed using a transect sampling method. The ontogeny of Stipa species was divided into five stages: the seedling, juvenile, reproductive, presenile, and senile. Dynamics of the population age speetra were determined mainly by the appearance of new individuals and their death rate. The survival rate of the seedlings was very low while that of file adults was high. The considerable longevity of bunch life allowed the old individuals to accumulate in the population. Both S. grandis and S. krylovii had higher proportion of seedlings than others. The proportion of the juveniles and the reproductives in the population decreased from S. baicalensis community to S. klemenzii community, but the old individuals including the preseniles and the seniles showed a reverse pattern. The aging process occurred in bunch level was characterized by the fragmentation of bunch and the within-bunch- self-thinning of the tillers. The process of within-bunch-self-thinning can be described by power equation Y: aXb. Meanwhile as a response to enviroument changes especially to the fluctuation of annual precipitation and its seasonal distribution both the numbers of reproductive shoots and vegetative shoot mass within a bunch were variable.     

知母分蘖一步法快速繁殖体系的初步构建

以知母分蘖为试材,对知母的一步法快速繁殖体系进行了初步研究。结果表明,知母分蘖直接再生植株的最佳培养基是MS+KT 1 mg/L+NAA 0.5 mg/L;知母分蘖愈伤组织诱导和再生的最佳培养基是MS+KT 2 mg/L+NAA 0.5 mg/L。本实验构建了知母分蘖的一步法快速繁殖体系,为知母试管苗的工厂化生产提供了理论和技术基础。     

Density‐related effects on the infectivity and aggressiveness of a sterilising smut in a wild population of Digitaria sanguinalis

Understanding host–pathogen evolutionary dynamics needs characterisation and quantification of processes occurring at many spatiotemporal scales. With this aim, the effects of smut on a naturally infected population of the summer annual Digitaria sanguinalis were followed for 4 years in an uncropped field. The main purpose of the study was to quantify the effects of within‐population density on the infectivity and the aggressiveness of the pathogen in a range of densities that occurred naturally. The infectivity‐related variable measured was the proportion of smutted plants at the end of each growing season; proportions were analysed using a generalised linear model with a binomial distribution considering the year, the density and their interaction as effects. The aggressiveness‐related variables chosen were the number of smutted inflorescences per plant and per area, obtained over the last 2 years; they were analysed by means of ancova considering disease status (seeded or smutted), year, density and all the interactions between them. Although the disease is monocyclic, results showed clearly that infectivity increased with plant density. The number of inflorescences per plant was 1.5 times higher in smutted plants than in healthy plants throughout the range of densities. This variable declined when density increased, but as the infectivity increased at a higher rate, the aggressiveness also increased with density. The surprising results on infectivity are discussed in the context of current knowledge of plant–pathogen interaction dynamics, as well as neighbour effects on pathogen aggressiveness. Moreover, the results could be useful to develop weed biological control strategies.     

替考游动放线菌发酵生产替考拉宁的动力学模型

根据丝状菌的生长机理和替考拉宁的发酵动力学特征提出了一个简化的形态学结构模型,并用于描述替考拉宁的发酵过程．模型将菌丝分为三种类型：具有生长活性的菌丝(G)、具有代谢活性的菌丝(N)和失活的菌丝(D)．菌丝G可因失去生长活性而转化为菌丝N,菌丝N可因失去代谢活性而转化为菌丝D．菌丝G与菌丝生长有关,而菌丝N则与替考拉宁的合成有关．该模型能较好地描述替考拉宁发酵过程、     

A comparison of spike and spikelet survival in mainstem and tillers of barley

Initiation and abortion of spikelet primordia on primary tillers and mainstem were compared for plants of spring barley, Maris Mink, sown on two sowing dates during 1983, in plots at the Scottish Crop Research Institute (SCRI) and at Long Ashton Research Station (LARS). Sowing date had no effect on the number of spikelets initiated on either mainstem or surviving tillers and many more spikelets were initiated on equivalent stems at LARS than at SCRI but more spikelets aborted at the former site. The final number of spikelets produced was eventually similar. Spikelet abortion was complete by anthesis and coincided with the period of rapid stem and rachis elongation and with the time over which tiller death occurred. Despite the fact that plants at SCRI produced fewer fertile tillers they outyielded those at LARS because much heavier grains were produced on the mainstem and tiller 1 of plants at the Scottish site. An interval of 2 wk between sowing had only small effects on the components of yield.     

白蚁巢上生长的子囊菌——黑柄炭角菌的深层培养及其生理研究

黑柄炭角菌Xylaria nigripes(K1.)Sacc.是著名的滋补药用真菌,尤其是菌核部位生长在白蚁废弃的蚁巢中,生态条件特殊,资源稀少,研究和开发该菌具有重要意义。为了提高黑柄炭角菌菌丝体和多糖的产量,以便于组织工业化生产,本文探索了该菌的营养条件,测定其生长过程中菌丝体和多糖形成的动态变化,并研究了酯酶同工酶谱和多糖含量变化的相关性。结果表明:在深层培养时,碳源以葡萄糖、淀粉最佳;花生、黄豆、蛋白胨是适宜菌丝生长的良好氮源;Mg~(2+),Zn~(2+)等是其生长的必需元素;有机酸中仅柠檬酸对其菌丝生长有促进作用,在蚁酸影响下,pH值为4.0时,菌丝生长受抑制。在上述实验基础上,进行了产多糖和菌丝体的适宜培养基筛选试验,在适宜条件下,能培养出密集、白色、均匀的菌球和丰富的多糖,经4天培养的培养液中粗多糖量可达15.35g/L,菌丝干重为26.89g/L,符合了工业化生产要求。该菌的菌丝体酯酶同工酶谱较稳定,均为二条酶带,但它们的酶活性有所不同,与菌丝体生长的天数有关。并与多糖含量变化具有一定关系。     

The Growth and Survival of Severely-shaded Tillers in Lolium perenne L.

The effect of shading a single tiller to below its compensationpoint for a period of 5 weeks in vegetative plants of Loliumperenne L. cv. S23, was studied in two different experimentseach employing two light regimes, one of which was common toboth experiments. In the first experiment tillers in the axils of the first leafwere shaded three weeks from appearance at both 40 and 70 Wm^–2. None of the shaded tillers died and they continuedto produce new leaves and increase in dry weight but at a reducedrate. In the second experiment, tillers with one emerged leafin any leaf axil position were shaded at 70 W m^–2 andin a treatment in which light was reduced to 13 W m^–2after initial growth at 70 W m^–2. As in the first experimentall shaded tillers survived at 70 W m^–2 but in the 70 13 W m^–2 transfer regime all shaded tillers died. In the second experiment shaded tillers in both light regimeswere supplied with ¹⁴C-assimilate by translocation from theremainder of the plant but in the 70 13 W m^–2 the initialsupport was withdrawn within 5 weeks of shading. The results are discussed in terms of the physiological relationshipsbetween the tillers of the grass plant. Lolium perenne L., growth of tillers, survival of tillers, effect of light