Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Critical Nitrogen Dilution Curve in Processing Potato Cultivars  [PDF]
Claudia Marcela Giletto, Hernán Eduardo Echeverría
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.619306
Abstract: The critical nitrogen dilution curve (CNDC) can be used as a diagnostic tool to assess crop N nutrition during the growing season. Potato cultivars have different biomass production and accumulation of N and consequently different growth patterns. These differences among cultivars may result in different CNDC. The aims were a) to determine the CNDC for different potato cultivars; b) to compare these curves with reference curves; and c) to assess the possibility of using the CNDC to estimate the N nutritional status of the crop. The biomass production and N concentration of shoots and tubers of potato cultivars Innovator, Gem Russet, Umatilla Russet, Bannock Russet and Markies Russet were measured. The harvest index (HI) and N harvest index (NHI) were determined. The coefficient a of the CNDC was similar among cultivars, while the coefficients b for Innovator and Gem Russet (-0.42 and -0.36, respectively) were smaller than those for the other cultivars (average -0.25). HI and NHI were greater in Innovator, smaller in Markies Russet, and intermediated in the other three cultivars. The coefficients b of the CNDC were correlated with HI and NHI (HI, r = -0.62, p < 0.0001 and -0.53, p < 0.0001; NHI, r = -0.60, p < 0.0001 and -0.61, p < 0.0001 for 2004/5 and 2005/6, respectively). The relationship between relative tuber yield (RY) and N nutrition index (NNI) was fit by a quadratic-plateau function. At similar situations of N deficiency, Innovator had lower yield and greater response to N rate than the other potato cultivars. The differences in HI and NHI among cultivars may explain the differences in the coefficient b of the CNDC. The NNI identified the status of N adequately in potato cultivars.
Dry Matter Accumulation and Partitioning and Growth of Garlic as Influenced by Land Configuration and Cultivars  [PDF]
Md. Shahidul Haque,Md. Abdus Sattar,M. Habibur Rahman Pramanik
Pakistan Journal of Biological Sciences , 2002,
Abstract: Study was conducted to determine the effects of various land configurations on dry matter production, distribution and growth of garlic. Ridge planting method significantly influenced total dry matter (TDM) production and its distribution into root, stem and leaf. It had higher total, stem, root and leaf dry matter, leaf area index (LAI) and crop growth rate (CGR) over furrow and flat methods of planting. Varietal difference in dry matter partitioning and growth of garlic was revealed in this study. The cv. Faridpur that had highest clove weight produced higher total, stem, root and leaf dry matter, LAI and CGR over the other two cultivars.
Effect of Salt Stress on Growth, Na+ Accumulation and Proline Metabolism in Potato (Solanum tuberosum) Cultivars  [PDF]
Rinse Jaarsma, Rozemarijn S. M. de Vries, Albertus H. de Boer
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0060183
Abstract: Potato (Solanum tuberosum) is a major crop world-wide and the productivity of currently used cultivars is strongly reduced at high soil salt levels. We compared the response of six potato cultivars to increased root NaCl concentrations. Cuttings were grown hydroponically and treated with 0 mM, 60 mM and 180 mM NaCl for one week. Growth reduction on salt was strongest for the cultivars Mozart and Mona Lisa with a severe senescence response at 180 mM NaCl and Mozart barely survived the treatment. The cultivars Desiree and Russett Burbank were more tolerant showing no senescence after salt treatment. A clear difference in Na+ homeostasis was observed between sensitive and tolerant cultivars. The salt sensitive cultivar Mozart combined low Na+ levels in root and stem with the highest leaf Na+ concentration of all cultivars, resulting in a high Na+ shoot distribution index (SDI) for Mozart as compared to Desiree. Overall, a positive correlation between salt tolerance and stem Na+ accumulation was found and the SDI for Na+ points to a role of stem Na+ accumulation in tolerance. In stem tissue, Mozart accumulated more H2O2 and less proline compared to the tolerant cultivars. Analysis of the expression of proline biosynthesis genes in Mozart and Desiree showed a clear reduction in proline dehydrogenase (PDH) expression in both cultivars and an increase in pyrroline-5-carboxylate synthetase 1 (P5CS1) gene expression in Desiree, but not in Mozart. Taken together, current day commercial cultivars show promising differences in salt tolerance and the results suggest that mechanisms of tolerance reside in the capacity of Na+ accumulation in stem tissue, resulting in reduced Na+ transport to the leaves.
Relationships between grain yield and accumulation of biomass, nitrogen and phosphorus in common bean cultivars
Araújo, Adelson Paulo;Teixeira, Marcelo Grandi;
Revista Brasileira de Ciência do Solo , 2008, DOI: 10.1590/S0100-06832008000500019
Abstract: shoot biomass is considered a relevant component for crop yield, but relationships between biological productivity and grain yield in legume crops are usually difficult to establish. two field experiments were carried out to investigate the relationships between grain yield, biomass production and n and p accumulation at reproductive stages of common bean (phaseolus vulgaris) cultivars. nine and 18 cultivars were grown on 16 m2 plots in 1998 and 1999, respectively, with four replications. crop biomass was sampled at four growth stages (flowering r6, pod setting r7, beginning of pod filling r8, and mid-pod filling r8.5), grain yield was measured at maturity, and n and p concentrations were determined in plant tissues. in both years, bean cultivars differed in grain yield, in root mass at r6 and r7 stages, and in shoot mass at r6 and r8.5, whereas at r7 and r8 differences in shoot mass were significant in 1998 only. in both years, grain yield did not correlate with shoot mass at r6 and r7 and with root mass at r6. grain yield correlated with shoot mass at r8 in 1999 but not in 1998, with shoot mass at r8.5 and with root mass at r7 in both years. path coefficient analysis indicated that shoot mass at r8.5 had a direct effect on grain yield in both years, that root mass at r7 had a direct effect on grain yield in 1998, and that in 1999 the amounts of n and p in shoots at r8.5 had indirect effects on grain yield via shoot mass at r8.5. a combined analysis of both experiments revealed that biomass accumulation, n and p in shoots at r6 and r7 as well as root mass at r6 were similar in both years. in 1998 however bean accumulated more root mass at r7 and more biomass and n and p in shoots at r8 and r8.5, resulting in a 57 % higher grain yield in 1998. this indicates that grain yield of different common bean cultivars is not intrinsically associated with vegetative vigor at flowering and that mechanisms during pod filling can strongly influence the final crop yield. the esta
Growth, Gas Exchange, Chlorophyll a Fluorescence, Biomass Accumulation and Partitioning in Droughted and Irrigated Plants of Two Enset (Ensete ventricosum Welw. Cheesman) Clones  [PDF]
Solomon Zewdie,Mats Olsson,Masresha Fetene
Journal of Agronomy , 2007,
Abstract: Enset (Ensete ventricosum) plants grown in the middle and low altitudes are experiencing different degrees and length of summer drought every year. Information is lacking on plant responses to drought stress, underlying mechanisms of response and effect of drought on the growth and yield of enset. The effect of induced drought/irrigation on growth parameters, gas exchange and biomass accumulation and partitioning of enset clones was studied in the field at Guebre, Southern Ethiopia. One year old plants of two enset clones were either irrigated or droughted by with holding water for 90 days. Prolonged drought markedly and significantly reduced growth parameters of both enset clones. Drought stress significantly reduced specific leaf area and net assimilation rate and these reductions showed significant positive correlations with relative growth rate. Stomatal conductance, net photosynthesis rate and transpiration declined considerably after 60 and 90 days of drought. Despite the reduction in stomatal conductance, leaf water status showed little change. Quantum yield of PSII photochemistry showed a reversible diurnal depression which was accompanied by a marked increase in non-photochemical fluorescence quenching. Proportionally, droughted plants accumulated significantly more dry matter to belowground parts and drought appeared to increase harvest index of the corm. The enset clone Ameratye produced a significantly higher total dry matter than Yesherakinkye both under drought and/or irrigation. Both stomatal and non-stomatal factors might have contributed for the observed decline in carbon dioxide uptake rates of droughted plants. Present findings indicated that seasonal dry periods could considerably alter enset physiology and reduce growth and yield. Moreover, harvest index of the corm can be used as a selection criterion in screening enset clones suitable for drought prone areas.
Effect of Growth Stage-Based Irrigation Schedules on Biomass Accumulation and Resource Use Efficiency of Wheat Cultivars  [PDF]
Muhammad Mubeen, Ashfaq Ahmad, Tasneem Khaliq, Syeda Refat Sultana, Shahid Hussain, Amjed Ali, Hakoomat Ali, Wajid Nasim
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.47175

Climate and weather conditions greatly affect the performance of new wheat cultivars for yield and resource use efficiency. In order to know the effect of irrigation schedules based on growth stage (the most vital criterion in the region) on growth, yield and radiation use efficiency of wheat cultivars in Faisalabad conditions, a study was planned at Agronomic Research Area, University of Agriculture, Faisalabad during 2009-2010. Split plot design with irrigation levels in main plots and cultivars in sub-plots was implied. Irrigation levels were: IT = irrigation at tillering stage, ITS = irrigation at tillering and stem elongation stage, ISB = irrigation at stem elongation and booting stage and ITSBG = irrigation at tillering, stem elongation, booting and grain filling stage. Cultivars selected were: Faisalabad-2008, Lasani-2008, Miraj-2008, Shafaq-2006 and Chakwal-97. Irrigation treatment ITSBG gave higher grain yield (4.23 t·ha-1) followed by ISB (3.60 t·ha-1), however ITSBG was statistically similar to ISB in radiation use efficiency (RUE) for grain yield (RUEGY). Similarly the two treatments were statistically at par in maximum leaf area index, total dry matter (TDM) accumulation, cumulative photosynthetically active radiation (PAR), and RUETDM. Hence where less numbers of irrigations are available, irrigation at stem elongation and booting stage is suitable for achieving economic yield. Lasani-2008 produced maximum grain yield (4.37 t·ha-

Cd Uptake and Accumulation in Grains by Hybrid Rice in Two Paddy Soils:Interactive Effect of Soil Type and Cultivars

GONG Wei-qun,LI Lian-qing,PAN Gen-xing,

环境科学 , 2006,
Abstract: Cd translocation through soil-food crop-diet is considered as one of most important pathway for human Cd exposure. Rice is considered as a particular crop with high Cd uptake and accumulation in grains among the main food crops. In this study, a pot experiment was conducted to elucidate mutual interaction of soil and cultivars on uptake and grain accumulation of Cd by hybrid rice with or without Cd spiking at 2.5 mg x kg(-1) under continuous submerging condition. Two hybrid rice cultivars (Shanyou 63, a common hybrid rice and II Youming 86, a super-rice) and two paddy soils (a Wushantu, Gleyic Stagnic Anthrosols and a Hongshanitian, Ultic Stagnic Anthrosols) were used. The results show significant differences in Cd uptake and grain partitioning between soils, cultivars and the soil-cultivar interactions. The cultivars effect on uptake of indigenous soil Cd seems stronger than the soil effect while soil effect turns significant over that of cultivars on spiked Cd. However, intense Cd accumulation in grains is found under the positive interaction of soil with high Cd availability and cultivar with high Cd affinity (super rice on acidic paddy soil). This study demonstrates a phenomenon of intense Cd uptake and grain accumulation by super rice and, thus, imposing a very high Cd exposure risk (as several times as the acceptable daily intake, ADI) to subsistence-diet farmers. The low Cd cultivar Shanyou 63 tends to hamper the up-taken Cd in root while the super rice II Youming 86 promotes higher partitioning to grain. Furthermore, the difference in total biomass between the two cultivars is small compared to that in total Cd uptake under Cd spiking. It is suggested that the Cd uptake behavior should be taken into account in super rice breeding and practical measures should be taken while spread of super rice cultivars in rice areas with acidic soils and under Cd pollution in order to control the human Cd exposure by diet.
Accumulation and distribution of dry matter in relation to root yield of cassava under a fluctuating water table in inland valley ecology
M Lahai, IJ Ekanayake
African Journal of Biotechnology , 2009,
Abstract: Cassava an important staple food is grown both in upland and inland valley in the tropics. A trial to assess dry matter production and partitioning in relation to root yield was conducted in 3 positions along inland valley toposequence using 4 x 4 Latin square design. Dry matter partitioning differed among cultivars, toposequence positions, sites and years due to differences in water table depth and weather conditions. High dry matter partitioning to leaves, stems, fibrous roots and rootstocks reduced yield, while high biomass allocation to storage roots increased yield. High dry matter partitioning to leaves reduced yield more in the landrace likely due to low sink capacity. Partitioning high dry matter to leaves reduced yield more at deep than shallow water table depth. Excess moisture stress increased dry matter accumulation in rootstock, fibrous and storage roots, but decreased partitioning to stems and leaves. Drought stress reduced dry matter allocation to storage roots, but increased partitioning to rootstocks, fibrous roots and stems. TMS 91/02324 and TMS 91/02327 with lowest dry matter accumulation in stems and fibrous roots and highest in storage roots had the highest yields and therefore better adapted to inland valley conditions.
干旱胁迫和施肥对巨能草生物量及 C、N、P积累与分配的影响
Effect of drought stress and fertilization on accumulation and partitioning of biomass,C,N and P of Puelia sinese Roxb

- , 2016,
Abstract: 【目的】研究干旱胁迫和施肥对巨能草生物量及C、N、P积累与分配的影响,为巨能草栽培中的水肥管理提供理论依据。【方法】以巨能草为研究对象,采用盆栽试验,利用控水、控肥的试验方法,设计干旱(田间持水量的25%)和正常水分(田间持水量的75%)2个水分梯度以及低肥(复合肥施肥量为2 g/盆)、中肥(复合肥施肥量为4 g/盆)、高肥(复合肥施肥量为8 g/盆)3个养分水平,进行完全随机组合试验,共计6个处理,研究不同处理下巨能草生物量及其分配比例,C、N、P积累与分配特征,N、P吸收和利用效率,以及C∶N、C∶P、N∶P的变化。【结果】在正常水分条件下,随着施肥量的增加,巨能草的地上、地下生物量和总生物量都显著增加;干旱胁迫后,巨能草地上和地下生物量的积累显著降低,施肥对巨能草的地上、地下生物量和总生物量也有显著影响。在正常水分条件下,施肥对巨能草地上和地下生物量的分配比例没有显著影响;在干旱条件下,除低肥处理外,中施肥量和高施肥量均能显著提高巨能草地下生物量的分配比例。施肥和干旱胁迫处理对C、N、P积累量及分配比例也有一定的影响,与正常水分条件相比,干旱胁迫后巨能草的C、N、P积累总量均降低。在正常水分条件下,尽管低肥处理的N、P吸收效率显著低于中、高肥处理,但其N、P利用效率却显著高于中、高肥处理;干旱条件下,不同施肥处理的N、P吸收效率和P利用效率并无显著差异,但N的利用效率随着施肥量的增加而降低。正常水分条件下,施肥处理对地上部分的C∶P、N∶P无显著影响,但高肥处理显著降低了地下部分的N∶P,中、高肥处理显著降低了地上部分的C∶N和地下部分的 C∶P;干旱条件下,施肥处理对地上和地下部分的C∶P及N∶P的影响都不显著,但高肥处理显著降低了地上和地下部分的C∶N。【结论】干旱胁迫处理减少了巨能草的生物量及其对C、N、P的积累,影响了C、N、P的分配,施肥在一定程度上降低了干旱胁迫对植物生长的影响,在巨能草的施肥管理中,应更多地注重对N素的管理。
【Objective】A controlled pot-culture experiment was conducted to investigate effects of drought stress and fertilization on accumulation and partitioning of biomass,C,N and P of Puelia sinese Roxb.【Method】The experiment was a completely randomized design with 6 factorial combinations of 2 moisture gradients (drought,25% field capacity and control,75% field capacity) and 3 levels of fertilization (low,2 g/pot;moderate,4 g/pot;and high,8 g/pot).【Result】Under controlled condition,with the increase of fertilization amount,the below-ground biomass,above-ground biomass and total biomass of Puelia sinese Roxb increased significantly.Under drought stress,the below-ground biomass and above-ground biomass of Puelia sinese Roxb decreased significantly,indicating that fertilization had significantly positive effect on the below-ground biomass,above-ground biomass and total biomass.Under controlled condition,the effects of fertilization on the allocation proportion of the below ground and above-ground biomass were not significant.Under drought stress,both moderate and high fertilizations could significantly improve the allocation proportion of the below-ground biomass,except for low fertilization.Fertilization and drought stress also had certain influences on the accumulation and distribution of C,N and P.Compared with controlled condition,the accumulation quantities of C,N and P decreased after drought stress.Under controlled condition,the absorption efficiencies of N and P under low fertilization treatment were lower than moderate and high fertilizations,while the use efficiencies of N and P were higher un
Regeneration and transformation of Polish cultivars of potato
Anna Nadolska-Orczyk,Lidia Mi?kowska,Andrzej Pa?ucha,Pawe? Czembor
Acta Societatis Botanicorum Poloniae , 1995, DOI: 10.5586/asbp.1995.043
Abstract: The article presents the results of regeneration and transformation experiments of 12 Polish cultivars of potato. The cultivars Brda, Bzura, Elipsa and Irga regenerated the highest number of shoots from leaf explants (60% to 100% of explants regenerated 4.9 to 16.5 shoots per explant). The cultivars Brda, Bzura, Elipsa and Irys were the source of the best regenerating tuber explants (66% to 100% of explants regenerated 6.2 to 11.9 shoots from one explant). Both types of explants (from leaves and tubers) were used for transformation experiments. Agrobacterium tumefaciens strains used for transformation contained binary vector system: LBA 4404 (pAL 4404:pBI 121) and C58C1 (pGV2260:pVU104). There was a strong correlation between regeneration ability of tested cultivars and transformation efficiency. GUS-positive, kanamycin resistant and well rooted plants from leaf explants in cultivars Bzura, Brda and from tuber explants in Bzura and Elipsa were obtained. Northern blot analysis confirmed the presence of β-glucuronidase mRNA in transgenic plants.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.