Effects of seedling age and size on chloride accumulation by juvenile citrus seedlings treated with sodium chloride under glasshouse conditions

1985 ◽  
Vol 25 (4) ◽  
pp. 943 ◽  
Author(s):  
SR Sykes

Chloride accumulation by juvenile citrus seedlings treated with sodium chloride for 56 days, using either nutrient solution culture (50 mM NaCl) or pot culture (75 mM NaCl) techniques under glasshouse conditions, was investigated in relation to seedling age. Ranking of cultivars on the basis of leaf chloride concentrations varied according to the age of seedlings examined. Leaf chloride concentrations of 6-, 5-, 4- and 3-month-old seedlings of eight cultivars examined in solution culture decreased with seedling age and were negatively correlated with seedling dry weight within some cultivars. Cultivar differences in leaf chloride concentrations, which occurred for all age groups, were negatively correlated with shoot growth and seedling dry weight for 5-month-old seedlings only. Leaf chloride concentrations of seedlings treated with NaCl in pot culture also changed with the age of seedlings (5, 17- and 29-monthsold) and varied between cultivars, with significant cultivar x age interactions. The effect of seedling size on chloride accumulation was investigated using nutrient solution culture. Six-month-old seedlings of four varieties were treated with NaCl (50 mM) for 56 days. Two size classes were obtained by growing seedlings at two densities before salt treatment. Small seedlings had greater shoot chloride concentrations than equivalent large seedlings and cultivar ranking, based on shoot chloride concentrations, changed with seedling size. Cultivar differences in leaf chloride concentrations were negatively correlated with seedling growth and dry weight for small seedlings but not for large seedlings. Seedling size had no effect on root chloride concentrations. The results suggest that screening very small seedlings for chloride exclusion is not feasible since rankings based on leaf chloride concentrations did not agree with documented data for grafted trees. There appeared to be a critical or threshold seedling age or size at or above which rankings for shoot chloride accumulation by good chloride excluders were consistent with documented field data. The results are discussed in relation to screening citrus hybrids for chloride exclusion under glasshouse conditions.


2008 ◽  
Vol 53 (No. 2) ◽  
pp. 65-71 ◽  
Author(s):  
S.J. Miao ◽  
X.Z. Han ◽  
X.B. Liu ◽  
Y.F. Qiao

The effect of three seedling treatments: T<sub>0</sub>, normal germination; T<sub>1</sub>, cotyledons removed; T<sub>2</sub>, cotyledons removed 5 days earlier than in T<sub>1</sub>; and two phosphorus levels (P<sub>0</sub> and P<sub>30</sub>) on nodulation and nodule function in soybean [<i>Glycine max</i> (L.) Merr.] were investigated in nutrient solution culture. The number of nodules formed at P<sub>0</sub> was in the order T<sub>2</sub> > T<sub>0</sub> > T<sub>1</sub>, but it was T<sub>0</sub> > T<sub>2</sub> > T<sub>1</sub> at P<sub>30</sub>. Nodule dry weight per plant had the same tendency as the nodule number. Nodule size (dry weight per nodule) in seedlings ranged from 0.601 to 1.089 mg in the order T<sub>0</sub> > T<sub>1</sub> > T<sub>2</sub>, regardless of P level. For example, nodule size in T<sub>0</sub> was larger by 86% and 52% than T<sub>2</sub> at P<sub>0</sub> and P<sub>30</sub>, respectively. Furthermore, regardless of P level, a specific acetylene reduction activity (ARA, &micro;M C<sub>2</sub>H<sub>4</sub>/h/g nodule) increased with P content in seedlings, but no significant difference was found (<i>P</i> < 0.05). Leghemoglobin (Lb) content was not significantly affected by P level; however, seedlings (T<sub>0</sub> and T<sub>1</sub>) significantly affected the Lb content per unit plant biomass (<i>P</i> < 0.05). All these results suggest that seedling P content plays a key role in nodulation and nodule function of soybean.



1984 ◽  
Vol 11 (6) ◽  
pp. 471 ◽  
Author(s):  
EJ Luard ◽  
MH El-Lakany

Ten species of Casuarina and Allocasuarina were exposed to increasing levels of NaCl (max 550 mM) in solution culture over a period of 5 months. Na+ and Cl- ion concentrations increased in the tissues of all species as the salinity increased and K+ was selectively accumulated. Those species which ultimately survived to the highest salinities tested had lower concentrations of Na+ and Cl- in both shoot and roots and lower Na+/K+ ratios than the more sensitive species at low external salinities. Osmotic adjustment of the Casuarina species was principally accounted for by Na+ and Cl- in the shoots. Turgor pressure was not lost until the plants were close to death, so that inhibition of height growth by NaCl was probably due to the high cellular ion concentrations. Plants were more sensitive to osmotic shock than to a gradual increase in salinity.



1979 ◽  
Vol 57 (12) ◽  
pp. 1345-1348 ◽  
Author(s):  
P. S. Baenziger ◽  
R. A. Kilpatrick ◽  
J. G. Moseman

We determined the effects of infection by Erysiphe graminis f. sp. tritici on root and shoot growth of the susceptible wheat cultivar 'Chancellor,' of the intermediately resistant line C.I. 14122 and of the highly resistant line C.I. 14120. Lines C.I. 14122 and C.I. 14120 are near isogenic lines of 'Chancellor' that carry resistant genes Pm3c and Pm3a respectively, conditioning their resistance to E. graminis tritici. Seedlings were grown in nutrient solution culture, inoculated with cultured of E. graminis tritici, and harvested 21 days after inoculation. The root dry weight of ‘Chancellor' was 54% less than the root dry weight of the highly resistant line C.I. 14120. The root dry weight of the intermediately resistant line C.I. 14122 was 16% less than the root dry weight of the highly resistant line C.I. 14120. The shoot dry weight of ‘Chancellor' was 46% less than that of the highly resistant line C.I. 14120. Tiller number was also significantly reduced by E. graminis tritici.



HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1119A-1119
Author(s):  
Dean A. Kopsell ◽  
David E. Kopsell ◽  
Joanne Curran-Celentano

Kale (Brassica oleracea L.) ranks highest among vegetable crops for lutein and beta-carotene carotenoids, which function as antioxidants in disease prevention. Nitrogen (N) rate and N form influence plant growth and alter pigment composition and accumulation. The objectives of these experiments were to investigate the effect of N rate and form on biomass and accumulation of plant pigments in the leaf tissues of kale. Three kale cultivars were grown using nutrient solution culture. In the first study, N treatment rates were 6, 13, 26, 52, and 105 mg·L–1, at a constant NH4-N:NO3-N ratio. Kale biomass increased linearly in response to increasing N rate. On a fresh weight basis, lutein and beta-carotene were not affected by N rate. However, carotenoids calculated on a dry weight basis increased linearly in response to increasing N rate. In a second study, kale was grown under: 100% NH4-N:0% NO3-N, 75% NH4-N:25% NO3-N, 50% NH4-N:50% NO3-N, 25% NH4-N:75% NO3-N, and 0% NH4-N:100% NO3-N, at a N rate of 105 mg·L–1. Linear increases in biomass were observed for each kale cultivar as percentage of NO3-N increased. Lutein concentrations increased 155%, 73%, and 39% for `Toscano', `Winterbor', and `Redbor' kale, respectively, as N form changed 0% NO3-N to 100% NO3-N. Concentration of leaf beta-carotene increased linearly in response to increasing NO3-N in each cultivar tested. Nitrogen management should be considered in crop production programs designed to increase the concentrations of nutritionally important carotenoids.



Weed Science ◽  
1979 ◽  
Vol 27 (3) ◽  
pp. 278-279 ◽  
Author(s):  
W. S. Hardcastle

Twenty-eight commercial soybean [Glycine max(L.) Merr.] cultivars of maturity classes V through VIII were evaluated for differences in response to metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] 0.125 ppm w/w in hydroponic culture. Top dry weight (TDW) of treated ‘FFR 666’ soybeans equaled that of the cultivar check and five other cultivars were not significantly different (P = 5%). ‘Semmes' was most sensitive to the herbicide with TDW 40% of cultivar check. ‘Tracy’ and ‘Coker 156’ were not significantly different (P = 5%) from Semmes. The other cultivars tested were intermediate in response to metribuzin.



1970 ◽  
Vol 62 (3) ◽  
pp. 351-352 ◽  
Author(s):  
N. Jerry Chatterton ◽  
C. M. McKell ◽  
F. T. Bingham ◽  
W. J. Clawson


1956 ◽  
Vol 7 (2) ◽  
pp. 98 ◽  
Author(s):  
JN Black

Changes in the pre-emergence distribution of dry matter in subterranean clover (Trifolium subterraneum L.) variety Bacchus Marsh were followed at 21°C, using three sizes of seed and three depths of sowing, ½, 1¼, and 2 in. Decreasing seed size and increasing depth of sowing both reduce the weight of the cotyledons a t emergence. Seed of the three sizes were sown a t three depths in pot culture a t staggered intervals so that emergence was simultaneous. Dry weight in the early vegetative stage was proportional to seed size, and total leaf area and leaf numbers showed similar trends. Plants of each seed size grew at the same relative rate. No effect of depth of sowing could be detected, and this was shown to be due to the cotyledon area a t emergence being constant for any given seed size, regardless of varying depth of sowing and hence of cotyledon weight. It was concluded that seed size in a plant having epigeal germination and without endosperm is of importance: firstly, in limiting the maximum hypocotyl elongation and hence depth of sowing, and secondly, in determining cotyledon area. Cotyledon area in turn influences seedling growth, which is not affected by cotyledon weight. Once emergence has taken place, cotyledonary reserves are of no further significance in the growth of the plants.



2014 ◽  
Vol 91 (4) ◽  
pp. 327-332 ◽  
Author(s):  
Filiz Koksel ◽  
Anatoliy Strybulevych ◽  
John H. Page ◽  
Martin G. Scanlon


2019 ◽  
Vol 5 (04) ◽  
pp. 243-246
Author(s):  
Debnirmalya Gangopadhyay ◽  
Ashmita Ghosh ◽  
Mrinal Ray

Nitric oxide (NO) is an important bioactive signaling molecule in plants which modulates a variety of physiological processes and responses to abiotic and biotic stresses. In this study, the effects of exogenous NO supplied as sodium nitroprusside (SNP) in wheat seedlings under ironinduced oxidative damage was investigated. An appropriate concentration of NO was determined by conducting a preliminary experiment. In solution culture, wheat seeds were grown in the control (100 μM Fe), and toxic Fe (400 μM Fe) levels and the toxic Fe supply was treated with various levels of (50, 100, 200 and 500 μM) sodium nitroprusside (SNP). The results indicated that 400 μM Fe significantly decreased percentage germination, tolerance index, root lengths as well as fresh and dry weight compared to control. Exogenous SNP attenuated the inhibition of wheat seed germination. The promoting effect was most pronounced at 100 μM SNP. The accumulated concentration of iron and active Fe was significantly decreased by SNP treated Fe toxic seedlings. Toxicity of Fe caused oxidative stress by elevating hydrogen peroxide (H2O2), malondialdehyde (MDA) and proline contents in roots of wheat seedlings. One hundred μM SNP counteracted Fe toxicity by reducing the H2O2, MDA and proline contents of toxic Fe exposed seedlings. Meanwhile, application of SNP markedly reduced the activities of superoxide dismutases (SOD), catalases (CAT), peroxidase (POD), ascorbate peroxidases (APX), non protein thiols (NPT) and of glutathione reductase (GR) and increased ascorbate (ASc) compared with Fe toxic treatment alone, thereby indicating the modulation of the antioxidative capacity in the root under Fe stress by NO. The results indicated that the exogenous application of SNP, improved the antioxidant enzymes activity of wheat seedlings against Fe induced oxidative stress.



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