小麦族6种根茎型牧草叶表皮气孔特性与抗旱性的研究

本文对小麦族 6种根茎型牧草叶的气孔特性与抗旱性的关系进行了研究 ,结果表明 :6种禾草间气孔特性存在着基因型的本质差异 ;赖草属中 ,赖草叶对水分的蒸腾、气体交换的调控功能强于羊草和大赖草 ,其抗旱性强 ;在偃麦草属中 ,中间偃麦草叶的水分的蒸腾、气体交换的调控功能弱于其他 2种 ;在同种不同品种中 ,巴顿硬叶偃麦草叶的抗旱性强于茹莎娜硬叶偃麦草 ;6种禾草中 ,赖草属植物抗旱性强于偃麦草属植物。     

偃麦草属(Elytrigia Desv.)3种牧草营养器官解剖结构与抗旱性的研究

本文对偃麦草属 3种牧草进行了营养器官解剖结构的研究 ,结果表明营养器官的抗旱结构特性非常明显 ,表现在 :维管束数目多 ;靠近内皮层的 2 -3层皮层薄壁组织细胞 ,从内向外 ,由小到大呈辐射状排列 ;根茎的皮层薄壁组织环较宽 ,茎无色薄壁贮藏组织面积增大 ;泡状细胞的列数增多 ;叶肉细胞呈栅栏状 ,大型维管束两端形成较宽的维管束鞘延伸区 ,均为C3 植物。 3种牧草中 ,中间偃麦草的旱生特性较其他两种明显 ;巴顿硬叶偃麦草较茹沙娜硬叶偃麦草抗旱。     

我国几种禾谷类植物上Xanthomonas campestris致病变种的研究

 从我国新疆、内蒙、西藏、北京和山东等省区的小麦、大麦、野黑麦、冰草、偃麦草和雀麦上分离到13个黑颖病菌株,在苗期、分蘖期和孕穗期,喷雾接种16属27种禾本科植物,对其中感病的6属15种植物和燕麦又做注射接种。根据各个菌株对小麦、大麦、黑麦、冰草、偃麦草和雀麦的致病性差异,初步将其划分三个致病变种:1.禾谷类致病变种[X.campestris pv.cerealis (Hagborg) Dye.]:包括7个菌株,自然条件下发生在冰草、雀麦和偃麦草上;人工接种还可侵染小麦、大麦和黑麦。2.小麦致病变种(X.campestris pv.undulosa):包括4个菌株,自然条件下发生在小麦上,人工接种可侵染大麦和黑麦,但有一个菌株注射接种能轻度侵染雀麦。3.大麦致病变种(X.campestris pv.hordei):包括2个菌株,自然条件下发生在大麦上,注射接种能轻度侵染偃麦草。13个菌株喷雾接种猫尾草、早熟禾、画眉草、马唐、狗尾草、稗草、披碱草、羊茅草和水稻、均不侵染。     

三个小麦野生近缘种抗条锈性传递的初步研究

 以当前小麦条锈病菌的优势小种条中29号、30号和31号测定了小麦近缘植物长穗偃麦草、簇毛麦和华山新麦草及其各自与小麦的杂交后代的抗条锈性。试验结果表明,3个小麦近缘植物均含有宝贵的抗条锈基因,此类基因具有较强的传递性能,可在小麦遗传背景下高度表达,表现出良好的抗条锈性能,具有广阔的应用前景。     

三个小麦野生近缘种抗条锈性传递的初步研究

以当前小麦条锈病菌的优势小种条中２９ 号、３０ 号和３１ 号测定了小麦近缘植物长穗偃麦草、簇毛麦和华山新麦草及其各自与小麦的杂交后代的抗条锈性。试验结果表明,３ 个小麦近缘植物均含有宝贵的抗条锈基因,此类基因具有较强的传递性能,可在小麦遗传背景下高度表达,表现出良好的抗条锈性能,具有广阔的应用前景     

抗白粉病小麦-中间偃麦草双体异附加系的鉴定

 对从中间偃麦草与普通小麦品种烟农15杂交后代(BC₃F₆)中选育的双体异附加系山农Line15的形态学、白粉病抗性、细胞学、基因组荧光原位杂交(GISH)及RAPD进行鉴定分析.结果表明它的主要形态性状介于双亲之间;白粉病抗性鉴定结果表明山农Line15对白粉病高抗近免疫;根尖细胞染色体数目为2n=44,PMC MI染色体构型为2n=22Ⅱ;以中间偃麦草总基因组DNA为探针的基因组荧光原位杂交(GISH),结果表明山农Line15是在小麦的遗传背景中附加了2条中间偃麦草染色体,为小麦-中间偃麦草双体异附加系;遗传分析表明山农Line15的抗白粉病基因基本上可以确定来源于中间偃麦草的染色体;RAPD分析表明:在供试的120个随机引物中有1个引物S170(-5'-ACA ACG CGA G-3'-)能在山农Line15中稳定地扩增出特异带型,可以作为山农Line15所附加的中间偃麦草染色体的特异分子标记.     

抗白粉病小麦——中间偃麦草双体异附加系的鉴定

对从中间偃麦草与普通小麦品种烟农15杂交后代(BC3F6)中选育的双体异附加系山农Line15的形态学、白粉病抗性、细胞学、基因组荧光原位杂交(G ISH)及R A PD进行鉴定分析。结果表明,它的主要形态性状介于双亲之间;白粉病抗性鉴定结果表明,山农Line15对白粉病高抗近免疫;根尖细胞染色体数目为2n=44,PM CMⅠ染色体构型为2n=22Ⅱ;以中间偃麦草总基因组D N A为探针的基因组荧光原位杂交(G ISH),结果表明,山农Line15是在小麦的遗传背景中附加了2条中间偃麦草染色体,为小麦—中间偃麦草双体异附加系;遗传分析表明,山农Line15的抗白粉病基…     

抗白粉病小麦-中间偃麦草染色体小片段易位系的选育与鉴定

 对从普通小麦与中间偃麦草杂交后代中选育的一个抗白粉病新品系(AF-1)进行了形态学、细胞学和原位杂交(GISH)鉴定。结果表明:AF-1具有与小麦亲本相似的农艺性状,根尖细胞染色体数目为2n=42,花粉母细胞减数分裂中期(PMCMI)染色体构型为2n=21Ⅱ,且未见其他结构变异,细胞学上十分稳定。GISH结果表明,AF-1为中间偃麦草与普通小麦的一个小片段易位系,易位点位于一对染色体臂的中部偏着丝粒的位置。结合抗病调查结果,推断该片段上携带了一个来自偃麦草的抗白粉病基因。该片段可能是在杂种早期世代通过部分同源染色体配对或者单价染色体错分裂而形成的。     

远中5号中来自天兰偃麦草的一个染色体组对三种锈病的抗性作用

 八倍体小偃麦具有偃麦草的抗锈、大穗、多花等优良性状,是小麦育种中的重要种质资源。本研究通过体细胞染色体组型的观察和比较推断八倍体的小偃麦品种远中5号比其变异系多一组来自天兰(中间)偃麦草(Agropyron glaucum)的特有的染色体组EE或FF。远中5号与其变异系之间对三种锈病的抗性差异表明:远中5号对条锈菌七个生理小种(条中22、23、25、26、27、28、29)和对秆锈菌六个生理小种(21C3、34、34C1、34C2、34C4、119)的抗病基因由来自天兰偃麦草的EE或FF染色体组所携带,而在AABBDD染色体组上存在着对叶锈菌四个生理小种(叶中3、4、20、38)的抗病基因。在EE或FF染色体组上也可能含有抗叶锈病的基因,至少由于EE或FF染色体组的存在大大地提高了远中5号对叶锈病的抗病性。     

七种与小麦近缘的野生植物对禾谷缢管蚜抗性的生化机制

研究了7种与小麦近缘的多年生野生植物长穗偃麦草Elytrigia elongata、费尔干偃麦草E. ferganensis、垂穗披碱草Elymus nutans、华山新麦草Psathyrostachys huanshanica、竖立鹅观草Roegneria japonensis、鹅观草R. kamoji和R. tsukushiensis对禾谷缢管蚜Rhopalosiphum padi抗性的生化机制.禾谷缢管蚜内禀自然增长率(rm)与叶片游离脯氨酸和蛋氨酸含量呈极显著和显著正相关,其逐步回归方程为:rm=-0.0198 0.1930X脯氨酸** 0.3350X蛋氨酸* ;总酚含量与禾谷缢管蚜内禀自然增长率无显著相关关系;丁布含量与内禀自然增长率呈极显著的负相关(r=-0.941**,p<0.01).低含量的游离脯氨酸﹑蛋氨酸及高含量的丁布是小麦近缘多年生野生物种抗蚜的重要生化因子.     

Partitioning evapotranspiration of desert plants under different water regimes in the inland Heihe River Basin,Northwestern China

Plant transpiration (T), soil evaporation (E), and the proportion of evaporation in evapotranspiration (ET), and their patterns of change were analyzed in a desert habitat along the middle and lower reaches of the Heihe River Basin, Gansu Province, China. Typical desert plants with different life forms were selected and small lysimeter observations were conducted; various species were measured under two soil water regimes using 50% (FC 50%) and 20% (FC 20%) of field capacity in 2 years. Under the FC 50% treatment the observed ratio of T to ET of desert plants was less than one-third, making the ratio of E to ET greater than two-thirds; the proportion of T to ET of desert plants increased to above 40%, and that of E declined to below 60% under the FC 20% treatment. The lowest T of desert plants was 130–140 mm based on the plant crown projection area. The characteristic coefficient of ET of desert plants was twice that of the characteristic coefficient of transpiration. This study found that when ET was measured for the same desert plant species growing in different regions, the ET differed significantly (P < 0.05) under the same water regimes; when comparing different plant species in the same region no obvious differences in the transpiration water requirement and ET were observed. The proportion of T in ET increased significantly and E in ET decreased markedly (P < 0.05), if the soil moisture content declined to where the plants experienced water stress.     

Influence of herbicides on photosynthetic activity and transpiration rate of intact plants

The effect of various herbicides on photosynthesis, respiration and transpiration of intact plants has been studied in a routine assembly. Simultaneous measurements were made under different experimental conditions in four small plant chambers, in which the shoots of various plant species can be accommodated. The herbicide is applied during measurement, so that the effect can be related to the photosynthetic activity of the same plants before treatment. The selectivity of various herbicides was studied by determining the capacity of a plant species to inactivate a herbicide absorbed by the roots. These and other differential effects of various herbicides on photosynthetic activity of different plant species coincide with the selective properties in the field. Such differences are also observed after leaf sprayings. The duration of the experiments is kept short. Bean plants were studied under various experimental conditions of air humidity, light intensity and temperature resulting in different transpiration rates. The decrease in photosynthetic activity owing to the presence of a herbicide in the nutrient solution at a standard concentration was more rapid at the higher transpiration rates. The total transpiration during treatment up to 50% inhibition of photosynthesis was constant under the various experimental conditions. Specific inhibitors of the photosynthetic process had a more pronounced effect on the photosynthetic activity than on transpiration rate. Some other herbicides affect transpiration as well as photosynthesis.     

Strobilurin fungicides induce changes in photosynthetic gas exchange that do not improve water use efficiency of plants grown under conditions of water stress

The effects of five strobilurin (beta-methoxyacrylate) fungicides and one triazole fungicide on the physiological parameters of well-watered or water-stressed wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and soya (Glycine max Merr.) plants were compared. Water use efficiency (WUE) (the ratio of rate of transpiration, E, to net rate of photosynthesis, A(n)) of well-watered wheat plants was improved slightly by strobilurin fungicides, but was reduced in water-stressed plants, so there is limited scope for using strobilurins to improve the water status of crops grown under conditions of drought. The different strobilurin fungicides had similar effects on plant physiology but differed in persistence and potency. When applied to whole plants using a spray gun, they reduced the conductance of water through the epidermis (stomatal and cuticular transpiration), g(sw), of leaves. Concomitantly, leaves of treated plants had a lower rate of transpiration, E, a lower intercellular carbon dioxide concentration, c(i), and a lower net rate of photosynthesis, A(n), compared with leaves of control plants or plants treated with the triazole. The mechanism for the photosynthetic effects is not known, but it is hypothesised that they are caused either by strobilurin fungicides acting directly on ATP production in guard cell mitochondria or by stomata responding to strobilurin-induced changes in mesophyll photosynthesis. The latter may be important since, for leaves of soya plants, the chlorophyll fluorescence parameter F(v)/F(m) (an indication of the potential quantum efficiency of PSII photochemistry) was reduced by strobilurin fungicides. It is likely that the response of stomata to strobilurin fungicides is complex, and further research is required to elucidate the different biochemical pathways involved.     

抑制蒸腾对番茄生长及植株镁、钾、钙吸收的影响

北方日光温室生产中蔬菜频繁出现营养失调,导致产量、品质明显下降,为探明番茄养分失调是否与蒸腾受到抑制有关,通过2个水培试验分别研究了短期（24 h）及长期（24 d）喷施蒸腾抑制剂对中杂9号和改良毛粉两个番茄品种蒸腾、生物量和镁、钾及钙养分吸收的影响。结果表明：短期（24 h）抑制蒸腾,蒸腾量减少20.6%、镁吸收量减少4.5%,蒸腾与番茄镁吸收呈显著正相关关系;长期（24 d）喷施蒸腾抑制剂减少了番茄生长量、光合速率,蒸腾量减少47.5%时镁吸收量减少17.1%,钾、钙吸收量分别减少12.9%和44.1%,不同番茄品种间对钾、钙、镁的吸收无显著差异。可见,抑制蒸腾减少番茄对镁、钾、钙的吸收。北方日光温室冬茬栽培中高湿、寡照等不良环境因子会诱导番茄营养失调症的发生。     

荒漠植物蒸腾速率的变化与组织含水量的关系

荒漠植物在长期适应环境过程中表现出相应的水分生理适应性。本文在塔克拉玛干沙漠腹地通过对两年不同时段不同植物的蒸腾速率和植物组织含水量的测定结果进行统计分析 ,结果表明 ,蒸腾速率的大小与植物组织含水量的多少无关     

Effects of EPTC, fluorodifen and monuron on transpiration and photosynthetic oxygen output in Eupatorium odoratum plants

The influence of foliar sprays of EPTC, fluorodifen and monuron on transpiration and photosynthetic oxygen output of Eupatorium odoratum plants is demonstrated. Foliar sprays with 100 ppm EPTC or monuron led to a significant decrease in transpiration for a continuous period of 14 days. Treatment with 100 ppm fluorodifen led to a noticeable increase in transpiration during the first eight days. All three herbicides significantly reduced photosynthetic oxygen output from the Eupaiorium plants. EPTC and monuron however, gave greatest effect. Reduction in transpiration from the plants was due to stomatal closure while reduction in photosynthetic oxygen output was due to both stomatal closure and probably also inhibition of the Hill reaction.     

浑善达克沙地植物蒸腾特征的研究

采用 L i-1 60 0型气孔仪测定了浑善达克沙地主要建群乡土植物种不同季节的蒸腾速率及其环境因子的日进程 ,结果表明 :浑善达克沙地中榆树、黄柳、圆叶桦、砂杞柳、羊草蒸腾速率的日变化均呈单峰曲线 ,而叉分蓼和楔叶茶子呈双峰曲线。同一种植物在不同样地土壤水分条件下 ,蒸腾速率不同。各植物种蒸腾速率的季节变化明显 ,7、8月份蒸腾速率高 ,6月份最低。各植物种中 ,黄柳为低蒸腾植物。回归分析表明 ,影响蒸腾速率最主要的因子为光照强度 ,其次为气温和空气相对湿度 ;蒸腾速率与各因子呈线性相关 ,其关系可用方程 Tr=a+b RH+c T+d Q表示。通过蒸腾速率的比较 ,提出了浑善达克沙地植被恢复应以建立“人工疏林草原”为主。     

SELECTIVITY AND PHYSIOLOGICAL INACTIVATION OF SOME HERBICIDES INHIBITING PHOTOSYNTHESIS

Summary. The effects of several herbicides on the rates of CO₂ uptake and transpiration of intact plants were measured. A simple technique is described which reveals whether photosynthesis-inhibiting herbicides are inactivated by plants. By this method, the inactivation of simazine by maize could be confirmed. Evidence is presented for physiological inactivation of monuron by Plantago lanceolata , of cycluron (OMU) and pyrazon by sugar beet, of N'-(4-butoxyphenyl)-NN-dimethylurea by of 5-bromo-6-methyl-3-phenyluracil by flax. Certain plant species showed different reactions to some other new herbicides. The effect of herbicides in the culture solution on CO₂ uptake by the leaves is probably largely determined by the rate of transpiration of the plants. Assuming that uptake in proportional to transpiration rate, estimates of the concentration of the herbicides inside the plant were made.
L'inactivation physiologique de quelques herbicides produisant une inhibition de la photosynthèse     

Some effects of competition between Emex australis and E. spinosa

When plants of Emex australis Steinh. and E. spinosa Campd. were grown in pots in monoculture or in competition, there was greater seedling mortality in E. australis. In competition with E. spinosa, E. australis was later-flowering and had lower seed, leaf, root and total dry weights. However, in E. spinosa leaf, stem, seed and total dry weight were greater than they were in mono-culture. The more bulbous root and more erect stems of E. spinosa may be linked with its greater competitive ability. Although at present much more restricted in occurrence in Australia than E. australis, the results suggest that E. spinosa will in time become the dominant species where the two occur together.     

CTV强弱毒株促进褐色橘蚜的取食

正由柑橘衰退病病毒(Citrus tristeza virus,CTV)引起的柑橘衰退病,对全世界柑橘产业造成了严重威胁。褐色橘蚜Toxoptera citricida(Kirkaldy)属半翅目蚜科,以非循回型半持久方式传播CTV,是CTV的最有效传播媒介~([1])。我国广泛分布着CTV的各种株系和传媒褐色橘蚜,对我