Leaf morphology of Claytonia virginica: racial and clinal variation

1984 ◽  
Vol 62 (7) ◽  
pp. 1469-1473 ◽  
Author(s):  
Jeff J. Doyle

Differences in average leaf length to width ratio are found to characterize the four chemical and cytological races of the geophytic spring ephemeral Claytonia virginica L. (Portulacaceae). Two races with wide leaves are mostly northern in distribution, while two other races having narrower leaves are predominantly southern. Within each race, a statistically significant north–south cline in leaf ratio is observed, mirroring the variation pattern observed for the species as a whole. Several ecological variables, including zenith angle of the sun and total solar radiation, also show north–south gradients when measured over the aboveground portion of the Claytonia virginica seasonal cycle and corrected for the time of flowering of the species at different latitudes. It is suggested that the clinal pattern of variation observed in the species has evolved in response to these environmental gradients.

2017 ◽  
Vol 7 (4) ◽  
pp. 432-439 ◽  
Author(s):  
Seyed Mehdi Talebi ◽  
Reza Rezakhanlou ◽  
A V. Matsyura

<p><em>Salvia multicaulis</em> is a widespread species of Lamiaceae family in Iran. There are many discussions about its infraspecific variations. Although some varieties were definite for this species in various parts of the world, no infraspecific taxon was reported in Iran and all samples of this species were named as S. multicaulis. In this study, morphological characteristics of S. multicaulis populations, naturally growing in Iran, was examined. Twenty-two traits were examined in 94 individuals of this species to<br />identify their phenotypic difference. Most of the investigated features were showing a high degree of variability, but it was highly pronounced for some characteristics such as basal leaf shape, basal leaf width, basal leaf length/ width ratio and basal petiole length. Significant positive/negative correlations were observed between some morphological variables. Furthermore, significant negative correlations were found between the eastern distribution of populations with basal leaf petiole length and basal leaf length/ width ratio. Based on the UPGMA cluster analysis, populations were divided into two main branches. The first branch contained four populations, while the second branch was bigger and clustered in two sub-branches. In one of them,<br />three populations and in another one the rest populations arranged in two groups. CA joined plot confirmed that each of studied populations or group of populations had distinct morphological trait(s), which were useful in identification of them. Our findings supported population no. 13 had unique morphological traits such as the largest bracts and basal leaf petiole, highest flower number of each inflorescence cycle, widest and largest calyx. The conservation of the highly diverse populations of<br />Iranian S. multicaulis is recommended.</p>


1981 ◽  
Vol 29 (4) ◽  
pp. 631 ◽  
Author(s):  
K Pearse ◽  
ND Murray

Analyses of variation in seven wing pattern characters in H. merope merope females, from 22 sites throughout the range of the subspecies, show that the variation generally has a substantial genetic component. All characters exhibit significant interpopulation variation and one character (S) shows an obvious clinal pattern in a north-south direction. Variation in the total wing phenotype was examined by a multivariate principal component analysis. The first two principal components identified also show a clinal pattern: a north-south cline in component 1 and an east-west cline in component 2. Variation in component 1 is significantly associated with winter humidity and that in the second with yearly rainfall. Because the components cannot be identified simply as size, shape or colour vectors the possible adaptive significance of the results is not clear, although there is some indirect evidence that the pattern of variation is due to natural selection rather than random processes.


2010 ◽  
Vol 3 (3) ◽  
pp. 199-207 ◽  
Author(s):  
Charles T. Bryson ◽  
L. Jason Krutz ◽  
Gary N. Ervin ◽  
Krishna N. Reddy ◽  
John D. Byrd

AbstractCogongrass is a highly invasive, perennial grass that is found on all continents, except Antarctica. It continues to spread at an alarming rate in the southeastern United States. Cogongrass has been reported from a wide array of habitats; however, soils from areas where cogongrass grows have never been characterized. Live cogongrass plants, herbarium specimens, and soil samples were collected from 53 cogongrass populations from across the 10 physiographic regions and land use areas in Mississippi. Cogongrass leaf and inflorescence morphology varied among sites, and plants were found in soils varying widely in texture (ranging from 28 to 86% sand, 3 to 48% silt, and 6 to 43% clay), organic matter content (ranging from 0.9 to 5.0%), pH (ranging from 4.4 to 8.0), and nutrient status: 6 to 190 kg ha−1(15 to 470 lb A−1) of phosphorus (P), 46 to 734 kg ha−1of potassium (K), 150 to 7,620 kg ha−1of calcium (Ca), 26 to 1,090 kg ha−1of magnesium (Mg), 1 to 190 kg ha−1of zinc (Zn), 145 to 800 kg ha−1of estimated sulfur (S) based on organic matter, and 57 to 300 kg ha−1of sodium (Na). These soil parameters were highly variable among cogongrass populations, even within physiographic regions or land use areas, and encompassed much of the soil physiochemical diversity within the state. Soil characteristics were significantly correlated with leaf length (Ca, K, Mg, P, Zn, and percentage of sand and silt), leaf width (Ca, P, Mg, and percentage of sand and silt), the leaf length-to-width ratio (K and P), inflorescence length (Na, P, and pH), inflorescence width (S, organic matter, and pH), and the inflorescence length-to-width ratio (S and organic matter). These data indicate that cogongrass is able to establish, emerge, grow, and reproduce on a wide array of soils in Mississippi. This ability provides cogongrass an advantage over other plant species that are more limited in the soil types that support their growth.


Botany ◽  
2008 ◽  
Vol 86 (1) ◽  
pp. 91-97 ◽  
Author(s):  
Julie R. Etterson ◽  
Daniel E. Delf ◽  
Timothy P. Craig ◽  
Yoshino Ando ◽  
Takayuki Ohgushi

The ability of exotic species to proliferate and expand their range may hinge critically upon their potential for adaptive evolution. The finding of parallel patterns of genetically based clinal variation in native and non-native ranges across similar environmental gradients supports the hypothesis that adaptive evolution has played a role in establishment and spread. In this common garden study, we compared patterns of phenotypic variation among 12 populations of Solidago altissima L. that were sampled across similar latitudes in the native range in central USA (25°N–43°N) and across its invasive range in Japan (26°N–43°N). Significant clinal variation in phenotype corresponding to latitude was found among US and Japanese populations for height, leaf number, leaf length, leaf width, stem diameter, and stomatal guard-cell size. Only the slope of leaf width differed significantly between the native and invasive range, and the slope was significantly steeper in Japan. These results indicate that patterns of selection across latitude are similar in these two countries. We suggest that populations of S. altissima have rapidly differentiated in response to the cline in selection in Japan, possibly by the sorting of lineages from multiple introductions, and this has contributed to their success as an exotic invader.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
M. Sohrabi ◽  
M. Y. Rafii ◽  
M. M. Hanafi ◽  
A. Siti Nor Akmar ◽  
M. A. Latif

Genetic diversity is prerequisite for any crop improvement program as it helps in the development of superior recombinants. Fifty Malaysian upland rice accessions were evaluated for 12 growth traits, yield and yield components. All of the traits were significant and highly significant among the accessions. The higher magnitudes of genotypic and phenotypic coefficients of variation were recorded for flag leaf length-to-width ratio, spikelet fertility, and days to flowering. High heritability along with high genetic advance was registered for yield of plant, days to flowering, and flag leaf length-to-width ratio suggesting preponderance of additive gene action in the gene expression of these characters. Plant height showed highly significant positive correlation with most of the traits. According to UPGMA cluster analysis all accessions were clustered into six groups. Twelve morphological traits provided around 77% of total variation among the accessions.


PhytoKeys ◽  
2020 ◽  
Vol 145 ◽  
pp. 47-56
Author(s):  
Zhiqiang Lu

Carpinus gigabracteatus Z. Qiang Lu, a new hornbeam species from southeast Yunnan of China, is described and illustrated in this study. It possesses extremely large bracts and is closely related to C. tsaiana Hu and C. tschonoskii Maxim., based on the characters of large bract size and bracts without lobes at the base of inner margins. Furthermore, morphological comparison suggested it was distinctly different from C. tschonoskii by a series of characters from leaf, infructescence, bract and nutlet and from C. tsaiana by its leaf length to width ratio (1.4–2.0 vs. 2.0–2.4), lateral veins significantly impressed adaxially, number of lateral veins on each side of midvein (9–14 vs. 14–17), bract length (3.9–4.8 vs. 2.5–3.2 cm) and bract length to width ratio (2.3–3.1 vs. 1.5–2.1). Therefore, this hornbeam, based on only one population from southeast Yunnan, is here erected as a new species, named as C. gigabracteatus.


HortScience ◽  
2002 ◽  
Vol 37 (3) ◽  
pp. 585-592 ◽  
Author(s):  
Tae-Ho Han ◽  
Herman J. van Eck ◽  
Marjo J. De Jeu ◽  
Evert Jacobsen

An F1 population, derived from an intraspecific cross between two Alstroemeria aurea accessions, was used to map quantitative trait loci (QTL) involved in ornamental and morphological characteristics. One QTL for leaf length was mapped on linkage group three of both parents near marker E+ACCT/M+CGCA-I165 explaining 20% and 14.8% phenotypic variation. Two putative QTL were detected on leaf width on A002-3 and A002-6. One QTL and three putative QTL, involved in the leaf length/width ratio were identified accounting for 46.7% of the phenotypic variance in total. Significant interaction was observed between two QTL, S+AC/M+ACT-I162 and S+AC/M+AGA-I465 in a two-way analysis of variance (ANOVA). For the main color of the flower one QTL and putative QTL accounted for up to 60% of phenotypic variance suggesting simple genetic control of flower color. A two-way ANOVA of these QTL suggested an epistatic interaction. A QTL was detected for color of the inner side of outer lateral tepal with 26.5% of the phenotypic variance explained. This QTL was also associated with main color of the flower just below the 95% threshold value. Two QTL were detected with the Kruskal-Wallis test for the tip color of inner lateral tepal near QTL for other flower color traits. Consequently flower color traits were significantly correlated. A QTL and a putative QTL for the flower size was mapped near marker E+ACCG/M+CGCT-I193 and E+ACCG/M+CGCG-197, respectively. One putative QTL was detected for the stripe width of the inner lateral tepal.


1998 ◽  
Vol 76 (8) ◽  
pp. 1340-1349 ◽  
Author(s):  
Wendy B Anderson ◽  
William G Eickmeier

Because of their unique phenology and physiology, spring ephemeral herbs are believed to play an important role in intrasystem nutrient cycling in deciduous forest ecosystems. It was hypothesized that they function as a "vernal dam" by temporarily sequestering nutrients and preventing leaching from the system during a period of high nutrient availability. However, spring ephemerals require high-irradiance growing conditions. How do their physiological and morphological responses to ambient light and shade limit their ability to sequester excess nutrients? We performed field experiments using Claytonia virginica L. as a model to test several responses to shade and increasing levels of nutrient additions. We also examined the biomass responses and nutrient storage capacities of other spring ephemeral herbs. In C. virginica, shading reduced ribulose 1,5-bisphosphate carboxylase-oxygenase (Rubisco) activity, photosynthesis rate, specific leaf weight, leaf width/length (W/L), and biomass; nutrient additions increased W/L and biomass only under unshaded conditions. Other herbs responded similarly but reached maximum biomass at lower nutrient addition levels than C. virginica. Shading reduced and nutrient additions increased nitrogen and phosphorus concentrations in both C. virginica and other herbs. Shaded herbs generally reached nutrient saturation at lower nutrient addition levels than unshaded herbs. Overall, unshaded plants sequestered larger amounts of nutrients than shaded plants. This pattern is best explained by a reduction in biomass under shaded conditions. We concluded that C. virginica and other spring herbs, although important components in forest nutrient cycling in the early spring, are limited in their capacity to store excess nutrients, particularly when shaded.Key words: Claytonia virginica, nutrient cycling, spring ephemerals, vernal dam.


2020 ◽  
pp. 1-9
Author(s):  
Rouzbeh Zangoueinejad ◽  
Mohammad Taghi Alebrahim ◽  
Te-Ming Tseng

Herbicide tolerance is commonly associated with reduced absorption and translocation of the herbicide; we hypothesized that the mechanism of dicamba tolerance in wild tomato (Solanum lycopersicum L.) accessions is due to these characteristics. The absorption and translocation of dicamba were investigated at a drift rate of 2.8 g a.e. ha−1 in three predetermined dicamba-tolerant (DT) wild accessions (TOM199, TOM198, and TOM300) and compared with two dicamba-susceptible (DS) commercial tomato cultivars [Money Maker (MM) and Better Boy (BB)]. Dicamba was quantified in three different parts of the tomato plant: two upper leaves, two lower leaves, and the roots at 1, 3, and 7 d after treatment. Both MM and BB absorbed more dicamba then all the three DT accessions. The overall translocation pattern of dicamba was similar between DS cultivars and DT accessions, thus suggesting that tolerance to dicamba in wild accessions may not be associated with reduced translocation but instead with reduced uptake of the herbicide. Additionally, reduced dicamba absorption in DT accessions may be attributed to their leaf characteristics, such as the presence of narrower leaves (3.42 leaf length/width ratio) and higher trichome density (20 no. mm−2) in DT accessions, than compared with DS cultivars (1.92 leaf length/width ratio and 8 no. mm−2 trichome density).


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