Rhizome Length Research Articles

GGE biplot analysis of multi-location yield trial of ginger (Zingiber Officinale Rosc.) Genotypes in South-Eastern, Nigeria

Multi-location trials were conducted in 2016 and 2017 at Calabar, Ikom and Ogoja in Cross River State, Nigeria, to determine the yield stability of 17 ginger genotypes (G1–G17) using genotype and genotype by environment (GGE) biplot model. The location and year combination gave six environments (E1–E6). The experiment was laid out in split plots using a randomized complete block design with three replications. Yield related traits like rhizome fingers, rhizome length, and rhizome yield were determined. E3 (i.e. Ikom in 2016) was ranked as the ideal environment for ginger production in Cross River State. While G5 (UGI-5-04) was classified as the ideal genotype for rhizome yield in Calabar, Ikom and Ogoja. Ikom in 2016 (E3) and 2017 (E4) were identified as mega-environments for UG1-13-02, UG1-5-04, UG1-5-18, UG1-5-35, UG1-5-38, UG2-11-03 and UG2-9-01 while Ogoja in 2016 (E5) and 2017 (E6) were identified as mega-environments for UG1-2-35, UG1-5-48, UG1-5-52 and UG1-7-24 ginger mutants. Ikom is recommended as a suitable environment for the cultivation of generally adapted ginger genotypes namely, UG1-5-04, UG1-5-38, UG1-13-02 and UG2-9-01). Ogoja was suitable for specific adaptation of UG1-7-24 and UG1-5-48 ginger mutants. These mutants are recommended for consideration in subsequent ginger breeding and improvement programmes.

三峡库区多年高水位运行对消落带狗牙根生长恢复的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 三峡库区多年高水位运行对消落带狗牙根生长恢复的影响 DOI: 10.5846/stxb201809061909 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（51409030）；重庆市科委自然科学基金计划项目（cstc2015jcyjA 20028）；重庆高校创新团队建设计划项目（CXTDX201601037）；重庆市技术创新与应用发展专项面上项目（csct2019jscx-msxm0578） Influence of multi-year high water level running on growth recovery of Cynodon dactylon population in water-level-fluctuating zone of the Three Gorges Reservoir Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为深入了解三峡库区多年高水位运行对消落带优势植物生长恢复的影响，分别于2008年和2017年定量调研了库区长寿段消落带狗牙根（Cynodon dactylon）种群的变化，探讨了库区高水位运行对消落带狗牙根萌发、生长和物质分配的影响。结果表明，多年的高水位运行导致不定芽形成和萌发显著被促进，形成更多的分株；高水位运行导致狗牙根分株的株高、茎宽和叶片数被显著抑制，而叶长和种群的总叶片数被显著促进，且随着消落带水位的降低叶长呈降低趋势，而叶宽和总叶片数呈增加趋势；高水位运行导致狗牙根种群匍匐茎和地下茎的茎长、茎节数和总茎长均被显著促进，且随着消落带水位降低匍匐茎茎长和茎节数呈显著的降低趋势，而地下茎茎长和茎节数呈增加趋势；高水位运行导致狗牙根地下茎储存的干质量呈增加趋势，而分株和匍匐茎的干质量呈降低趋势，而且在种群物质分配中地下茎所占的比例呈增大趋势，低水位狗牙根种群的分株和高水位种群的匍匐茎所占的比例也呈增加趋势。因此，狗牙根不仅具有很强的耐淹和生长恢复能力，也具有很强的拓殖能力，可以作为库区中低位消落带恢复和重建的主要原生物种。 Abstract:To clarify influence of multi-year high water level running on growth recovery of dominant plants in water-level-fluctuating zone of the Three Gorges Reservoir, the quantitative changes of Cynodon dactylon population in Changshou area were investigated in 2008 and 2017. We also discussed the influences of high water level on the germination, growth, and material allocation of C. dactylon. The results showed that multi-year high water level running significantly promoted the formation and germination of adventitious buds which made more ramets to be formed. Multi-year high water level running significantly restrained plant height, stem width, and leaf number of the ramets, while leaf length and total leaf number of the population were significantly promoted. Furthermore, the leaf length was decreased with water level decreasing. However, the leaf width and total leaf number showed the opposite increasing trend. Simultaneously, multi-year high water level running led to the significant promotion of stem length, stem nodes number and total stem length of stolons and rhizomes. The stem length and stem nodes number of the stolons were decreased with the water level decreasing. On the contrary, stem length and stem nodes number of the rhizomes were increased with water level decreasing. As a result of high-water-level operation for many years, dry mass of the rhizomes showed an increasing trend, while dry mass of the ramets and the stolons showed an opposite decreasing trend. In addition, the proportion of the rhizomes, ramets in low water level, and stolons in high water level also showed an increasing trend in material distribution of the population. Therefore, C. dactylon not only have strong flood resistance and growth recovery ability, but also have strong colonization ability, which can be used as one of the primary native species for vegetation recovery and reconstruction of in low or middle water-level-fluctuating zone of the Three Gorges Reservoir. 参考文献 相似文献 引证文献

Pre-commercial thinning enhances competitive traits of boreal ericaceous shrubs and reduces soil fertility

Boreal ericaceous shrubs, such as Kalmia angustifolia, have evolved various traits allowing them to interfere with the growth of conifer trees. These include the ability to spread through rhizomatous growth and to produce high amounts of tannins that interfere with soil N cycling. We examined how pre-commercial thinning (PCT) of young black spruce (Picea mariana) stands, a common silvicultural practice, increases the aboveground and belowground spread of various ericaceous shrubs, the chemical quality of leaves and litter, as well as soil nitrogen cycling. We compared these effects in relatively cool-moist and relatively warm-dry climates. Within the warm-dry climate, we also compared the effects of PCT on fertile clay and on nutrient-poor till deposits. The total cover of ericaceous shrubs was higher in PCT than in control plots in all three site types. On nutrient poor till deposits (in both climates), the current-year rhizome length and specific rhizome mass of K. angustifolia were higher in PCT than in control plots. Soil mineralizable NH4+-N was lower under patches of K. angustifolia than under patches of feather moss (Pleurozium schreberi). Across all 24 plots, canopy openness had a positive relationship with ericaceous shrub cover, current-year rhizome length, foliar tannins and phenolic concentrations. Although PCT might increase tree growth in the short-term, its positive effects on ericaceous shrubs increases the risk of conifer seedling growth check when the next clearcut harvest occurs, especially in cool moist climates and on nutrient poor soil deposits.

Vegetative propagation of Solidago canadensis – do fragment size and burial depth matter?

SummaryClonal species may benefit from human disturbance because their vegetative fragments may be distributed via soil. Solidago canadensis is an invasive rhizomatous perennial frequently found in ruderal environments. When creating new infrastructure, digging and cutting are two main factors that may influence the spread of S. canadensis into new areas. To have a better understanding of the invasive potential of S. canadensis, we investigated whether S. canadensis was able to survive and grow from stem cuttings as well as from rhizomes. Rhizomes and cuttings were collected from three populations in Eastern Norway. The rhizomes and cuttings were planted in a pot experiment to assess their vegetative ability to propagate. Rhizome fragments (5 and 10 cm long) were buried at 0.5, 10 and 30 cm depths. The cuttings were planted as 15 cm stems, with the bottom 5 cm pushed into the soil. The results showed that rhizome length did not have an effect on survival. Although some sprouting occurred at all burial depths, increasing depth had a negative effect on rhizome survival. In general, development of the cuttings was good, but there were differences between population performance and survival. These results imply that care must be taken when (i) constructing new sites, because digging and transport of soil masses may spread S. canadensis into new areas by rhizomes or cuttings, and (ii) mowing road verges and other ruderal areas to prevent the spread of stem cuttings from one area to another.

The potential of Cosmos sulphureus flower extract as a bioherbicide for Cyperus rotundus

Abstract. Respatie. D. W, Yudono P, Purwantoro A, Trisyono Y.A. 2019. The potential of Cosmos sulphureus flower extract as a bioherbicide for Cyperus rotundus. Biodiversitas 20: 3568-3574. Cosmos (Cosmos sulphureus Cav.) flower is recognized as natural source of bioherbicide compounds for several weeds. The purple nutsedge (Cyperus rotundus L.) is an important weed, and this research was aimed to determine the effects of cosmos flower extract on this weed. Dried cosmos flowers were threshed and extracted using maceration method with 70% alcohol. The experiment was conducted in the greenhouse using a completely randomized design (CRD) with three replications. Purple nutsedge tubers were planted in polybags and treated with cosmos flower extract applicated once to three times with 300 mL polybag-1 at the concentration of 40%. Different levels of inhibitions on purple nutsedge growth were observed at 30 and 60 days after sowing (DAS) due to the presence of gallic acid in the extract. Growth parameters for purple nutsedge were analyzed using Analysis of Variance (ANOVA) and followed by Least Significant Differences (LSD) at α=0.05. Significant reductions in the number of mother shoots, daughter shoots, and roots, length of mother leaves, length of rhizomes, root, and total leaf area of the purple nutsedge treated with the cosmos flower extract at 30 DAS compared to those in the control. A significant reduction was also observed in foliage dry weight, underground organs dry weight, and total dry weight of purple nutsedge. The three application times yielded maximum inhibition. In addition, these treatments reduced N, P, and K content, chlorophyll content, and photosynthesis rates at 30 DAS. These results suggest that cosmos flower extract has the potential for controlling purple nutsedge.

지황의 비대시기와 수확시기 구명 연구

Background: There have been no studies to date on rhizome development and optimal harvest timing for Rehmannia glutinosa. We therefore, undertook this investigation.BR Methods and Results: R. glutinosa ‘Jihwang 1’ was sown in early May and harvested in early November. Growth investigations were carried out at intervals of 10 days between 90 and 180 days after sowing (DAS). Leaf length, leaf width, and number of leaves increased until 150 DAS but decreased after 160 DAS. Rhizome length increased until 120 DAS subsequently, rhizome diameter increased rapidly between 130 and 150 DAS. Thus, the key period for rhizome enlargement in R. glutinosa is thought to be 130 to 150 DAS. Fresh root yield increased sharply from 916 ㎏/10a to 1,914 ㎏/10a between 4 and 5 months after sowing (MAS). Dry matter ratio increased gradually from 19.2% at 4 MAS to 24.4% at 6 MAS. Finally, the level of catalpol, a key active ingredient, increased sharply from 0.41% to 4.21% between 5 and 6 MAS. Given the dry matter ratio, catalpol content and yield measured, we suggest that optimal R. glutinosa harvest time is 6 MAS.BR Conclusions: Based on our results, the key period for rhizome enlargement is 130 to 150 DAS and optimal harvest timing is 6 MAS. We anticipate that these and other results of this study can be used to inform cultivation of R. glutinosa.

Relationships between key functional traits of the waterlily Nuphar lutea and wetland nutrient content.

Little attention has been paid to how aquatic habitat characteristics affect the traits of plant species. Nuphar lutea (L.) Sm. is a keystone species distributed across temperate regions of Europe, northwest Africa and western Asia. Its apparently low phenotypic variability compared to other aquatic plants led us to test whether the species exhibited significant phenotypic variability and whether trait values correlated to environmental parameters. The hypotheses were that (1) the environmental variation within our set of wetlands (both water and sediment characteristics) led to significant variation among four sets of traits related respectively to growth, reproduction, defence and storage and (2) that nutrient limitation (nitrogen and especially phosphorus) should affect plant traits towards a higher investment in storage and defence and a lower investment in growth and reproduction, thereby negatively affecting the success of N. lutea. To test these hypotheses, 11 populations of N. lutea were sampled in wetlands differing in physicochemical characteristics and spread along three rivers. A total of 15 traits, grouped into four sets (growth, reproduction, storage and defence), were measured during the growing season. Most N. lutea traits were related to the environmental characteristics of wetlands. The growth and reproduction traits were mostly positively related to habitat resource conditions, whereas the defence traits were positively correlated with both ammonium concentration and temperature, outlining possible anoxic stress (habitat adversity). Nitrogen or phosphorus limitation led to the variation of only a few traits: the rhizome starch content was higher in phosphorus-limited wetlands, while the rhizome length and volume, and the number of flowers were higher in nitrogen-limited wetlands.

Effects of mowing disturbance and competition on spatial expansion of the clonal plant Leymus chinensis into saline-alkali soil patches

Mowing disturbance and interspecific competition could affect the expansion of clonal plant under homogeneous conditions. However, with the current degradation of patchy grasslands, how these factors affect the expansion of clonal plant–Leymus chinensis, a dominant perennial grass in meadow steppe, into saline-alkali patches with different stress levels is largely unknown. To test this, we conducted an experiment in which L. chinensis was grown in a pot with half healthy and half saline-alkali soils and the healthy part was treated with mowing and interspecific competition (with Hierochloe glabra). Results showed that mowing or competition treatment alone significantly promoted the expansion of L. chinensis in healthy patches into saline-alkali patches under a moderate saline-alkali stress (i.e., higher rhizome length was found), while this effect was not significant in the combined mowing and competition treatment. On the contrary, all of the mowing and competition treatments decreased the expansion of L. chinensis into the saline-alkali patches (i.e. lower rhizome length) under a severe saline-alkali stress. Also, results showed that mowing or competition alone reduced aboveground biomass of ramets in healthy patches, but increased their above- and below-ground biomass in saline-alkali patches under a moderate stress, indicating that mowing and competition promoted L. chinensis to allocate more biomass to improve expansion abilities. Moreover, compensatory growth was induced by mowing treatment from a physiological perspective (e.g., with an increase in photosynthesis rate). L. chinensis employed different adaptive strategies in response to mowing and competition during the process of expansion. We conclude that mowing and competition can significantly affect the expansion of L. chinensis into saline-alkali patches, and the effects strongly depend on the stress level of saline-alkali patches. Overall, our results imply that in slightly degraded patchy grasslands, moderate grazing or mowing utilization may accelerate their restoration, and that L. chinensis communities with more diverse species mixtures could have larger potential to restore the degraded patches.

Evaluation of Agro-morphological Traits in 20 Genotypes Selected of Curcuma aeruginosa Roxb.

The present study aimed to evaluate different agro-morphological traits among twenty genotypes of Curcuma aeruginosa Roxb. and three varieties of Curcuma zanthorrhiza Roxb. Agro-morphological data traits were investigated based on qualitative and quantitative parameters from PPVFRA descriptors with modification. All the recorded data was analyzed through SPSS 16.0 and R 3.4.2 for ANOVA and similarity analysis, respectively. Significant differences (P <0.05) were observed in the traits studied of the habit of the rhizome, the shape of the rhizome, length of primary rhizome, number of mother rhizome, plant height, pseudostem diameter, number of leaves, leaf length, leaf width, and number of shoots. Hierarchical cluster analysis (HCA) classified the genotypes into three groups. The principal component analysis (PCA) were showed consistent with results of the HCA. These genotypes could be used as novel genotype in agricultural biochemistry for breeding programs.

Rhizome and stolon development of bermudagrass cultivars in a transition-zone environment

ABSTRACTBermudagrass (Cynodon spp.) is a warm season turfgrass that spreads by stolons and rhizomes. The present study aimed to increase knowledge on development of stolons and rhizomes in fertile (‘LaPaloma’ and ‘Yukon’) and sterile (‘Patriot’ and ‘Tifway’) cultivars of bermudagrass. A plot trial was established in May 2013 in Legnaro, northeastern Italy. Fertile cultivars were seeded while sterile cultivars were established by vegetative plugs. Turf samples were collected from autumn 2013 until summer 2015 on March, July, and October. Total length of stolons and rhizomes was measured and total dry weight was determined. The concentration of starch in stolons and rhizomes in October was also determined. The stolon and rhizome density per unit area, the rhizome specific weight, and the rhizome/stolon length and weight ratios were calculated. Sterile cultivars had higher stolon and rhizome density compared to fertile cultivars for both length. In all cultivars, the production of stolons was favoured over that of rhizomes and rhizomes began to develop more in the second season after establishment. Cultivars did not differ significantly in starch content, indicating no relationship between stolon and rhizome density and carbohydrate reserve accumulations.Abbreviations: LD: length density per unit area; WD: weight density per unit area; SW: specific weight; LR: rhizome-to-stolon length ratio; WR: rhizome-to-stolon weight ratio; TS: total starch per unit area

The shaping role of self-organization: linking vegetation patterning, plant traits and ecosystem functioning.

Self-organized spatial patterns are increasingly recognized for their contribution to ecosystem functioning, in terms of enhanced productivity, ecosystem stability, and species diversity in terrestrial as well as marine ecosystems. Most studies on the impact of spatial self-organization have focused on systems that exhibit regular patterns. However, there is an abundance of patterns in many ecosystems which are not strictly regular. Understanding of how these patterns are formed and how they affect ecosystem function is crucial for the broad acceptance of self-organization as a keystone process in ecological theory. Here, using transplantation experiments in salt marsh ecosystems dominated by Scirpus mariqueter, we demonstrate that scale-dependent feedback is driving irregular spatial pattern formation of vegetation. Field observations and experiments have revealed that this self-organization process affects a range of plant traits, including shoot-to-root ratio, rhizome orientation, rhizome node number, and rhizome length, and enhances vegetation productivity. Moreover, patchiness in self-organized salt marsh vegetation can support a better microhabitat for macrobenthos, promoting their total abundance and spatial heterogeneity of species richness. Our results extend existing concepts of self-organization and its effects on productivity and biodiversity to the spatial irregular patterns that are observed in many systems. Our work also helps to link between the so-far largely unconnected fields of self-organization theory and trait-based, functional ecology.

Measuring Stolons and Rhizomes of Turfgrasses Using a Digital Image Analysis System.

Length and diameter of stolons or rhizomes are usually measured using simple rulers and calipers. This procedure is slow and laborious, so it is often used on a limited number of stolons or rhizomes. For this reason, these traits are limited in their use for morphological characterization of plants. The use of digital image analysis software technology may overcome measurement errors due to human mistakes, which tend to increase as the number and size of samples also increase. The protocol can be used for any kind of crop but is particularly suitable for forage or grasses, where plants are small and numerous. Turf samples consist of aboveground biomass and an upper soil layer to the depth of maximum rhizome development, depending on the species of interest. In studies, samples are washed from the soil, and stolons/rhizomes are cleaned by hand before analysis by digital image analysis software. The samples are further dried in a laboratory heating oven to measure dry weight; therefore, for each sample, the resultant data are total length, total dry weight, and average diameter. Scanned images can be corrected before analysis by excluding visible extraneous parts, such as remaining roots or leaves not removed with the cleaning process. Indeed, these fragments normally have much smaller diameters than stolons or rhizomes, so they can be easily excluded from analysis by fixing the minimum diameter below which objects are not considered. Stolon or rhizome density per unit area can then be calculated based on sample size. The advantage of this method is quick and efficient measurement of the length and average diameter of large sample numbers of stolons or rhizomes.

Variation and heritability of morphological and physiological traits among Leymus chinensis genotypes under different environmental conditions

Intraspecific trait variation and heritability in different environmental conditions not only suggest a potential for an evolutionary response but also have important ecological consequences at the population, community, and ecosystem levels. However, the contribution of quantitative trait variation within a grassland species to evolutionary responses or ecological consequences is seldom documented. Leymus chinensis is an important dominant species in semi-arid grasslands of China, which has seriously suffered from drought and high temperature stresses in recent decades. In the present study, we measured variation and heritability of 10 quantitative traits, namely the number of tillers, maximum shoot height, number of rhizomes, maximum rhizome length, rhizome mass, aboveground mass, root mass, maximum net photosynthetic rate (Pmax), specific leaf area (SLA), and leaf length to leaf width ratio (LL/LW), for 10 genotypes of L. chinensis under one non-stress (Ck) condition and three environmental stress conditions (i.e., drought (Dr), high temperature (Ht), and both drought and high temperature (DrHt)). Result indicated that (1) the interaction of genotype and environmental condition (G×E) was significant for 6 traits but not significant for the other 4 traits as shown by two-way analysis of variance (ANOVA), suggesting that different selection forces were placed for different traits on the factors dominating phenotypic responses to different environmental conditions. Moreover, these significant G×E effects on traits indicated significantly different phenotypic adaptive responses among L. chinensis genotypes to different environmental conditions. Additionally, individuals could be grouped according to environmental condition rather than genotype as shown by canonical discriminant analysis, indicating that environmental condition played a more important role in affecting phenotypic variation than genotype; (2) by one-way ANOVA, significant differences among L. chinensis genotypes were found in all 10 traits under Ck and Dr conditions, in 8 traits under DrHt condition and only in 4 traits under Ht condition; and (3) all 10 traits showed relatively low or non-measurable broad-sense heritability (H2) under stress conditions. However, the lowest H2 value for most traits did not occur under DrHt condition, which supported the hypothesis of 'unfavorable conditions have unpredictable effects' rather than 'unfavorable conditions decrease heritability'. Results from our experiment might aid to improve predictions on the potential impacts of climate changes on L. chinensis and eventually species conservation and ecosystem restoration.

扎龙湿地芦苇种群不同龄级根茎构件的季节动态

PDF HTML阅读 XML下载 导出引用 引用提醒 扎龙湿地芦苇种群不同龄级根茎构件的季节动态 DOI: 10.5846/stxb201807211565 作者: 作者单位: 齐齐哈尔大学 生命科学与农林学院,齐齐哈尔大学 生命科学与农林学院,东北师范大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31472134，31672471）；黑龙江省省属高等学校基本科研业务费科研项目（135309484，YSTSXK201880） Seasonal dynamics of rhizome modules in different age classes of Phragmites australis populations in the Zhalong Wetland Author: Affiliation: College of Life Science and Agriculture,Forestry ,Qiqihar University,College of Life Science and Agriculture,Forestry ,Qiqihar University, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:克隆植物根茎具有营养繁殖和扩展种群的功能，也是芽和分株生理整合的通道。根茎构件具有出生、死亡及年龄等种群统计特征，不同龄级根茎的季节动态可以反映根茎的存活和衰老过程。采用单位土体挖掘取样，对扎龙湿地4个生境芦苇种群根茎构件进行野外调查，比较不同龄级根茎长度、生物量和干物质贮量的季节动态。结果表明：7-10月份，1a根茎长度、生物量和干物质贮量均呈指数函数增加，在生长季中后期有一个持续时间较长的生长和物质积累时期。6-10月份，2a、3a根茎长度呈线性函数增加，4-6a根茎长度呈线性函数减少；2-4a根茎生物量和2-5a根茎干物质贮量呈二次函数先减少后增加，5a、6a根茎生物量和6a根茎干物质贮量呈幂函数减少。整个生长期内，根茎长度和根茎生物量均以3a最大，根茎长度以最高的6a最小，根茎生物量以最低的1a最小；根茎干物质储量以5a最大，以最低的1a最小。4个生境芦苇种群根茎长度、生物量和干物质贮量在龄级间的差异及差异序位稳定，在新根茎的产生、老根茎的存活以及根茎寿命与养分消耗和储藏上均具有稳定的生物学特性，不同龄级根茎在种群中的地位和作用以及对种群的贡献不同。 Abstract:Clonal plant rhizomes not only function in vegetative propagation and population expansion, but also act as a physiological channel, integrating buds and ramets. Examining the rhizome components can reveal information regarding the birth, death, and age of the plants, and the seasonal dynamics of rhizomes at different ages can reflect survival and senescence processes. A field investigation was carried out on the rhizomes of Phragmites australis populations in different habitats of the Zhalong Wetland. Soil from a unit area was sampled to assess the seasonal dynamics of rhizome length, biomass, and dry matter storage at different ages. The results showed that rhizome length, biomass, and dry matter storage of 1st increased exponentially from July to October and that there was a long period of growth and material accumulation in the middle and late growing period. From June to October, the rhizome lengths of 2nd and 3rd increased linearly, and the rhizome length of 4th to 6th decreased linearly. The rhizome biomass of 2nd to 4th and the dry matter storage of 2nd to 5th decreased initially and then increased quadratically. The rhizome biomass of 5th or 6th and the dry matter storage of 6th decreased with the power function. During the entire growing period, the rhizome length and biomass of 3rd were the highest and the rhizome length of the 6th were the lowest and the biomass of the 1st the lowest; The dry matter storage of 5th was the highest and that of 1st was the lowest. There was a relatively stable difference and differential sequence between age classes in rhizome length, biomass, and dry matter storage of P. australis populations in the four different habitats. The emergence of new rhizomes, survival of old rhizomes, lifetime of rhizomes, and nutrient consumption and storage showed relatively stable biological characteristics. The status and function of rhizomes and their contribution to the population varied in different age classes. 参考文献 相似文献 引证文献

Analiza performansi agregata traktor - sadilica rizoma kurkume

A field performance analysis of a developed prototype tractor-drawn turmeric planter is presented. The experiment was randomized in a factorial design of three planter levels of rhizome lengths (30, 45 and 60 mm) and operational speeds of 8, 10, and 12 kmh-1. An average mass of 3 kg of wholesome turmeric rhizomes were introduced into the hopper of the planter and planted in 90 m 2 of experimental plot. During field evaluation of the machine, the effective field capacity, field efficiency, missing index, multiple index and planting depth were considered; whereas laboratory tests were conducted to evaluate the planter's seed rate, percentage rhizome bruise wheel slippage and fuel consumption. Results obtained show that the maximum seed rate was 0.283 th-1. The maximum percent bruised turmeric rhizome was found to be 30.08%. The mean effective field capacity varied between 0.63-0.96 hah-1, at operational speeds of 8 and 12 kmh-1, respectively and 45 mm rhizome length. The mean field efficiency was obtained to be 65.8%. The maximum wheel slippage of 4.37% and fuel consumption of 3.8 lha-1 were obtained at the machine speeds of 8 kmh-1 and 12 kmh-1, respectively; whereas the minimum wheel slippage of 3.14% and fuel consumption of 2.2 lha-1 were obtained at the machine speeds of 12 kmh-1 and 8 kmh-1, respectively for the range of the studied turmeric rhizome length. The highest and lowest percentage turmeric rhizome miss index of 35% were recorded for turmeric rhizome length of 30 mm at a speed of 10 kmh-1 and 8 kmh-1, respectively. An average planting depth of 68 mm was obtained. The numerical optimization approach was adopted to obtain an optimal operational parameters of 12 kmh-1 speed and 45 mm turmeric rhizome grading size with an overall desirability index of 0.73. An economic evaluation was calculated using the principle of payback period which was obtained to be very small (1.64 years) compared to the life of the planter of 17 years. Prospects for future works were suggested.

Impacts of Sand Burial and Wind Erosion on Regeneration and Growth of a Desert Clonal Shrub.

Sand burial and wind erosion caused by sand movement are common phenomena in desert environments, but the effects on clonal shrub have rarely been investigated. Here, we assessed how sand movements affect the population regeneration capacity of juvenile clonal fragments of the shrub Calligonum mongolicum growing in mobile desert sand dunes. We investigated the population status and natural regeneration capacity in three types of mobile dunes (heavy wind erosion, heavy sand burial and moderate sand burial). Clonal propagation of C. mongolicum was markedly different across sites. Moderate sand burial sites had the largest ramet density and bud number per unit length of rhizome, and the overwinter survival rate was significantly higher at sand burial sites than at wind erosion sites, suggesting that C. mongolicum may have well adapted to the moderate sand burial environment. We further examined the effects of clonal integration on clonal regeneration of this species. Physiological, biochemical and morphological characteristics of parent and daughter ramets growing in heterogeneous sandy habitats (sand burial or wind erosion) were measured. The results showed that being connected or severed from the maternal plant critically determined survival of daughter ramets on wind eroded rhizomes. When eroded rhizomes remained connected, the mother ramets had the highest chlorophyll a, b and a + b contents. However, both the mother plant and the daughter ramets undergoing erosion had higher proline and soluble protein levels than sand buried ramets. Meanwhile, the daughter ramets undergoing sand burial had higher photosynthetic rates (Pn), chlorophyll fluorescence parameters (Fm and Fo), and phenotypic traits of assimilating shoots, i.e., node number, length and volume than wind-eroded ramets. However, significant differences with mother plants, whether connected or severed, were very limited. It was concluded that moderate sand burial environments promoted clonal reproduction and growth of C. mongolicum. Additionally, physiological integration with mother raments in favorable conditions can alleviate stress on daughter ramets exposed to wind erosion. This physiological effect may do not occur for sand buried daughter ramets. These survival strategies and phenotypic responses should be carefully considered in shrub and sand dune management in sand fixation plantations of C. mongolicum.

The impact of short-term depositions of macroalgal blooms on widgeon-grass meadows in a river-dominated estuary

Macroalgal blooms can trigger adverse biogeochemical conditions at the sediment-water interface of shallow coastal areas, hence threatening critical habitats such as seagrasses meadows. The direction and magnitude of macroalgal blooms impacts on the aquatic ecosystem can be context-dependent, varying according to the local hydrodynamic conditions. Thus, studies investigating the impacts of stagnant algal depositions on the benthos may fail to address realistic situations and interactions which are common in well-flushed systems. This is especially true for the South America coast, where no study has investigated the effects of macroalgal blooms on seagrasses meadows. To fully understand the impacts of macroalgal blooms on sediment biogeochemistry and seagrass habitats across distinct environmental conditions and biogeographical regions, two independent, complementary field experiments replicated the natural temporal patterns of drift macroalgal mats depositions on unvegetated and vegetated (Ruppia maritima meadows) shoals of the Patos Lagoon estuary (PLE), a subtropical, high hydrodynamic system in southern Brazil. Transitory depositions of algal mats alleviated deleterious biogeochemical conditions in the sediment-water interface of unvegetated bottoms. Nevertheless, these unstable algal depositions promoted significant reductions in R. maritima biomass, by reducing their shoot height and density, and rhizome length. That plant biomass reductions were followed by a decrease in the abundance of the dominant infaunal tanaidacean Monokalliapseudes schubarti, indicating that algal impacts on seagrasses were transferred to higher trophic levels. Our results suggest that, although unstable deposition of drift algal mats can attenuate potential adverse impacts at the sediment-water interface, the physical stress during mats advection can still trigger small seagrass losses. This process may diminish the resilience of R. maritima meadows in the PLE, with impacts on estuarine nutrient cycling and secondary production. We conclude that, although harmful drift macroalgal blooms area global phenomenon, the mechanisms through which macroalgae impair seagrass habitats may vary according to the environmental context. Therefore, further studies are necessary to identify the underlying mechanisms of drift macroalgae-seagrass-macrofauna interactions in high hydrodynamic systems and their generality across distinct biogeographical areas.

Living in the intertidal: desiccation and shading reduce seagrass growth, but high salinity or population of origin have no additional effect.

The limiting effects of stressors like desiccation, light and salinity on seagrass growth and distribution are well-studied. However, little is known about their interactive effects, and whether such effects might differ among populations that are adapted to different local conditions. In two laboratory experiments we tested (a) if growth and development of intertidal, temperate Zostera noltii is affected by emergence time (experiment 1 and 2), and (b) how this is affected by an additional, second stressor, namely shading (experiment 1) or high salinity (25, 30 and 35, experiment 2). In addition, we tested (c) whether the effects of emergence time and salinity varied between three different European seagrass populations (Saint-Jacut/France, Oosterschelde/The Netherlands, and Sylt/Germany), which are likely adapted to different salinity levels (experiment 2). In both experiments, emergence of 8 h per tidal cycle (of 12 h) had a negative effect on seagrass relative growth rate (RGR), and aboveground biomass. Emergence furthermore reduced either rhizome length (experiment 1) or belowground biomass (experiment 2). Shading (experiment 1) resulted in lower RGR and a two-fold higher aboveground/belowground ratio. We found no interactive effects of emergence and shading stress. Salinity (experiment 2) did not affect seagrass growth or morphology of any of the three populations. The three tested populations differed greatly in morphology but showed no differential response to emergence or salinity level (experiment 2). Our results indicate that emergence time and shading show an additive negative effect (no synergistic or antagonistic effect), making the plants still vulnerable to such combination, a combination that may occur as a consequence of self-shading during emergence or resulting from algal cover. Emergence time likely determines the upper limit of Z. noltii and such shading will likely lower the upper limit. Shading resulted in higher aboveground/belowground ratios as is a general response in seagrass. Z. noltii of different populations originating from salinity 30 and 35 seem tolerant to variations in salinity within the tested range. Our results indicate that the three tested populations show morphotypic rather than ecotypic variation, at least regarding the salinity and emergence, as there were no interactive effects with origin. For restoration, this implies that the salinity regime of the donor and receptor site of Z. noltii is of no concern within the salinity range 25–35.

Sand-burial and wind erosion promote oriented-growth and patchy distribution of a clonal shrub in dune ecosystems

Habitat selection by oriented-growth of plants has been investigated but field evidence for such growth is scarce, impeding efforts at sand stabilization and dune ecosystem restoration. Further, how clonal shrubs adapt to dune environments is unknown. In this study, we test the hypotheses that oriented-growth and patchiness are adaptive strategies of clonal shrubs to dune environments, while wind erosion and sand burial are the driving factors. We sampled 250 rhizomatous fragments to assess oriented-growth of Calligonum arborescens, and investigated the distribution (east, southeast, south, southwest, west, northwest, north and northeast) of C. arborescens in four different habitats of active dunes: inter-dune areas, windward slope, leeward slope, and the top of dune. We found that most of the fragments of C. arborescens grew in the northeastern and southwestern directions. Ramet number and biomass, and rhizome length and biomass in these two directions were significantly higher than those found in other directions. Interestingly, these directions were perpendicular to the direction of prevailing winds. Distribution of C. arborescens differed among habitats. Total number of individuals was significantly higher in inter-dune areas and on windward slopes than on top and leeward slopes of dunes; more clonal ramets were produced on top of dunes than elsewhere, and only 16.7% were found on leeward slopes. Both sand-burial and wind erosion affected the growth and regeneration of C. arborescens. Ramet number and biomass production decreased with increasing depth of burial and severity of erosion, but increased in moderate erosion treatments. We conclude that fragments of C. arborescens exhibited oriented-growth; most of the rhizomes grew in the direction perpendicular to the prevailing wind direction. Most of C. arborescens were found in inter-dune lands and on windward slopes. C. arborescens was well established in active dune fields through both vegetative propagation and sexual reproduction. Sand-burial and wind erosion were the key factors which led to the oriented-growth and patchiness of C. arborescens.

Size and fitness responses of eelgrass (Zostera marina L.) following reciprocal transplant along an estuarine gradient

Eelgrass (Zostera marina) differs in shoot size, growth rate, and life history investment along a 30-km estuarine gradient in Willapa Bay, Washington (USA). In this study, reciprocal transplants were carried out among four sites in the estuary to test the roles of source population and outplant site for summer-season performance, a method that distinguishes any advantage of locally-tuned phenotypes and whether such trait differences are fixed or phenotypically-plastic. Shoots were measured after 2–3 months for size, leaf emergence rate (productivity) and shoot emergence rate (fitness), as well as simply finding them again (retrieval). Results generally did not support that best performance came from local shoots (few source x outplant site interactions). However, at one site, local shoots had higher fitness than other sources, and for one source, local retrieval exceeded that at other sites. Across all outplants, retrieval improved with rhizome length, suggesting that longer rhizomes provided better anchors. Fitness and productivity were both reduced for transplants into eelgrass relative to those in nearby bare areas at most sites, likely reflecting strong intraspecific competition for transplanted shoots. At this within-estuary scale in summer, morphology appeared entirely plastic, given convergence to local size, but annual vs. perennial life history was strictly a function of source population regardless of outplant site. This reciprocal transplant study supports many of the best practices for restoration, which include effective anchoring of shoots into locations with suitable environmental conditions. Matching donor populations for life history may be more important than for size, given differential phenotypic plasticity in these traits.