Mycorrhizae and growth of white fir seedlings in mineral soil with and without organic layers in a California forest

1979 ◽  
Vol 9 (3) ◽  
pp. 311-315 ◽  
Author(s):  
Isabel F. Alvarez ◽  
David L. Rowney ◽  
Fields W. Cobb Jr.
Keyword(s):  
Sierra Nevada ◽  
Lateral Roots ◽  
Mineral Soil ◽  
Dry Weight ◽  
Root Systems ◽  
North Central ◽  
Organic Layers ◽  
Total Length ◽  
The North ◽  
White Fir

White fir (Abiesconcolor (Gord. et Glend.) Lindl.) seedlings appear to survive and grow better in mineral soil alone than in mineral soil with organic layers. To determine whether the better growth observed in seedlings in mineral soil (M), compared with those in mineral soil with organic layers (MO), could be related to the incidence of mycorrhizae in their root systems, natural M and MO seedlings were examined from five sites in the north central Sierra Nevada. Statistical analysis of the data showed that seedling dry weight was significantly related to total length of roots, number of main lateral roots, and presence of mycorrhizae on the roots. Dry weight, total length of roots, total number of mycorrhizal tips, and number of mycorrhizal tips per centimetre of roots were significantly higher for M compared with MO seedlings. Age, number of main lateral roots, and number of mycorrhizal tips per centimetre of roots are highly significant in distinguishing M from MO seedlings. The data indicate that mycorrhizae play an important role in the growth of white fir seedlings, and that both growth and presence of mycorrhizae are favored by the absence of organic layers.

Mycorrhizae of Abies concolor in California

1977 ◽  
Vol 55 (10) ◽  
pp. 1345-1350 ◽  
Author(s):  
Isabel F. Alvarez ◽  
Fields W. Cobb Jr.
Keyword(s):  
Sierra Nevada ◽  
Mycorrhizal Fungi ◽  
Abies Concolor ◽  
North Central ◽  
Chemical Reagents ◽  
The North ◽  
Naturally Occurring ◽  
White Fir ◽  
Different Types ◽  
Cenococcum Graniforme

Nine different types of mycorrhizae were observed on naturally occurring white fir seedlings in the north central Sierra Nevada, including one formed by the ubiquitous Cenococcum graniforme. The macro- and micro-scopic characteristics and reactions to different chemical reagents are described for five types. Possible mycorrhizal fungi of white fir are listed. Nursery-grown seedlings examined were ectomycorrhizal; intracellular penetration was not observed. None of the naturally occurring mycorrhizal types were found on nursery seedlings.

scholarly journals Effects of Root Pruning on Germinated Pecan Seedlings

HortScience ◽  
2015 ◽  
Vol 50 (10) ◽  
pp. 1549-1552 ◽  
Author(s):  
Rui Zhang ◽  
Fang-Ren Peng ◽  
Pan Yan ◽  
Fan Cao ◽  
Zhuang-Zhuang Liu ◽  
...  
Keyword(s):  
Lateral Roots ◽  
Dry Weight ◽  
Root Systems ◽  
Root Pruning ◽  
Root Weight ◽  
Stem Height ◽  
Growth Season ◽  
Total Length ◽  
Transplanting Shock ◽  
Taproot Pruning

Root systems of pecan trees are usually dominated by a single taproot with few lateral roots, which are commonly thought to inhibit successful transplanting. This study aimed to evaluate early growth and root/shoot development of pecan seedlings in response to taproot pruning. Taproots of ‘Shaoxing’ seedling pecan trees were mildly (1/3 of the total length of the radicle removed) and severely (2/3 of the total length of the radicle removed) pruned at different seedling development stages shortly after germination. At the end of the first growing season, top growth was measured and then trees were uprooted so that root system regrowth could be evaluated. The results showed that root pruning had no impact on increases in stem height or stem diameter. However, pruning the taproot could stimulate primary growth in taproot branches. Root weight and the number of taproot branches per tree increased with decreasing taproot length. This study indicated that severe root pruning when three to five leaves had emerged resulted in root systems with more taproot branches and the greatest root dry weight after one growth season, which may increase survival and reduce transplanting shock.

Alternate Strip Clearcutting in Upland Black Spruce: VIII. Shallow-soil Ecosystems and Their Classification

1988 ◽  
Vol 64 (1) ◽  
pp. 70-75 ◽  
Author(s):  
Richard A. Sims ◽  
William D. Towill
Keyword(s):  
Black Spruce ◽  
Mineral Soil ◽  
Fragile Sites ◽  
Soil Types ◽  
Northern Ontario ◽  
North Central ◽  
The North ◽  
Shallow Soil ◽  
Soil Ecosystems ◽  
Shallow Soils

Shallow-soil sites in the Nipigon-Beardmore area of northern Ontario are widespread and pose unique operational problems for forest managers. Several working definitions of shallow soils are used in Ontario. More accurate regional definitions are required in order that silvicultural decisions for these sometimes fragile sites may be refined or new ones developed. Harvesting and silvicultural options for shallow-soil sites are limited in the North Central Region.A program of Forest Ecosystem Classification (FEC) for the North Central Region has been designed to provide better understanding of shallow sites and a framework of standardized definitions. The FEC describes several shallow-soil types that occur over boulder pavement or bedrock, and differentiates mainly on the basis of depth-to-rock contact, surface organic material thickness and texture of the primary mineral soil particles. Operational application of this classification may require identification of complexes of shallow-soil types.

Bear Paw Petroglyphs and the Prehistoric Martis Complex

1994 ◽  
Vol 15 (1) ◽  
pp. 69-76
Author(s):  
Willis A. Gortner
Keyword(s):  
Sierra Nevada ◽  
Rock Art ◽  
North Central ◽  
The North ◽  
Frequent Use

People of the Martis Complex occupied lands adjoining the north-central Sierra Nevada from approximately 2000 B.C. to 500 A.D. They left their rock art on 100 or more rock outcroppings. The appearance of glyphs clearly resembling a bear paw or bear track at several dozen petroglyph sites suggested that this symbol in the north-central Sierra Nevada might be unique to the Martis people. A review of the occurrence of bear paw glyphs at ninety nine recorded sites in Nevada and 265 petroglyph sites in California showed that none of these glyphs appeared at the 293 sites more than 90 km from Martis territory. By contrast, 133 bear paw glyphs were recorded at twenty-nine sites in or near Martis territory. The frequent use of the bear paw symbol in the Martis rock art suggests that it may be a ritualistic symbol related to a bear cult, bear clan, or a family or clan totem in the culture of these prehistoric people.

BULK DENSITY OF SURFACE SOILS AND PEAT IN THE NORTH CENTRAL UNITED STATES

1989 ◽  
Vol 69 (4) ◽  
pp. 895-900 ◽  
Author(s):  
D. F. GRIGAL ◽  
S. L. BROVOLD ◽  
W. S. NORD ◽  
L. F. OHMANN
Keyword(s):  
Bulk Density ◽  
Forest Floor ◽  
Mineral Soil ◽  
Loss On Ignition ◽  
North Central ◽  
Dummy Variable ◽  
The North ◽  
A Value ◽  
Central United States ◽  
Surface Mineral

Relationships between bulk density (BD) and loss on ignition (LOI) for forest floor, shallow mineral soil (0–25 cm depth), and peat were described by exponential functions. The data were collected in forests across the North Central US. For forest floor, predicted BD, BDp = 0.073 + 2.369 exp(− 0.073 LOI), R2 = 0.75, (BDp in Mg m−3 and LOI in percent dry wt), and for surface mineral soil, BDp = 0.669 + 0.941 exp(− 0.240 LOI), R2 = 0.95. For peat, BDp = 0.043X + 4.258 exp(− 0.047 LOI), R2 = 0.89, where X is a dummy variable with a value of 0 for surface peat (0–25 cm depth) and 1 for subsurface peat (25–175 cm). Key words: Bulk density, loss-on-ignition

scholarly journals Genotypic variability of root and shoot traits of bread wheat (Triticum aestivum L.) at seedling stage

Genetika ◽  
2021 ◽  
Vol 53 (2) ◽  
pp. 687-702
Author(s):  
Milica Blazic ◽  
Dejan Dodig ◽  
Vesna Kandic ◽  
Dragoslav Djokic ◽  
Tomislav Zivanovic
Keyword(s):  
Bread Wheat ◽  
Root Length ◽  
Lateral Roots ◽  
Primary Root ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Stem Length ◽  
Total Length ◽  
Seminal Roots ◽  
Primary Root Length

The evaluation of the embryonic root and stem of bread wheat (Triticum aestivum L.) in the early stage of development (seedling stage) can be a powerful tool in wheat breeding aimed at obtaining progenies with a greater early vigour. It is revealed that genotypes with faster early vigour have produced higher biomass and grain yield. In this study, the evaluation of traits of the embryonic root and the embryonic stem of 101 bread wheat genotypes was preformed at the 10-day old seedlings. The following eight morphological traits of roots and stems were analysed: primary root length, branching interval, the number of roots, total length of lateral roots, angle of seminal roots, stem length, root dry weight and the stem dry weight. Analysed lateral roots included seminal roots. The greatest, i.e. the smallest variability of observed traits was detected in the branching interval, i.e. the stem length, respectively. The highest positive correlation was determined between the primary root length and the total length of lateral roots. The cluster analysis, based on observed traits, shows that genotypes were clearly divided into two main clusters, A and B. The two clusters essentially differed from each other in the values of the following traits: primary root length, total length of lateral roots, root dry weight, stem dry weight and the stem length. Genotypes with shorter primary and lateral roots, lower root and stem dry weight and a shorter stem were grouped in the cluster B. On the other hand, the cluster A encompassed genotypes with values of these traits above or around the average. The values of the remaining analysed traits: the angle of seminal roots, the number of lateral roots and the branching interval varied greatly between obtained clusters. The cluster analysis showed the homogeneity of genotypes originating from Serbia and the region; their values of the root and stem length and weight were mostly around and below the average. However, the values of the angle of seminal roots, number of lateral roots and the branching interval were above average.

The effects of drought and subsequent rehydration on the structure and vitality of Zea mays seedling roots

1991 ◽  
Vol 69 (6) ◽  
pp. 1170-1178 ◽  
Author(s):  
Elida Stasovski ◽  
Carol A. Peterson
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Lateral Roots ◽  
Dry Weight ◽  
Root Systems ◽  
Outer Cortex ◽  
Drought Period ◽  
Lateral Root Primordia ◽  
Cell Vitality ◽  
Cell Layers

Drought was induced in Turface and vermiculite-grown seedlings of Zea mays L. by withholding water. Despite a 34-day drought period, the roots of stressed plants increased in dry weight by continued elongation of existing roots and initiation of new roots. A differential response to desiccation, with respect to structure and cell vitality, was observed along the root axes. In apical regions (terminal 20 mm) of seminal roots, all cell layers typically remained alive. In midlength regions (half way between the apex and base), the epidermis died in both control and treatment plants. The cortex of control roots displayed some distortion, but most of the cells were alive; the cortex of stressed roots displayed severe collapse and death of the majority of these cells. In basal regions (20 mm distal to the kernel), cells of the outer cortex were sclerified and less susceptible to collapse. Cells of stelar tissues retained their normal shapes and vitality. Upon rehydration, the root systems of stressed plants resumed growth by elongation of existing seminal, adventitious, and lateral roots and, in some cases, also by emergence of previously dormant lateral root primordia. The root systems' capacity for recovery diminished with increasing stress. Key words: drought, roots, Zea mays L., exodermis, hypodermis.

scholarly journals 169 Root Characteristics of Peach Trees with Different Shoot Growth Habits

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 419C-419
Author(s):  
T.J. Tworkoski ◽  
R. Scorza
Keyword(s):  
Tree Growth ◽  
Shoot Growth ◽  
Lateral Roots ◽  
Dry Weight ◽  
Root Systems ◽  
Peach Tree ◽  
Root Characteristics ◽  
Growth Habits ◽  
Lateral Branches ◽  
Peach Trees

Peach trees (Prunus persica L.) with diverse shoot growth habits have been developed, but little is known about their root systems. Characterizing shoot and root systems can improve basic understanding of peach tree growth and be important in the development of rootstocks and own-rooted trees. This research determined shoot and root characteristics of four peach tree growth habits (compact, dwarf, pillar, and standard). Seed from four peach growth habits were planted in 128-L containers, grown outside during the 1998 growing season, and then harvested. Compact tree leaf number (1350/tree) was twice, but leaf area (6 cm2/leaf) was half, that of pillar and standard trees. The number of lateral branches in compact trees (34) was nearly three-times more than in pillar and standard trees. The leaf area index (LAI) of pillar trees was greater than compact and standard trees (13 compared with 4 and 3, respectively) due to a narrower crown diameter. Dwarf tree shoots were distinct with few leaves (134 per tree) and a large LAI of 76. Compact trees grew more higher-order lateral roots than pillar and standard trees. More second-order lateral (SOL) roots were produced by compact than standard trees (1.2 vs. 0.8 SOL roots/cm first-order lateral root). Pillar trees had higher shoot-to-root dry weight ratios (2.4) than compact and standard trees (1.7 for both) due to smaller root dry weights. The results indicate fundamental differences in root characteristics among the peach tree growth habits. Compact trees had more higher order lateral roots in roots originating near the root collar (i.e., more fibrous roots), and this correlated with more lateral branches in the canopy. Shoot weights were the same among pillar, compact, and standard trees but root weights were less in pillar trees, resulting in greater shoot-to-root dry weight ratios. These results indicate significant differences in root as well as shoot architecture among growth habits that can affect their use as scion or rootstock varieties.

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