Photosynthetic Rate, Growth, and Yield of Mustard Plants Sprayed with 28-Homobrassinolide

Thirty-day-old plants of mustard (Brassica juncea L.) were sprayed with 10⁻¹⁰, 10⁻⁸, or 10⁻⁶ M aqueous solution of 28-homobrassinolide (HBR). The HBR-treated plants were healthier than those treated with water and yielded more. Maximum increase over control was found in 60-d-old, 10⁻⁸ M-HBR-treated plants in fresh and dry mass per plant, carbonic anhydrase (CA, E.C. 4.2.1.1) activity, and net photosynthetic rate (P _N), at harvest in number of pods per plant and seed yield per plant (the respective values were 25, 30, 34, 69, 24, and 29 %). A further increase in the concentration of HBR (10⁻⁶ M) did not make any additional impact on the growth and yield. Increased CA activity and P _N were correlated with growth and seed yield. This revised version was published online in August 2006 with corrections to the Cover Date.     

Plant Growth Analysis: Additive and Multiplicative Components of Growth

Three techniques used to investigate whole-plant growth areplant growth analysis, yield component analysis and demographicanalysis. Each subdivides growth into morphological or physiologicalcomponents. This paper derives several relationships which definethe contributions made by components to the performance of thewhole plant. For example, the additive contributions by differentplant parts to overall unit leaf rate may be determined. Also,for multiplicative components, the relative growth rate of yieldis the sum of the relative growth rates of yield components.The relationships developed here serve to link different approachesto growth analysis, and they are illustrated using data fromgrowth studies of bean and sunflower. Plant growth analysis, yield component analysis, demographic analysis, Phaseolus vulgaris L., Helianthus annus L.     

The Rate of Growth and Partitioning of Assimilates in Young Grass Plants: A Mathematical Model

A model describing the increase in weight with time of younggrass plants is formulated. The parameters are the relativegrowth rates of the root and shoot systems; k, the ratio ofthe relative growth rate of the root system relative to thatof the shoot system; b, the weight of the root system when thatof the shoot system is unity, and u the rate of increase inweight of the whole plant per unit of shoot system per unitof time, k and b are the constants in the allometric formula,r = bs^k where r and are the weights of the root and shoot systems.The model enables the effect of changes in the distributionof assimilates between the root and shoot systems upon the rateof growth of the plant to be assessed. Data from a number ofexperiments are analysed in this manner and the significanceof the results discussed.     

Amino Acid Pools in Perennial Plants at the Wintering Stage and at the Beginning of Growth

Free amino acids in plants at the stages of wintering and thebeginning of growth were analyzed under natural conditions.From the major amino acid contents, the pools were separatedinto the following types: 1) a group which accumulated argininealone (11 out of 31 samples); 2) a group which accumulated prolinealone (4 out of 31) and 3) a group which accumulated arginineand proline (15 out of 31). Comparison of the compositions atstages of wintering and the beginning of budding indicated thatthe increase in the proline level is related to the onset ofgrowth. Synthesis of arginine and roline and translocation ofproline would seem to indicate that these substances play therole of filling-in materials in any particular tissue. For plants which require chilling temperatures for growth, theaccumulation of arginine and proline was considered to be anormal event, since temporal changes in the major amino acidsfrom arginine (and proline) through glutamate to asparagineplus aspartate were generally observed. Uncoupling between aminoacid syntheses and the commencement of development was alsoobserved in plants which were housed in a greenhouse duringwinter. A possible function of proline as a natural cryoprotectantis discussed. ¹ Contribution No. 2270 from the Institute of Low TemperatureScience, Hokkaido University, Sapporo, Japan. (Received August 2, 1982; Accepted January 5, 1983)     

生物技术在几种植物生物活性物质生产中的应用

近年来肉苁蓉、红豆杉、铁皮石斛、怀槐等植物生物活性物质的研究已成热点。综述生物技术在这几种植物生物活性物质生产中的应用,展示了植物生物活性物质在医药、保健食品和化妆品等方面的广阔应用前景。     

The Determination of Relative Elemental Growth Rate Profiles from Segmental Growth Rates (A Methodological Evaluation)

Relative elemental growth rate (REGR) profiles describe spatial patterns of growth intensity; they are indispensable for causal growth analyses. Published methods of REGR profile determination from marking experiments fall in two classes: the profile is either described by a series of segmental growth rates, or calculated as the slope of a function describing the displacement velocities of points along the organ. The latter technique is usually considered superior for theoretical reasons, but to our knowledge, no comparative methodological study of the two approaches is currently available. We formulated a model REGR profile that resembles those reported from primary roots. We established the displacement velocity profile and derived growth trajectories, which enabled us to perform hypothetical marking experiments on the model with varying spacing of marks and durations of measurement. REGR profiles were determined from these data by alternative methods, and results were compared to the original profile. We find that with our model plotting of segmental relative growth rates versus segment position provides exact REGR profile estimations, if the initial segment length is less than 10% of the length of the whole growing zone, and if less than 20% of the growing zone is displaced past its boundary during the measurement. Based on our analysis, we discuss systematic errors that occur in marking experiments.     

The Influence of Removing Tubers on Dry-matter Production and Net Assimilation Rate of Potato Plants

To study the effect of removing tubers on growth and net assimilationrate (E) of potato, plants were grown in pots partly filledwith soil with the shoot growing through a polythene cover.Tubers developed in the space between the cover and the soilsurface. Removing tubers immediately they began to form had little effecton E at the beginning of the experiment but later greatly reducedit. Shading reduced E more at the beginning of the experimentthan later. Removing tubers decreased total dry weight, butmuch of the material that would have moved to tubers accumulatedin leaves and stems. In intact plants the loss of weight byshading was mainly from the tubers; in plants without tubersit was mainly from stems and leaves. Removing tubers increasedleaves on lateral stems. Increasing the amount of nitrogen supplieddiminished the effect on E of removing tubers, presumably becausethe extra allowed other sinks for carbohydrate to develop. Thegrowth of some buds of the potato plant is so strongly inhibitedthat they cannot grow and act as sinks for excess carbohydratewhen tubers are removed. Such internal inhibition of growthmay sometimes suffice to influence the magnitude of E of normalplants. Removing tubers usually increased sugar and starch contentand protein N content of stems and leaves.     

The Growth and Development of Simulated Swards of Perennial Ryegrass: I. Leaf Growth and Dry Weight Change as Related to the Ceiling Yield of a Seedling Sward

The leaf growth, tiller production, light interception, anddry weight increase of a simulated sward of S24 perennial ryegrass(Lolium perenne) were followed during the development of thesward from a collection of two-leaved seedlings to a closedcanopy with an LAI of 23, of which 15 consisted of green leaflaminae. The dry weight of live shoots increased exponentiallyat first, but then entered a long linear phase of increase.This was equivalent to a crop growth rate of 200 Kg ha^–1day^–1 and a conversion efficiency of radiant energy (400–700nm) of 7.2 per cent. Towards the end of the growth period therate of increase of live shoots declined rapidly to zero anda ceiling yield was reached equivalent to 10 metric tons ha^–1.Leaf growth continued at a high rate, but was equalled by therate of leaf death, so that the weight of live leaf tissue remainedconstant. By this time the swards had achieved a stable tillerpopulation (about 1 cm^–1), each tiller bore a constantnumber of live leaves (about three), and the length of eachnewly expanded leaf equalled the length of the old leaf it replaced(about 70 cm). The swards were grown in Perlite so that in theabsence of soil fauna dead leaves accumulated at the base ofthe sward where, after 12 weeks, they accounted for 19 per centof the total weight of dry matter produced.     

The Production of Bacillus cereus Enterotoxins Is Influenced by Carbohydrate and Growth Rate

Enterotoxin production is a key factor in Bacillus cereus food poisoning. Herein, the effect of the growth rate (μ) on B. cereus toxin production when grown on sucrose was studied and the Hemolytic BL enterotoxin (HBL) and nonhemolytic enterotoxin (Nhe) production by B. cereus was compared according to carbohydrate at μ = 0.2 h⁻¹. The anaerobic growth was carried out on continuous cultures in synthetic medium supplemented with glucose, fructose, sucrose, or an equimolar mixture of glucose and fructose. Concerning the HBL and Nhe enterotoxin production: (1) the highest enterotoxin production has occurred at μ = 0.2 h⁻¹ when growing on sucrose; (2) HBL production was repressed when glucose was consumed and the presence of fructose (alone or in mixture) cancelled glucose catabolite repression; (3) the consumption of sucrose increased Nhe production, which was not affected by the catabolite repression. Furthermore, analysis of the fermentative metabolism showed that whatever the μ or the carbon source, B. cereus used the mixed acid fermentation to ferment the different carbohydrates. The enterotoxin productions by this strain at μ = 0.2 h⁻¹ are highly influenced by the carbohydrates that do not involve any fermentative metabolism changes.     

Crop Growth, Disease and Yield Components of Rusted Phaseolus Beans in Ethiopia

Crop growth and disease epidemics in sprayed and non-sprayed bean plots, artificially infected with rust (Uromyces appendiculatus) 3 weeks after emergence. were assessed weekly in two cultivars, at two locations for two seasons. Disease intensity was regulated by the application of a fungicide at 5 spray frequencies. Fungicide application influenced leaf area index (LAI) and reduced rust intensity. The fungicide had no significant effect on other diseases and dead leaf area. Fungicide application increased seed yield (SY) by increased numbers of pods per plant (PP). Rust severity was strongly correlated with pustule density but the overall relationships among rust assessment parameters depended on cultivar and location. Seed yield and pods per plant were highly correlated with LAI. The relationships between LAI and seeds per pod or seed weight depended on cultivar and location. Overall rust assessment parameters (rust severity and pustule density) showed close, negative relationships with seed yield. seed weight and pods per plant but not with seeds per pod. The relationships obtained in the partially resistant line 6-R-395 were less definite than those in the susceptible line Mexican 142. The yield parameters seed yield and pods per plant, showed strong positive relationships.     

The Influence of Plant Extracts on Phytotoxin Production and Growth Rate of Alternaria helianthi

When liquid cultures of Alternaria helianthi were supplemented with aqueous extracts of leaf tissue of its host plant (sunflower), pronounced effects on both growth and production of the toxin deoxyradicinin were apparent. Very low levels of leaf extract stimulated toxin production but did not significantly affect growth, while higher levels markedly stimulated mycelial growth and at the same time toxin production was greatly suppressed. Leaf extracts of non-host plant species were also stimulatory to phytotoxin biosynthesis.     

B-Nine Reversal of Benzimidazole-or IAA-induced Inhibition of Growth and Yield of Cowpea Plants

Growth, flowering, and yield of Cowpea (Vigna catjang) wereinhibited by Benzimidazole (10^-3M) or IAA (10^-2M). These growthinhibitions were reversed by B-Nine (2x10^-3M) which alone waswithout any effect. In combination, IAA and Benzimidazole weremutually antagonistic. A common mechanism is suggested for theB-Nine reversal of the Benzimidazole or IAA inhibition of growth.     

Variation of Relative Growth Rate and Survival in Ecologically Contrasting Populations of Agrostis stolonifera

Abstract Significant differentiation in relative growth rate (RGR) was found among three ecologically contrasting populations of Agrostis stolonifera. Under low nitrogen conditions the sand dune population had the highest mean RGR. The plastic response in RGR to different levels of nitrogen supply was significantly higher in the inland meadow population than in the polder and sand dune populations. The (colonizing) polder population tended to have the highest variation for RGR. Variation in RGR within populations was mainly environmentally determined, although in the polder population significant effects of genotype and of genotype × nitrogen level were found. The repeatability for RGR in this population proved to be different from zero under both nitrogen conditions. Root/shoot ratios of the three populations were not different from each other, independent of the level of nitrogen supply. Correlations between RGR and survival of genotypes within the populations were not significant, which points at the influence of genotype × environment interactions or the possibility that genotypic differences in RGR do not necessarily indicate an adaptation to any habitat, not even the home site.     

Cyclic Variations in Nitrogen Uptake Rate in Soybean Plants: Uptake During Reproductive Growth

Net uptake of by non-nodulated soybean plants [Glycme max(L ) Merr cv Ransom] growing in flowing hydroponicculture was measured daily during a 63 d period of reproductivedevelopment between the first florally inductive photopenodand late seed growth Removal of from a replenished solution containing 10 mol m^– was determined by ion chromatography Uptake of continued throughout reproductive development The net uptakerate of cycled between maxima and minima with a periodicity of oscillation of 3 to 7 d during the floralstage and about 6 d during the fruiting stage. Coupled withincreasing concentrations of carbon and C:N ratios in tissues,the oscillations in net uptake rates of are evidence that the demand for carbohydrate by reproductiveorgans is contingent on the availability of nitrogen in theshoot pool rather than that the demand for nitrogen followsthe flux of carbohydrate into reproductive tissues. Key words: Nitrate uptake rate, carbon-nitrogen partitioning, Glycme max (L ) Merrill     

水分胁迫对入侵植物薇甘菊幼苗生长的影响

水分是影响薇甘菊(Mikania micrantha)生长的重要环境因子,但通过调控生长环境包括土壤水分和空气湿度来探讨这一入侵植物的适应能力的报道较少.本文通过设置2个水分梯度:处理Ⅰ土壤含水量30%～60%和空气相对湿度80%～90%,处理Ⅱ土壤含水量10%～20%和空气相对湿度20%～30%进行试验.结果发现土壤含水量在10%～20%且空气相对湿度在20%～30%时,水分胁迫能显著影响薇甘菊的幼苗生长和光合特性.胁迫条件下植株生长速率明显降低,最大净光合速率和最大量子效率分别是1.94 μmol·m-2·s-1和64.91 mmol·mol-1,比对照8.63 μmol·m-2·s-1和211.34 mmol·mol-1明显偏低.本文将空气相对湿度作为水分胁迫条件之一,阐述了空气相对湿度的增加能扩大薇甘菊的适生范围,并分析得出气孔限制可能是水分胁迫下薇甘菊生长受抑制的主要原因.     

Rates of Leaf and Tiller Production in Young Spaced Perennial Ryegrass Plants in Relation to Soil Temperature and Solar Radiation

In an experiment designed to investigate the rate of leaf appearanceand tiller production in young spaced plants of three clonesof perennial ryegrass grown in the field, it was found thatthe rate of leaf appearance per tiller increased linearly withmean soil temperature up to approx. 14 °C. The rate of productionof tillers in relation to the rate of leaf appearance (sitefilling) appeared to be virtually independent of weather conditions.In plants which were adequately established, but still relativelysmall, site filling was equal to or exceeded the theoreticalsteady state; all the tiller buds which were being formed weredeveloping into visible tillers. Thus the relative rate of tillerproduction was controlled by the rate of leaf appearance. Inlarger plants site filling was less complete, and site redundancieswere probably caused by within-plant competition for light atthe tiller bases. Lolium perenne L., perennial ryegrass, tillering, leaf production, solar radiation, soil temperature     

Response of Insect Relative Growth Rate to Temperature and Host-Plant Phenology: Estimation and Validation from Field Data

Between 1975 to 2011, aphid Relative Growth Rates (RGR) were modelled as a function of mean outdoor temperature and host plant phenology. The model was applied to the grain aphid Sitobion avenae using data on aphid counts in winter wheat at two different climate regions in France (oceanic climate, Rennes (western France); continental climate, Paris). Mean observed aphid RGR was higher in Paris compared to the Rennes region. RGR increased with mean temperature, which is explained by aphid reproduction, growth and development being dependent on ambient temperature. From the stem extension to the heading stage in wheat, there was either a plateau in RGR values (Rennes) or an increase with a maximum at heading (Paris) due to high intrinsic rates of increase in aphids and also to aphid immigration. From the wheat flowering to the ripening stage, RGR decreased in both regions due to the low intrinsic rate of increase in aphids and high emigration rate linked to reduced nutrient quality in maturing wheat. The model validation process showed that the fitted models have more predictive power in the Paris region than in the Rennes region.     

壳斗科植物的化学成分及生物活性研究进展

本文综述了1970年以来壳斗科植物的化学成分及生物活性的研究进展。     

Comparative Growth,Biomass Production and Fuel Properties Among Different Perennial Plants,Bamboo and <Emphasis Type="Italic">Miscanthus</Emphasis>

Bamboo and Miscanthus species are perennial low-input plants that are excellent candidates for bioenergy feedstock production. Biological characteristics, dry matter yields and fuel properties of the bamboo and Miscanthus have been studied. Genotype growth characteristics were determined by measurements of plant height, tillering, tuft diameter, and shoot diameter. To date, comparisons of biomass yields of bamboo and Miscanthus have not been previously reported in the literature. Bamboo and Miscanthus species were collected and previous articles describing the productivity of bamboo and Miscanthus were examined. Genotypes differed in plant height, tillering, tuft diameter, and shoot diameter. Nitrogen, temperature, water and plant density have effects on mature stands biomass production, which ranged from 5.9 to 49.5 tonnes/ha/yr for bamboo and 3.2 to 49.0 tonnes/ha/yr for Miscanthus. With such biomass yields, bamboo and Miscanthus should be considered as two very promising plants for biomass production in Zhejiang, China in the near future.