Heteroblastic seedlings of green ash. I. Predictability of leaf form and primordial length

1986 ◽  
Vol 64 (11) ◽  
pp. 2645-2649 ◽  
Author(s):  
E. K. Merrill
Keyword(s):  
Leaf Development ◽  
Leaf Growth ◽  
Leaf Primordia ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Leaf Form ◽  
Compound Leaf ◽  
Controlled Conditions ◽  
Plastochron Index

Green ash (Fraxinus pennsylvanica var. subintegerrima) seedlings are heteroblastic; during development they produce two types of leaves, simple and compound. When grown under controlled conditions, the sequence of leaf types is predictable. Simple leaves are always at the first four nodes; compound leaves are always at node 8 and above. Nodes 5 through 7 have progressively fewer simple leaves and more compound leaves. Leaf growth on seedlings meets the preconditions of the plastochron index and leaf plastochron index. These indices, as well as the length of single expanding leaves, can be used to predict lengths of leaf primordia at nodes 4 and 8 so that early, simple and compound leaf development can be compared in further studies of green ash.

Structure and development of terminal bud scales in green ash

1990 ◽  
Vol 68 (1) ◽  
pp. 12-20 ◽  
Author(s):  
E. K. Merrill
Keyword(s):  
Developmental Stages ◽  
Early Summer ◽  
Leaf Primordia ◽  
Apical Region ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Foliage Leaf ◽  
Terminal Bud ◽  
Terminal Buds ◽  
Early Developmental

Structure and development of terminal bud scales of green ash (Fraxinus pennsylvanica var. subintegerrima) were studied to provide a basis for comparison with foliage leaves of the same species. To identify early developmental stages of bud scales, structure and phenology of terminal buds were investigated first. Overwintering terminal buds have typically three or four pairs of bud scales and three to six pairs of foliage leaf primordia. Bud scales have a flattened base topped by rudimentary leaflets. After bud break, the first leaf primordia that are initiated develop and mature into terminal bud scales by early summer. Although morphology and anatomy of mature foliage leaves and bud scales are very different, primordia of leaf forms are similar until they reach a length of 500 μm. At that length both leaf forms have a base and apical leaflets. Bud scale bases widen and elongate without much thickening, while growth in the apical region is restricted. Marginal growth of the bud scale base is different from that described for most leaf blades. Terminal bud scales could be interpreted as being ontogenetically derived from foliage leaf primordia.

Heteroblastic seedlings of green ash. II. Early development of simple and compound leaves

1986 ◽  
Vol 64 (11) ◽  
pp. 2650-2661 ◽  
Author(s):  
E. K. Merrill
Keyword(s):  
Early Development ◽  
Leaf Primordia ◽  
The Other ◽  
Terminal Leaflet ◽  
Green Ash ◽  
Lateral Leaflet ◽  
Leaf Type ◽  
Simple Leaf ◽  
Compound Leaf

Simple and compound leaf primordia of green ash seedlings differ in shape from initiation. Simple leaf primordia are flattened until their lamina margins grow out at a primordial length of 150 μm. Compound leaf primordia are rounded and peglike at initiation and lateral leaflet buttresses appear when primordia are 150 μm long. Terminal leaflet margins appear when compound leaf primordia are 200 μm long. At initiation both types of leaf primordia are composed of densely cytoplasmic cells. Vacuolation proceeds so that densely cytoplasmic cells remain only in areas developing blades and leaflets and in procambium. Because simple and compound leaves of green ash differ from initiation, neither leaf type can be considered to result from a change in the ontogeny of the other.

Rachis vascularization and leaflet venation in developing leaves of Fraxinus pennsylvanica

1985 ◽  
Vol 63 (12) ◽  
pp. 2383-2392 ◽  
Author(s):  
Philip R. Larson
Keyword(s):  
Leaf Development ◽  
Close Association ◽  
Terminal Leaflet ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Leaf Base ◽  
Lateral Leaflet ◽  
Curve Upward

Leaves of Fraxinus pennsylvanica are served by a double trace that exits the stem vasculature through a single gap. During embryonic leaf development, the leaf traces subdivide in the node to produce subsidiary bundles that differentiate acropetally in the leaf base and basipetally in the stem. The acropetal bundles converge distally in the node to form a rachis vasculature consisting of a semicircular arc joined by a ventral chord. Each lateral leaflet is vascularized by bundles contributed by both the semicircular arc and the ventral chord of the rachis. One rachis ridge bundle divides to form two leaflet ridge bundles and a new rachis ridge bundle diverges from the ventral chord. The leaflet ridge bundles diverge as basal veins and subsequent secondary veins diverge from the midvein in an approximate right–left sequence. Green ash has odd pinnate leaves; the terminal leaflet is vascularized by the rachis residual following departure of the last leaflet pair. Secondary veins extend to the lamina margins and then curve upward to initiate the marginal loops of the brochidodromous venation. Periclinal divisions occur in close association with secondary veins in the prospective plate meristem region. Anticlinal divisions occur in subepidermal layers of the internal ridge points in the prospective palisade mesophyll region.The latter divisions probably contribute both to lamina extension and to spreading of the conduplicately folded lamina wings.

Shoot ontogeny in Fraxinus pennsylvanica (green ash). I. Seasonal cycle of terminal meristem activity

1989 ◽  
Vol 67 (6) ◽  
pp. 1624-1632 ◽  
Author(s):  
W. R. Remphrey
Keyword(s):  
Seasonal Cycle ◽  
Histological Analysis ◽  
Leaf Primordia ◽  
Leaf Primordium ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Heat Unit ◽  
Foliage Leaf ◽  
Axillary Meristems ◽  
Bud Initiation

Terminal meristem ontogeny of mature Fraxinus pennsylvanica var. subintegerrima (Vahl) Fern, (green ash) was investigated by bud dissection, histological analysis, and scanning electron microscopy. The shoots were completely preformed and bud-scale initiation for the next bud began in the spring shortly before any visible sign of swell. Foliage-leaf initiation began in May and ceased in late June or early July, but there were certain differences in primordium production patterns between the two trees investigated and between the years of the study. Although temperature, as measured by heat-unit accumulation, played a significant role in the onset of shoot expansion and primordium initiation, its importance in controlling these processes diminished as the season progressed. Buds formed in the axil of every leaf primordium, but those in the axils of scales remained small. There was evidence of axillary bud initiation as early as the P1, stage. By P2 or P3 there was a clearly discernable shell zone of elongated cells. Such cells had relatively large vacuoles concentrated at each end, in contrast with the essentially nonvacuolate cells of the incipient bud meristem. In the terminal resting bud, there were well-developed scale-axil buds and protruding axillary meristems associated with foliage-leaf primordia.

scholarly journals Transcriptome Analysis of Ginkgo biloba L. Leaves across Late Developmental Stages Based on RNA-Seq and Co-Expression Network

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 315
Author(s):  
Hailin Liu ◽  
Xin Han ◽  
Jue Ruan ◽  
Lian Xu ◽  
Bing He
Keyword(s):  
Ginkgo Biloba ◽  
Leaf Development ◽  
Developmental Stages ◽  
Leaf Growth ◽  
Rna Seq ◽  
Final Size ◽  
Dioecious Species ◽  
Related Factors ◽  
New Genes ◽  
Gene Modules

The final size of plant leaves is strictly controlled by environmental and genetic factors, which coordinate cell expansion and cell cycle activity in space and time; however, the regulatory mechanisms of leaf growth are still poorly understood. Ginkgo biloba is a dioecious species native to China with medicinally and phylogenetically important characteristics, and its fan-shaped leaves are unique in gymnosperms, while the mechanism of G. biloba leaf development remains unclear. In this study we studied the transcriptome of G. biloba leaves at three developmental stages using high-throughput RNA-seq technology. Approximately 4167 differentially expressed genes (DEGs) were obtained, and a total of 12,137 genes were structure optimized together with 732 new genes identified. More than 50 growth-related factors and gene modules were identified based on DEG and Weighted Gene Co-expression Network Analysis. These results could remarkably expand the existing transcriptome resources of G. biloba, and provide references for subsequent analysis of ginkgo leaf development.

The growth and development of the leaf in tomato (Lycopersicon esculentum). I. The plastochron index, a suitable basis for description

1976 ◽  
Vol 54 (21) ◽  
pp. 2421-2428 ◽  
Author(s):  
Warren K. Coleman ◽  
Richard I. Greyson
Keyword(s):  
Lycopersicon Esculentum ◽  
Seasonal Variability ◽  
Growth And Development ◽  
Growth Analysis ◽  
Growth Habit ◽  
Leaf Growth ◽  
Growth Stages ◽  
Flower Buds ◽  
Morphological Status ◽  
Plastochron Index

Growth analysis indicates that the plastochron index (PI) is consistently applicable for describing the morphological status of the vegetative tomato shoot in quantitative terms, and pronounced seasonal variability in the growth habit is minimized. However, the PI is not applicable to tomato shoots after flower buds are produced at the vegetative apex. True leaf no. 3 goes through four growth stages which can be characterized in terms of the leaf plastochron index (LPI3). A basipetal trend in leaf growth and development is evident.

Regulation of compound leaf development in mungbean (Vigna radiata L.) by CUP-SHAPED COTYLEDON/NO APICAL MERISTEM (CUC/NAM) gene

Planta ◽  
2018 ◽  
Vol 249 (3) ◽  
pp. 765-774 ◽  
Author(s):  
Keyuan Jiao ◽  
Xin Li ◽  
Yafang Guo ◽  
Yining Guan ◽  
Wuxiu Guo ◽  
...  
Keyword(s):  
Leaf Development ◽  
Vigna Radiata ◽  
Apical Meristem ◽  
Compound Leaf

scholarly journals Phased Control of Expansin Activity during Leaf Development Identifies a Sensitivity Window for Expansin-Mediated Induction of Leaf Growth

2009 ◽  
Vol 151 (4) ◽  
pp. 1844-1854 ◽  
Author(s):  
Jennifer Sloan ◽  
Andreas Backhaus ◽  
Robert Malinowski ◽  
Simon McQueen-Mason ◽  
Andrew J. Fleming
Keyword(s):  
Leaf Development ◽  
Leaf Growth

scholarly journals Desiccation Tolerance of Green Ash and Sugar Maple Fine Roots

2009 ◽  
Vol 27 (4) ◽  
pp. 229-233 ◽  
Author(s):  
Gary W. Watson
Keyword(s):  
Root Growth ◽  
Fine Roots ◽  
Acer Saccharum ◽  
Sugar Maple ◽  
Fine Root ◽  
Cell Damage ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Root Electrolyte Leakage ◽  
Bare Root

Abstract Exposed fine roots are subject to desiccation, which may affect their survival as well as new root growth following bare root transplanting. Fine roots of dormant 1-year-old green ash (Fraxinus pennsylvanica) and sugar maple (Acer saccharum) seedlings, subjected to desiccation treatments of 0, 1, 2, or 3 hours in December and March, lost up to 82 percent of their water. Root electrolyte leakage, a measure of cell damage, tripled after three hours of desiccation. The increase was moderately, but significantly, greater in March for both species. Desiccation treatments had no effect on fine root survival. Growth of new roots (RGP) was also unaffected by desiccation treatments. RGP of maple was greater in March than December, but not ash.

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