Seasonal Development of the Secondary Phloem in Populus tremuloides

1968 ◽  
Vol 129 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Jerry D. Davis ◽  
Ray F. Evert
Keyword(s):  
Populus Tremuloides ◽  
Seasonal Development ◽  
Secondary Phloem

SEASONAL DEVELOPMENT OF THE SECONDARY PHLOEM IN PINUS

1968 ◽  
Vol 55 (4) ◽  
pp. 518-528 ◽  
Author(s):  
Frank J. Alfieri ◽  
Ray F. Evert
Keyword(s):  
Seasonal Development ◽  
Secondary Phloem

Hyperhydric Tissue Formation in Flooded Populus Tremuloides Seedlings

IAWA Journal ◽  
1990 ◽  
Vol 11 (1) ◽  
pp. 85-96 ◽  
Author(s):  
Guillermo Angeles
Keyword(s):  
Cell Division ◽  
Water Intake ◽  
Populus Tremuloides ◽  
Small Area ◽  
Irregular Shape ◽  
Tissue Formation ◽  
Bark Thickness ◽  
Secondary Phloem ◽  
Starch Grains ◽  
Cortical Parenchyma

Formation and development of hyperhydric tissue (HHT) were investigated morphologically and anatomically in Populus tremuloides seedlings flooded for 5, 9, 15,22,30, 45, and 80 days. HHT was initiated after 5 days of flooding (DF) by swelling of the filling tissue of lenticels, probably by water intake. At the same time, cell division was initiated in the phellogen and phelloderm of lenticels. Repeated divisions'of the phellogen of flooded lenticels produced long files of cells that pushed the filling tissue outwards. After 9 DF the activity of the phellogen extended beyond the lenticels. When large, extensive areas of phellogen were involved, HHT formed patches of short tissue covering most of the stem surface. When the activity of the phellogen was restricted to a small area, long columns of HHT were produced instead. In one case, in a stem flooded for 80 days, the formation of a new phellogen immediately below the old one was observed. Cells produced centrifugally by the active phellogen of flooded seedlings were thinwalled, not suberised, without nuclei, radially elongated or with irregular shape, firmly connected by their tangential walls, but with only a few points of contact with neighbouring cells by their radial walls, mainly by knoblike projections. After 22 DF the cortical parenchyma and rays of the secondary phloem started to take part in HHT formation, producing new, larger cells, rich in starch grains, with large aerenchyma spaces that greatly increased bark thickness and porosity.

Structure and Seasonal Development of the Secondary Phloem in the Pinaceae

1973 ◽  
Vol 134 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Frank J. Alfieri ◽  
Ray F. Evert
Keyword(s):  
Seasonal Development ◽  
Secondary Phloem

Structure and seasonal development of secondary phloem of Juglans regia

1970 ◽  
Vol 48 (6) ◽  
pp. 1049-1053 ◽  
Author(s):  
Norman W. Schaad ◽  
E. E. Wilson
Keyword(s):  
Juglans Regia ◽  
Growth Increment ◽  
Seasonal Development ◽  
Secondary Phloem ◽  
Early Season ◽  
Central California ◽  
Late Season ◽  
Growth Increments ◽  
Parenchyma Cells ◽  
Sieve Tubes

In Persian walnut (Juglans regia L.), as in other deciduous dicotyledonous trees, a small (0.5 mm) amount of secondary phloem is functional for only one season and a large amount is nonfunctional. In 1968 in Central California the cycle of phloem development began in late February and ended sometime before mid-October. The phloem annual ring was composed of distinctive tangential bands, allowing easy distinction of seasonal growth increments. Each growth increment could be divided into early- and late-season tissue. Early-season phloem, composed principally of large sieve tubes, was separated from late-season phloem by a band of fibers. The late-season phloem was composed of a mixture of narrow sieve tubes, parenchyma cells, and, occasionally, an incomplete tangential band of fibers. The annual rings were not crushed except for the early-season phloem, which was somewhat compressed by growth of the woody cylinder. The bark of walnut becomes thicker with age because of this and the enlargement of parenchyma cells.

NOTES ON THE CANADIAN TUCKAHOE, ITS OCCURRENCE IN CANADA AND THE INTERFERTILITY OF ITS PERFECT STAGE, POLYPORUS TUBERASTER JACQ. EX FRIES

1951 ◽  
Vol 29 (2) ◽  
pp. 147-157 ◽  
Author(s):  
T. C. Vanterpool ◽  
Ruth Macrae
Keyword(s):  
Populus Tremuloides ◽  
Western Canada ◽  
Single Spore ◽  
Canadian Prairies ◽  
Perfect Stage

The Canadian tuckahoe is the perennial sclerotium of Polyporus tuberaster jacq. ex Fries. It is commonly found in the parkland belt of the Canadian prairies where land supporting, virgin poplar groves, mainly Populus tremuloides Michx., is being brought under cultivation. Sporophore as many as three to a single sclerotium, appear in late June and July. Interfertility studies with single spore cultures isolated from sporophores derived from four sources in Western Canada and from one source in Italy have shown that both the Canadian fungus and the European P. tuberaster are heterothallic, have the tetrapolar type of interfertility, and are interfertile.

Wood and Bark Anatomy of Lauraceae. ii. Licaria Aublet

IAWA Journal ◽  
1985 ◽  
Vol 6 (3) ◽  
pp. 187-199 ◽  
Author(s):  
Hans Georg Richter
Keyword(s):  
Diagnostic Tool ◽  
Secondary Xylem ◽  
Secondary Phloem ◽  
Structural Profile ◽  
Quantitative Characters ◽  
Important Diagnostic Tool ◽  
Species Groups ◽  
Bark Anatomy

Qualitative features of the secondary xylem of Licaria present a rather uniform structural profile. Constant differences in primarily quantitative characters lead to the formation of speeies groups wh ich loosely correspond to infrageneric sections based on floral and vegetative morphology. This subdivision is strongly corroborated by the highly variable secondary phloem structurc revealing considerable diversity in type and distribution of sc1erenchymatic tissues. Inorganic inclusions in the secondary xylem, crystals and silica, constitute an important diagnostic tool for differentiating certain species and species groups, but are hardly of importance in the bark.

scholarly journals Ethylene enhances root water transport and aquaporin expression in trembling aspen (Populus tremuloides) exposed to root hypoxia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiangfeng Tan ◽  
Mengmeng Liu ◽  
Ning Du ◽  
Janusz J. Zwiazek
Keyword(s):  
Gas Exchange ◽  
Water Transport ◽  
Populus Tremuloides ◽  
Leaf Gas Exchange ◽  
Hydraulic Conductance ◽  
Root Hydraulic Conductance ◽  
Trembling Aspen ◽  
Expression Levels ◽  
Root Hypoxia ◽  
Exogenous Ethylene

Abstract Background Root hypoxia has detrimental effects on physiological processes and growth in most plants. The effects of hypoxia can be partly alleviated by ethylene. However, the tolerance mechanisms contributing to the ethylene-mediated hypoxia tolerance in plants remain poorly understood. Results In this study, we examined the effects of root hypoxia and exogenous ethylene treatments on leaf gas exchange, root hydraulic conductance, and the expression levels of several aquaporins of the plasma membrane intrinsic protein group (PIP) in trembling aspen (Populus tremuloides) seedlings. Ethylene enhanced net photosynthetic rates, transpiration rates, and root hydraulic conductance in hypoxic plants. Of the two subgroups of PIPs (PIP1 and PIP2), the protein abundance of PIP2s and the transcript abundance of PIP2;4 and PIP2;5 were higher in ethylene-treated trembling aspen roots compared with non-treated roots under hypoxia. The increases in the expression levels of these aquaporins could potentially facilitate root water transport. The enhanced root water transport by ethylene was likely responsible for the increase in leaf gas exchange of the hypoxic plants. Conclusions Exogenous ethylene enhanced root water transport and the expression levels of PIP2;4 and PIP2;5 in hypoxic roots of trembling aspen. The results suggest that ethylene facilitates the aquaporin-mediated water transport in plants exposed to root hypoxia.

Sign in / Sign up

Export Citation Format

Share Document