Differentiation of adventitious root primordia in callus of Pinusbanksiana seedling cuttings

1983 ◽  
Vol 13 (1) ◽  
pp. 195-200 ◽  
Author(s):  
Cheryl R. Montain ◽  
Bruce E. Haissig ◽  
John D. Curtis
Keyword(s):  
Adventitious Root ◽  
Secondary Xylem ◽  
Root Systems ◽  
Vascular Cambium ◽  
Root Primordia ◽  
Specific Identification ◽  
Resin Canals

The root systems of 97-day-old seedlings of Pinusbanksiana Lamb, were severed just below the lowermost needles, and the cuttings were placed in misted propagation benches. A complex of tissues including callus, vascular cambium, secondary xylem, periderm, and resin canals formed at the base of cuttings. Adventitious root primordia were initiated at the periphery of the basal-most portions of this complex in association with resin canals, tracheid "nests", periderm, and, possibly callus vascular cambium. Anatomical complexity of the developing tissues precluded more specific identification of sites of primordium initiation.

Initiation of adventitious root primordia in very young Pinusbanksiana seedling cuttings

1983 ◽  
Vol 13 (1) ◽  
pp. 191-195 ◽  
Author(s):  
Cheryl R. Montain ◽  
Bruce E. Haissig ◽  
John D. Curtis
Keyword(s):  
Transition Zone ◽  
Adventitious Root ◽  
Secondary Xylem ◽  
Vascular Cambium ◽  
Root Initiation ◽  
Secondary Phloem ◽  
Root Primordia ◽  
Cortical Cells ◽  
Parenchyma Cells ◽  
Resin Canals

The present work describes the anatomy of adventitious root initiation in 20-day-old Pinusbanksiana Lamb, seedling cuttings propagated under intermittent mist. Shortly after cuttings were made, basal necrosis occurred in all tissues (epidermis, periderm, cortex, primary and secondary phloem, and vascular cambium) that surrounded the central xylem cylinder. Thereafter, a relatively small "callus complex" composed of parenchyma cells, a few secondary xylem tracheids, and incompletely differentiated callus vascular cambium and periderm developed at the base of cuttings. One or sometimes two root primordia initiated in the transition zone between the lowermost cortical cells of the hypocotyl and the uppermost callus parenchyma cells. Primordia invariably arose just outside one of the four axial resin canals in the hypocotyl. Results suggested that adventitious root primordia may be initiated in P. banksiana cuttings only in association with differentiated or differentiating resin canals.

Carboniferous pteridosperm studies: morphology and anatomy of Schopfiastrum decussatum

1972 ◽  
Vol 50 (12) ◽  
pp. 2649-2658 ◽  
Author(s):  
Gar W. Rothwell ◽  
Thomas N. Taylor
Keyword(s):  
Secondary Xylem ◽  
Vascular Cambium ◽  
Secondary Phloem ◽  
Outer Cortex ◽  
Southern Illinois ◽  
Leaf Arrangement ◽  
Resin Canals ◽  
Inner Cortex

The monostelic seed fern Schopfiastrum decussatum Andrews is described from a specimen collected at a Middle Pennsylvanian petrifaction locality in southern Illinois. The specimen measures 24 cm long and is about 1.1 cm in diameter. Two petioles are attached to the axis and abundant foliar material is also present. Leaf arrangement is alternate and distichous. The stem consists of an exarch protostele surrounded by a prominent zone of secondary xylem. Secondary phloem and a vascular cambium are also preserved. The cortex is characterized by an undulating outer epidermal zone consisting of alternating ridges and furrows; internally this zone is delimited by conspicuous lacunae. Sclerenchyma bands occur in the outer cortex, with prominent resin canals present in the inner cortex. The fronds are represented by dichotomizing rachides, primary pinnae, and laminar pinnules. Features of the plant are compared to those of other Carboniferous pteridosperms, and a reconstruction of Schopfiastrum is included.

Alteration in gene expression in hypocotyls of sunflower (Helianthus annuus) seedlings associated with derooting and formation of adventitious root primordia

1994 ◽  
Vol 90 (3) ◽  
pp. 481-489 ◽  
Author(s):  
Melvin J. Oliver ◽  
Ilabanta Mukherjee ◽  
David M. Reid
Keyword(s):  
Gene Expression ◽  
Helianthus Annuus ◽  
Adventitious Root ◽  
Root Primordia

scholarly journals Adventitious root primordia formation and development in the stem of Ananas comosus var. bracteatus slip

2021 ◽  
pp. 1949147
Author(s):  
Mark Owusu Adjei ◽  
Yixuan Xiang ◽  
Yehua He ◽  
Xuzixin Zhou ◽  
Meiqin Mao ◽  
...  
Keyword(s):  
Adventitious Root ◽  
Ananas Comosus ◽  
Root Primordia

scholarly journals Endogenous Development of Adventitious Root Primordia in Lettuce Hypocotyls

1985 ◽  
Vol 55 (2) ◽  
pp. 267-268 ◽  
Author(s):  
H. A. KORDAN
Keyword(s):  
Adventitious Root ◽  
Endogenous Development ◽  
Root Primordia

scholarly journals Planting Depth Affects Root Form of Three Shade Tree Cultivars in Containers

2010 ◽  
Vol 36 (3) ◽  
pp. 132-139
Author(s):  
Edward Gilman ◽  
Chris Harchick ◽  
Maria Paz
Keyword(s):  
Root Morphology ◽  
Adventitious Root ◽  
Substrate Surface ◽  
Root Systems ◽  
Planting Depth ◽  
Trunk Diameter ◽  
Shade Tree ◽  
Container Wall ◽  
Stem Girdling

Study was designed to evaluate impact of planting depth on root morphology inside nursery containers. Trees were planted shallow (13 mm) or deep (64 mm) into #3 Air-Pot™ containers, then shallow (0 mm) or deep (64 mm) into #15 containers prior to shifting them to their final #45 container size at the same depth. Trunk diameter (caliper) was significantly larger for both magnolia and maple planted shallow (13 mm) into #3, and then shallow into #15 containers when compared to planting deeper. However, differences were small and may not be relevant to a grower. No caliper or height differences among planting depths were found for elm. Presence of stem girdling roots in elm and magnolia growing in #45 containers increased with planting depth into # 3 containers. Downward re-orientation of main roots comprising the flare by #3 container wall, likely contributed to amount of roots growing over root flare. Maple root systems were not impacted by planting depth into #3 primarily due to adventitious root emergence from the buried portion of stem. Distance between substrate surface and top of root flare in finished #45 containers was not impacted by planting depth into #3 containers for any species. Planting elm and maple deeply into #15 led to more trunk-girdling by roots, a deeper root flare, and more roots growing over flare compared to planting shallow. Most root defects in all species were hidden from view because they were found below substrate surface. Presence of a visible root flare was not related to occurrence of root defects. Root balls on elm and maple were packed with roots which made it time consuming to remove substrate and roots above the root flare. Planting depth appears most crucial when shifting into #15 containers.

Regeneration of vascular tissue through redifferentiation of interxylary phloem after complete girdling in Aquilaria sinensis

IAWA Journal ◽  
2021 ◽  
pp. 1-16
Author(s):  
Bei Luo ◽  
Arata Yoshinaga ◽  
Tatsuya Awano ◽  
Keiji Takabe ◽  
Takao Itoh
Keyword(s):  
Time Course ◽  
Potential Role ◽  
Vascular Tissue ◽  
Secondary Xylem ◽  
Vascular Cambium ◽  
Aquilaria Sinensis ◽  
Phloem Fibers ◽  
Interxylary Phloem ◽  
Time Course Study

Abstract We studied the time-course of stem response for six months following complete girdling in branches of Aquilaria sinensis to determine the potential role of interxylary phloem (IP) in this response. It was found that the vascular cambium, as well as its derivative secondary xylem and phloem, regenerated fully through redifferentiation of IP. We confirmed that vascular cambium regenerated within one month after girdling based on observation of new vessels, IP, and secondary phloem fibers. The time-course study showed that IPs made connections with each other, merged, and became larger through the proliferation of IPs parenchyma cells and the cleaving of secondary xylem in a narrow zone 400 to 1000 μm deep inside the girdled edge. This led to the formation of a complete circular sheath of vascular cambium, followed by the regeneration of vascular tissue. It is worth noting that the secondary xylem is regenerated always following the formation of a thick belt of wound xylem.

Small RNA sequencing identifies cucumber miRNA roles in waterlogging-triggered adventitious root primordia formation

2019 ◽  
Vol 46 (6) ◽  
pp. 6381-6389 ◽  
Author(s):  
Xuewen Xu ◽  
Kaixuan Wang ◽  
Jiawei Pan ◽  
Xuehao Chen
Keyword(s):  
Rna Sequencing ◽  
Small Rna ◽  
Adventitious Root ◽  
Small Rna Sequencing ◽  
Root Primordia

Geometric analysis of intrusive growth of wood fibres in Robinia pseudoacacia

IAWA Journal ◽  
2018 ◽  
Vol 39 (2) ◽  
pp. 191-208 ◽  
Author(s):  
Anna B. Wilczek ◽  
Muhammad Iqbal ◽  
Wieslaw Wloch ◽  
Marcin Klisz
Keyword(s):  
Secondary Xylem ◽  
Robinia Pseudoacacia ◽  
Geometric Analysis ◽  
Cell Types ◽  
Vascular Cambium ◽  
Tangential Plane ◽  
Intrusive Growth ◽  
Thin Sections ◽  
Growing Cell ◽  
Vessel Elements

ABSTRACTAll cell types of the secondary xylem arise from the meristematic cells (initials) of the vascular cambium and grow under mechanical constraints emerging from the circular-symmetrical geometry that characterises many tree trunks. The course of intrusive growth of cambial initials has been elucidated, but is yet to be described in the case of xylem fibres. This study explains the geometry of intrusive growth of the secondary xylem fibres in the trunk ofRobinia pseudoacacia.Long series of serial semi-thin sections of the vascular cambium and the differentiating secondary xylem were analysed. Since fibres grow in close vicinity to expanding cells of the derivatives of the vascular cambium, we assumed that they have similar growth conditions. Dealing with the cylindrical tissue of the vascular cambium in a previous study, we used a circularly symmetrical equation for describing the growth mechanism of cambial initials. Like the cambial initials, some of the cambial derivatives differentiating into the various cell types composing the secondary xylem also exhibit intrusive growth between the tangential walls of adjacent cells. As seen in cross sections of the cambium, intrusively growing initials form slanted walls by a gradual transformation of tangential (periclinal) walls into radial (anticlinal) walls. Similarly, the intrusive growth of xylem fibres manifests initially as slants, which are formed due to axial growth of the growing cell tips along the tangential walls of adjacent cells. During this process, the tangential walls of adjacent cells are partly separated and dislocated from the tangential plane. The final shape of xylem fibres, or that of vessel elements and axial parenchyma cells, depends upon the ratio of their intrusiveversussymplastic growths in the axial, circumferential and radial directions.

Effect of naphthaleneacetic acid on the formation of lateral roots in the adventitious root of Allium cepa: number and arrangement of laterals along the parent root

1992 ◽  
Vol 70 (9) ◽  
pp. 1891-1896 ◽  
Author(s):  
Pedro G. Lloret ◽  
Antonio Pulgarín
Keyword(s):  
Allium Cepa ◽  
Adventitious Root ◽  
Lateral Root ◽  
Root Formation ◽  
Lateral Roots ◽  
Naphthaleneacetic Acid ◽  
Root Primordia ◽  
Sharp Rise ◽  
Allium Cepa L ◽  
Do So

The exogenous application of an auxin (α-naphthaleneacetic acid) to the adventitious root of Allium cepa L. promotes lateral root formation and inhibits main root elongation. If the adventitious roots are released from the influence of this auxin, they may resume elongation after 10−5 M but not after 10−4 treatment. Auxin leads to the appearance of late-forming root primordia intercalated between previously formed laterals. The arrangement of laterals along the adventitious root is another feature altered by treatment, i.e., control roots develop the same number of laterals throughout the length of the zone in which laterals appear, whereas in treated roots the number of laterals rises steadily as the distal end of this zone is approached. In 10−5 M auxin-treated roots, no increase in the number of laterals occurs in basal zones of the parent root, whereas treatment with 10−4 M naphthaleneacetic acid leads to a sharp rise in the number of laterals formed at these zones. Our results suggest that the basal part of onion roots is less sensitive than the apical portion of the effects of naphthaleneacetic acid. This chemical seems to have a rejuvenating effect on cells of the pericycle, enabling them to initiate lateral primordia when under normal conditions they would no do so. Key words: Allium cepa, auxin, lateral root, naphthaleneacetic acid, onion.

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