Effect of seed provenance and fungal species on bead formation in roots of Piceamariana seedlings

1990 ◽  
Vol 20 (11) ◽  
pp. 1746-1752 ◽  
Author(s):  
J. Thomson ◽  
U. Matthes-Sears ◽  
R. L. Peterson
Keyword(s):  
Lateral Roots ◽  
Fungal Species ◽  
Seed Source ◽  
Factorial Anova ◽  
First Order ◽  
Bead Formation ◽  
Peaty Soil ◽  
Single Bead ◽  
Aseptic Conditions ◽  
Seed Provenance

The effects of both seed source and fungal species on the formation of beads in roots of Piceamariana (Mill.) B.S.P. were examined. Seed was collected from two sites near Chapleau, Ontario. One provenance was an upland site with sandy soil, the second a lowland site with peaty soil. Seedlings were grown under aseptic conditions in test tubes and inoculated with either Laccariabicolor (Maire), Laccarialaccata (Scop, ex Fr.), Laccariaproximo (Boud.) Pat., or agar plugs. Each constriction or striation on the root was counted as a single bead. These constricted regions were associated with the accumulation of a darkly stained substance and the absence of a Hartig net. Bead formation on first order lateral roots from each treatment was assessed and the data were analyzed for significance with a two-way factorial ANOVA. There was a significant interaction between seed source and fungal species on the numbers of beads formed. Bead formation was significantly more common on the lowland seed source in the L. laccata treatment only. L. laccata inoculation resulted in the greatest number of beads on first order lateral roots followed by control and L. proximo treatments. Colonization of seedlings with L. bicolor resulted in the formation of significantly fewer beads than in the control or any other treatment.

Effects of seed provenance and mycorrhizal fungi on early seedling growth in Piceamariana

1990 ◽  
Vol 20 (11) ◽  
pp. 1739-1745 ◽  
Author(s):  
J. Thomson ◽  
U. Matthes-Sears ◽  
R. L. Peterson
Keyword(s):  
Seedling Growth ◽  
Mycorrhizal Fungi ◽  
Lateral Roots ◽  
Dry Weight ◽  
Fungal Species ◽  
Seed Source ◽  
Shoot Dry Weight ◽  
Early Seedling Growth ◽  
Early Seedling ◽  
Aseptic Conditions

The importance of provenance and fungal species effects on mycorrhiza formation in Piceamariana was determined. Seed was collected from two sites near Chapleau, Ontario. One provenance was collected from an upland site with sandy soil, the second from a lowland site with peaty soil. Seedlings were grown under aseptic conditions in test tubes. Two experiments were performed: in the first, seedlings were inoculated with Hebelomacylindrosporum, Laccarialaccata, or Paxillusinvolutus, whereas in the second, seedlings were inoculated with Laccariabicolor, Laccarialaccata, Laccariaproximo or noninoculated agar plugs. Counts of ectomycorrhiza and lateral root formation were analyzed for significance with two-way factorial ANOVAS. When inoculated with L. laccata, seedlings from the lowland seed source had significantly more mycorrhizal second order lateral roots than seedlings from the upland seed source. Lowland seedlings also had greater shoot dry weight and foliage length values. However, overall differences between provenances were small. In contrast, differences between fungal treatments were pronounced. Both L. laccata and L. bicolor initiated good ectomycorrhiza formation and increased seedling growth.

Differential Root Growth of FourSetariaTaxa

Weed Science ◽  
1975 ◽  
Vol 23 (5) ◽  
pp. 364-368 ◽  
Author(s):  
P. L. Orwick ◽  
M. M. Schreiber
Keyword(s):  
Root Growth ◽  
Lateral Roots ◽  
Root Diameter ◽  
Seminal Root ◽  
Setaria Viridis ◽  
First Order ◽  
Setaria Faberi ◽  
Giant Foxtail ◽  
Green Foxtail ◽  
Controlled Environments

We studied the early root growth of fourSetariataxa: giant foxtail (Setaria faberiHerrm.), giant green foxtail [Setaria viridisvar.major(Gaud.) Posp.], robust white foxtail (Setaria viridisvar.robusta-albaSchreiber), robust purple foxtail (Setaria viridisvar.robusta-purpureaSchreiber). Growth studies in controlled environments showed significant differences in root elongation among the taxa at three photoperiods. Seminal root lengths after 4 days followed the order presented for selectivity and metabolism of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] and propazine [2-chloro-4,6-bis(isopropylamino)-s-triazine] (robust white foxtail > giant green foxtail = robust purple foxtail > giant foxtail). Giant foxtail had the greatest root diameter, resulting in the greatest surface area and volume when lengths were equated. The order of seminal root lengths or diameters changed little after 7 days. Robust white foxtail had the most and longest first order lateral roots. Diameter of first order laterals showed giant foxtail > giant green foxtail = robust purple foxtail > robust white foxtail.

Effects of root severing treatments on loblolly pine

1988 ◽  
Vol 18 (11) ◽  
pp. 1376-1385 ◽  
Author(s):  
William C. Carlson ◽  
Constance A. Harrington ◽  
Peter Farnum ◽  
Stephen W. Hallgren
Keyword(s):  
Soil Moisture ◽  
Water Potential ◽  
Root System ◽  
Loblolly Pine ◽  
Water Status ◽  
Lateral Roots ◽  
Second Order ◽  
Plant Water Status ◽  
Plant Water ◽  
First Order

Six-year-old loblolly pine seedlings were subjected to root severing treatments varying from 0 to 100% of first-order lateral roots. Separate treatments severed surface-oriented or deep-oriented roots. Plant water status was monitored periodically for several months. After all measurements were taken, gross root system structure was determined by excavation. Treatment responses were evident on all dates of measurement. Relationships between percentage of root system cut and leaf conductance or water potential were stronger when surface-oriented roots were cut than when deep-oriented roots were cut. Severing surface-oriented first-order lateral (SOFOL) roots probably resulted in greater impact on plant water status than severing deep-oriented first-order lateral (DOFOL) roots because (i) SOFOL roots had both surface-oriented and deep-oriented second-order lateral roots that could tap both surface and subsurface soil horizons for soil moisture, and (ii) the deep-oriented second-order roots (originating from the SOFOL roots) were spatially distributed over a much larger area than the DOFOL roots and thus would have access to soil water in a larger volume of soil. For SOFOL roots the relationship between percentage cut and leaf conductance or transpiration was strongly negative; for DOFOL roots, no relationship between these variables was observed. Initially water potential decreased with the percentage of roots cut in both groups; in later measurements, water potential was affected more by severing SOFOL than DOFOL roots. Calculation of soil moisture depletion by depth indicated that both surface- and deep-oriented second-order lateral roots were important for water uptake. Severing SOFOL roots significantly decreased nitrogen, phosphorus, and potassium levels in needles of the first growth flush of the year. Levels of these elements in terminal buds were not affected by severing SOFOL roots, but were significantly reduced by severing DOFOL roots. Secondary xylem production was reduced proportionately to the amount of root system cross-sectional area severed.

Longitudinal variation in cadmium influx in intact first order lateral roots of sunflower (Helianthus annuus. L)

2013 ◽  
Vol 372 (1-2) ◽  
pp. 581-595 ◽  
Author(s):  
Marie A. Laporte ◽  
Laurence Denaix ◽  
Loïc Pagès ◽  
Thibault Sterckeman ◽  
Francis Flénet ◽  
...  
Keyword(s):  
Helianthus Annuus ◽  
Lateral Roots ◽  
Longitudinal Variation ◽  
First Order ◽  
Helianthus Annuus L

scholarly journals Immature Loblolly Pine Growth and Biomass Accumulation: Correlations with Seedlings Initial First-Order Lateral Roots

1998 ◽  
Vol 22 (2) ◽  
pp. 117-123 ◽  
Author(s):  
Paul P. Kormanik ◽  
Shi-Jean S. Sung ◽  
Stanley J. Zarnoch
Keyword(s):  
Loblolly Pine ◽  
Root Biomass ◽  
Lateral Roots ◽  
Biomass Accumulation ◽  
Root Penetration ◽  
Cross Sectional ◽  
First Order ◽  
Pinus Taeda L ◽  
Initial Root ◽  
Tree Development

Abstract Five to seven years after being graded by first-order lateral root (FOLR) numbers and outplanted, loblolly pine (Pinus taeda L.) seedlings were excavated using a commercial tree spade and root systems re-evaluated. Current competitive position of trees was related to initial FOLR numbers of 1-0 seedlings. Current FOLR numbers were comparable among tree size classes, but root diameters where the spade severed the root were different. The dominant and codominant individuals had much larger FOLR cross sectional area at the severed point. The larger diameter laterals allow exploration of larger soil volume since they extended greater distances from the tree. Root biomass allometric equations were developed from excavating 175 individuals in 3 separate plantations. Root biomass was readily predicted based on either stem diameter breast height squared (D²H), or total aboveground biomass. Approximately 75% of standing tree biomass was aboveground and 25% belowground for all initial root grades, current crown classes, and sites. Subsoil compaction layers appeared to have a major impact on tree development at any specific location within a plantation. Compaction layers affected heights and diameters but not root/top ratios or the relative competition position based on initial FOLR numbers. These compaction layers resulted in plate-like taproots that suggested further root penetration was unlikely. South. J. Appl. For. 22(2):117-123.

Ontogeny of Eucalyptus pilularis – Pisolithus tinctorius ectomycorrhizae. I. Light microscopy and scanning electron microscopy

1987 ◽  
Vol 65 (9) ◽  
pp. 1927-1939 ◽  
Author(s):  
H. B. Massicotte ◽  
R. L. Peterson ◽  
A. E. Ashford
Keyword(s):  
Lateral Root ◽  
Lateral Roots ◽  
Ectomycorrhizal Fungus ◽  
Pisolithus Tinctorius ◽  
Broad Host Range ◽  
Lateral Root Development ◽  
First Order ◽  
Hartig Net ◽  
Ectomycorrhizal Roots ◽  
Eucalyptus Pilularis

Eucalyptus pilularis Sm. seedlings were grown in growth pouches and inoculated with the broad host range ectomycorrhizal fungus Pisolithus tinctorius (Pers.) Coker & Couch. External morphology and internal structure of all stages of ectomycorrhiza formation on first-order and second-order laterals were studied. The morphology of the ectomycorrhiza is dependent on the stage of lateral root development at the time of colonization by fungal hyphae. Emerging lateral roots are colonized by hyphae originating from the inner mantle of the parent root. The Hartig net does not spread internally from the parent root to the lateral root. All primary tissues of mycorrhizal lateral roots are differentiated close to the apical meristem. The epidermal cells undergo a marked increased in radial growth instead of the usual elongation in the axial plane. The hypodermis is a barrier to the penetration of hyphae so that Hartig net formation is paradermal only. Older portions of ectomycorrhizal roots show a degeneration of the epidermis, hypodermis, and cortex excluding the endodermis, and a proliferation of hyphae in these senescing tissues.

Variations in heat resistance of ecotypes of Eucalyptus camaldulensis Dehn. and their significance

1971 ◽  
Vol 19 (3) ◽  
pp. 261 ◽  
Author(s):  
R Karschon ◽  
L Pinchas
Keyword(s):  
Heat Resistance ◽  
Eucalyptus Camaldulensis ◽  
Seed Source ◽  
Maximum Temperature ◽  
Natural Habitats ◽  
Leaf Surfaces ◽  
The Mean ◽  
Wax Deposits ◽  
Resistance Value ◽  
Seed Provenance

Depending upon the seed provenance, the heat resistance value of leaves of E. carnaldulensis varies from 47.4 to 50.0°C. It is not related to the mean maximum temperature of the hottest month at the seed source. The relation of heat resistance to wax deposits, colour, and temperatures of leaf surfaces is examined. The implications of the findings in the phylogeny and ecotypic divergence of the species and its cultivation outside its natural habitats in Australia are discussed.

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