The rotated-lamina syndrome. II. The seedling of Ulmus glabra

1993 ◽  
Vol 71 (2) ◽  
pp. 222-228 ◽  
Author(s):  
W. A. Charlton
Keyword(s):  
Key Words ◽  
Leaf Development ◽  
Growing Season ◽  
Radial Symmetry ◽  
Axillary Buds ◽  
Ulmus Glabra ◽  
Show Evidence ◽  
Seedling Leaf

Seedlings of Ulmus glabra show heteroblastic development of the plumular axis, involving a change from an initial radial symmetry with leaves in decussate pairs to dorsiventral symmetry with distichously arranged foliage leaves displaying the rotated-lamina syndrome. The change is very variable in detail. The change to distichy usually precedes the appearance of the rotated-lamina syndrome and is usually accompanied by the formation of one or more bud scales. Contrary to an earlier suggestion, there is no anisophyllous phase of development. Axillary buds in the radially symmetrical region of the seedling also show heteroblastic development but have distichous phyllotaxis from the beginning. During the first growing season they initiate a small number of bud scales and then a series of foliage leaves showing progressively accentuated development of the rotated-lamina syndrome. Some early foliage leaves show evidence of rotation of the lamina region by torsion. This is not detectable in later leaves in the seedling or in adult shoots, and it is suggested that the rotated-lamina syndrome may have arisen by heterochronic shift of the rotation process into progressively earlier stages of leaf development. Key words: Ulmus glabra, seedling, leaf, development, dorsiventrality.

The rotated-lamina syndrome. IV. Relationships between rotation and symmetry in Magnolia and other cases

1994 ◽  
Vol 72 (1) ◽  
pp. 25-38 ◽  
Author(s):  
W. A. Charlton
Keyword(s):  
Key Words ◽  
Shoot Apex ◽  
Leaf Development ◽  
Leaf Primordia ◽  
The State ◽  
Axillary Buds ◽  
Reverse Direction ◽  
Ulmus Glabra ◽  
Young Leaves

Further variations of the rotated-lamina syndrome are described in Magnolia spp. and Rhamnus imeretinus, as well as an abnormal adult shoot of Ulmus glabra without lamina rotation. All magnolias investigated show lamina rotation, but there are four possible forms of shoot symmetry: (i) dorsiventral distichous shoots with the form of rotated-lamina syndrome previously described, i.e., laminae of young leaves all face towards the same (upper) side of the bud or towards the parental axis in axillary buds; (ii) another form of dorsiventral symmetry in which lamina rotation occurs in the reverse direction; (iii) spiral phyllotaxis with laminae rotated to face up the genetic spiral; and (iv) spiral phyllotaxis with laminae rotated to face down the genetic spiral. Shoot symmetry and development of lamina rotation in leaf primordia correlate with the taxo-nomic subdivision of the genus. Shoots of R. imeretinus are dorsiventral, with leaves arranged in four ranks, and lamina rotation occurs towards the upper side of the shoot. The sense of rotation of leaf primordia reverses with a periodicity of two plastochrons. In the abnormal shoot of Ulmus without lamina rotation, phyllotaxis was distichous and leaf primordia were symmetrical. The various cases are discussed in relation to the previously erected hypothesis that control of development in dorsiventral shoots with the rotated-lamina syndrome resides in alternating states of asymmetry in the shoot apex, and the corollary that a shoot with spiral phyllotaxis and one sense of lamina rotation should result if the state of asymmetry is maintained and does not alternate. Key words: Magnolia spp., Rhamnus imeretinus, Ulmus glabra, leaf, development, dorsiventrality, lamina rotation.

Timing and rate of bud formation in Pinus resinosa

1971 ◽  
Vol 49 (10) ◽  
pp. 1821-1832 ◽  
Author(s):  
Edward Sucoff
Keyword(s):  
Quantitative Data ◽  
Shoot Growth ◽  
Pinus Resinosa ◽  
Growing Season ◽  
Axillary Buds ◽  
Growing Degree Days ◽  
Degree Days ◽  
Bud Formation ◽  
Late Season ◽  
Apical Dome

During the 1969 and 1970 growing season buds were collected almost weekly from matched trees in northeastern Minnesota. Cataphyll primordia for the year n + 1 shoot began forming at the time that internodes in the year n shoot started elongating (late April) and continued forming until early September. Primordia for axillary buds started forming about 2 months later and stopped forming at the same time as cataphylls. The size and deposition activity of the apical dome simultaneously increased during the early growing season and decreased during the late season. The maximum rates in July were over nine cataphylls per day.Rate of cataphyll deposition paralleled elongation of the needles on subtending shoots. Forty to fifty percent of the cataphylls had been formed when shoot growth was 95% complete. Although the bulk of the depositions occurred earlier in 1970, when growing degree days were used as the clock, the 2 years were similar.The results provide quantitative data to complement the histologic emphasis of previous studies.

scholarly journals Asexual Propagation of Eggplant (Solanum melongena L.) through Encapsulated Axillary Buds

1970 ◽  
Vol 19 (2) ◽  
pp. 263-288 ◽  
Author(s):  
A.K.M. N. Huda ◽  
, M.A. Bari ◽  
M. Rahman
Keyword(s):  
Key Words ◽  
Plant Tissue ◽  
Short Communication ◽  
Solanum Melongena ◽  
Axillary Buds ◽  
Synthetic Seed ◽  
Asexual Propagation

 Key words: Auxillary buds, Eggplant, Encapsulation, Synthetic seed D.O.I. 10.3329/ptcb.v19i2.5445 Plant Tissue Cult. & Biotech. 19(2): 263-288, 2009 (December)       - Short communication

MEASUREMENT OF EVAPORATION FROM SOIL BENEATH CROP CANOPIES

1983 ◽  
Vol 63 (1) ◽  
pp. 137-141 ◽  
Author(s):  
G. K. WALKER
Keyword(s):  
Zea Mays ◽  
Key Words ◽  
Leaf Area ◽  
Energy Supply ◽  
Zea Mays L ◽  
Growing Season ◽  
Soil Core ◽  
Crop Cover ◽  
Intact Soil Core ◽  
Intact Soil

Evaporation rates beneath maize canopies were measured using an intact soil core technique. Early in the growing season evaporation rates were periodically high (4.0 mm∙day−1) following rain, but declined rapidly. At full crop cover, when energy supply normally limits evaporation, significant differences in evaporation were detected between canopies with leaf area indices of 3.0 and 4.0. Key words: Evaporation measurement, energy supply, Zea mays L., leaf area, soil evaporimeter, lysimeter

Forage sorghum in southern Manitoba

1996 ◽  
Vol 76 (1) ◽  
pp. 123-125 ◽  
Author(s):  
W. P. McCaughey ◽  
M. C. Therrien ◽  
R. Mabon
Keyword(s):  
Sorghum Bicolor ◽  
Key Words ◽  
Total Variation ◽  
Growing Season ◽  
Yield Stability ◽  
Forage Sorghum ◽  
Sorghum Sudangrass ◽  
Sorghum Genotypes ◽  
Sorghum Bicolor L

After a series of hot, dry years in the late 1980s a study was conducted to assess the suitability and yield stability of forage sorghum (Sorghum bicolor L. Moench.) in southern Manitoba. The effects of genotype and environment on DM yield of seven forage sorghum genotypes were evaluated (1990–1992) in six different environments. Genotype, environment and genotype × environment accounted for 3.9% (P < 0.0001), 84.8% (P < 0.0001) and 3.3% (P < 0.001) of the total variation in DM yield, respectively. The fact that environment accounted for most of the variability in DM yield and that relative rankings of varieties differed across environments indicated that yield was unstable. Forage sorghum produced acceptable DM yield only in years which were warmer (> 2700 CHU) than average (2200–2600 CHU) for southern Manitoba. Forage sorghum is not recommended for southern Manitoba unless the climate warms to where 2700 CHU are consistently accumulated during the growing season. Key words: Forage, sorghum, sorghum-sudangrass, C4, temperature, yield

The rotated-lamina syndrome. VI. The range from partial to near-complete rotation in Tiliaceae and Sterculiaceae

1997 ◽  
Vol 75 (1) ◽  
pp. 170-187 ◽  
Author(s):  
W. A. Charlton
Keyword(s):  
Key Words ◽  
Shoot Apex ◽  
Leaf Development ◽  
Leaf Primordia

The rotated-lamina syndrome is a condition most commonly found in dorsiventral shoots with distichous phyllotaxis. Typically, young laminae in bud appear to be rotated to face towards the upper side of the shoot. The syndrome arises by asymmetrical growth from leaf primordia that initially face the shoot apex in approximately the normal way. It was previously described in Tilia. Further genera of Tiliaceae and the closely related Sterculiaceae were examined for the presence of the syndrome. Altogether it was found in 9 genera of the 30 examined. The syndrome is well developed in representatives of Commersonia, Corchorus, and Pterospermum, and less well developed in Luehia seemannii. Expression of the syndrome is minimal in Luehia divaricata, Theobroma, Byttneria, and Grewia. In all cases with distichous phyllotaxis that were examined in these families, the leaf primordia show at least some asymmetry in development and consequently there appears to be a predisposition to lamina rotation within the group. The syndrome is probably becoming suppressed in cases with minimal expression. The situation in dorsiventral shoots of Corchorus and Byttneria is complicated by the presence of inflorescences that arise in a leaf-opposed position. Key words: Sterculiaceae, Tiliaceae, leaf, development, dorsiventrality, lamina rotation.

TILLAGE SYSTEMS AND ATRAZINE AND ALACHLOR RESIDUES ON A POORLY DRAINED SOIL

1987 ◽  
Vol 67 (4) ◽  
pp. 959-963 ◽  
Author(s):  
J. D. GAYNOR ◽  
J. A. STONE ◽  
T. J. VYN
Keyword(s):  
Key Words ◽  
Growing Season ◽  
Zero Tillage ◽  
Triazine Herbicide ◽  
Tillage Systems ◽  
Sampling Depth ◽  
Herbicide Residues ◽  
Soil Dilution ◽  
Ridge Tillage

Seasonal residues of an acetanilide and triazine herbicide were monitored in ridge, conventional, and zero tillage systems. Alachlor (2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide), and atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine) residues were less than 8% of the spring application concentration at the end of the growing season. Moldboard plowing in the fall reduced herbicide residues in spring because of soil dilution by plowing to greater than the sampling depth. Ridge tillage systems had higher spring residues apparently because of reduced herbicide dissipation on the drier ridge tops. The higher residues of the triazines on ridge tops may be injurious to triazine sensitive crops. Key words: Herbicide, till-plant, ridge tillage, des-ethyl atrazine

Growth of dormant buds on severed rhizomes of Calamagrostis canadensis

1991 ◽  
Vol 71 (4) ◽  
pp. 1093-1099 ◽  
Author(s):  
R. A. Powelson ◽  
V. J. Lieffers
Keyword(s):  
Key Words ◽  
Apical Dominance ◽  
Carbohydrate Content ◽  
Axillary Buds ◽  
Regeneration Potential ◽  
Bud Development ◽  
Calamagrostis Canadensis ◽  
Lateral Buds ◽  
Loam Soil ◽  
Shoot Base

The regeneration potential and dormancy of lateral buds on rhizome segments near the parent shoot base or the distal rhizome apex of Calamagrostis canadensis were assessed. Apical and basal segments of various length, with and without the parental shoot base or rhizome apex attached, were planted 1 cm deep in loam soil. When the apex or base was attached axillary buds on the rhizome usually remained dormant. When the parental shoot base was excised, the bud closest to the rhizome base was more likely to sprout than more distal buds. When the apex was excised from the apical segments, more axillary buds emerged but no priority of bud development arose. Buds near the apex position generally had a higher frequency of sprouting than buds adjacent to the parental base. Rhizome segments adjacent to the apex were heavier and had a higher nonstructural carbohydrate content than rhizome segments adjacent to the parental base. Key words: Calamagrostis canadensis, rhizome, dormancy, apical dominance, competition

Soil temperatures and suckering response of trembling aspen (Populus tremuloides Michx.) following disposal of hog on winter-logged cutblocks

2004 ◽  
Vol 80 (6) ◽  
pp. 687-693 ◽  
Author(s):  
Timothy Conlin ◽  
Dave Cheyne ◽  
John Dymond
Keyword(s):  
British Columbia ◽  
Soil Temperature ◽  
Key Words ◽  
Populus Tremuloides ◽  
Growing Season ◽  
Soil Warming ◽  
Wood Residue ◽  
Application Rates ◽  
Soil Temperatures ◽  
Temperature Levels

Bark and wood residue, commonly referred to as "hog fuel" or "hog," from a portable pulp chipper was deposited on aspen cutblocks in replicated 10 x 10 m treatment plots during winter logging operations in northeastern British Columbia. The treatments emulated disposal of hog under conditions that simulated on-site chipping operations. Three different rates of hog disposal were applied; 34, 68 and 102 kg m-2, and three cutblocks were treated, one each during February of 1997, and March of 1998 and 1999. We originally hypothesized that the deposition of hog would lower soil temperatures in the treated plots and reduce aspen sucker density during the following growing season. However, our observations showed an initial lag in soil warming in the treatments followed by temperature levels that rose above that exhibited in the control plots. Higher soil temperatures were correlated with greater rates of hog disposal. Increased suckering was not observed in response to higher soil temperatures and stem densities decreased as hog application rates increased. Key words: in-woods, on-site, chipping, Populus tremuloides, hog fuel, soil temperature

Evaluation of the "fall rosette" procedure for perennial sowthistle control in fallow

1999 ◽  
Vol 79 (4) ◽  
pp. 633-637 ◽  
Author(s):  
A. L. Darwent ◽  
K. N. Harker ◽  
J. M. Broatch ◽  
P. Mills
Keyword(s):  
Key Words ◽  
Field Experiments ◽  
Growing Season ◽  
Shoot Density ◽  
Early Summer ◽  
Late Fall ◽  
Herbicide Treatment ◽  
Spray Volume ◽  
Sonchus Arvensis

Field experiments conducted near Grande Prairie, Alberta, compared the effectiveness of the fall rosette procedure to other procedures used in a year of fallow for the control of perennial sowthistle (Sonchus arvensis L.). The fall rosette procedure, which consisted of discontinuing normal cultivation in late July, allowing the perennial sowthistle plants to grow for 6 wk and then applying glyphosate plus dicamba at 0.6 + 0.6 kg ha−1 plus Agral 90 at 0.5% vol/vol of spray volume, reduced shoot density by 84, 90 and 96% approximately 1 yr after imposition in 1992, 1993 and 1994, respectively. By comparison, the bud stage procedure, which consisted of allowing plants to grow to the bud stage in the spring/early summer, applying the same herbicide treatment and conducting tillage for the rest of the year, reduced shoot densities by 58, 86 and 85% when imposed in the same years, respectively. The fall rosette procedure was also more effective than frequent tillage throughout the growing season without herbicide, or than chemfallow (glyphosate plus dicamba applied in early July and again in early September, with or without late fall tillage) in reducing perennial sowthistle shoot density. Mowing, whenever the perennial sowthistle reached 8–10 cm in height, did not reduce shoot density. Key words: Fall rosette, bud stage, Sonchus arvensis L., tillage, mowing, chemfallow

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