Effects of increasing NaCl concentration on stem elongation, dry mass production, and macro- and micro-nutrient accumulation in Poncirus trifoliata

2000 ◽  
Vol 27 (1) ◽  
pp. 35 ◽  
Author(s):  
Ilhami Tozlu ◽  
Gloria A. Moore ◽  
Charles L. Guy

The effects of salinization with 0, 30, 60, 90, and 120 mМ sodium chloride (NaCl) on Poncirus trifoliata (L.) Raf. cv. Pomeroy were studied by means of stem elongation patterns, whole plant and tissue mass production, and mineral nutrient accumulation. The elements analyzed in leaf, stem, structural root and fine root tissues included Na, Cl, P, K, Ca, Mg, Mn, Fe, Cu, Al, and Zn. At the end of the 12-week experimental period, shoot length was reduced 30–80% in the 30 to 120 mМ NaCl treatments. The linear relationship found between stem elongation and salt concentration, and different tissues and salt concentration suggests that a 40–60 mМ NaCl concentration is optimal to test P. trifoliata or its progeny for salt stress. Root production was found to be continuous and plants apparently used this process as an avoidance mechanism to remove excess ions and delay onset of ion accumulation in this tissue. This phenomenon, designated ‘Fine Root Turnover’, is unique to P. trifoliata and may be used as a genetic resource to improve Citrus for salinity tolerance through intergeneric hybridization. Plants were able to delay accumulation of Na ions in leaves but not Cl ions, resulting in high Cl accumulation in leaves and accumulation of both ions in fine roots. The data suggested that, while Cl ions were more toxic in leaf tissues, Na ions were at least as toxic in fine root tissues. Among other nutrients, K was affected the most in response to salinity, decreasing within root tissues and increasing in leaf tissues with increased salin-ization. A similar phenomenon was observed for P levels in salinized tissues. Changes in tissue and whole plant accumulation patterns of the other tested elements as well as possible mechanisms for how excess Na and Cl ions are removed from and/or transported to less vulnerable tissues in Poncirus trifoliata during salinization are discussed.

2000 ◽  
Vol 27 (1) ◽  
pp. 27 ◽  
Author(s):  
Ilhami Tozlu ◽  
Gloria A. Moore ◽  
Charles L. Guy

Salt stress responses of C. grandis L. (Osb.), P. trifoliata (L.) Raf. and their F 1 were investi-gated. Growth, growth rates, as well as leaf, stem, structural root (> 2 mm diameter), fine root (≤ 2mm diameter) and whole plant dry masses were determined for the three genotypes tested in 0, 40 and 80 mМ NaCl environments for 20 weeks. P. trifoliata and C. grandis were phenotypically distinct and their F1 had features that were a combination of both parents. The different growth habits resulted in significant differences between the net growth and growth ratios ([net growth / initial growth] × 100) of the three genotypes and between control and salinized plants within each genotype. The average growth and dry weights of nearly all tissues were reduced in salinized plants compared to those of control plants. The exceptions were the fine roots of P. trifoliata at both salinities and of the F1 plants at 40 mМ NaCl. The 40 mМ NaCl treatment stimulated fine root production in P. trifoliata plants, significantly increasing dry weight by 30% compared to control plants. Average shoot dry weight reduction was greatest in C. grandis and least in P. trifoliata in the 40 mМ NaCl treatment. While leaf tissues of P. trifoliata were the most sensitive to salinity, root tissues were the most sensitive in C. grandis. To avoid salt accumulation, P trifoliata plants increased root dry mass production while C. grandis plants increased leaf mass production. These traits appeared to be heritable, since the F1 plants displayed responses intermediate to its parents leading to increased salinity tolerance. We suggest that not only ion content of leaf tissues, but ion content and mass production of all tissues should be considered when the salinity tolerance of Citrus and related genera is characterized.


1989 ◽  
Vol 40 (5) ◽  
pp. 421 ◽  
Author(s):  
P.J. Hocking

A study was made of the seasonal changes in dry matter production and patterns of nutrient accumulation by Phragmites australis in a nutrient-enriched swamp in inland Australia. The density of live shoots was highest (224 m-2) in October, but the peak standing crop of live shoots (9890 g m-2) occurred in early May. Peak below-ground biomass (21 058 g m-2) occurred in early August. Rhizome biomass constituted 75% of the below-ground biomass, and showed a distinct seasonal pattern. Net annual above-ground primary production (NAAP), estimated by the maximum-minimum method, was 9513 g m-2. Correction for shoot mortality and leaf shedding before, and production after, the maximum standing crop was attained increased NAAP to 12 898 g m-2. Whole plant production estimated by the maximum-minimum method was 9960 g m-2, and the corrected estimate was 14 945 g m-2. A model of dry-matter production indicated that translocation of carbohydrate from rhizomes could have provided 33% of the dry matter of shoots. About 23% of the dry matter of shoots was redistributed to below-ground organs during senescence. Concentrations of N, P, K, S, Cl and Cu declined, but concentrations of Ca, Mg, Na, Fe and Mn increased as shoots aged. Concentrations of N, P and Zn in rhizomes reached maxima in winter, and decreased in spring. Rhizomes usually contained the greatest quantity of a nutrient in the whole plant, and roots usually had less than 25% of the total plant content. There were seasonal fluctuations in the quantities of N, P, K, Zn and Cu in rhizomes. Nutrient accumulation by live shoots was underestimated by 22-55% using the maximum-minimum method. Nutrient budgets showed considerable internal cycling of N, P, K, S and Cu from rhizomes to developing shoots in spring, and from senescing shoots to rhizomes during autumn and winter.


Weed Science ◽  
2015 ◽  
Vol 63 (3) ◽  
pp. 613-622 ◽  
Author(s):  
Robert B. Cross ◽  
Lambert B. McCarty ◽  
Nishanth Tharayil ◽  
J. Scott McElroy ◽  
Shu Chen ◽  
...  

Glyphosate is used in the transition zone to control annual bluegrass in fully dormant warm-season grasses. A suspected resistant (R) biotype of annual bluegrass was identified on a golf course in South Carolina after at least 10 consecutive years of glyphosate application. Greenhouse bioassays revealed the R biotype was 4.4-fold resistant to glyphosate compared with a standard susceptible (S) biotype. Further studies were conducted to investigate the mechanism conferring glyphosate resistance in the R biotype. Leaf discs of both biotypes accumulated shikimate in response to increasing glyphosate concentration, but the glyphosate concentration resulting in 50% EPSP synthase inhibition as a result of shikimate accumulation (I50) was 4.2-fold higher in the R biotype compared with the S biotype. At the whole plant level, similar levels of shikimate accumulation were observed between biotypes at 6 and 24 h after treatment (HAT) with glyphosate, but greater shikimate accumulation occurred in the S biotype at 72, 120, and 168 HAT. Shikimate levels decreased in the R biotype after 72 HAT. There were no differences in14C-glyphosate absorption between biotypes. However, more14C-glyphosate translocated out of the treated leaf in the R biotype and into root tissues over time compared with the S biotype. Partial sequencing of the EPSP synthase gene revealed a point mutation that resulted in an Ala substitution at Pro106. Although other mechanisms may contribute to glyphosate resistance, these results confirm a Pro106to Ala substitution is associated with resistance to glyphosate in the R annual bluegrass biotype.


1994 ◽  
Vol 34 (6) ◽  
pp. 845 ◽  
Author(s):  
M Buntain ◽  
B Chung

A field experiment was conducted to study the effects of irrigation and nitrogen applied at different growth stages on the oil and anethole yields of fennel (Foeniculum vulgare Mill.), and its yield components. Irrigation increased the yield of whole plant dry matter, with the stem elongation stage being the most sensitive. Full irrigation and irrigation applied during the flowering and late flowering growth stages increased umbel and oil yields. Irrigation during the late flowering stage made the greatest contribution to oil yield, accounting for >80% of the yield due to full irrigation. This was attributed to the concurrent timing of irrigation during the late flowering stage with dry conditions and the development of the main oil-bearing structures, the secondary and tertiary umbels. Irrigation had no significant effect on the anethole concentration of the oil. The best economic return was achieved by irrigating during the late flowering stage. There was no significant effect of nitrogen on any of the yield components measured in this study.


Genome ◽  
2004 ◽  
Vol 47 (3) ◽  
pp. 579-589 ◽  
Author(s):  
S Hocquigny ◽  
F Pelsy ◽  
V Dumas ◽  
S Kindt ◽  
M-C Heloir ◽  
...  

Vitis vinifera 'Pinot' clones were analysed at 50 microsatellite loci to assess intravarietal genetic diversity. When analysing leaf tissue DNAs, polymorphism mainly resulted from the appearance of a third allele when two were expected for heterozygous loci in a diploid species. The sequencing of the three microsatellite alleles at two loci has confirmed their simultaneous presence in the leaf tissues. A hypothesis explaining the triallelic profiles at a locus is the presence of a periclinal chimera meristem structure, in which genetically different cell layers coexist. The periclinal chimeric state of two Vitis vinifera 'Pinot gris' clones was confirmed by splitting and analysing the genotypes resulting from L1 and L2 cell layers in progeny derived from self-fertilization, in root tissues, and in plants regenerated from somatic embryogenesis. Prevalence of chimerism in polymorphic clones observed in a collection of 145 accessions belonging to 'Pinot gris', 'Pinot noir', Pinot blanc', 'Pinot meunier', and 'Pinot moure' cultivars was demonstrated. The accumulation of somatic mutations and cell layer rearrangements allowed us to deduce the relationships between the various genotypes and to open a way for understanding the diversification process and the phylogeny in the 'Pinot' group.Key words: microsatellite, diversity, somatic mutation, chimerism, Vitis vinifera L., 'Pinot'.


2022 ◽  
Vol 7 (1) ◽  
pp. 51-56
Author(s):  
Agáta Fargašová ◽  
Katarína Szárazová

The dry and fresh biomass and metal concentration (Cr, Ni) in roots and shoots of mustard (S. alba L.) seedlings was evaluated in laboratory experiments with three types of washing waste-waters from cutlery production line. All tested washing waters reduced root dry mass, where-as the dry mass of shoots was either not affected or it increased. The effect of tested washing waters was stronger on fresh mass production than on dry mass production. This indicates problems in water reception and translocation. While the accumulation of Cr was higher in the roots, Ni was distributed equally through the whole plant seedling. Cr uptake in the roots and shoots was in average about 1.7 and 7.3 times, respectively, lower than that of Ni. Ni percentage uptake from washing waters in the roots and shoots was nearly equal and range from 10.2 to 15.8%.


2003 ◽  
Vol 93 (2) ◽  
pp. 186-192 ◽  
Author(s):  
Wade H. Elmer

The role of NaCl in suppression of Fusarium crown and root rot of asparagus was investigated in split root culture so the direct effects of NaCl on the root and rhizosphere could be separated from effects that were translocated to the nontreated root side. One side of the root system was exposed to 100 ml of 0, 0.5, or 1.0% NaCl, while the other side received deionized water. Both sides of the root system were inoculated with conidial suspensions of the pathogens Fusarium oxysporum and F. proliferatum. When plants were harvested and assayed, root lesions and CFUs of F. oxysporum or F. proliferatum per centimeter of root from both exposed and nonexposed roots decreased as the NaCl rate increased to 1.0%, but the reduction relative to the control was significantly greater on roots that were directly exposed to NaCl (51% reduction in root lesions) than on adjacent nonexposed roots (31% reduction in root lesions). On both sides of the root systems, disease suppression with NaCl was associated with increases in the rhizosphere densities of fluorescent pseudomonads and Mn-reducing bacteria in the rhizosphere soil. In addition, as the NaCl rate increased, root tissues had marked reductions in malic acid and amino acids while concentrations of Cl and Mn increased in equal proportions on both sides of the root system. Chloride ions were absorbed in greater amounts than Na ions, and were more mobile in the plant than Na. Plants treated with 1% NaCl (171 meq of Cl- per liter) had soil leachates 1 week later of 47 meq of Cl- per liter from pots exposed to NaCl, but in the adjacent nonexposed pots, the amount of Cl in the leachates slowly increased over the course of the study to 20 meq/liter, presumably through the root exudation. These findings suggest that suppression of Fusarium crown and root rot of asparagus with NaCl may be due to multiple mechanisms. Maximum suppression occurs when NaCl is directly applied to roots, but suppression still occurs on distal non-treated roots resulting from systemic mechanisms. The latter mechanism may be associated with a root-mediated alteration in the rhizobacteria.


1990 ◽  
Vol 20 (9) ◽  
pp. 1524-1529 ◽  
Author(s):  
Alexander L. Friend ◽  
Marvin R. Eide ◽  
Thomas M. Hinckley

The proliferation of roots in soil microenvironments was studied to gain an understanding of how nitrogen (N) stress affects root growth. By placing one major lateral root (<10% of the root system) of a Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedling into a small pot (microenvironment) and the remaining roots into a large pot, it was possible to manipulate the growth of a small part of the root system while having only minor effects on the growth of the entire seedling. Nitrogen stress was successfully induced by large-pot treatments and resulted in greatly decreased foliage growth and slightly decreased total fine (<2 mm diam.) root growth. Nitrogen stress had minimal effects on total fine root growth, but large effects on the distribution of growth within the root system. Fine roots grew preferentially in high compared with low N microenvironments, and root proliferation in high N microenvironments was enhanced twofold in N-stressed compared with nonstressed seedlings. The root proliferation response of Douglas-fir seedlings to N stress illustrates a potential means of N-stress compensation. It also implies that root distribution among soil microenvironments may depend not only upon chemical activity of nutrient ions in the rooting environment, but also upon nutrient stress in the whole plant.


Genome ◽  
1999 ◽  
Vol 42 (4) ◽  
pp. 692-705 ◽  
Author(s):  
Ilhami Tozlu ◽  
Charles L Guy ◽  
Gloria A Moore

The effects of salinization with 40 mM NaCl on Poncirus trifoliata (L.) Raf., Citrus grandis (L.) Osb., their F1, and a BC1 progeny population (C. grandis × (F1)) were investigated by means of Na+ and Cl- analyses and QTL (quantitative trait loci) mapping. A total of 38 traits related to different tissue or whole-plant Na+ and (or) Cl- accumulation was analyzed in salinized and nonsalinized BC1 progeny clones. The comparison of the three parental types with the BC1 progeny under control and saline conditions showed that the BC1 progeny plants segregated transgressively for many traits. First mapping analyses resulted in a total of 73 potential quantitative trait loci (PQTL) with LOD scores [Formula: see text]3.0 located on a previously generated linkage map. Fifty-three percent of the mapped PQTLs were for traits associated with salinity. The small progeny population size used made further analyses of these PQTLs necessary. By considering LOD scores, map locations, and correlation analyses of the traits, it was possible to identify 17 regions of the citrus genome of interest: 8 of them may contain genuine QTLs of large effect and 9 regions are worthy of further study. Correlation analyses and locations of PQTLs indicated that many traits were controlled by fewer genes than the actual number of QTLs mapped for them. For example, 21 PQTLs mapped for Na+ accumulation and Cl-/Na+ ratios were located in a cluster at the beginning of one linkage group (LG), while 10 PQTLs mapped for Cl- accumulation and Cl-/Na+ ratios were located in a cluster at the beginning of another LG. This is the first step in identifying QTLs that have a major impact on salt tolerance and (or) mineral accumulation in citrus.Key words: Citrus grandis, Poncirus trifoliata, salinity stress, QTL mapping, transgressive segregation, mineral analysis, sodium, chloride, salt tolerance, citrus genetics.


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