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In the present study, six potato varieties (Evora, Hannat white, Lacetta, Mustang, SH-5, Anats) were evaluated for phenotypic diversity and pest management based on various qualitative and quantitative traits. Data on various morphological traits and insect/pest infestation frequencies were compile for three plants of each variety. Statistical investigation of data showed significant variations in different morphological characteristics such as plant height, leaf length, leaf width, tuber diameter, and tuber yield, and insects/frequencies (aphids, leafhopper, thrips and whiteflies). Our results showed that despite the maximum infestation frequency for aphids (20.80 insect/plot), leafhopper (24.22 insect/plot), thrips (11.09 insect/plot) and whiteflies (15.73), significantly higher plant height (22.65 cm), leaf length (6.20 cm), leaf width (4.66 cm), tuber diameter (3.43 cm), and tuber yield (12.80 kg), of Lacetta (v.no3) revealed, indicating that this variety is highly resistant/tolerant to these insects/pests. While SH-5 was second to it as regards insect infestation rate and yield, potato varieties Hannat white showed minimum plant height (18.18 cm), leaf length (4.09 cm), leaf width (3.41 cm), tuber diameter (2.41 cm), and tuber yield (7.55 kg), with lowest infestation frequencies for aphids (14.43 insects per plot), leafhopper (17.72 insects/plot), thrips (7.22 insects/plot), and whiteflies (12.97 insects/plot), indicating that this variety is more susceptible to various insects. Based on these results, the varieties Lacetta and SH-5 should be recommended for the cultivation of agro-climatic conditions of Mansehra in order to get maximum yield and to protect the environment and human health from the adverse effects of insecticides and pesticides. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the feasibility of noncoplanar volumetric modulated arc stereotactic radiotherapy (VMAT-SRT) using a 5-mm multileaf collimator (MLC) for multiple brain metastases. We identified 34 multiple-target cases (3 to 19 targets in each case) with a total of 257 of targets and constructed noncoplanar VMAT-SRT plans using 5-mm and 2.5-mm MLCs with 4-arc. The prescribed dose was 36 Gy/6 fr. Plans were evaluated using the Paddick conformity indices (PCI), Paddick gradient index (PGI), and normal brain dose (NBD, equal to the mean brain dose minus gross tumor volume). There were no significant differences in PCI (median [range]: 5 mm, 0.88 [0.78 to 0.94]; 2.5 mm, 0.89 [0.78 to 0.94]; p = 0.691), PGI (median [range]: 5 mm, 3.96 [2.21 to 6.63]; 2.5 mm, 3.96 [2.24 to 6.45]; p = 0.358), or NBD (median [range]: 5 mm, 7.5 Gy [2.5 to 12.4]; 2.5 mm, 7.5 Gy [2.5 to 12.5]; p = 0.675). The performance of the 5-mm MLC was not inferior to the 2.5-mm MLC in applications of noncoplanar VMAT-SRT for multiple brain metastases with regards to dose conformity, gradient, and NBD. This study provides the necessary background for generalizing noncoplanar VMAT-SRT approaches in treating multiple brain lesions. [ABSTRACT FROM AUTHOR]

Receptor-like kinases (RLKs) are important for plant growth, development and defense responses. The S-receptor protein kinases (SRKs), which represent an RLK subfamily, control the self- incompatibility among Brassica species. However, little information is available regarding SRK functions in rice. We identified a gene OsSRK1 encoding an atypical SRK. The transcript of OsSRK1 was induced by abscisic acid (ABA), salt and polyethylene glycol. OsSRK1 localized to the plasma membrane and cytoplasm. Leaf width was increased in OsSRK1 -overexpression (OsSRK1 -OX) transgenic rice plants, likely because of an increase in cell number per leaf. Furthermore, the expression levels of OsCYCA3-1 and OsCYCD2-1, which encode positive regulators of cell division, were up-regulated in leaf primordium of OsSRK1 -OX rice plants relative to those in wild type. Meanwhile, the expression level of OsKRP1 , which encodes cell cycle inhibitor, was down-regulated in the OsSRK1 -OX plants. Therefore, it is deduced that OsSRK1 regulates leaf width by promoting cell division in the leaf primordium. Additionally, Os SRK1 -OX plants exhibited enhanced ABA sensitivity and salt tolerance compared with wild type. These results suggest that OsSRK1 plays important roles in leaf development and salt responses in rice. [ABSTRACT FROM AUTHOR]

Many plant species produce ovate leaves, but there is no general parametric model for describing this shape. Here, we used two empirical nonlinear equations, the beta and Lobry–Rosso–Flandrois (LRF) equations, and their modified forms (referred to as the Mbeta and MLRF equations for convenience), to generate bilaterally symmetrical curves along the x-axis to form ovate leaf shapes. In order to evaluate which of these four equations best describes the ovate leaf shape, we used 14 leaves from 7 Neocinnamomum species (Lauraceae) and 72 leaves from Chimonanthus praecox (Calycanthaceae). Using the AIC and adjusted root mean square error to compare the fitted results, the modified equations fitted the leaf shapes better than the unmodified equations. However, the MLRF equation provided the best overall fit. As the parameters of the MLRF equation represent leaf length, maximum leaf width, and the distance from leaf apex to the point associated with the maximum leaf width along the leaf length axis, these findings are potentially valuable for studying the influence of environmental factors on leaf shape, differences in leaf shape among closely related plant species with ovate leaf shapes, and the extent to which leaves are bilaterally symmetrical. This is the first work in which temperature-dependent developmental equations to describe the ovate leaf shape have been employed, as previous studies lacked similar leaf shape models. In addition, prior work seldom attempted to describe real ovate leaf shapes. Our work bridges the gap between theoretical leaf shape models and empirical leaf shape indices that cannot predict leaf shape profiles.

Introduction: Spinach is an important leafy vegetable in the cold season, and despite the fact that is considered as low-calorie food source contains significant amount of minerals such as iron, and vitamin A and C. According to the University of Utah 3.8 dS m-1 is salinity tolerance threshold for the spinach and yield decrease that have been reported by 10%, 25% and 50% at 5.5, 7 and 8 dS m-1 salinity. The necessity to supply adequate potassium has been demonstrated in salinity conditions. In salt stress conditions, foliar application of K in spinach, reduces the harmful effects of salt and increase the ratio of potassium to sodium (1.61 to 2.72). Foliar application of K with prevent of potassium transfer from root to shoot is causing continuation of photosynthesis and reduce the effects of salinity. Absorption of potassium from the leaves depends on the type of used compound. In this context, characteristics of plant (leaves with a waxy composition, duration of growth and leaf area) are important. 100 kg ha-1 of potassium in salt stress conditions by reducing the absorption of sodium, increased salt tolerance on the sunflower. Materials and Methods: In order to evaluate the foliar application of K on the yield and yield components of spinach in salt stress condition, a study was conducted in 2012 by using split plot randomized based on complete block design with four replications at Isfahan Agricultural and Natural Resources Research Station. Three levels of irrigation water salinity consisted of a control (2 dS m-1), well water with salinity (4 dS m-1) and well water with salinity (8dS m-1) arranged in main plots and two levels of control and foliar applications of potassium fertilizer containing potassium oxide solubility in water (2.5 ml per liter) arranged in subplots. Statistical analysis was conducted by using SAS software and statistical tests were compared with Duncan at 5 percent. Result and Discussions: The results showed that the yield of spinach with foliar application of K and 4 dS m-1 salinity was equaled 35300 kg ha-1 which had not significantly different from control treatment. Foliar application of K and 8 dS m-1 salinity, and also 8 dS m-1 salinity and without foliar potassium, had 20.2 and 38% yield reduction, respectively. In salinity 2.1, 4 and 8 dS m-1 plants m-2 were 40, 38.1 and 29.1, respectively. Leaf dry matter percent was improved with foliar application of K in 8 dS m-1 salinity. Effect of potassium, as modulators of salt in spinach, by researches of Shannon and Greve (24) and Kaya et al (14) have also been emphasized. Spinach leaves number was from 11.4 to 16.7 in different treatments. Foliar application of K in 4 and 8 dS m-1 salt treatment was increase in the number of leaves. This increased in treatment of 4 and 8 dS m-1 was 15.3 and 28.9 percent, respectively. In both saline treatments of 4 and 8 dS m-1, leaf length was positively affected by the application of potassium but in salinity 4 dS m-1 (unlike the eight salinity dS m-1) leaf width was not affected by the potassium spraying. The ability of plants to maintain intracellular potassium to sodium ratio leaves in certain extent is necessary for a salt tolerance. In fact, the application of potassium in salinity conditions by increasing the concentration of the K in organs is a kind of acclimation to the salt stress and activates repair mechanisms of the damage against of stress agent. The length of tail leaves in 4 dS m-1 salt was not significantly affected by the spraying of potassium while in 8 dS m-1 salinity, spraying potassium led to an increase of 28 percent in length of leaf tail. The effect of K application on the dry matter content in the 8 dS m-1 salinity was statistically significant. Potassium is the most abundant cation-forming in many plants (typically more than 10% of dry weight) and less than 10 grams per kg-1 of dry weight appear deficiency symptoms in most plants. Conclusion: According to the results, in salinity conditions, the foliar application of K can be used as a factor to reduce the harmful effects of salinity. While the lack of fresh water for irrigation in arid and semi-arid crops has become a challenge, attention to the moderated mechanisms of the harmful effects of salt, is one of the approaches to face the challenges ahead.

Introduction: This study explores the feasibility of SRS/SRT treatment with MLC leaves wider than 2.5 mm at isocenter by inter-comparing treatment plans produced with 2.5, 5.0, and 10.0 mm leaves for various target sizes and shapes.Materials and methods: Forty previously treated patients were re-planned using 2.5, 5.0, and 10.0 mm wide MLC leaves. For each patient, all three plans were evaluated and contrasted between them in terms of five metrics: target dose homogeneity, conformity index, organs at risk dose, dose fall off outside the target, and dose to normal tissues. A regularity index RI was introduced that quantified the degree of target shape irregularity. The effect of target size and shape irregularity on feasibility of 5.0 and 10.0 mm leaves was analyzed.Results: Consistent plan degradation was observed for 10.0 mm (sometimes for 5.0 mm) compared to 2.5 mm MLC in terms of the above five plan metrics, but this degradation was small to clinically insignificant. As an exception, when target (PTV) size was smaller than about 1 cm diameter, clinically significant differences were found between 2.5, 5.0, and 10.0 mm MLC.Conclusion: 5.0 and 10.0 mm MLC can be used in SRS/SRT for targets (PTV) diameter larger than 1 cm. For smaller targets, 2.5 mm MLC is clinically superior, 5.0 is acceptable and 10.0 mm MLC is discouraged in terms of PTV dose conformity.

A model for estimating the area of individual leaves (LA) by employing their dimensions was developed for chrysanthemum. Further hypotheses were tested: (a) LA estimation is improved by considering blade length (Lb) rather than leaf length (L), and (b) a reasonable LA estimation can be attainable by considering L in conjunction to a shape trait, which is cultivar dependent. For the model development, six cultivars were employed (1500 leaves in total), while for model validation, an independent set of nine cultivars was utilized (1125 leaves in total). Several characteristics were digitally assessed in fully expanded leaves which included petiole length, leaf L, width (W), perimeter, shape traits (aspect ratio, circularity, roundness, solidity), together with LA. LA estimation was more accurate by considering both L and W, as compared to a single dimension. A linear model, employing the product of L by W as independent variable, provided the most accurate LA estimation (R2 = 0.84). The model validation indicated a highly significant correlation between computed and measured LA (R2 = 0.88). Replacing L by Lb reasonably predicted LA (R2 = 0.832) but at some expense of accuracy. Contrary to expectation, considering L (or W) and a cultivar-specific shape trait generally led to poor LA estimations.

Understanding the genetic architecture of leaf-related traits is important for improving alfalfa yield. Leaf size has a great influence on the protein content and yield for alfalfa. In this study, a low-yielding precocious alfalfa individual (paternal parent) and a high-yielding late-maturing alfalfa individual (maternal parent) were used to build a hybrid F1 population of 149 individuals. The linkage map was constructed using simple sequence repeat and single nucleotide polymorphism markers, and quantitative trait loci (QTL) for leaf length, leaf width, and leaf area were mapped using 3 years phenotypic data. We identified a total of 60 QTLs associated with leaf size. These QTLs were located on chromosomes 1 to 8, and the percent of phenotypic variation explained by QTL ranged from 2.97% to 18.78%. There were 13 QTLs explain more than 10% of phenotypic variation, most of which represent novel loci controlling leaf traits that have not been found in previous studies. The nearest markers of QTL may be used in marker-assisted selection and breeding alfalfa new varieties with high yield. [ABSTRACT FROM AUTHOR]

Introduction: This study explores the feasibility of SRS/SRT treatment with MLC leaves wider than 2.5 mm at isocenter by inter-comparing treatment plans produced with 2.5, 5.0, and 10.0 mm leaves for various target sizes and shapes. Materials and methods: Forty previously treated patients were re-planned using 2.5, 5.0, and 10.0 mm wide MLC leaves. For each patient, all three plans were evaluated and contrasted between them in terms of five metrics: target dose homogeneity, conformity index, organs at risk dose, dose fall off outside the target, and dose to normal tissues. A regularity index RI was introduced that quantified the degree of target shape irregularity. The effect of target size and shape irregularity on feasibility of 5.0 and 10.0 mm leaves was analyzed. Results: Consistent plan degradation was observed for 10.0 mm (sometimes for 5.0 mm) compared to 2.5 mm MLC in terms of the above five plan metrics, but this degradation was small to clinically insignificant. As an exception, when target (PTV) size was smaller than about 1 cm diameter, clinically significant differences were found between 2.5, 5.0, and 10.0 mm MLC. Conclusion: 5.0 and 10.0 mm MLC can be used in SRS/SRT for targets (PTV) diameter larger than 1 cm. For smaller targets, 2.5 mm MLC is clinically superior, 5.0 is acceptable and 10.0 mm MLC is discouraged in terms of PTV dose conformity. [ABSTRACT FROM AUTHOR]

Main conclusion: Cell-size enlargement plays a pivotal role in increasing the leaf size of triploid poplar, and polyploidization could change leaf shape. ABP1 was highly expressed in triploid plants and positively related to cell size.In the plant kingdom, the leaf is the most important energy production organ, and polyploidy often exhibits a "Gigas" effect on leaf size, which benefits agriculture and forestry. However, little is known regarding the cellular and molecular mechanisms underlying the leaf size superiority of polyploid woody plants. In the present study, the leaf area and abaxial epidermal cells of diploid and triploid full-sib groups and their parents were measured at three different positions. We measured the expression of several genes related to cell division and cell expansion. The results showed that the leaf area of triploids was significantly larger than that of diploids, and the triploid group showed transgressive variation compared to their full-sib diploid group. Cell size but not cell number was the main reason for leaf size variation. Cell expansion was in accordance with leaf enlargement. In addition, the leaf shape changes in triploids primarily resulted from a significant decrease in the leaf ratio of length to -width. Auxin-binding protein 1 (ABP1) was highly expressed in triploids and positively related to leaf size. These results enhanced the current understanding that giant leaf is affected by polyploidy vigor. However, significant heterosis is not exhibited in diploid offspring. Overall, polyploid breeding is an effective strategy to enhance leaf size, and Populus, as an ideal material, plays an important role in studying the leaf morphological variations of polyploid woody plants. [ABSTRACT FROM AUTHOR]

Purpose: To quantify the contribution of penumbra in the improvement of healthy tissue sparing at reduced source‐to‐axis distance (SAD) for simple spherical target and different prescription isodoses (PI). Method: A TPS‐independent method was used to estimate three‐dimensional (3D) dose distribution for stereotactic treatment of spherical targets of 0.5 cm radius based on single beam two‐dimensional (2D) film dosimetry measurements. 1 cm target constitutes the worst case for the conformation with standard Multi‐Leaf Collimator (MLC) with 0.5 cm leaf width. The measured 2D transverse dose cross‐sections and the profiles in leaf and jaw directions were used to calculate radial dose distribution from isotropic beam arrangement, for both quadratic and circular beam openings, respectively. The results were compared for standard (100 cm) and reduced SAD 70 and 55 cm for different PI. Results: For practical reduction of SAD using quadratic openings, the improvement of healthy tissue sparing (HTS) at distances up to 3 times the PTV radius was at least 6%–12%; gradient indices (GI) were reduced by 3–39% for PI between 40% and 90%. Except for PI of 80% and 90%, quadratic apertures at SAD 70 cm improved the HTS by up to 20% compared to circular openings at 100 cm or were at least equivalent; GI were 3%–33% lower for reduced SAD in the PI range 40%–70%. For PI = 80% and 90% the results depend on the circular collimator model. Conclusion: Stereotactic treatments of spherical targets delivered at reduced SAD of 70 or 55 cm using MLC spare healthy tissue around the target at least as good as treatments at SAD 100 cm using circular collimators. The steeper beam penumbra at reduced SAD seems to be as important as perfect target conformity. The authors argue therefore that the beam penumbra width should be addressed in the stereotactic studies. [ABSTRACT FROM AUTHOR]

Leaf area is among the most important leaf functional traits, and it determines leaf temperature and alters light harvesting. The calculation of individual leaf area is the basis of calculating the leaf area index (i.e., the total leaf area per unit ground area) that is directly associated with the ability of plants to intercept light for photosynthesis. It is valuable to provide a fast and reliable approach to measuring leaf area. Here, we examined the validity and calculation accuracy of the Montgomery equation (ME), which describes the area of a leaf as a product of leaf length, width and a specific coefficient referred to as the Montgomery parameter, MP. Using ME, we calculated leaf areas of different age groups of bamboo culms. For most broad-leaved plants, leaf area is proportional to the product of leaf length and width, and MP falls within a range of 1/2 to π/4, depending on leaf shape. However, it is unknown whether there is an intra-specific variation in MP resulting from age structure and whether such a variation can significantly reduce the predictability of ME in calculating leaf area. This is relevant as a population of perennial plants usually composes of different age groups. We used Moso bamboos as model as this species is of ecological and economic importance in southern China, and pure stands can cover six to seven plant age groups. We used five age groups of moso bamboo and sampled 260–380 leaves for each group to test whether ME holds true for each group and all groups combined, whether there are significant differences in MP among different age groups, and whether the differences in MP can lead to large prediction errors for leaf area. We observed that for each age group and all groups combined, there were significant proportional relationships between leaf area and the product of leaf length and width. There were small but significant differences in MP among the five age groups (MP values ranged from 0.6738 to 0.7116 for individual plant ages; MP = 0.6936 for all age groups combined), which can be accounted for by the minor intergroup variation of leaf shape (reflected by the leaf width/length ratio). For all age classes, MP estimated for the pooled data resulted in

The use of warm season turfgrasses is a consolidated trend in the climatic transition zone of Mediterranean countries, in particular St. Augustinegrass (Stenotaphrum secundatum (Walt.) Kuntze) begins to be widespread in warm coastal areas. However, little is known about the performance of the different cultivars of this species in southern Europe. In 2016-2017 a trial was carried out in three locations in Italy, Padova, Pisa, and Palermo, located in the north, center and south of the country respectively. Four cultivars (Floratine, Captiva, Sapphire, Palmetto) and five ecotypes (CeRTES 201, CeRTES 202, CeRTES 203, CeRTES 204, CeRTES 205) were compared in terms of their growth characteristics and morphological traits during establishment. The results highlighted that stolon growth was significantly affected by the location, as well as green colour retention. Stolon growth rate, internode length and internode volume and turf quality were, however, significantly determined by the accession effect. The quality of the ecotypes was also in some cases comparable to that of the cultivars. In Padova, winterkill occurred in most of the accessions, while in Pisa and Palermo, all the entries survived. In conclusion, St. Augustinegrass is suitable for turf use in the central and southern coastal area of Italy.

Leaf width (LW) influences canopy architecture of population-cultured maize and can thus contribute to density breeding. In previous studies, almost all maize LW-related mutants have extreme effect on leaf development or accompanied unfavorable phenotypes. In addition, the identification of quantitative trait loci (QTLs) has been resolution-limited, with cloning and fine-mapping rarely performed. Here, we constructed a bin map for 670 recombinant inbred lines (RILs) using ∼1.2 billion 100-bp re-sequencing reads. QTL analysis of the LW trait directly narrowed the major effect QTL, qLW4, to a ∼270-kb interval. A fine-mapping population and near-isogenic lines (NILs) were quickly constructed using a key RIL harboring heterozygous genotypes across the qLW4 region. A recombinant-derived progeny testing strategy was subsequently used to further fine-map qLW4 to a 55-kb interval. Examination of NILs revealed that qLW4 has a completely dominant effect on LW, with no additional effect on leaf length. Candidate gene analysis suggested that this locus may be a novel LW controlling allele in maize. Our findings demonstrate the advantage of large-population high-density bin mapping, and suggest a strategy for efficiently fine-mapping or even cloning of QTLs. These results should also be helpful for further dissection of the genetic mechanism of LW variation, and benefit maize density breeding.

Area (LA) estimation, based on individual leaf dimensions [length (L) and width (W)], was addressed in olive tree. Ten cultivars exposed to two watering regimes (irrigated versus rainfed) under field conditions were examined. Petiole length, leaf L, W, perimeter, base and apex angles, four shape indicators, together with LA were digitally assessed in fully-expanded leaves (480 leaves per treatment; 9.600 leaves in total). Large cultivar differences mainly in leaf size and secondarily in leaf shape were apparent. All parameters were affected by water deficit, but to a cultivar dependent extent. Leaf size was generally reduced by lack of irrigation in most cultivars. LA was estimated with higher accuracy by employing L alone, as compared to W alone, in eight cultivars. LA estimation was always improved by considering both L and W simultaneously, as compared to a single dimension. By studying each cultivar individually, LA estimation was within accepted limits (0.71 ≤ R 2 ≤ 0.92) in nine cultivars, whereas in the tenth one a moderate R 2 (0.63) was obtained. The accuracy of this estimation was not improved by pooling the data of all cultivars. Watering did not significantly affect the relation between estimated and measured LA. The obtained data indicate that a universal LA estimation model for olive tree carries the pitfall of moderate accuracy, owing only to cultivar differences, since environmental effects were trivial. [ABSTRACT FROM AUTHOR]

The use of warm season turfgrasses is a consolidated trend in the climatic transition zone of Mediterranean countries, in particular St. Augustinegrass (Stenotaphrum secundatum (Walt.) Kuntze) begins to be widespread in warm coastal areas. However, little is known about the performance of the different cultivars of this species in southern Europe. In 2016-2017 a trial was carried out in three locations in Italy, Padova, Pisa, and Palermo, located in the north, center and south of the country respectively. Four cultivars (Floratine, Captiva, Sapphire, Palmetto) and five ecotypes (CeRTES 201, CeRTES 202, CeRTES 203, CeRTES 204, CeRTES 205) were compared in terms of their growth character-istics and morphological traits during establishment. The results highlighted that stolon growth was significantly affected by the location, as well as green colour retention. Stolon growth rate, internode length and internode volume and turf quality were, how-ever, significantly determined by the accession effect. The quality of the ecotypes was also in some cases comparable to that of the cultivars. In Padova, winterkill occurred in most of the accessions, while in Pisa and Palermo, all the entries survived. In conclusion, St. Augustinegrass is suitable for turf use in the central and south-ern coastal area of Italy. [ABSTRACT FROM AUTHOR]

Highlights • Drought tolerance in Andropogon gerardii ecotypes relates to surface area. • Morphology in A. gerardii ecotypes is mostly controlled by genetics. • Drought-adapted A. gerardii plants had fewer and smaller leaves. • There is little effect of environment on morphology in A. gerardii. Abstract Big bluestem ( Andropogon gerardii Vitman) is a dominant tallgrass species that has a wide range in North America with numerous genetically-distinct ecotypes, each adapted to conditions in their native habitat. In an evolutionary context, it was hypothesized that drought adaptation in A. gerardii would relate to plant surface area, where drought-adapted ecotypes were expected to be short with narrow leaves, thin stems, and few leaves per tiller. In the context of individual plants acclimating to reduced rainfall, rainout shelters were hypothesized to cause morphological reductions in surface area of individual plants. Morphological measurements were taken from four genetically-distinct ecotypes of A. gerardii across a precipitation gradient ranging from 500 to 900 mm rain per year at three common garden sites in Colby, Hays, and Manhattan, Kansas, USA. Evolutionary responses to drier soils in A. gerardii resulted in reduction of evaporative surface area from leaves, as drought-adapted plants had fewer and smaller leaves. The most mesic ecotype of A. gerardii had the highest maximum leaf width, stem diameter, and leaf count across sites. There were few effects of environment on morphology in A. gerardii with reduced rainfall, however, indicating genetics plays a more prominent role than environment to influence morphology. We conclude that increased drought tolerance is related to an evolutionary reduction in evaporative surface area. [ABSTRACT FROM AUTHOR]

• Explanations of leaf size variation commonly focus on water availability, yet leaf size also varies with latitude and elevation in environments where water is not strongly limiting. We provide the first conclusive test of a prediction of leaf energy balance theory that may explain this pattern: large leaves are more vulnerable to night-time chilling, because their thick boundary layers impede convective exchange with the surrounding air. • Seedlings of 15 New Zealand evergreens spanning 12-fold variation in leaf width were exposed to clear night skies, and leaf temperatures were measured with thermocouples. We then used a global dataset to assess several climate variables as predictors of leaf size in forest assemblages. • Leaf minus air temperature was strongly correlated with leaf width, ranging from -0.9 to -3.2°C in the smallest- and largest-leaved species, respectively. Mean annual temperature and frost-free period were good predictors of evergreen angiosperm leaf size in forest assemblages, but no climate variable predicted deciduous leaf size. • Although winter deciduousness makes large leaves possible in strongly seasonal climates, large-leaved evergreens are largely confined to frost-free climates because of their susceptibility to radiative cooling. Evergreen leaf size data can therefore be used to enhance vegetation models, and to infer palaeotemperatures from fossil leaf assemblages. [ABSTRACT FROM AUTHOR]

Abstract: Given anticipated climate changes, it is crucial to understand controls on leaf temperatures including variation between species in diverse ecosystems. In the first study of leaf energy balance in tropical montane forests, we observed current leaf temperature patterns on 3 tree species in the Atlantic forest, Brazil, over a 10‐day period and assessed whether and why patterns may vary among species. We found large leaf‐to‐air temperature differences (maximum 18.3 °C) and high leaf temperatures (over 35 °C) despite much lower air temperatures (maximum 22 °C). Leaf‐to‐air temperature differences were influenced strongly by radiation, whereas leaf temperatures were also influenced by air temperature. Leaf energy balance modelling informed by our measurements showed that observed differences in leaf temperature between 2 species were due to variation in leaf width and stomatal conductance. The results suggest a trade‐off between water use and leaf thermoregulation; Miconia cabussu has more conservative water use compared with Alchornea triplinervia due to lower transpiration under high vapour pressure deficit, with the consequence of higher leaf temperatures under thermal stress conditions. We highlight the importance of leaf functional traits for leaf thermoregulation and also note that the high radiation levels that occur in montane forests may exacerbate the threat from increasing air temperatures. [ABSTRACT FROM AUTHOR]

Abstract: Leaf‐related traits (leaf length, leaf width, leaf area and leaf angle) are very important for the yield of maize (Zea mays L) due to their influence on plant type. Therefore, it is necessary to identify quantitative trait loci (QTLs) for leaf‐related traits. In this report, 221 doubled haploid lines (DHLs) of an IBM Syn10 DH population were provided for QTL mapping. In total, 54 QTLs were detected for leaf‐related traits in single environments using a high‐density genetic linkage map. Among them, only eight common QTLs were identified across two or three environments, and the common QTLs for the four traits explained 4.38%–19.99% of the phenotypic variation. qLL‐2‐1 (bin 2.09), qLW‐2‐2 (bin 2.09), qLW‐6‐3 (bin 6.07) and qLA‐5‐2 (bin 2.09) were detected in previous studies, and qLL‐1‐1, qLAr‐1‐1, qLAr‐2‐1 and qLA‐7‐1 may be new QTLs. Notably, qLW‐6‐3 and qLA‐5‐2 were found to be major QTLs explaining 19.99% and 10.96% of the phenotypic variation, respectively. Interestingly, we found three pairs of QTLs (qLW‐2‐2 and qLAr‐2‐1, qLW‐8‐1 and qLL‐8‐2, qLL‐3‐3 and qLAr‐3‐3) that control different traits and that were located on the same chromosome or in a nearby location. Moreover, nine pairs of loci with epistatic effects were identified for the four traits. These results may provide the foundation for QTL fine mapping and for an understanding of the genetic basis of variation in leaf‐related traits. [ABSTRACT FROM AUTHOR]

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Leaf width (LW) influences canopy architecture of population-cultured maize and can thus contribute to density breeding. In previous studies, almost all maize LW-related mutants have extreme effect on leaf development or accompanied unfavorable phenotypes. In addition, the identification of quantitative trait loci (QTLs) has been resolution-limited, with cloning and fine-mapping rarely performed. Here, we constructed a bin map for 670 recombinant inbred lines (RILs) using 1.2 billion 100-bp re-sequencing reads. QTL analysis of the LWtrait directly narrowed the major effect QTL, qLW4, to a 270-kb interval. A fine-mapping population and near-isogenic lines (NILs) were quickly constructed using a key RIL harboring heterozygous genotypes across the qLW4 region. A recombinant-derived progeny testing strategy was subsequently used to further fine-map qLW4 to a 55-kb interval. Examination of NILs revealed that qLW4 has a completely dominant effect on LW, with no additional effect on leaf length. Candidate gene analysis suggested that this locus may be a novel LW controlling allele in maize. Our findings demonstrate the advantage of large-population high-density bin mapping, and suggest a strategy for efficiently fine-mapping or even cloning of QTLs. These results should also be helpful for further dissection of the genetic mechanism of LW variation, and benefit maize density breeding. [ABSTRACT FROM AUTHOR]

Purpose To investigate the changes in quality of the volumetric modulated arc therapy (VMAT) plans with couch-shift between arcs by half of a multi-leaf collimator (MLC) leaf width. Methods A total of 22 patients with head-and-neck cancer were retrospectively selected. Since the smallest MLC leaf width was 5 mm in this study, the couch was shifted by 2.5 mm in the longitudinal-direction between arcs to increase the resolution of fluence map. A total of three types of VMAT plans were generated for each patient; the three types of plans were a two-full-arc plan without couch-shift ( NS plan ), a two-half-arc-pair plan with couch-shift ( HAS plan ), and a two-full-arc pair plan with couch-shift ( FAS plan ). Changes in the dose-volumetric parameters were investigated. Results The FAS plan showed the best plan quality for the target volumes and organs at risk compared to the NS and HAS plans . However, the magnitudes of differences among the three types of plans were minimal, and every plan was clinically acceptable. The average integral doses of the NS , HAS , and FAS plans were 160,549 ± 37,600 Gy-cc, 147,828 ± 33,343 Gy-cc, and 156,030 ± 36,263 Gy-cc, respectively. The average monitor unit of the NS , HAS , and FAS plans were 717 ± 120 MU, 648 ± 100 MU, and 763 ± 158 MU, respectively. Conclusions The HAS plan was better than the others in terms of normal tissue sparing and plan efficiency. By shifting the couch by half of the MLC leaf width in the longitudinal direction between arcs, the VMAT plan quality could be improved. [ABSTRACT FROM AUTHOR]

Summary: Molecular genetic analyses revealed that the WUSCHEL‐related homeobox (WOX) gene superfamily regulates several programs in plant development. Many different mechanisms are reported to underlie these alterations. The WOX family member STENOFOLIA (STF) is involved in leaf expansion in the eudicot Medicago truncutula. Here, we report that when this gene was ectopically expressed in a locally adapted hard red winter wheat cultivar (Triticum aestivum), the transgenic plants showed not only widened leaves but also accelerated flowering and increased chlorophyll content. These desirable traits were stably inherited in the progeny plants. STF binds to wheat genes that have the (GA)n/(CT)n DNA cis element, regardless of sequences flanking the DNA repeats, suggesting a mechanism for its pleiotropic effects. However, the amino acids between position 91 and 262 in the STF protein that were found to bind with the (GA)n motif have no conserved domain with any other GAGA‐binding proteins in animals or plants. We also found that STF interacted with a variety of proteins in wheat in yeast 2 hybrid assays. We conclude that the eudicot STF gene binds to (GA)n/(CT)n DNA elements and can be used to regulate leaf width, flowering time and chlorophyll content in monocot wheat. [ABSTRACT FROM AUTHOR]

Background and Aims While the 'worldwide leaf economics spectrum' (Wright IJ, Reich PB, Westoby M, et al. 2004. The worldwide leaf economics spectrum. Nature 428: 821-827) defines mineral nutrient relationships in plants, no unifying functional consensus links size attributes. Here, the focus is upon leaf size, a much-studied plant trait that scales positively with habitat quality and components of plant size. The objective is to show that this wide range of relationships is explicable in terms of a seed-phytomer-leaf (SPL) theoretical model defining leaf size in terms of trade-offs involving the size, growth rate and number of the building blocks (phytomers) of which the young shoot is constructed. Methods Functional data for 2400+ species and English and Spanish vegetation surveys were used to explore interrelationships between leaf area, leaf width, canopy height, seed mass and leaf dry matter content (LDMC). Key Results Leaf area was a consistent function of canopy height, LDMC and seed mass. Additionally, size traits are partially uncoupled. First, broad laminas help confer competitive exclusion while morphologically large leaves can, through dissection, be functionally small. Secondly, leaf size scales positively with plant size but many of the largest-leaved species are of medium height with basally supported leaves. Thirdly, photosynthetic stems may represent a functionally viable alternative to 'small seeds þ large leaves' in disturbed, fertile habitats and 'large seeds+ small leaves' in infertile ones. Conclusions Although key elements defining the juvenile growth phase remain unmeasured, our results broadly support SPL theory in that phytometer and leaf size are a product of the size of the initial shoot meristem = seed mass) and the duration and quality of juvenile growth. These allometrically constrained traits combine to confer ecological specialization on individual species. Equally, they appear conservatively expressed within major taxa. Thus, 'evolutionary canalization' sensu Stebbins (Stebbins GL. 1974. Flowering plants: evolution above the species level. Cambridge, MA: Belknap Press) is perhaps associated with both seed and leaf development, and major taxa appear routinely specialized with respect to ecologically important size-related traits. [ABSTRACT FROM AUTHOR]

Leaf-level anatomical variation is readily apparent within tall tree crowns, yet the relative importance of water and light availability in controlling this variation remains unclear. Sitka spruce (Picea sitchensis, (Bong.) Carr.) thrives in temperate rainforests of the Pacific Northwest, where it has historically reached heights >100m, despite rarely living more than 400 years alongside redwoods that are five times older. We examined leaves of trees up to 97m tall using a combination of transverse sections, longitudinal sections, epidermal imprints and whole-leaf measurements to explore the combined effects of water stress and light availability on leaf development in P. sitchensis. In contrast to the situation in tall Cupressaceae, light availability--not hydraulic limitation--is the primary ecological driver of leaf-level anatomical variation in P. sitchensis. While height-associated decreases in leaf length and mesoporosity are best explained by hydrostatic constraints on leaf elongation, the majority of anatomical traits we measured reflect acclimation to light availability, including increases in leaf width and vascular tissue areas in the brightest parts of the crown. Along with these changes, the appearance of abaxial stomata in the bright upper crown, and the arrangement of mesophyll in uniseriate, transverse plates--with radially arranged apoplastic pathways leading directly to stomata before bridging them with a V-shaped cell--may enhance gas exchange and hydraulic conductivity. This suite of leaf traits suggests an adaptive strategy that maximizes photosynthesis at the expense of water-stress tolerance. Anatomical investigations spanning the height gradient in tall tree crowns build our understanding of mechanisms underlying among-species variation in growth rates, life spans, and potential responses to climate change. [ABSTRACT FROM AUTHOR]

Leaf expansion depends on both carbon and water availabilities. In cereals, most of experimental effort has focused on leaf elongation, with essentially hydraulic effects. We have tested if evaporative demand and light could have distinct effects on leaf elongation and widening, and if short-term effects could translate into final leaf dimensions. For that, we have monitored leaf widening and elongation in a field experiment with temporary shading, and in a platform experiment with 15 min temporal resolution and contrasting evaporative demands. Leaf widening showed a strong (positive) sensitivity to whole-plant intercepted light and no response to evaporative demand. Leaf elongation was (negatively) sensitive to evaporative demand, without effect of intercepted light per se. We have successfully tested resulting equations to predict leaf length and width in an external dataset of 15 field and six platform experiments. These effects also applied to a panel of 251 maize hybrids. Leaf length and width presented quantitative trait loci (QTLs) whose allelic effects largely differed between both dimensions but were consistent in the field and the platform, with high QTL × Environment interaction. It is therefore worthwhile to identify the genetic and environmental controls of leaf width and leaf length for prediction of plant leaf area. [ABSTRACT FROM AUTHOR]

Convenient and effective methods to determine seasonal changes in individual leaf area (LA) and leaf mass (LM) of plants are useful in research on plant physiology and forest ecology. However, practical methods for estimating LA and LM of elm ( Ulmus japonica) leaves in different periods have rarely been reported. We collected sample elm leaves in June, July and September. Then, we developed allometric models relating LA, LM and leaf parameters, such as leaf length (L) and width (W) or the product of L and W (LW). Our objective was to find optimal allometric models for conveniently and effectively estimating LA and LM of elm leaves in different periods. LA and LM were significantly correlated with leaf parameters ( P < 0.05), and allometric models with LW as an independent variable were best for estimating LA and LM in each period. A linear model was separately developed to predict LA of elm leaves in June, July and September, and it yielded high accuracies of 93, 96 and 96%, respectively. Similarly, a specific allometric model for predicting LM was developed separately in three periods, and the optimal model form in both June and July was a power model, but the linear model was optimal for September. The accuracies of the allometric models in predicting LM were 88, 83 and 84% for June, July and September, respectively. The error caused by ignoring seasonal variation of allometric models in predicting LA and LM in the three periods were 1-4 and 16-59%, respectively. [ABSTRACT FROM AUTHOR]

Exploring genes with impact on yield-related phenotypes is the preceding step to accomplishing crop improvements while facing a growing world population. A genome-wide association scan on leaf blade area ( LA) in a worldwide spring barley collection ( Hordeum vulgare L.), including 125 two- and 93 six-rowed accessions, identified a gene encoding the homeobox transcription factor, Six-rowed spike 1 ( VRS1). VRS1 was previously described as a key domestication gene affecting spike development. Its mutation converts two-rowed (wild-type VRS1, only central fertile spikelets) into six-rowed spikes (mutant vrs1, fully developed fertile central and lateral spikelets). Phenotypic analyses of mutant and wild-type leaves revealed that mutants had an increased leaf width with more longitudinal veins. The observed significant increase of LA and leaf nitrogen (%) during pre-anthesis development in vrs1 mutants also implies a link between wider leaf and grain number, which was validated from the association of vrs1 locus with wider leaf and grain number. Histological and gene expression analyses indicated that VRS1 might influence the size of leaf primordia by affecting cell proliferation of leaf primordial cells. This finding was supported by the transcriptome analysis of mutant and wild-type leaf primordia where in the mutant transcriptional activation of genes related to cell proliferation was detectable. Here we show that VRS1 has an independent role on barley leaf development which might influence the grain number. [ABSTRACT FROM AUTHOR]

Based on a linear mixed-effect model, we propose here a non-destructive, rapid and reliable way for estimating leaf area, leaf mass and specific leaf area (SLA) at leaf scale for broadleaf species. For the construction of the model, the product of leaf length by width (LW) was the optimum variable to predict the leaf area of five deciduous broadleaf species in northeast China. In contrast, for species with leaf thickness (T) lower than 0.10 mm, the surface metric of a leaf (e.g., LW or width) was more suitable for predicting leaf mass; and for species with leaf thickness larger than 0.10 mm, the volume metric of a leaf (e.g., the product of length, width and thickness together, LWT) was a better predictor. The linear mixed-effect model was reasonable and accurate in predicting the leaf area and leaf mass of leaves in different seasons and positions within the canopy. The mean MAE% (mean absolute error percent) values were 6.9% (with a scope of 4.1–13.0%) for leaf area and 13.8% (9.9–20.7%) for leaf mass for the five broadleaf species. Furthermore, these models can also be used to effectively estimate SLA at leaf scale, with a mean MAE% value of 11.9% (8.2–14.1%) for the five broadleaf species. We also propose that for the SLA estimation of the five broadleaf species examined, the optimum number of sample leaves necessary for good accuracy and reasonable error was 40–60. The use of the provided method would enable researchers or managers to rapidly and effectively detect the seasonal dynamic of leaf traits (e.g., leaf area, leaf mass or SLA) of the same sample leaves in the future. [ABSTRACT FROM AUTHOR]

Non destructive estimation of leaf area is necessary for taking successive observations on the same leaf. Usually, a common method for developing leaf area estimation models was to execute regression analysis by taking leaf area as dependant variable and leaf parameters as independent variables. However, the regression analysis applicable only when there is a relation between dependent and independent variables. Therefore, the objective of this work was to develop an artificial neural network (ANN) model including leaf length and leaf width as inputs and to make comparison with regression models. Leaf area (LA) of Durain ( Durio zibethinus ) was estimated by ANN and regression models. Among the linear regression models (LRM), the equation LA = 0.888 (L*W) − 4.961 ( R 2 = 0.91, MSE = 5.17) was found to be the best fitting for durian. In ANN modelling best fitting results were obtained with two input nodes (leaf length and leaf width), one hidden layer, and one output layer (leaf area) as 2-1-1. Based on the values of root mean square error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE) and coefficient determination ( R 2 ), ANN model was found to be more accurate both in terms of training ( R 2 = 0.96, RMSE = 3.77, MAE = 2.41 and MAPE = 7.77) and testing phases ( R 2 = 0.94, RMSE = 4.81, MAE = 2.91 and MAPE = 0.05) than the best fitting regression model. Hence ANN method may be used as an alternative or supportive model in the estimation of leaf area of durian. [ABSTRACT FROM AUTHOR]

Artificial neural network (ANN) is applied for many subjects in agricultural science such as: crop yield and evapotranspiration prediction, soil parameters estimation, water demand forecasting, hydrological forecasting. Leaf area is one of parameters that is used to assess the plant vegetative growth. In this study, leaf areas of 61 plant species with different leaf shapes were estimated by ANNs and the effect of input data and pre-processing methods on ANNs performance was assessed. Results showed that the ANNs could provide good estimation of leaf area. ANNs input variable combination affected the ANNs performance to estimate the leaf area. With increase in number of hidden layers the epochs decreased and accuracy of the leaf area prediction and running speed increased. Results of test data set showed that MinMax pre-processing method resulted in more accurate prediction in comparison with the no pre-processed method and Norm STD method. The most conclusive result of this study is the application of ANNs for all of plant species, whereas, in application of other methods: specific equation should be prepared for each plant. [ABSTRACT FROM AUTHOR]

The estimative of the leaf area using a nondestructive method is paramount for successive evaluations in the same plant with precision and speed, not requiring high-cost equipment. Thus, the objective of this work was to construct models to estimate leaf area using artificial neural network models (ANN) and regression and to compare which model is the most effective model for predicting leaf area in sesame culture. A total of 11,000 leaves of four sesame cultivars were collected. Then, the length (L) and leaf width (W), and the actual leaf area (LA) were quantified. For the ANN model, the parameters of the length and width of the leaf were used as input variables of the network, with hidden layers and leaf area as the desired output parameter. For the linear regression models, leaf dimensions were considered independent variables, and the actual leaf area was the dependent variable. The criteria for choosing the best models were: the lowest root of the mean squared error (RMSE), mean absolute error (MAE), and absolute mean percentage error (MAPE), and higher coefficients of determination (R 2 ). Among the linear regression models, the equation y ˆ = 0.515 + 0.584 * L W was considered the most indicated to estimate the leaf area of the sesame. In modeling with ANNs, the best results were found for model 2-3-1, with two input variables (L and W), three hidden variables, and an output variable (LA). The ANN model was more accurate than the regression models, recording the lowest errors and higher R 2 in the training phase (RMSE: 0.0040; MAE: 0.0027; MAPE: 0.0587; and R 2 : 0.9834) and in the test phase (RMSE: 0.0106; MAE: 0.0029; MAPE: 0.0611; and R 2 : 0.9828). Thus, the ANN method is the most indicated and accurate for predicting the leaf area of the sesame., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Joao Everthon da Silva Ribeiro reports administrative support, article publishing charges, equipment, drugs, or supplies, statistical analysis, travel, and writing assistance were provided by 10.13039/100017134Federal Rural University of the Semi-Arid. There was no financial interest., (© 2023 The Author(s).)