scholarly journals Morphology and Anatomy of the Fused Vein Trait in Cucurbita pepo L.

1996 ◽  
Vol 121 (1) ◽  
pp. 6-12
Author(s):  
R. Bruce Carle ◽  
J. Brent Loy
Keyword(s):  
Genetic Background ◽  
Leaf Blade ◽  
Cucurbita Pepo ◽  
Leaf Growth ◽  
Leaf Size ◽  
Leaf Number ◽  
Central Vein ◽  
Vascular Bundles ◽  
Leaf Production ◽  
Leaf Stage

The morphology, growth rate and anatomy of the fused vein trait were characterized in Cucurbita pepo using the inbreds NH2405 (fused vein), NH7210 (moderately fused vein), and NH614 (normal). Morphological analysis showed that the trait is characterized by a partial fusion of the five primary leaf veins. Fusion begins at the distal point of the petiole and extends along the central vein. Branching of the veins is delayed and there is a reduction of the interveinal leaf blade. Consequently, the upper leaf surface appears puckered or wrinkled. Depending on genetic background, the onset of fused vein leaf production starts at the fourth to tenth leaf stage and continues throughout vegetative growth. The extent of fusion increases with leaf number but stabilizes by the twentieth leaf stage maximum extent of vein fusion also varies with genetic background (5-20 cm). Though fused vein and normal inbreds differed in the rate and pattern of leaf growth, examination of F2 and BC populations revealed no significant effect of the fused vein trait on leaf number, leaf size, and rate of leaf initiation. Anatomical examination revealed different vascular patterns in the transition zone between petiole and leaf blade for normal and fused vein leaves. In normal leaves, the vascular bundles of the petiole enlarge and coalesce to form a vascular crescent. The crescent reorganizes and diverges as large vascular columns and pairs of smaller flanking vascular bundles into each vein. In contrast, two cycles of enlargement, coalescence, and dispersal occur in fused vein leaves.

scholarly journals Stem and leaf growth rates define the leaf size vs. number trade-off

AoB Plants ◽  
2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Jun Sun ◽  
Mantang Wang ◽  
Min Lyu ◽  
Karl J Niklas ◽  
Quanlin Zhong ◽  
...  
Keyword(s):  
Leaf Growth ◽  
Elevation Gradient ◽  
Leaf Size ◽  
Cross Sectional Area ◽  
Leaf Number ◽  
Stem Volume ◽  
Sectional Area ◽  
Cross Sectional ◽  
Trade Off ◽  
Individual Leaf

Abstract The trade-off between leaf number and individual leaf size on current-year shoots (twigs) is crucial to light interception and thus net carbon gain. However, a theoretical basis for understanding this trade-off remains elusive. Here, we argue that this trade-off emerges directly from the relationship between annual growth in leaf and stem mass, a hypothesis that predicts that maximum individual leaf size (i.e. leaf mass, Mmax, or leaf area, Amax) will scale negatively and isometrically with leafing intensity (i.e. leaf number per unit stem mass, per unit stem volume or per stem cross-sectional area). We tested this hypothesis by analysing the twigs of 64 species inhabiting three different forest communities along an elevation gradient using standardized major axis (SMA) analyses. Across species, maximum individual leaf size (Mmax, Amax) scaled isometrically with respect to leafing intensity; the scaling constants between maximum leaf size and leafing intensity (based on stem cross-sectional area) differed significantly among the three forests. Therefore, our hypothesis successfully predicts a scaling relationship between maximum individual leaf size and leafing intensity, and provides a general explanation for the leaf size-number trade-off as a consequence of mechanical-hydraulic constraints on stem and leaf growth per year.

Phenological studies of Acrostichum danaeifolium (Pteridaceae, Pteridophyta) at a mangrove site on the Gulf of Mexico

2003 ◽  
Vol 19 (2) ◽  
pp. 155-162 ◽  
Author(s):  
Klaus Mehltreter ◽  
Mónica Palacios-Rios
Keyword(s):  
Life Span ◽  
Leaf Growth ◽  
Leaf Size ◽  
Avicennia Germinans ◽  
Strongly Correlated ◽  
Wet Season ◽  
Leaf Production ◽  
La Mancha ◽  
Spore Release ◽  
The Mean

A population of the giant leather fern Acrostichum danaeifolium was observed during an 18-mo period at La Mancha (19°36′00″N, 96°22′40″W), Veracruz, Mexico. The study site was 230 m from a brackish-water lagoon, in the understorey of the mangroves, which are dominated by Avicennia germinans (Avicenniaceae). Acrostichum danaeifolium showed a clumped distribution pattern, and one third of the population became fertile during this time. Plants had a mean number of 9.4 ± 0.45 sterile leaves, which developed continuously at a rate of 14.6 ± 0.44 leaves y-1. The mean life span of sterile leaves was 7.7 mo. Although soil water was always available, phenological patterns of fertility, leaf production and leaf growth were strongly correlated with the seasonal climate. Individual leaf growth and leaf size increased significantly during the rainy season. Fertile leaves emerged exclusively from April to August and had a mean life span of 4.1 mo. Spore release was restricted to the wet season, when conditions for germination were favourable. Environmental triggers of fertility are discussed and phenological patterns are compared with ferns and angiosperms from other habitats.

Effects of harvesting programme and sowing date on leaf growth in forage barley in Cyprus

1988 ◽  
Vol 110 (2) ◽  
pp. 353-366
Author(s):  
D. Wilman ◽  
D. N. Droushiotis
Keyword(s):  
Leaf Blade ◽  
Field Experiments ◽  
Leaf Growth ◽  
Main Stem ◽  
Available Nitrogen ◽  
Leaf Production ◽  
Primary Tiller ◽  
Sowing Dates ◽  
Number Of Leaves ◽  
Applied Nitrogen

SummaryAll combinations of four harvesting treatments and two sowing dates were compared in each of 2 years in field experiments near Nicosia. In one of the years, two levels of applied nitrogen were compared. The harvesting treatments were: (1) a milk-stage cut, (2) a boot-stage cut and a regrowth cut, (3) a grazing-stage cut and a regrowth cut, and (4) three grazing-stage cuts and a regrowth cut. The sowing dates were (1) normal (12 November) and (2) early (15 October), with sufficient irrigation to ensure establishment.Applied nitrogen had virtually no effect on leaf growth, evidently because of high reserves of available nitrogen in the soil. Early sowing increased the rates of leaf emergence, extension and expansion up to the time of the first ‘grazing’ cut (when the first node was showing) and reduced the number of leaves which died in that period. Where growth was uninterrupted to the milk stage, early sowing did not affect the number of leaves produced by a main stem or primary tiller, but increased the longevity of the later leaves. Where there were three ‘grazing’ cuts, early sowing allowed time for the production of more and larger leaf blades, with longer sheaths, between the third 'grazing’ cut and the final harvest.The ‘grazing’ cuts considerably reduced the rates of extension and expansion and the final size of the leaves which emerged soon after a cut. There was good recovery subsequently, however, in rates of extension and expansion and final leaf size, particularly with October sowing.During almost all the period of leaf production on a main stem or primary tiller, several leaves (up to six) were expanding at the same time. The stage, during the period between emergence and death, at which a leaf blade reached its full length was typically half-way between emergence and death. Where growth was uninterrupted, area per leaf blade was positively correlated with both the number of days between the emergence of successive leaves and the number of days between emergence and death.

Effect of Application Rate, Weed Species, and Weed Stage of Growth on Imazethapyr Activity

Weed Science ◽  
1992 ◽  
Vol 40 (2) ◽  
pp. 227-232 ◽  
Author(s):  
Tracy E. Klingaman ◽  
Charles A. King ◽  
Lawrence R. Oliver
Keyword(s):  
Field Experiments ◽  
Leaf Growth ◽  
Application Rate ◽  
Leaf Number ◽  
Red Rice ◽  
Weed Species ◽  
Leaf Stage ◽  
Time Of Application ◽  
True Leaf ◽  
Application Rates

Field experiments were conducted in 1986, 1987, and 1988 to evaluate imazethapyr rate and time of application on postemergence control of 24 weed species. Contour graphs were developed that predicted imazethapyr rates required for various levels of weed control based upon weed leaf number at application. Rates below the labeled rate (70 g ha−1) provided 90% or greater control of common cocklebur, smallflower morningglory, and smooth pigweed if applied to 3 true-leaf or smaller weeds and of barnyardgrass, seedling johnsongrass, and Palmer amaranth if applied while weeds were in the cotyledon or 1 true-leaf stage. A rate of 70 g ha−1provided 90% control of large crabgrass in the 1 true-leaf stage. Entireleaf morningglory, red rice, pitted morningglory, and velvetleaf are not susceptible enough to imazethapyr for 90% or greater control to be obtained with rates lower than 70 g ha−1at the 1 true-leaf growth stage. These data demonstrate how control data can be used for developing effective reduced-rate herbicide recommendations based on weed leaf number.

EFFECTS OF GROWTH STAGE ON TRANSLOCATION OF GLYPHOSATE IN QUACK GRASS

1974 ◽  
Vol 54 (2) ◽  
pp. 397-401 ◽  
Author(s):  
R. RIOUX ◽  
J. D. BANDEEN ◽  
G. W. ANDERSON
Keyword(s):  
Growth Stage ◽  
Leaf Growth ◽  
Toxic Metabolite ◽  
Main Shoot ◽  
Leaf Production ◽  
Leaf Stage ◽  
Visual Symptoms ◽  
Glycine Transport ◽  
Agropyron Repens

Visual symptoms of toxicity (inhibition of leaf growth and bud germination) were used to study the influence of growth stage of quack grass (Agropyron repens (L.) Beauv.) on glyphosate (N-phosphonomethyl glycine) transport and efficiency. Glyphosate (or a toxic metabolite) moved in sufficient quantity from the point of application on the leaf within 1 day to significantly affect the regrowth and within 2 days to affect the regenerative potential of rhizomes. As quack grass plants developed to the four-leaf stage the effect of glyphosate treatment increased. When only one shoot was sprayed on a rhizome supporting two shoots at the same leaf stage, glyphosate inhibited leaf growth on the untreated shoot at the two-leaf stage but not at the four-leaf stage. Similarly, glyphosate inhibited leaf growth on tillers when only the main shoot was sprayed. However, when only the tiller was sprayed, leaf production was not affected on the main shoot suggesting that glyphosate is phloem mobile.

scholarly journals GAMETOPHYTIC SELECTION OF THE FUSED VEIN TRAIT IN SQUASH

HortScience ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 245a-245
Author(s):  
R. Bruce Carle ◽  
J. Brent Loy
Keyword(s):  
Pollen Tube ◽  
Leaf Morphology ◽  
Cucurbita Pepo ◽  
Leaf Size ◽  
Leaf Number ◽  
Reproductive Competition ◽  
Gametophytic Selection ◽  
Pollen Loads ◽  
Loads Analysis ◽  
Selection Of

Three experiments were conducted to delineate gametophytic selection of the fused vein trait in Cucurbita pepo L. Gametophytic subvitality was verified by comparing fused vein and normal pollen tube growth. Microscopic examination of partitioned, co-pollinated flowers revealed fewer and slower growing fused vein tubes than normal. The effects of gametophytic subvitality on seed yield and inheritance were shown by manipulating the severity of reproductive competition. Fused vein, normal, and F1 lines were pollinated with fused vein, normal, 50:50 mix, and F1 pollen at three different pollen loads. Analysis showed that fused vein pollen generated significantly fewer seed per fruit in all lines. In ensuing F2 and testcross populations, a reduction in load and thus competition significantly increased the number of fused vein individuals. Leaf number and area for normal, fused vein, F1, F2, and testcross plants were assessed to test pleiotropic effects on growth common to gametophytic subvitals. Although normal and fused vein lines differed in leaf number and size, their total leaf areas were not significantly different. F2 and testcross plants showed no difference between normal and fused vein individuals; leaf size and number were independent of leaf morphology.

Clonal growth and reproductive strategies of the understory tropical palm Geonoma brevispatha: an ontogenetic approach

2003 ◽  
Vol 81 (2) ◽  
pp. 101-112 ◽  
Author(s):  
Alexandre F Souza ◽  
Fernando R Martins ◽  
Luis Carlos Bernacci
Keyword(s):  
Leaf Size ◽  
Structured Populations ◽  
Survival Strategies ◽  
Leaf Number ◽  
Stem Length ◽  
Southeastern Brazil ◽  
Swamp Forest ◽  
Leaf Production ◽  
Ontogenetic Stages ◽  
Palm Species

We investigated the patterns of growth and reproduction of the understory clonal palm Geonoma brevispatha based on the identification of post-germinative ontogenetic stages, over a 3-year period. Genets were monitored in 100 5 × 5 m plots and 100 2 × 2 m subplots, in a 1-ha area of swamp forest in São Paulo state, southeastern Brazil. Ramets pass through four ontogenetic stages (bifid-leafed juveniles, pinnatifid-leafed stemless immatures, stemmed nonreproductive virgins, and reproducers). Leaf size, leaf number, and leaf production rate increased during ontogeny, but diameter growth rate was higher among immatures. Stem length, number of nodes, and leaf rachis length were positively correlated across ontogenetic stages, but crown height was smaller than stem length in adult palms because of frequent leaning. Leaf number and sexual fecundity increased with ramet size, but declined in larger, senescent ramets. Clonal fecundity preceded sexual fecundity, and sexual and clonal fecundity increased continuously with genet size. No relationship was found between sexual and clonal fecundity. Growth and survival strategies of G. brevispatha were consistent with the patterns found in other tropical clonal palm species. Sexual fecundity and cloning seem to be two integrated processes favored by environmental conditions that also support the growth of existing ramets.Key words: stage-structured populations, ontogenetic stages, swamp forest, Brazil, Atlantic forest, senescence.

Growth of `Bartlett' Pear Seedlings in Response to Number of Root-lesion Nematodes and Temperature

HortScience ◽  
1990 ◽  
Vol 25 (3) ◽  
pp. 318-320
Author(s):  
J.L. Townshend
Keyword(s):  
Root Growth ◽  
Pyrus Communis ◽  
Leaf Number ◽  
Pratylenchus Penetrans ◽  
Leaf Production ◽  
Lesion Nematodes ◽  
Effects Of Temperature ◽  
Root Lesion Nematodes

The effects of temperature and root-lesion nematodes [Pratylenchus penetrans (Cobb)] on the growth of newly germinated `Bartlett' pear seedlings (Pyrus communis L.) were examined. At five temperatures from 10 to 30C, P. penetrans (five per gram of soil) did not purple the leaves. After 8 weeks, leaf number, trunk height, and top and root weights were reduced only at 25C. The number of P. penetrans in the roots were greatest at 15 and 20C. At 20C, P. penetrans (16 per gram of soil) caused the leaves of seedlings to turn purple, and, by 6 weeks after treatment, the nematodes had reduced leaf production, trunk elongation, and top and root growth.

scholarly journals Sensitivity and Recovery of Grain Sorghum to Simulated Drift Rates of Glyphosate, Glufosinate, and Paraquat

Agriculture ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 70 ◽  
Author(s):  
Ralph Hale ◽  
Taghi Bararpour ◽  
Gurpreet Kaur ◽  
John Seale ◽  
Bhupinder Singh ◽  
...  
Keyword(s):  
Growth Stage ◽  
Leaf Growth ◽  
Flag Leaf ◽  
Grain Sorghum ◽  
Yield Reduction ◽  
Leaf Stage ◽  
Herbicide Treatments ◽  
Significant Yield ◽  
Glyphosate Drift ◽  
Herbicide Drift

A field experiment was conducted in 2017 and 2018 to evaluate the sensitivity and recovery of grain sorghum to the simulated drift of glufosinate, glyphosate, and paraquat at two application timings (V6 and flag leaf growth stage). Paraquat drift caused maximum injury to sorghum plants in both years, whereas the lowest injury was caused by glyphosate in 2017. Averaged over all herbicide treatments, injury to grain sorghum from the simulated herbicide drift was 5% greater when herbicides were applied at flag leaf stage, as compared to herbicide applications at the six-leaf stage in 2017. In 2018, injury from glyphosate drift was higher when applied at the six-leaf stage than at the flag leaf stage. Paraquat and glufosinate drift caused more injury when applied at flag leaf stage than at six-leaf stage at 14 days after application in 2018. About 21% to 29% of injury from the simulated drift of paraquat led to a 31% reduction in grain sorghum yield, as compared to a nontreated check in 2017. The simulated drift of glyphosate and glufosinate did not result in any significant yield reduction compared to the nontreated check in 2017, possibly due to the recovery of sorghum plants after herbicides’ drift application.

scholarly journals Two maize cultivars of contrasting leaf size show different leaf elongation rates with identical patterns of extension dynamics and coordination

AoB Plants ◽  
2021 ◽  
Author(s):  
Tiphaine Vidal ◽  
Hafssa Aissaoui ◽  
Sabrina Rehali ◽  
Bruno Andrieu
Keyword(s):  
Genotypic Variation ◽  
Leaf Size ◽  
High Rate ◽  
Time Interval ◽  
Extension Rate ◽  
Leaf Production ◽  
Maize Cultivars ◽  
Plant Environment ◽  
The Difference ◽  
Leaf Extension

Abstract Simulating leaf development from initiation to maturity opens new possibilities to model plant–environment interactions and the plasticity of plant architecture. This study analyses the dynamics of leaf production and extension along a maize (Zea mays) shoot to assess important modelling choices. Maize plants from two cultivars originating from the same inbred line, yet differing in the length of mature leaves were used in this study. We characterised the dynamics of the blade and sheath lengths of all phytomers by dissecting plants every 2–3 days. We analysed how differences in leaf size were built up and we examined the coordination between the emergence of organs and phases of their extension. Leaf extension rates were higher in the cultivar with longer leaves than in the cultivar with shorter leaves; no differences were found in other aspects. We found that (i) first post-embryonic leaves were initiated at a markedly higher rate than upper leaves; (ii) below ear position, sheaths were initiated at a time intermediate between tip emergence and appearance, while above the ear position, sheaths were initiated at a high rate, such that the time interval between the blade and sheath initiations decreased for these leaves; and (iii) ear position also marked a change in the correlation in size between successive phytomers with little correlation of size between upper and lower leaves. Our results identified leaf extension rate as the reason for the difference in size between the two cultivars. The two cultivars shared the same pattern for the timing of initiation events, which was more complex than previously thought. The differences described here may explain some inaccuracies reported in functional-structural plant models. We speculate that genotypic variation in behaviour for leaf and sheath initiation exists, which has been little documented in former studies.

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