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Maize leaf length, leaf width, leaf angle, and leaf orientation value are determinant traits influencing leaf shape, yield potential, and can sense water stress signals. However, little is known regarding their genetic controls under drought stress. Using two F3 populations, we identified 72 QTLs under contrasting environments at V18 and R1 stages by single-environment mapping, 58.3% QTLs were identified under drought-stressed environments. Thirty-three joint QTLs were detected by joint analysis of all environments, 7 QTLs involved in QTL-by-environment interactions, 11 pair epistasis exhibited additive-by-additive effects. Twelve constitutive QTLs were dissected that will be potentially useful for genetic improvement of maize leaf development through QTL pyramiding. Additionally, 13 meta-QTLs were identified via meta-analysis, 15 candidate genes were identified in these meta-QTLs. These results provide valuable information for QTLs fine mapping, revealing genetic mechanisms of leaf shape under contrasting watering environments, and alleles provide useful targets for marker-assisted selection breeding.

Sesamum indicum ‘Baekseol’ plug seedlings were treated with the fungicide diniconazole as a growth retardant in comparison to paclobutrazole. Seeds were sown in 128-cell plug trays. Paclobutrazole (0, 15, 30, and 60 mg L−1) and diniconazole (100, 200, 300, and 400 mg L−1) were foliage sprayed when first leaves were developed. Stem growth was similar between paclobutrazole and the control, but strongly retarded by increasing concentrations of diniconazole. Leaf numbers did not differ in all treatments. As the diniconazole concentration increased, leaves became thicker, while leaf width and length decreased. In diniconazole treatment, shoot fresh weight decreased, but root fresh weight increased. Therefore, the T/R ratio was lowered by diniconazole treatment. After transplanting, the taking roots of paclobutrazol-treated plants were below average (

This study aimed to determine the morphological and cytogenetic differences in an intraspecific Asiatic F1Lilium hybrid. The results indicated that leaf color and shape, flower morphology including color, spot size on petal, and filament color in the F1 hybrid showed significant variations as compared to parents, while days to flowering were similar to those of the parents. Moreover, stem height, leaf number, and leaf width showed distinct variations. Interestingly, the intraspecific F1 progeny obtained from Asiatic lily parents showed higher pollen viability. In addition, FISH results revealed significant variation in the number of 18S rDNA and 5S rDNA loci identified in both parents and the F1 progeny. The female (2n = 4x = 48) parent had 12 loci of 18S rDNA, whereas the male (2n = 2x = 24) parent and the F1 (2n = 3x = 36) had 8 and 11 loci of 18S rDNA, respectively. Moreover, the F1 progeny had 9 loci of 5S rDNA compared with the 7 and 4 loci identified in the female and male parents, respectively. All 5S rDNA signals were observed on the long arm in both the female parent and the F1; however, one 5S rDNA signal was observed on the short arm in the male parent. Therefore, this study demonstrated that the distribution of ribosomal DNA was greatly different in the F1 progeny than that of parents.

BackgroundLeaf length and width could be a functioning relationship naturally as plant designs. Single-vein leaves have the simplest symmetrical distribution and structural design, which means that fast-growing single-vein species could interpret the scheme more efficiently. The distribution of leaf length and width can be modulated for better adaptation, providing an informative perspective on the various operational strategies in an emergency, while this mechanism is less clear. Here we selected six age groups ofCunninghamia lanceolatapure forests, including saplings, juveniles, mature, and old-growth trees. We pioneered a tapering model to describe half-leaf symmetric distribution with mathematical approximation based on every measured leaf along developmental sequence, and evaluated the ratio of leaf basal part length to total length (called tipping leaf length ratio).ResultsThe tipping leaf length ratio varied among different tree ages. That means the changes of tipping leaf length ratio and leaf shape are a significant but less-noticed reflection of trees tradeoff strategies at different growth stages. For instance, there exhibited relatively low ratio during sapling and juvenile, then increased with increasing age, showing the highest value in their maturity, and finally decreased on mature to old-growth transition. The tipping leaf length ratio serves as a cost-benefit ratio, thus the subtle changes in the leaf symmetrical distribution within individuals reveal buffering strategy, indicating the selection for efficient design of growth and hydraulic in their developmental sequences.ConclusionsOur model provides a physical explanation of varied signatures for tree operations in hydraulic buffering through growth stages, and the buffering strategy revealed from leaf distribution morphologically provides evidence on the regulation mechanism of leaf biomechanics, hydraulics and physiologies. Our insight contributes greatly to plant trait modeling, policy and management, and will be of interest to some scientists and policy makers who are involved in climate change, ecology and environment protection, as well as forest ecology and management.

In North American wetlands, two cattail species -native Typha latifolia and exotic T. angustifolia- hybridize generating T. x glauca. Typha angustifolia and the hybrid spread invasively, negatively affecting wetlands. Due to high trait variability and hybridization, Typha species are difficult to identify morphologically. Building on previous work that relied on microsatellite markers to differentiate Typha species (including hybrids, parental backcrosses, and advanced-generation hybrids) in southern Canada and in the US upper Midwest and northeast, our goals were to 1) estimate relative frequencies of parental species in additional Midwestern cattail populations, and 2) quantify their hybridization. We also assessed level of agreement between morphological identification based on leaf width and gap between inflorescences and molecular identification. Using 6 microsatellites markers (4 used previously in other populations and 2 novel ones), we identified ~25% of the samples as native T. latifolia, while ~6% were exotic T. angustifolia. Furthermore, 19% of the samples were first-generation hybrids (T. x glauca) and 50% were advanced-generation hybrids, with backcrosses to native T. latifolia being almost twice as high as those to exotic T. angustifolia, rates that are much larger than previously reported. Agreement between morphological and molecular identification was lower than expected highlighting the fact that these morphological traits can be misleading when used alone in cattail identification. We caution that the seemingly asymmetric hybridization towards the native Typha latifolia could potentially lead to its extinction in the Midwest. Cattail management may thus require efforts to preserve the native cattail through seed banking and/or other approaches.

Malus orientalis Uglitzk. is considered as one of the probable ancestors of domestic apples (M. × domestica) and has valuable traits such as late-blooming, adaptation to a wider array of habitats, and capacity for longer storage of the fruits. In the present investigation, morphological and pomological characteristics of M. orientalis were evaluated. Results showed significant differences among the accessions in terms of the recorded traits. Leaf length ranged from 38.56 to 101.36 mm and leaf width varied from 20.27 to 45.31 mm. Fruit length ranged from 14.69 to 39.98 mm, while fruit width varied from 22.16 to 47.39 mm. Fruits weighted between 4.76 and 36.32 g with an average of 15.28. Fruit weight showed positive and significant correlations with dimensions of leaf and fruit. Principal component analysis (PCA) confirmed that fruit-related characteristics were more important in explaining the variation among the accessions. The dendrogram generated using Ward’s method and Euclidean distance showed that the accessions were placed into two major clusters. The dissimilarity level in terms of morphological and pomological characteristics showed a wide range of phenotypic diversity, allowing the effective selection of parents in various breeding programs, referring to fruit quality and high yield. The current findings confirmed that conservation of M. orientalis genetic resources is important for future breeding programs.

Pistacia atlantica Desf. subsp. mutica is widely distributed in the Zagros Mountains in Iran and its fruits are used as food. In the present study, the morphological and pomological variation of naturally grown male and female genotypes of this species was investigated. Considerable variations were observed among male and also among female genotypes studied based on the characters measured. Leaf length ranged from 11.03 to 17.67 cm in male genotypes and also from 11.98 to 16.14 cm in female genotypes. Furthermore, leaf width varied from 7.32 to 13.08 cm in male genotypes and from 9.18 to 13.31 cm in female genotypes. Inflorescence length ranged between 4.62 and 5.83 cm in male genotypes and between 5.05 and 9.04 cm in female genotypes. Also, 100-nut weight varied from 13.74 to 22.81 g with an average of 16.09, while 100-kernel weight ranged from 2.11 to 3.60 g with an average of 2.65 in female genotypes. Leaf length was significantly and positively correlated with leaf width. Furthermore, 100-kernel weight was positively and significantly correlated with leaf and nut dimensions. Principal component analysis showed that the characters measured accounted for 77.41% of the total variance in male genotypes and also 83.24% of the total variance in female genotypes. The genotypes studied showed high variation based on the characters recorded. The wide adaptation of P. atlantica Desf. subsp. mutica highlights its potential as a genetic resource for pistachio breeding for resistance to abiotic and biotic stresses such as drought. The current findings may be useful to select conservation strategies and genetic improvement of the species studied.

The aim of this study was to evaluate oat genotypes for grain yield and yield components in both 2014-2015 and 2015-2016 growing seasons using GGE biplot analysis. Experiments were laid out according to lattice design. Biomass at harvest, grain yield, number of grain per panicle, weight of grain per panicle, flag leaf width, flag leaf height, plant height, stem diameter, thousand kernel weight, time of panicle emergence, harvest index, panicle length, and spikelet per panicle were evaluated for 56 oat genotypes. GGE biplot graphics of the first and second years explained 54.4 and 55% of total variation, respectively. Grain yield, number of grains per panicle, and weight of grain per panicle were closely and positively associated in both growing seasons. Recently registered cultivar Sari and lines 26, 29, and 30 were found as promising genotypes for Canakkale conditions. Traits of genotype at different growing seasons can be visually studied using different genotype-by-trait (GT) biplots.

To develop a controlled-release fertilizer (CRF) suitable for nutrient absorption characteristics of Phalaenopsis, four kinds of new controlled-release fertilizer (NCRF 1–4) with different dissolution rates were developed and studied to determine the concentration and amount suitable for growth of Phalaenopsis. To make NCRF, new acryl-based polymers were developed and used as fertilizer coating solutions. In addition, a fluidized bed coater for coating fertilizer was developed and used in this study. To test the growth of Phalaenopsis, 10-month-old Phalaenopsis seedlings were planted in plastic pots (diameter 10 cm) filled with 100% Sphagnum moss and cultivated for approximately 100 days from May 29, 2015, to September 11, 2015. NCRF 1, NCRF 2, and Osmocote, an imported fertilizer, consistently exhibited release patterns of fertilizer nutrients in a directly proportional form; however, NCRF 3 and NCRF 4 displayed a sigmoid-like tendency of fertilizer nutrient release with a slower initial dissolution rate. Furthermore, leaf length, leaf width, fresh weigh, and root weight of Phalaenopsis were the highest when growing in 1.5 g/pot of NCRF 3 fertilizer, and the pH and electrical conductivity (EC) of the soil were stable at this concentration of NCRF 3. Based on our results, we suggest that 1.5 g/pot of NCRF 3 fertilizer is the ideal concentration and fertilizer for growing Phalaenopsis.

Semecarpus kurzii Engl. is an important ethnomedicinal plant used for curing tumours, inflammation, fever and pain, and is also a source of iso ricinoleic acid. During the present investigation, effect of chemical pre-treatments on germination and seedling growth revealed significant differences. Different pre-treatments could improve germination and treatment with KNO3 (9.9 mM) was significantly superior (94%) to the untreated control (76%). Mean daily germination varied among the treatments (0.90–4.14 seeds per day), when compared with 2.27 seeds per day in control. Mean germination time was significantly reduced from 22.14 days (control) to 16.40 days (19.8 mM KNO3) and 17.16 days (1.45 mM GA3). Treatment with KNO3 (19.8 mM) and GA3 (1.45 and 2.90 mM) significantly reduced the time for 50% germination. Treatment with higher concentrations of GA3 and KNO3 exhibited significantly faster germination initiation (11.0 and 12.0 days, respectively) over the control (17.0 days). Seedling vigour index was not improved by pre-treatments. Chemical treatments did not improve shoot growth, collar thickness, or number of seedling leaves; however, root growth was significantly improved over control. Treatment with GA3 (2.90 mM) promoted leaf elongation but reduced leaf width significantly. Treatment with KNO3 and GA3 could be recommended to obtain healthy seedlings for establishing new plantations of this important medicinal plant species.

This study aims to determine the differences in leaf functional traits and phenotypic plasticity of leaf functional traits between exotic and native Compositae plant species. Leaf width of exotic plants was significantly lower than that of native species. Leaf length, specific leaf area (SLA), single-leaf wet and dry weights, leaf moisture, and leaf thickness of exotic plants were also lower than those of native species but not significantly. The leaf shape index of exotic plants was higher than that of native species but not significantly. This implies that the relatively low leaf construction cost for exotic plants may play an important role in the success of their invasions. The higher leaf shape index and lower leaf width of exotic plants can enhance the efficiency of resource capture (especially sunlight capture) via adjustments to leaf shape and size, thereby increasing the survival of exotic plants. The plasticity indices of single-leaf wet weight and leaf thickness of exotic plants were significantly lower than those of native species. The lower phenotypic plasticity of single-leaf wet weight and leaf thickness of exotic plants may be the result of a cost to plasticity. That is, if the plasticity is too high, the fitness of plant species might be reduced sharply under unfavorable environments. Thus, lower plasticity of leaf functional traits may compensate for the negative impact of adverse environments and stabilize leaf construction costs for exotic plants. Moreover, reduced phenotypic plasticity might be one of the key competitive strategies by which exotic plants successfully invade new habitats. Overall, exotic plants did not always exhibit higher values of leaf functional traits or increased phenotypic plasticity of leaf functional traits compared with native species.

A study on the morphological variability and ecological differentiation among the species in the genus Daphne was carried out which included seven species from the Balkan Peninsula: Daphne mezereum, D. laureola, D. alpina, D. oleoides, D. malyana, D. cneorum and D. blagayana. In the Balkan Peninsula, the ranges of the species in this genus overlap, which does not occur anywhere else in Europe. Descriptive statistics were measured for 20 quantitative characters of the leves and stems. A comparative analysis of the morpho-anatomical adaptations of these species shows that: D. cneorum, D. malyana and D. oleoides belong to the adaptive type of xerophytes; D. alpina is a xeromesophyte; D. blagayana and D. laureola are mesoxerophytes; and D. mezereum is a mesophyte. Principal component analysis shows the largest contribution to the formation of the variability between the different species is made by characters that are related to leaf shape (leaf length, distance between the largest leaf width and the leaf top, largest width of the leaf, leaf surface area), followed by surface area of abaxial stomata, stem characters (stem cortex thickness and stem diameter) and leaf anatomy characters (thickness of the palisade tissue, thickness mesophyll, number of palisade layers). These features can use to discriminate among the seven studied species, suggesting that leaves and stems of Daphne can represent a source for taxonomically useful characters. Canonical discriminant analysis and the clustering method based on Mahalanobis distances shows that there is significant morphological differentiation among the species studied. The results show that various combinations of morphological and anatomical features contribute to the adaptive capacity of plants to different degrees. The morpho-anatomical features found in all seven species agree with previous infrageneric taxonomic classifications of this genus.

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

This study aimed to evaluate the genetic difference between 43 F1 hybrids and 8 parents, seven of Iris germanica and one of I. spuria and to estimate genetic parameters by using 10 descriptors and the morphological variation to determine their potential for genetic improvement. The mean comparisons showed that the Iris hybrids 10 and 11 had higher flower size than other Iris hybrids and the parental, a coveted trait that could be used in breeding programs, with the aim of increase sales. The Iris hybrid 8 showed the most significantly difference in crown diameter, flower branches diameter and flower peduncle diameter. The cluster of largely are could separation hybrids in terms of morphological characteristics. Irises a trait correlation with other traits makes possible indirect measurement. Relatively high heritability values, in broad sense, were found 97% for height plant, fall width and length, flower size and leaf width. These characters may be applied as useful traits in Iris breeding and for selection hybrids.

At an early stage of crop development, the rate of growth is largely determined by leaf characteristics. Plants with rapid leaf area development could save more water for transpiration and crop growth. In our study, a recombinant inbred family was used to identify quantitative trait loci (QTL) controlling leaf length (LL), leaf width (LW), and leaf area (LA) in wheat seedlings under well-watered (WW) and PEG-induced water-deficit (WD) conditions. A total of five QTL for LW, LL, and LA were detected, most of which were reported for the first time. A “constitutive” QTL for LW (Qheb.LW-3B), located on the long arm of chromosome 3B, was consistently detected under two water conditions, explaining 17.7 % of the phenotypic variance with a LOD value of 7.20 under WW condition and 13.3 % of the phenotypic variance with a LOD value of 4.87 under WD condition. The other four “adaptive” QTL were detected under a single water condition only. These QTL include the following: Qheb.LW-5B for LW (WW condition), Qheb.LL-3A, and Qheb.LL-5B for LL (WD condition) and Qheb.LA-3B for LA (WW condition). Four pairs of near isogenic lines (NILs) were developed to validate the effects of Qheb.LW-3B. The allele from the parent “CSCR6” increased the LW by an average of 8.2 % under WW condition and 13.8 % under WD condition, respectively. The position and effects of Qheb.LW-3B was confirmed. Qheb.LW-3B would be a valuable genetic resource to improve wheat seedling early establishment. The NILs we have generated would be useful for further characterization of Qheb.LW-3B, in studying its interaction with other traits of agronomic importance and in developing markers that can be reliably used to follow this major locus.

Ten quantitative morphological characters were studied in 56 Morus alba L. trees representing three natural populations from the trans-Himalayan Ladakh region. The altitude of collection sites ranged from 2815 to 3177 m above the sea level (asl). Coefficient of variation (CV) showed high phenotypic variation in M. alba. Linear regression analysis revealed that leaf and fruit size decreases with an increase in altitude. High CV was observed for leaf length, leaf width, petiole length, leaf area, inter-nodal distance, number of nodes, bud length, fruit length, fruit width and fruit weight. Similarly, a high phenotypic plasticity index was observed for bud length, leaf length, leaf width, petiole length, leaf area, inter-nodal distance, number of nodes, fruit length, fruit width and fruit weight. For every 100 m increase in altitude, leaf length, leaf width and leaf area decreased by 1 cm, 0.8 cm and 16.6 cm2, respectively. Analysis of covariance showed a predominant altitudinal effect on the morphological characters in comparison to the population effect. A small change in the altitude caused significant change in the plant morphological characteristics. The present investigation represents to our knowledge the first study addressing phenotypic variation in mulberry along an altitudinal gradient.

Pseudostems of bunching onion (Allium fistulosum L.) show wide variation in morphological traits and skin color. However, despite being one of the most important agronomic traits, molecular studies of bunching onion pseudostems remain limited. In this study, six morphological traits (plant height, leaf length, pseudostem length, leaf width, pseudostem width and number of leaf sheaths) along with pseudostem pigmentation indices were evaluated in two field trials using an F2:3 population derived from a single F1 cross between a white single pseudostem (non-tillering) and a red tillering bunching onion. Plant height was highly correlated with both leaf length and pseudostem length, but not the number of leaf sheaths. In contrast, the number of leaf sheaths was significantly negatively correlated with both leaf width and pseudostem width. A total of 27 QTLs for the six morphological traits were detected in 16 regions of 11 linkage groups, with a major QTL for the number of leaf sheaths repeatedly detected on Chr. 8. Meanwhile, two QTLs associated with pseudostem pigmentation were repeatedly detected on linkage groups Chr. 4a and Chr. 5a-2. The latter (qPig5a-2) was considered a major QTL, and its location estimated by marker genotyping of the F2 population around the qPig5a-2 region as being within a 7.6 cM interval.

Linaria semnanensis is described as a new species discovered in Semnan Province. This newly discovered species is compared with its closest relatives L. grandiflora and L. dalmatica. The new species is similar to L. grandiflora in bract size, stem height and seed form and differs in leaf width, capsule size, adaxial lip sinus of corolla, style length, the length of testa cell and ornamentation of the seed coat. L. semnanensis is similar to L. dalmatica in capsule size, seed shape and size and differs in corolla, spur, pedicel and calyx lobe size, stem height, length of adaxial lip sinus of corolla, distance between apex of adaxial lips of corolla, testa cells shape and ornamentation of the seed coat. Information about the species’ morphology, micromorphology, habitats and distribution is provided.

This study compares the quality of intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans optimized for an Elekta Agility(TM) (Elekta, Stockholm, Sweden) multileaf collimator (MLC; leaf width 5 mm) and an Elekta MLCi2 (leaf width 10 mm) for complex target volumes (anal, AC; head and neck, HN and prostate cancer, PC).For plan comparisons, 15 patients who had been treated with IMRT or VMAT using the MLCi2 were selected. For each patient, a retrospective treatment plan using the MLCi2 for the technique not applied was created, as were treatment plans for both techniques using the Agility(TM) MLC. Dose-volume histograms (DHVs) for planning target volumes (PTVs) and organs at risk (OARs) were compared. Further parameters relating to dose conformity, dose homogeneity and mean dose (Dmean) to the PTV, compliance with the intended OAR dose criteria and overall dose to normal tissue were analyzed. Verification measurements were performed and optimization and treatment times were compared.Compared to the MLCi2 plans, the Agility(TM) IMRT and VMAT plans show better or equivalent results in terms of PTV dose conformity and homogeneity. Compliance with the intended OAR dose criteria does not differ according to technique or MLC type. Slight differences are shown for dose distributions in OARs and normal tissue. Verification measurements show that all plans fulfill the acceptance criteria of a minimum of 95 % matched dose points for the 3 %/3 mm γ criterion. Optimization times for the VMAT plans increase compared to the IMRT plans, whereas treatment times decrease.With the MLCi2, treatment of complex target volumes with VMAT was only possible with compromises in terms of target coverage. Using the Agility(TM) MLC, even complex target volumes can be treated with VMAT without compromising target coverage or resulting in higher exposure of OARs or normal tissue.

In this research, 53 male fig (caprifig) accessions were analyzed for phenotypic diversity using 32 morphological variables. Significant phenotypic diversity was detected between male fig accessions based on morphological traits. Principal component analysis revealed that the first ten components explained 76.09 % of the total morphological variation, where petiole length, petiole thickness, leaf length, leaf width, fruit width, fruit shape, length of central lobe, number of lobes and leaf shape contributed most of the total variation. Simple correlation coefficient analysis showed the existence of significant positive and negative correlations among characteristics. The majority of significant correlation coefficients were found in the characteristics representing fruit sizes with leaf size. Unweighted pair-group method of arithmetic average cluster analysis identified two major clusters and several subclusters for studied accessions. According to the present results, accessions Caprifig 35, Caprifig 6, Caprifig 12, Caprifig 36, Caprifig 38, Caprifig 28, Caprifig 30, Caprifig 26 and Caprifig 18 with the highest Blastophaga number are suitable in this important trait to be used for caprification. Also, the conservation of the highly diverse native accessions of Iranian male figs is recommended.

Flag leaf width (FLW) is directly related to photosynthetic capacity and yield potential in wheat. In a previous study, Qflw.nau-5A controlling FLW was detected on chromosome 5A in the interval possessing Fhb5 for type I Fusarium head blight (FHB) resistance using a recombinant inbred line population derived from Nanda2419 × Wangshuibai.Qflw.nau-5A near-isogenic line (NIL) with the background of Mianyang 99-323 and PH691 was developed and evaluated. FLW inheritance was investigated using two F2 populations developed from crossing the Qflw.nau-5A NILs with their recurrent parents. One hundred ten and 28 recombinants, which included 10 and 5 types of recombinants, were identified from 2816 F2 plants with Mianyang 99-323 background and 1277 F2 plants with PH691 background, respectively, and phenotyped in field trials for FLW and type I FHB resistance. Deletion bin mapping was applied to physically map Qflw.nau-5A.The introduction of Wangshuibai Qflw.nau-5A allele reduced the FLW up to 3 mm. In the F2 populations, Qflw.nau-5A was inherited like a semi-dominant gene, and was therefore designated as TaFLW1. The FLW of the recombinant lines displayed a distinct two-peak distribution. Recombinants with wider leaves commonly have Mianyang 99-323 or PH691 chromatin in the 0.2 cM Xwmc492-Xwmc752 interval that resided in the 5AL12-0.35-0.57 deletion bin, and recombinants with narrow leaves were Wangshuibai genotype in this interval. Phenotypic recombination between FLW and type I FHB resistance was identified, implying TaFLW1 was in close linkage with Fhb5. These results should aid wheat breeders to break the linkage drag through marker-assisted selection and assist in the map-based cloning of TaFLW1.

Vitellaria paradoxa C. Gaertn. (shea butter tree) is an indigenous African tree species that is widely distributed in the dry areas of northern and eastern Uganda. The species is widely known for its oil which is used in cooking, cosmetics and traditional medicine. Local folk classification recognises the presence of different ethno-varieties on the basis of fruit and nut characters. In the present study, 176 trees representing 44 ethno-varieties from three farming systems of Uganda were assessed to determine the patterns of morphological variation and establish the congruence between morphological variation and folk classification. The results show high variation in pulp weight (CV = 35.9 %), stem diameter (CV = 28.48 %), fruit weight (CV = 27.81 %) and canopy diameter (CV = 26.69 %). There was a strong positive correlation between pulp and fruit weight (r = 0.963, p

Genetic improvement of sugarcane variety CoC 671 was carried out through somaclonal variation. The somaclones were obtained by developing callus on 0.8M EMS and 13.57M 2–4.D containing medium. All the 310 regenerated plants were hardened in green house and planted in field for preliminary selection. On the basis of biometric and biochemical parameters 17 somaclones were evaluated in rod row trial and then for smut resistance supplementing with smut inoculum and detection by PCR. The somaclonal variants TC 906 was resistant and TC 922 was moderately resistant to smut. Somaclone TC 922 (2.17 kg, 165 t/ha, 3.34 cm) and TC 906 (2.07 kg, 144.11 t/ha, 3.25 cm) were superior in single cane weight, cane yield and cane diameter over their donor CoC 671 (1.72 kg, 128 t/ha, 2.74 cm). The morphological variations viz. stem colour, internodal alignment, internodal waxiness and leaf width were distinct and stable. The present study reports beneficial traits of the somaclones derived from CoC 671 and their field performance, especially for smut resistance and yield traits and early maturity.

To enhance understanding of the genetic basis of trait correlation in rice, a recombinant inbred line (RIL) population (F6 and F7) from a cross between Zhenshan97 and HR5 was employed to identify main quantitative trait loci (QTLs) and epistatic QTL (E-QTL). Highly significant positive correlations were detected among five traits of heading date (HD), plant height (PH), panicle length (PL), flag leaf length (FLL) and flag leaf width (FLW) in 2 environments. Four to 8 main QTLs were detected for an individual trait. No E-QTL was detected for PH. One, 4, 4 and 5 E-QTLs were detected for FLL, HD, FLW and PL, respectively. Each E-QTL individually explained less than 3% of trait variation except E-QFll1. Comparison of QTL results was made in order to dissect the genetic basis of trait correlation. We found that main QTLs with pleiotropic effects and QTL clusters were the main genetic basis of trait correlation. No E-QTL had pleiotropic effects. E-QTL played an important role in the genetic basis of individual trait, but it made a little contribution to trait correlation.

To investigate whether a new multileaf collimator with a leaf width of 5 mm (MLC-5) over the entire field size of 40 × 40 cm2 improves plan quality compared to a leaf width of 10 mm (MLC-10) in intensity-modulated radiotherapy (IMRT) with integrated boost for head and neck cancer. A plan comparison was performed for ten patients with head and neck cancer. For each patient, seven plans were calculated: one plan with MLC-10 and nine beams, four plans with MLC-5 and nine beams (with different intensity levels and two-dimensional median filter sizes [2D-MFS]), and one seven-beam plan with MLC-5 and MLC-10, respectively. Isocenter, beam angles and planning constraints were not changed. Mean values of common plan parameters over all ten patients were estimated, and plan groups of MLC-5 and MLC-10 with nine and seven beams were compared. The use of MLC-5 led to a significantly higher conformity index and an improvement of the 90% coverage of PTV1 (planning target volume) and PTV2 compared with MLC-10. This was noted in the nine- and seven-beam plans. Within the nine-beam group with MLC-5, a reduction of the segment number by up to 25% at reduced intensity levels and for increased 2D-MFS did not markedly worsen plan quality. Interestingly, a seven-beam IMRT with MLC-5 was inferior to a nine-beam IMRT with MLC-5, but superior to a nine-beam IMRT with MLC-10. The use of an MLC-5 has significant advantages over an MLC-10 with respect to target coverage and protection of normal tissues in step-and-shoot IMRT of head and neck cancer.

The practices with low clippings production to save time, money, or landfill space, were favored by turf managers. Understanding the responses of Kentucky bluegrass (Poa pratensis L.) to Trinexapac-ethyl (TE) would facilitate recommendations regarding its safe and effective use in Northern China. The objectives of this study are (1) to investigate the effects of TE on vertical growth, clipping yield, leaf width, and chlorophyll content of Kentucky bluegrass, and (2) to compare the seasonal application impacts of TE. Both spring and autumn experiment results demonstrated that Trinexapac-ethyl applied to Kentucky bluegrass, suppressed the vertical grass growth and significantly reduced the Kentucky bluegrass clippings production within a few weeks after initial treatment. Applied trinexapac-ethyl enhanced Kentucky bluegrass leaf width in both spring and autumn experimental periods. Discoloration on leaf tips was observed and lasted for four weeks when the same TE rate of 0.191 mL$m-2 was applied in early autumn. Darker leaves with higher chlorophyll content compared with non-TE-treatments appeared after the initial four weeks of the treatment in autumn and the treatment for the entire spring.

Wood from three tree species was used for making slow-releasing woodchip fertilizer. Fertilizer made from Populus tomentiglandulosa retained the highest amounts of N (29.04%), P2O5 (26.03%) and K2O (16.93%). On the other hand, woodchip fertilizer made from Pinus koraiensis retained the lowest amounts of N (26.22%), P2O5 (21.80%) and K2O (14.49%). A field experiment was performed in a 50 m2 experimental plot at Gangwon Agricultural Research and Extension Services, Chuncheon, Korea from August to November 1999. The effects of a general fertilizer along with compost and slow releasing woodchip fertilizer without compost on the cabbage production were observed. Cabbage production parameters, such as top height, head weight, head height, head width, number of outer and inner leaves, leaf width and head length, increased in the field where Larix kaempferi woodchip fertilizer was added as a basal dose. The result showed that the woodchip fertilizer made from Pinus koraiensis had faster releasing properties compared to other woodchip fertilizers. Without adding any compost in the woodchip fertilized field, woodchip fertilizer showed a superior outcome over a general chemical fertilizer. Although the amount of woodchip fertilizer was larger compared to that of a chemical fertilizer, it increased cabbage production.

Flag leaf-related traits (FLRTs) are determinant traits affecting plant architecture and yield potential in wheat (Triticum aestivum L.). In this study, a recombinant inbred line population with 188 lines, derived from the cross between Kenong9204 and Jing411, was developed to identify quantitative trait loci (QTL) for flag leaf width (FLW), length (FLL), and area (FLA) under both low nitrogen and high nitrogen treatments. A total of 38 QTLs were detected in eight environments (year × location × treatment). Of these, two QTLs for FLW on chromosomes 4B and 6B (qFlw-4B.3 and qFlw-6B.2) and one for FLA on chromosome 5B (qFla-5B) were major stable QTLs. Both phenotypic and QTL mapping analyses indicated that FLW was the major contributor to flag leaf size. To investigate the genetic relationship between FLRTs and yield-related traits (YRTs) at the QTL level, both unconditional and multivariable conditional QTL mapping for YRTs with respect to FLRTs were conducted. Twelve QTL clusters simultaneously controlling FLRTs and YRTs were identified. In comparison with unconditional QTL mapping, conditional QTL mapping analysis revealed that most but not all the QTL for YRTs were improved by FLRTs. At the QTL level, FLA had the greatest contribution to YRTs, followed by FLW and FLL. This study provided a genetic foundation from which to obtain desirable plant architecture and improve yield potential in wheat breeding programs.

The developmental stability indices, leaf width based fluctuating asymmetry (FA1), and lateral vein length based directional asymmetry (RDA1) of Platanus acerifolia were studied. All the leaves were sampled from 14 sites that were categorized based on different urban environmental stress levels (UESL) in Shanghai metropolitan, China. Besides, foliar stomatal density and stomatal length were also studied as the subsidiary indices to test the availability of developmental stability indices as the indicator under a stressful environment. Results showed seasonal variation of FA1 and RDA1 existed among the 14 sites, but the data showed significant negative correlation between FA1 and UESL (FA1 = 0.029 − 0.000 9UESL + 0.000 3UESL2, r = 0.766 5, P = 0.001 4). However, a similar trend was not found between RDA1 and UESL. Furthermore, the significant correlation among FA1 and leaf stomatal length and stomatal density implied they could be used as indicators of urban stress levels on a small scale. It seemed that RDA1 was possibly a normal parameter during leaf development but it was unavailable for use as an indicator of urban stresses.

Variations in Paederia foetida L. leaf shape were examined to evaluate the taxonomic validity of the small, narrow leaf form of P. foetida f. microphylla Honda from Miyajima Island, Honshu, Japan. There is considerable variation in P. foetida individuals in terms of leaf size and leaf index (leaf length:leaf width ratio). On Miyajima Island, some individuals have narrow leaves with a high leaf index value, a phenotype represented by the type specimen of P. foetida f. microphylla, and some do not. Given that the leaf size of individuals from Miyajima Island is smaller than that of individuals from other localities in Japan, and that the small leaf phenotype is stable even under cultivation, P. foetida f. microphylla is classified as the form having the smallest leaf size. Anatomical examination of leaf blades revealed that the large variation in leaf size was attributable to variation in the number of leaf cells but not to differences in cell size or cell shape. Based on these results, we discuss the endemism of P. foetida f. microphylla.

An European maize (Zea mays L.) landrace core collection (EMLCC) was formed with samples from several countries. Evaluation of the EMLCC may contribute to broad the genetic base of maize breeding programs. The objective of this study was to assess the variability of EMLCC under low nitrogen (N) in relation to high N input. Eighty-five landraces of the EMLCC, grouped in four maturity groups, and three check hybrids were evaluated for response to low (0 kg ha−1) and high (150 kg ha−1) N in Spain and Greece. Five plant size traits (plant height, ear height, leaf length, leaf width and leaf area index), two grain traits (1000-kernel weight and grain yield), and two agronomic traits [growing degree units (GDU) and lodging] were studied. Overall means of plant size and grain traits increased when genotypes were grown at 150-N relative to 0-N input. The relative increase for grain traits was smaller in landraces than in hybrids. This suggests that landraces had lower grain yield response to N supply compared to hybrids. Linear regressions of plant size traits on GDU indicated that vegetative development was primarily associated with flowering lateness. The maturity group was the main source of variation for all traits. Landrace variability within maturity groups was significant for all traits across environments, despite significant landrace × environment interactions. Estimates of genetic and genotype × environment variances, and heritabilities at both high and low N inputs were not significantly different from each other. However estimates were generally larger at high N. Genetic and phenotypic correlation coefficients between the two N levels were very high for all traits.

Standard multileaf collimators (MLCs) are now available with 1.0 and 0.5 cm leaf widths. The aim of this work is to compare the dose-undulation and effective penumbra of field edges formed by these MLC leaf widths and to determine how reducing the sampling distance (centre-to-centre distance between adjacent MLC leaves) for the 1.0 cm leaf width compares to the smaller leaf width. The undulation of the 50% isodose line and the 80–20% and 80–30% effective penumbra were compared for a field edge angled at 45° to the MLC leaf motion direction at 8 cm depth. The larger leaf width field was also segmented to form field edges with 0.5, 0.33 and 0.2 cm sampling distance. Random setup variation of 2 mm standard deviation was also incorporated. Dose undulation was 1.5 mm for the 0.5 cm MLC leaf width compared to 4.5 mm for the 1.0 cm width. The 80–20% effective penumbra was 2 mm less for the 0.5 cm leaf width and the 80–30% effective penumbra was ≈3 mm less. When random setup variation was incorporated the 0.5 cm leaf width isodoses were straight compared with ≈3 mm undulation for the larger MLC. Reducing the sampling distance for the 1.0 cm MLC leaf width to 0.33 cm resulted in penumbra only slightly greater than the 0.5 cm leaf width and removed the undulation. Effective penumbra and dose undulation are reduced for the 0.5 cm leaf width compared to a 1.0 cm leaf width. Reducing the sampling distance for the 1.0 cm MLC leaf can approximate the 0.5 cm leaf width, at the expense of longer treatment times, and increased quality assurance investment.

The antixenotic effects of foliar morphological and chemical characteristics, such as spine density, leaf colour, leaf width, hydroxamic acid (Hx) levels, and previous feeding damage, on feeding and oviposition of the sucking pest of sugarcanePyrilla perpusilla Walker were studied. Feeding preference was affected by the leaf colour ( c2 = 10.2; P< 0.05) and Hx levels (c2 = 21.668; P< 0.05); whereas oviposition preference was determined by leaf spine density (c2 = 8.959; P

Purpose We aim to evaluate the effects of multileaf collimator (MLC) leaf width (5 mm vs. 2.5 mm) on the radiosurgery planning for the treatment of spine lesions according to the modulated techniques (intensity-modulated radiotherapy [IMRT] vs. volumetric-modulated arc therapy [VMAT]) and the complexity of the target shape. Methods For this study, artificial spinal lesions were contoured and used for treatment plans. Three spinal levels (C5, T5, and L2 spines) were selected, and four types of target shapes reflecting the complexity of lesions were contoured. The treatment plans were performed using 2.5-mm and 5-mm MLCs, and also using both static IMRT and VMAT. In total, 48 treatment plans were established. The efficacy of each treatment plan was compared using target volume coverage (TVC), conformity index (CI), dose gradient index (GI), and V30%. Results When the 5-mm MLC was replaced by the 2.5-mm MLC, TVC and GI improved significantly by 5.68% and 6.25%, respectively, while CI did not improve. With a smaller MLC leaf width, the improvement ratios of the TVC were larger in IMRT than VMAT (8.38% vs. 2.97%). In addition, the TVC was improved by 14.42-16.74% in target type 4 compared to the other target types. These improvements were larger in IMRT than in VMAT (27.99% vs. 6.34%). The V30% was not statistically different between IMRT and VMAT according to the MLC leaf widths and the types of target. Conclusion The smaller MLC leaf width provided improved target coverage in both IMRT and VMAT, and its improvement was larger in IMRT than in VMAT. In addition, the smaller MLC leaf width was more effective for complex-shaped targets.

Lodging can strongly affect both the grain yield and the quality of wheat. Lodging represents a quantitative trait and is difficult to assess on a phenotypic basis. Marker-assisted selection (MAS) could therefore become an important tool in breeding for lodging resistance. In this study, we mapped and characterised quantitative trait loci (QTLs) for lodging resistance, as well as morphological traits correlated with lodging, in a segregating population of 226 recombinant inbred lines derived from the cross of the lodging-resistant wheat variety Forno with the susceptible spelt variety Oberkulmer. Lodging, plant height, leaf width, leaf-growth habit, culm stiffness, culm swinging, culm thickness, days to ear emergence and days to flowering were assessed in field trials at two locations in 1996 and at one location in 1997. Additionally, at one location weight and length parameters were also assessed. Plant height and culm stiffness explained 77% of the phenotypic variance of lodging in a multiple regression model over all three environments. QTL analysis of lodging and morphological parameters was based on a genetic map containing 230 loci with 23 linkage groups (2469 cM). With the method of composite interval mapping nine QTLs for lodging resistance were detected, explaining 63% of the phenotypic variance in a simultaneous fit. Seven of these QTLs coincided with QTLs for morphological traits, reflecting the correlations between these traits and lodging. In our population the most efficient way to improve lodging resistance would be by a combination of indirect selection on plant height and culm stiffness together with MAS on the two QTLs for lodging resistance which did not coincide with QTLs for morphological traits.

A correlation between genome size and agronomically important traits has been observed in many plant species. The goal of the present research was to determine the relationship between genome size, seed size, and leaf width and length in soybean [Glycine max (L.) Merr.] Twelve soybean strains, representing three distinct seed size groups, were analyzed. Flow cytometry was used to estimate their 2C nuclear DNA contents. Data on seed size and leaf size of the 12 strains were obtained from 1994 and 1995 field experiments. Variation of 2C nuclear DNA among the 12 soybean strains was 4.6%, ranging from 2.37 pg for a small-seed strain to 2.48 pg for a large-seed strain. Strain seed size was positively associated with leaf width (r=0.92) and leaf length (r=0.93). Genome size was highly correlated with seed size (r=0.97), leaf width (r=0.90) , and leaf length (r=0.93). The results of our study indicate that there is a significant correlation between genome size and leaf and seed size in soybean. It is possible that selection for greater seed size either leads to, or results from, greater genome size. If so, this relationship might be worth exploring at a more fundamental level.

Development of maize (Zea mays L.) types that produce leaf area rapidly and finish vegetative development quickly would increase production of maize in mid- to short-season areas. The Leafy (Lfy1) and reduced-stature (rd1) traits each make contributions to this end. However, these two traits have not previously been combined. Our objective was to evaluate the morphological aspects of non-leafy normal-stature (NLNS), leafy reduced-stature (LRS), non-leafy reduced-stature (NLRS), and leafy normal-stature (LNS) maize inbreds. Two traits, Lfy1 and rd1, were incorporated into a series of inbreds, resulting in a range of canopy architectures. Twelve variables were recorded for each of 30 inbreds over three years. The 12 variables were: seed emergence, above-ear leaf number, below-ear leaf number, dead leaf number at tasselling, live leaf number at tasselling, total leaf number, above-ear leaf area, ear leaf length, ear leaf width, ear height, internode length, and plant height. Inbreds containing the Lfy1 trait had more above-ear leaf area, above-ear leaf number, dead leaf number at tasselling, total leaf number and number of live leaves at tasselling than non-leafy inbred lines. Below-ear leaf number was not different among LRS, LNS, and NLNS inbred lines. LRS and NLRS inbred lines were also not different for below-ear leaf number. Plant height, ear height, and ear leaf length and width were higher in normal-stature than reduced-stature plants. The proportion of the seeds which emerged was higher for LRS inbreds than the other trait groups.

Low ODAP somaclones have been evaluated for physiological and biochemical parameters especially in relation to attributes that lead to increased biomass production. All the somaclones during development had substantially lower ODAP content in leaves as compared to parent P24. Considerable variation was observed in relation to leaf width, leaf length, internodal length and leaf area. Somaclone Bio L12 had the highest whereas parent P24 and Bi0164 had the least leaf area. Harvest index was the highest and biomass production was the lowest in the Bio 164. Bio L08 gave the highest seed yield. Photosynthetic rates were also higher in Bio L12, although no significant positive correlation was observed in leaf photosynthesis and seed yield. The differences in physiolpgical and biochemical parameters indicate the possibility of development of high yielding genotypes. The results in present investigation show differences in photosynthetic rate, leaf characteristics, seed yield and ODAP content among somalones and parent. Somaclones with extremely low ODAP content with variability in leaf morphology and photosynthetic rate is indicative of variation induced during plant tissue culture.

Nature of resistance against the rice leaffolder, Cnaphalocrocis medinalis (Guenee) was studied in 16 rke varieties selected on the basis of greenhouse feeding test. Resistant varieties as a group were less preferred for feeding by the larvae in a free choice test lasting 10 days. Cut leaf assay with limited choice brought out subtle differences among some of the test varieties In larval settling response. Larval preference was correlated positively with the leaf area damage noted In feeding test, per cent pupation and leaf width, and negatively with trichome density. However, oviposltton preference was neither distinct nor correlated with resistance or leaf morphology. An antibiosis component in the test varieties ARC 11128, Balam, Gorsa, ARC 7064 and Ptb 19 was distinctly manifested as reduced larval survival, lower pupation rate and pupal weights in comparison with the susceptible check. When neonate larvae were reared on the meridic diets containing the leaves of the varieties Darukasail, Balam or Ptb 12, antibiotic effects were much more pronounced in comparison with the larvae reared on the diet containing the leaves of the susceptible check TN 1.

In this paper the variation pattern of the Sicilian Beta germplasm collection is analysed. Accessions from Sicily were grown under controlled conditions and were evaluated morphometrically. Geographical distribution patterns of morphological characters are identified and the putative classification of the collection into coastal and inland populations is reassessed. Between adjacent populations significant variation was found for Petiole length, Leaf length, Leaf width and Biomass, however no one variable unambiguously reflected a geographical pattern. Overall differences between coastal and inland populations were small. Petiole length and rate of generative development were found to be important for distinguishing between these groups. Interferences are drawn on how the collection from Sicily could be rationalized to avoid excessive duplication.

On average, irradiation of F2 seed of the cross of varieties 1 and 5 of Nicotiana rustica increases the additive genetical variation among inbred families in the F6 by about 60 per cent. This agrees with the increase predicted from a hierarchical analysis of F3 and F4 families but it is greater than that predicted from an F2 triple test cross analysis. This is as expected (Virk, Pooni, Ingram and Jinks, 1981). Both predictions, however, overestimate the increase observed in final height but underestimate those for leaf width and flowering time. The underestimates but not the overestimates can be accounted for if irradiation has increased the rate of recombination in the lineages derived from the irradiated F2 seed. The increased genetical variation following irradiation is accompanied by a shift in the distribution of F6 family means towards the lower end; the range of family means is extended and more families have means which are lower than that of the lower scoring parent of the cross. But final height is again unusual in showing a corresponding increase in the range at the upper end of the distribution and more families with means which are higher than that of the taller parent of the cross.

The vascular system of the leaves of Saccharum officinarum L. is composed in part of a system of longitudinal strands that in any given transverse section may be divided into three types of bundle according to size and structure: small, intermediate, and large. Virtually all of the longitudinal strands intergrade, however, from one type bundle to another. For example, virutually all of the strands having large bundle anatomy appear distally in the blade as small bundles, which intergrade into intermediates and then large bundles as they descend the leaf. These large bundles, together with the intermediates that arise midway between them, extend basipetally into the sheath and stem. Most of the remaining longitudinal strands of the blade do not enter the sheath but fuse with other strands above and in the region of the blade joint. Despite the marked decrease in number of bundles at the base of the blade, both the total and mean cross-sectional areas (measured with a digitizer from electron micrographs) of sieve tubes and tracheary elements increase as the bundles continuing into the sheath increase in size. Linear relationships exist between leaf width and total bundle number, and between cross-sectional area of vascular bundles and both total and mean cross-sectional areas of sieve tubes and tracheary elements.

The vascular system of the Zea mays L. leaf consists of longitudinal strands interconnected by transverse bundles. In any given transverse section the longitudinal strands may be divided into three types of bundle according to size and structure: small, intermediate, large. Virtually all of the longitudinal strands intergrade structurally however, from one bundle type to another as they descend the leaf. For example, all of the strands having large-bundle anatomy appear distally as small bundles, which intergrade into intermediates and then large bundles as they descend the leaf. Only the large bundles and the intermediates that arise midway between them extend basipetally into the sheath and stem. Most of the remaining longitudinal strands of the blade do not enter the sheath but fuse with other strands above and in the region of the blade joint. Despite the marked decrease in number of longitudinal bundles at the base of the blade, both the total and mean cross-sectional areas of sieve tubes and tracheary elements increase as the bundles continuing into the sheath increase in size. Linear relationships exist between leaf width and total bundle number, and between cross-sectional area of vascular bundles and both total and mean cross-sectional areas of sieve tubes and tracheary elements.

In sorghum, a new gene designatedInty is responsible for an extreme reduction in the internodal length, producing Tiny plants. Internodal number is not affected but internodal length only. The wide divergence in internodal length is less graphic in its effect on leaf-sheath length. With reference to the leaf-blade, its length is more affected than its breadth. This gene does not affect the number of whorls on the earhead but has its effect in the panicle having a lesser number and shorter length of secondary panicle branches resulting in fewer spikelets per earhead. Glume size remains practically unaffected. So also ovary and stigma size. The anthers and filaments are reduced in size. The anthers are devoid of pollen. Dwarf plants are therefore usually sterile. Stray pollen grains could be found in some anthers and fertilization by them results in seeds giving true-breeding Tiny plants. The stigmas are very receptive and natural crossing is chronic. Plants heterozygous for the character are the main source of their reproduction. Factorinty is a simple monogenic recessive toInty.

A study was made on the quantitative inheritance of seven characters viz., flowering time, plant height, leaf length, leaf width, number of curable leaves, green weight and cured weight for two crosses of flue-cured tobacco Chatham x Delcrest and 232 x Hicks. Six genetic populations P1, P2, F1, F2, B1 and B2 were observed in each cross.

In cantaloupe(Cucumis melo L. var.reticulatus Naud., cultivar PMR 45) leaf shape,fruit shape, and flesh proportion were associated as they varied from growing site to growing site. The same associations held as the characteristics varied between PMR 45 and a selection thereof. The conditions indicate that the three characteristics respond to both genetic and environmental stimuli via a common intermediate mechanism.

Width-to-length ratios of upper stem leaves ofLasallea novaeangliae andL. oblongifolia were determined from herbarium specimens and field collections. No distinct subgroups based on suchratios were found in either species. InL. novaeangliae the curve of the ratio versus number of individuals was skewed toward the narrow-leaf range. This phenomenon was present but less pronounced inL. oblongifolia. The histogram of leaf ratios forL. novaeangliae was somewhat weakly bimodal, suggesting a possible broad-leaf race, which has not been recognized nomenclaturally. The absence of bimodality in the histogram of leaf ratios forL. oblongifolia indicates the need to place Shinners’ narrow-leaved varietyangustatus in synonymy. Other traits such as height, degree of branching and the nature of the pubescence were also found to be of no significance. Slight geographic trends in leaf width occur in both species. No real evidence was found for nomenclaturally recognizing any eastern variant in either species. Thus, Shinners’ var.orientis is not recognized inL. oblongifolia either.