Solute flows from Hordeum vulgare to the hemiparasite Rhinanthus minor and the influence of infection on host and parasite nutrient relations

2004 ◽  
Vol 31 (6) ◽  
pp. 633 ◽  
Author(s):  
Fan Jiang ◽  
W. Dieter Jeschke ◽  
Wolfram Hartung

Using the facultative root hemiparasite Rhinanthus minor and Hordeum vulgare L. as a host, the flows and partitioning of mineral nutrients within the host, the parasite and between host and parasite have been studied during the study period 41–54 d after planting, i.e approximately 30–43 d after successful attachment of the parasite to the host. In parasitising Rhinanthus shoot growth was 12-fold, but root growth only 2-fold increased compared to non-parasitising plants. Conversely, in the Hordeum host, shoot dry matter growth was clearly reduced, by 33% in leaf laminae and by 52% in leaf sheaths, whereas root growth was only slightly reduced as a consequence of parasitism. Growth-dependent increments of total nitrogen (N) and phosphorus (P) and of potassium (K), calcium (Ca) and magnesium (Mg) in parasitising Rhinanthus shoot were strongly increased, particularly increments of total N and P, which were 18 and 42 times, respectively, higher than in solitary Rhinanthus. However, increments of the above mineral nutrients in leaf sheaths of parasitised Hordeum vulgare were more strongly decreased than in leaf laminae in response to parasitic attack. Estimation of the flows of nutrients revealed that Rhinanthus withdrew from the host xylem sap about the same percentage of each nutrients: 18% of total N, 22% of P and 20% of K. Within the host almost all net flows of nutrient ions were decreased due to parasitism, but retranslocation from shoot to root was somewhat increased for all nutrients. Quantitative information is provided to show that the substantially increased growth in the shoot of attached Rhinanthus and the observed decrease in Hordeum shoot growth after infection were related to strongly elevated supply of nitrogen and phosphorus in the parasite and to incipient deficiency of these nutrients in the parasitised host. The flows of nutrients between host and parasite are discussed in terms of low selectivity of nutrient abstraction from the host xylem by the hemiparasite Rhinanthus minor.


Agriculture ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 650
Author(s):  
Lisa Petzoldt ◽  
Miriam Athmann ◽  
Andreas Buechse ◽  
Timo Kautz

Biopores provide nutrients from root debris and earthworm casts. Inside large biopores, root function is limited due to the lack of root–soil contact. However, the immediate surroundings of biopores may hold a key function as “hotspots” for root growth in the subsoil. To date, sufficient quantitative information on the distribution of roots and nutrients around biopores is missing. In this field study, the biopore sheath was sampled at distances of 0–2, 2–4, 4–8, and 8–12 mm from the surface of the pore wall. The results show a laterally decreasing gradient from the pore towards 8–12 mm distance in root length density (RLD) of spring barley (Hordeum vulgare L.) and faba bean (Vicia faba L.), as well as in total nitrogen (Nt)- and total carbon (Ct)-content. In the biopore sheath (2–12 mm), the share of roots with a diameter of less than 0.4 mm was 92% for barley and 89% for faba bean. The findings support the view that roots can utilize biopores to gain access to deeper soil layers and may use the sheath for nutrient uptake and entrance through to the bulk soil. However, especially for barley, the inner layer of the biopore sheath appeared to be more important for root growth than the sheath of farer distance.



Hereditas ◽  
2010 ◽  
Vol 147 (3) ◽  
pp. 114-122 ◽  
Author(s):  
H. Bchini ◽  
M. Ben Naceur ◽  
R. Sayar ◽  
H. Khemira ◽  
L. Ben Kaab-Bettaeïb


1990 ◽  
Vol 127 (1) ◽  
pp. 81-89 ◽  
Author(s):  
E. Liljeroth ◽  
E. Bååth ◽  
I. Mathiasson ◽  
T. Lundborg


1987 ◽  
Vol 67 (2) ◽  
pp. 309-316 ◽  
Author(s):  
T. G. SOMMERFELDT ◽  
D. C. MACKAY

A 7-yr study was conducted to determine the effects of repeated annual applications of manure containing softwood shavings (M + S) at 50 t ha−1 on the soil and its productivity, relative to manure without shavings (M) at 50 t ha−1 and nitrogen fertilizer (F) at 67 kg ha−1. The EC, OM, total N and C:N ratio of the soil of the M + S and M + S + F plots to 60-cm depth were not significantly greater than those from the M plots, and in some instances they were significantly less. The NO3-N and total N and available P contents of the soil from the M + S treatment were significantly lower than those from the M treatment. Immobilization of N in the M + S and M + S + F treatments was indicated. Barley (Hordeum vulgare L. 'Gait') straw and grain yields and protein content of the grain were generally greater under the M than under the M + S treatment. When N fertilizer was included in the M + S treatment (M + S + F) the yields were similar to those of M, and the protein content increased. If manure with shavings is used for fertilizer, supplemental N should be applied to offset N immobilization. Key words: Manure disposal, manure, manure with wood shavings, nitrogen, crop yields



1972 ◽  
Vol 25 (4) ◽  
pp. 669 ◽  
Author(s):  
C Hackett ◽  
DA Rose

Previous papers have reported that relations between the total number, length, surface area, and volume of graminaceous root members tend to remain roughly constant during vegetative growth. Through the use of a model of the extension and branching of a seminal root of barley (Hordeum vulgare L.), which was developed for the purpose, an attempt has now been made to determine the properties of root growth responsible for the phenomenon.



HortScience ◽  
1990 ◽  
Vol 25 (6) ◽  
pp. 655-657 ◽  
Author(s):  
Ronald W. Garton ◽  
Irvin E. Widders

Seedlings of processing tomato `H 2653' (Lycopersicon esculentum Mill.) were cultured in 288-cell (< 6 cm3 volume) plug trays in a soilless growing medium. Pretransplant fertilization with nutrient solutions containing 10 or 20 mm N and 2 or 5 mm P for 10 days altered the total ammoniacal-N and P, and the soluble NO3-N and PO4-P concentrations in the shoot tissue at transplanting. Post-transplanting shoot and root growth were more rapid in late May plantings than in earlier plantings. The 20-mm N and 2-mm P pretransplant treatment caused the most rapid shoot growth following early season plantings in the field. Rapid seedling establishment after transplanting was generally not a good indicator of potential fruit yield. The 5-mm P pretransplant treatment produced higher marketable fruit yields in early plantings but not in later. Culture of seedlings under a low fertilization regime (5.4 mm N, 1.0 mm P, and 1.6 mm K) before pretransplant treatment produced as high or higher fruit yields than did seedlings from a higher regimen. Withholding fertilizer temporarily before transplanting resulted in a depletion in tissue N and P concentrations, slow post-transplanting shoot growth, and lower yields.



1988 ◽  
Vol 68 (2) ◽  
pp. 425-432 ◽  
Author(s):  
Y. K. SOON

A field study was conducted in 1984 and 1985 to determine the spatial distribution with time of root length density of spring barley (Hordeum vulgare L.) growing in a Black Solod in northwestern Alberta. The weakly solonetzic Bnt horizon present in the solodic soil appeared not to inhibit root growth, and roots were present to 90 cm depth of soil. Drought in 1985 reduced root growth in general, and in particular in the surface soil (0 – 15 cm depth) between crop rows. Root growth in both years continued well after ear emergence and attained a maximum total length (14.5 and 9.5 km m−2 in 1984 and 1985, respectively) some time into grain-filling. Water uptake rates of up to 1.3 cm3 m−1 d−1 were observed; this maximum rate was associated with younger roots in the 60- to 90-cm depth in 1984. Low availability of subsoil water in 1985, however, resulted in low root density and water uptake rates in the 60- to 90-cm depth. The weighted mean uptake rate for the entire root system was slightly more than 0.4 cm3 m−1 d−1 in 1984 and about half that in 1985. Key words: Barley, Hordeum vulgare L., solonetzic soil, water inflow, root growth, root length density



2011 ◽  
Vol 62 (11) ◽  
pp. 972 ◽  
Author(s):  
Qifu Ma ◽  
Richard Bell ◽  
Ross Brennan

In the agricultural lands of south-western Australia, salinity severely affects about 1 million hectares, and there is also widespread occurrence of potassium (K) deficiency. This study investigated whether the effects of sodium (Na) on crop K nutrition vary with plant salt sensitivity. In a glasshouse experiment with loamy sand, two barley cultivars (Hordeum vulgare L. cv. Gairdner, salt sensitive, and cv. CM72, salt tolerant) and one wheat cultivar (Triticum aestivum L. cv. Wyalkatchem, salt tolerant) were first grown in soil containing 30 mg extractable K/kg for 4 weeks to create mildly K-deficient plants, then subjected to Na (as NaCl) and additional K treatments for 3 weeks. Although high Na (300 mg Na/kg) reduced leaf numbers, moderate Na (100 mg Na/kg) hastened leaf development in barley cultivars but not in wheat. In the salt-tolerant CM72, moderate Na also increased tiller numbers, shoot dry weight and Na accumulation, but not root growth. The positive effect of moderate Na on shoot growth in CM72 was similar to that of adding 45 mg K/kg. Root growth relative to shoot growth was enhanced by adequate K supply (75 mg K/kg) compared with K deficiency, but not by Na supply. Soil Na greatly reduced the K/Na and Ca/Na ratios in shoots and roots, while additional K supply increased the K/Na ratio with little effect on the Ca/Na ratio. The study showed that the substitution of K by Na in barley and wheat was influenced not only by plant K status, but by the potential for Na uptake in roots and Na accumulation in shoots, which may play a major role in salt tolerance. The increased growth in shoots but not roots of salt-tolerant CM72 in response to moderate Na and the greater adverse effect of soil K deficiency on roots than shoots in all genotypes would make the low-K plants more vulnerable to saline and water-limited environments.



1999 ◽  
Vol 155 (4-5) ◽  
pp. 503-508 ◽  
Author(s):  
B.J. Mulholland ◽  
C.R. Black ◽  
I.B. Taylor ◽  
J.A. Roberts




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