Leaf Morphology Research Articles

Assessment of Durian Diversity and Its Wild Relatives (Durio spp.) Based on Leaf Morphology and Molecular Marker

Durian (Durio spp.) is native to Southeast Asia and has potential for development. However, some species are threatened due to deforestation and extensive land conversion. This study aimed to determine the genetic diversity and relationships of durian and wild relatives (Durio spp.) on the Indonesia Island Borneo using a leaf morphology and DNA barcoding (matK) marker. In this study, 15 durian samples from this region were used, excluding ‘Monthong’ (Durio zibethinus) and ‘Bengang’ (Neesia strigosa) as the outgroups from the GenBank database. The leaf morphology was analyzed descriptively, whereas the genetic diversity was by the nucleotide diversity index (π%). The relationship of durians was revealed by the maximum likelihood (ML) method and examined with the bootstrap statistics for 1000 replicates, also confirmed by the PCA (principal component analysis). Based on the leaf morphology, the durians are divided into five forms, i.e., obovate-lanceolate, elliptic, ovate, oblong, and linear-oblong. ‘Pampaken’ and ‘Pampaken Burung Kecil’ indicated the earliest form (obovate-lanceolate), whereas the linear-oblong was by ‘Kamundai.’ Following the molecular marker, it was seen that the durians have low genetic diversity (π%) with only 0.015. However, phylogenetically, the durians were separated into four similar clades or groups for ML and PCA. In this instance, it has appeared that most of the durians evaluated in the current study have close relationships, except for the taxa with the farthest relationship. The results provide valuable information for the local and global durian conservation mission, including future breeding programs.

Ecotype variation in the endemic tree Callicarpa subpubescens on small oceanic islands: genetic, phenotypic, and environmental insights.

Callicarpa subpubescens, endemic to the Ogasawara Islands, is suggested to have multiple ecotypes in the Hahajima Islands, specifically in the central part of the Ogasawara Islands. In this study, associations between genetic groups and spatial distribution, habitat, leaf morphology, size structure, and flowering time of each genetic group were investigated on Hahajima and the satellite Imoutojima Islands. Genetic groups were identified using EST-SSR markers, revealing four ecotypes named based on morphological features: Dwarf (D), Glabrescent (G), Tall (T), and Middle (M), with M being a result of the hybridization of G and T. Ecotype D, adapted to dry environments, is characterized by small tree size, dense thick leaves with abundant hairs, and is distributed in dry scrub. Ecotype G, adapted to understory of mesic forests, lacks leaf hairs. Ecotype T, adapted to the canopy of mesic forests, has hairy leaves and is tall in tree height. Ecotype M, adapted to the canopy of mesic scrub or edges of mesic forests, has hairy leaves but with a shorter tree height than ecotype T. Flowering peaks differed among all ecotype pairs except G and M, but the flowering times more or less overlapped among all ecotypes, suggesting that pre-mating isolation among ecotypes is not perfect. Post-mating isolation is considered absent, as there were no differences in the results, germination, and survival rates of one-year seedlings among inter- and intra-ecotype crossings. The existence of such ecotypes provides valuable insights into the ongoing speciation processes adapting to the oceanic island environments.

Hepatics from Rovno amber (Ukraine). 12. Jubula polessica sp. nov.

Hepatics from Rovno amber (Ukraine). 12. Jubula polessica sp. nov.

Impact of abandonment on leaf morphology traits and nutrient utilization strategies of dominant tree seedlings in Moso bamboo forests

The restoration of ecological functions in abandoned Moso bamboo forests facilitates positive succession in evergreen vegetation. Nevertheless, there is a limited understanding regarding the leaf functional traits and nutrient utilization strategies of understory vegetation after abandonment. This study investigated the impact of abandonment duration (9 and 21 years) on leaf morphological traits, soluble sugars characteristics, carbon (C), nitrogen (N), phosphorus (P), and their ratios in dominant tree seedlings (Lithocarpus brevicaudatus and Schima superba) within Moso bamboo forests. Leaf sizes increased significantly with prolonged abandonment in both species, accompanied by a consistent decrease in leaf thickness and leaf tissue density. These morphological indices were more pronounced in L. brevicaudatus compared to S. superba (P < 0.05), and they showed a positive correlation with tree sizes. Moreover, leaf soluble sugars, C, and C: N: P ratios of both tree species decreased over duration abandonment, while N and P contents increased. Specifically, L. brevicaudatus exhibited elevated levels of fructose, glucose, N, and P, whereas S. superba displayed higher sucrose, C, and C: N: P ratios. Our findings reveal that both species, with extended abandonment, enlarged their leaf area and improved carbon utilization, facilitating adaptation to competitive resource habitats. Particularly, L. brevicaudatus exhibited a propensity to augment leaf sizes, as well as N, and P contents, suggesting a strategy to enhance carbon assimilation through additional N and P nutrient supplementation. Conversely, S. superba primarily focused on bolstering carbohydrate reserves, indicating that moderate thinning or pruning of bamboo forests could boost sunlight penetration, along with the appropriate nutrient supplementation. These insights significantly contribute to the scientific understanding necessary for the classification and management of mixed stands in abandoned bamboo forests.

Leaf morphology related genes revealed by integrating Pan-transcriptome, GWAS and eQTL analyses in a Liriodendron population.

Leaf plays an indispensable role in plant development and growth. Although many known genes related to leaf morphology development have been identified, elucidating the complex genetic basis of leaf morphological traits remains a challenge. Liriodendron plants are common ornamental trees due to their unique leaf shapes, while the molecular mechanism underlying Liriodendron leaf morphogenesis has remained unknown. Herein, we firstly constructed a population-level pan-transcriptome of Liriodendron from 81 accessions to explore the expression presence or absence variations (ePAVs), global expression differences at the population level, as well as differentially expressed genes (DEGs) between the Liriodendron chinense and Liriodendron tulipifera accessions. Subsequently, we integrated a genome-wide association study (GWAS), expression quantitative trait loci (eQTL), and transcriptome-wide association study (TWAS) to identify candidate genes related to leaf morphology. Through GWAS analysis, we identified 18 and 17 significant allelic loci in the leaf size and leaf shape modules, respectively. In addition, we discerned 16 candidate genes in relation to leaf morphological traits via TWAS. Further, integrating the co-localization results of GWAS and eQTL, we determined two regulatory hotspot regions, hot88 and hot758, related to leaf size and leaf shape, respectively. Finally, co-expression analysis, eQTL, and linkage mapping together demonstrated that Lchi_4g10795 regulate their own expression levels through cis-eQTL to affect the expression of downstream genes and cooperatively participate in the development of Liriodendron leaf morphology. These findings will improve our understanding of the molecular regulatory mechanism of Liriodendron leaf morphogenesis and will also accelerate molecular breeding of Liriodendron.

The functional diversity-productivity relationship of woody plants is climatically sensitive.

Plot-scale experiments indicate that functional diversity (FD) plays a pivotal role in sustaining ecosystem functions such as net primary productivity (NPP). However, the relationships between functional diversity and NPP across larger scale under varying climatic conditions are sparsely studied, despite its significance for understanding forest-atmosphere interactions and informing policy development. Hence, we examine the relationships of community-weighted mean (CWM) and functional dispersion (FDis) of woody plant traits on NPP across China and if such relationships are modulated by climatic conditions at the national scale. Using comprehensive datasets of distribution, functional traits, and productivity for 9120 Chinese woody plant species, we evaluated the distribution pattern of community-weighted mean and functional dispersion (including three orthogonal trait indicators: plant size, leaf morphology, and flower duration) and its relationships with NPP. Finally, we tested the effects of climatic conditions on community-weighted mean/functional dispersion-NPP relationships. We first found overall functional diversity-NPP relationships, but also that the magnitude of these relationships was sensitive to climate, with plant size community-weighted mean promoting NPP in warm regions and plant size functional dispersion promoting NPP in wet regions. Second, warm and wet conditions indirectly increased NPP by its positive effects on community-weighted mean or functional dispersion, particularly through mean plant size and leaf morphology. Our study provides comprehensive evidence for the relationships between functional diversity and NPP under varying climates at a large scale. Importantly, our results indicate a broadening significance of multidimensional plant functional traits for woody vegetation NPP in response to rising temperatures and wetter climates. Restoration, reforestation actions and natural capital accounting need to carefully consider not only community-weighted mean and functional dispersion but also their interactions with climate, to predict how functional diversity may promote ecosystem functioning under future climatic conditions.

Physiological and Structural Changes in Leaves of Platycrater arguta Seedlings Exposed to Increasing Light Intensities.

Understanding the light adaptation of plants is critical for conservation. Platycrater arguta, an endangered deciduous shrub endemic to East Asia, possesses high ornamental and phylogeographic value. However, the weak environmental adaptability of P. arguta species has limited its general growth and conservation. To obtain a deeper understanding of the P. arguta growth conditions, we examined the leaf morphology and physiology via anatomical and chloroplast ultrastructural analyses following exposure to different natural light intensities (full light, 40%, and 10%). The findings indicated that P. arguta seedings in the 10% light intensity had significantly improved leaf morphological characteristics and specific leaf area compared to those exposed to other intensities. The net photosynthetic rate, chlorophyll (Chl) content, photosynthetic nitrogen use efficiency (PNUE), and photosynthetic phosphorus use efficiency (PPUE) exhibited marked increases at a 10% light intensity compared to both 40% light and full light intensities, whereas the light compensation point and dark respiration levels reached their lowest values under the 10% light condition. With reduced light, leaf thickness, palisade tissue, spongy tissue, and stomatal density significantly decreased, whereas the stomatal length, stomatal width, and stomatal aperture were significantly elevated. When exposed to 10% light intensity, the ultrastructure of chloroplasts was well developed, chloroplasts and starch grain size, the number of grana, and thylakoids all increased significantly, while the number of plastoglobules was significantly reduced. Relative distance phenotypic plasticity index analysis exhibited that P. arguta adapts to varying light environments predominantly by adjusting PPUE, Chl b, PNUE, chloroplast area, and the activity of PSII reaction centers. We proposed that P. arguta efficiently utilizes low light to reconfigure its energy metabolism by regulating its leaf structure, photosynthetic capacity, nutrient use efficiency, and chloroplast development.

Effects of Sun vs Shade and Leaf Age on Leaf Morphology, Herbivory, and Physical Defenses in the Swiss Cheese Plant (Monstera adansonii)

Abstract One important structural defense of plants is calcium oxalate crystals or raphides. In this project, I studied one species in the plant family Araceae, Monstera adansonii, a widely distributed plant in the tropics, that is known to contain raphides. Plants of this species were sampled in sun or shade locations. For each plant, three leaves were sampled, the first fully expanded leaf on a plant (leaf 1) and two more leaves below it, leaf 3 and leaf 5. For each leaf, I measured: leaf area, number of fenestrations (naturally occurring holes in the leaf), amount of herbivory, and density of raphides. I compared these measures on leaves of different ages from sun versus shade plants. Results showed that: 1) older leaves were significantly larger than younger leaves (P &lt; 0.001), but there was no effect of light environment (P = 0.199); 2) density of raphides was not significantly affected by sun (P = 0.147) and density of raphides decreased with leaf age (P = 0.0097); 3) the number of fenestrations was significantly higher in plants in the sun (P = 0.01), but did not differ with leaf age (P = 0.702); 4) herbivory was not affected by sun exposure (P = 0.29) but was marginally significantly affected by raphide density (P = 0.06). There was a significant interaction between raphide density and light exposure on herbivory, in that in the shade there was a negative relationship where herbivory decreased as raphides increased, but in the sun, a positive relationship where herbivory increases as raphides increase (P = 0.04). Lay Summary Deforestation poses significant threats to the fragile ecosystem of tropical rainforests. Costa Rica’s Monteverde Cloud Forest, known for its rich biodiversity, relies on canopy tree cover for habitat protection and the maintenance of ecological balance. Tree loss can have a cascading effect on the ecosystem, which may negatively affect many species. When this balance is disrupted through deforestation, understory plants, such as Monstera adansonii, or the well-known “Swiss cheese” houseplant, are exposed to direct sun and harsh environmental elements. They may be initially ill-equipped to handle these conditions, but plants can physically adapt to their surrounding environment. To understand how plants may adapt to new conditions, I studied physical differences in Monstera adansonii between shaded understory areas and sunny exposed areas, which are created by forest clearing. I examined its physical differences, including the concentration of calcium oxalate crystals within its leaves. Among others, my results showed that the plants in the sun experienced more damage by herbivores than the plants in the shade. Through this study, I have “shed light” on the effects of deforestation and what this plant and many other understory plants may face as the rate of deforestation increases. For the full text, please visit https://scholar.colorado.edu/concern/undergraduate_honors_theses/d791sh621.

Mutations alter pll gene promoter from constitutive to inducible, coffering palmately lobed leaf trait of melon

The leaves of the common melon are approximately round and uncut. A natural mutant of melon named bm7, which has palmately-lobed leaves. We found that bm7 plants were more conducive to increasing planting density and achieving higher yields, and showed better disease resistance. Therefore, the germplasm resources of muskmelon split leaves have the potential of application. Previous study showed that the palmately-lobed leaf trait was controlled by a single recessive gene, pll (numbered MELO3C010784). By cloning and sequencing the pll genes of Jiashi (wide-type) and bm7 (mutant) plants, we noticed that there was no mutation in this gene, but its expression level in bm7 was far below than that in Jiashi. The silencing of pll gene with virus induced gene silencing (VIGS) confers palmately-lobed leaf trait of Jiashi plants. We found three mutations in the pll gene promoter of bm7 plants, located at 373, 493, 506 bp upstream the translation initiation codon. Then, we had found the pll gene promoter activity of bm7 was significantly lower than that of Jiashi. In addition, the expression level and promoter activity of pll gene in Jiashi plants were not affected by environmental factors, but in bm7 plants, the expression level and promoter activity of pll gene, all decreased with the increase in light intensity and/or temperature. All the results indicated that the mutations convert the pll gene promoter from constitutive to inducible, and results in significantly reduced expression of pll gene, conferring the palmately-lobed leaf trait of melon.

Elliptic Fourier analysis of leaf shape of Callicarpa pedunculata and Callicarpa rubella (Lamiaceae)

Leaves play an important role in species discrimination. An elliptic Fourier analysis (EFA) based morphometric technique was used to assess divergence between the poorly differentiated species, Callicarpa pedunculata and C. rubella. Using leaf specimen images from herbarium collections, principal components (PCs) were extracted from the Fourier coefficients and used to describe leaf outline and leaf shape descriptors: circularity, aspect ratio, and solidity. The results indicate that symmetric (54%) and asymmetric (35%) components of the leaves of C. pedunculata and C. rubella are sources of shape variation, as shown in the width and leaf tips among the samples. MANOVA revealed significant interspecific differences (P = 0.03) between C. pedunculata and C. rubella. The jack-knife cross-validation showed 71% of correctly classified species both in C. pedunculata and C. rubella. Furthermore, the results of this study were able to reveal significant leaf shape descriptors like aspect ratio, circularity, and solidity as important diagnostic characters in discriminating C. pedunculata and C. rubella. Thus, in conclusion, leaf serrations, leaf size, and leaf lobes are important characteristics in discriminating between C. pedunculata and C. rubella.

Investigating biological performance, oviposition and diet preference of the twospotted spider mite feeding on various melon genotypes

The twospotted spider mite, Tetranychus urticae Koch, is one of the most dangerous pests for many crops worldwide, including the melon. Here, we raise the hypothesis that the resistance of melon genotypes to the spider mite is associated with the morphological characteristics of the leaves. We determined (i) the feeding preference and oviposition suitability of T. urticae on four melon genotypes, (ii) various biological parameters and population growth rate (ri) of T. urticae on different melon genotypes, (iii) the leaf morphology of the melon genotypes, and (iv) the relationship between the leaf characteristics and resistance to T. urticae. In no choice tests, lower numbers of adults and eggs of T. urticae were found in the genotypes CNPH 06–1047-343, CNPH 11–1071-43, and CNPH 06-1047-341 compared to control (Goldex). Individuals that fed on CNPH 06–1047-343, CNPH 06–1047-341, and CNPH 11–1071-43 genotypes had a longer egg incubation time, longer development time, lower immature viability, longer time to reach adult stage (egg–adult) and lower instantaneous rate of increase compared to control. These findings are in line with the fact that these three genotypes had thicker epidermis and greater mesophyll thickness than control genotype “Goldex”. Even the genotypes CNPH 06–1047-343, CNPH 06–1047-341, and CNPH 11–1071-43 had higher trichome densities, this morphological characteristic was not related with the resistance to T. urticae. CNPH 06–1047-343, CNPH 06–1047-341, and CNPH 11–1071-43 showed antibiosis and antixenosis against T. urticae and that resistance of the melon to T. urticae wss associated with the greater thickness of the leaf epidermis and mesophyll.

Multiple sources of evidence unravel a complex taxonomic history: the new genus Leonoria of the Spermacoce clade (Spermacoceae-Rubiaceae)

For a long time, the taxonomic status of Denscantia, a genus endemic to the Atlantic Forest along the Brazilian coast, has been a topic of discussion. Phylogenetic analyses using two nuclear and four chloroplast DNA markers from 82 accessions representing 19 genera of the Spermacoce clade (tribe Spermacoceae, Rubiaceae) confirm that the Brazilian genus Denscantia is biphyletic. Together with the recovered phylogenetic relationships, the analyses of reproductive morphological characters, leaf morphology and anatomy, histochemical, geographic distribution ranges, and ecological niche derived from climatic space further demonstrate that Denscantia calcicola is a distinct lineage from the other Denscantia species. Therefore, the above-mentioned species should be taxonomically designated as a new monospecific genus, Leonoria. Significant morphological differences between Leonoria and Denscantia were found in inflorescence organization, style shape, fruit dehiscence and pollen morphology. Morphological and anatomical variation among leaf traits was found in epidermal cells, trichome distribution, mesophyll histochemistry and vascular organization. The analysis of occurrence records of 207 specimens demonstrates a clear ecological distinction between of Denscantia s.s. and Leonoria, which is ecologically confined to limestone outcrops associated with seasonally dry forests. The current study highlights the importance of an integrative taxonomic approach combining multiple sources of evidence to unravel complex taxonomic history within Spermacoceae.

Genetic analysis and identification of molecular markers associated with lobed leaf shape in watermelons using next generation sequencing

Genetic analysis and identification of molecular markers associated with lobed leaf shape in watermelons using next generation sequencing

Morpho-genetic Diversity and Traits’ Relationship in Castor Germplasm

Adequate knowledge of the extent of dissimilarity among germplasm accessions and traits’ relationships are of great importance in active breeding programme. In the present study, genetic diversity and traits’ relationship were assessed among 74 castor germplasm accessions collected at the National Cereals Research Institute Badeggi, Nigeria. The accessions were evaluated on replicated plots of 7.5m2 size, arranged in a randomized complete block design. The data were taken on 20 individual plants, using standard castor descriptors. The results revealed significant variations for all the traits studied among the entries. Phenotypic and genotypic coefficients of variation estimated showed low environmental effects on the observed variations. High (≥ 70%) broad sense heritability coupled with high (≥ 20%) genetic advance as percentage of mean were observed in all the traits except days to days to first raceme maturity, number of leaf lobes and seed yield. Six cluster groups, with 4 to 38 members, were identified among the accessions. Significant positive correlations were observed between the seed yield and leaf length (0.269*), and spike length (0.972**). The partitioning of the correlations into direct and indirect yield contributors showed positive direct effects for number of internodes to first raceme, spike length and height to first raceme. The findings showed that selection for long spike early accessions could result in constituting a high yielding breeding population. The identified superior accessions could serve as good germplasm sources for castor breeding programme in Nigeria.

Leaf functional traits and ecological niche of Fagus grandifolia and Oreomunnea mexicana in natural forests and plantings as a proxy of climate change.

Functional traits reflect species' responses to environmental variation and the breadth of their ecological niches. Fagus grandifolia and Oreomunnea mexicana have restricted distribution in upper montane cloud forests (1700-2000 m a.s.l.) in Mexico. These species were introduced into plantings at lower elevations (1200-1600 m a.s.l.) that have climates predicted for montane forests in 2050 and 2070. The aim was to relate morphological leaf traits to the ecological niche structure of each species. Leaf functional traits (leaf area, specific leaf area [SLA], thickness, and toughness) were analyzed in forests and plantings. Atmospheric circulation models and representative concentration pathways (RCPs: 2.6, 4.5, 8.5) were used to assess future climate conditions. Trait-niche relationships were analyzed by measuring the Mahalanobis distance (MD) from the forests and the plantings to the ecological niche centroid (ENC). For both species, leaf area and SLA were higher and toughness lower in plantings at lower elevation relative to those in higher-elevation forests, and thickness was similar. Leaf traits varied with distance from sites to the ENC. Forests and plantings have different environmental locations regarding the ENC, but forests are closer (MD 0.34-0.58) than plantings (MD 0.50-0.70) for both species. Elevation as a proxy for expected future climate conditions influenced the functional traits of both species, and trait patterns related to the structure of their ecological niches were consistent. The use of distances to the ENC is a promising approach to explore variability in species' functional traits and phenotypic responses in optimal versus marginal environmental conditions.

Identification of Chromosomal Regions and Candidate Genes for Round leaf Locus in Cucumis melo L.

Leaf morphology plays a crucial role in plant classification and provides a significant model for studying plant diversity while directly impacting photosynthetic efficiency. In the case of melons, leaf shape not only influences production and classification but also represents a key genetic trait that requires further exploration. In this study, we utilized forward genetics to pinpoint a recessive locus, dubbed Cmrl (Round leaf), which is responsible for regulating melon leaf shape. Through bulked segregant analysis sequencing and extensive evaluation of a two-year F2 population, we successfully mapped the Cmrl locus to a 537.07 kb region on chromosome 8 of the melon genome. Subsequent genetic fine-mapping efforts, leveraging a larger F2 population encompassing 1322 plants and incorporating F2:3 phenotypic data, further refined the locus to an 80.27 kb interval housing five candidate genes. Promoter analysis and coding sequence cloning confirmed that one of these candidates, MELO3C019152.2 (Cmppr encoding a pentatricopeptide repeat-containing family protein, Cmppr), stands out as a strong candidate gene for the Cmrl locus. Notably, comparisons of Cmrl expressions across various stages of leaf development and different leaf regions suggest a pivotal role of Cmrl in the morphogenesis of melon leaves.

Hepatics from Rovno amber (Ukraine). 11. Radula oblongifolia and R. tikhomirovae sp. nov.

A study of Rovno amber has revealed two fossil leafy liverwort species of the genus Radula (Radulaceae, Marchantiophyta) that are new to the late Eocene flora of Rovno amber. One of these species, R. oblongifolia, was described previously from Eocene Baltic and Bitterfeld amber, whereas the other species, R. tikhomirovae, is described here as new. Radula tikhomirovae differs from R. oblongifolia and two other Eocene species of that genus, R. sphaerocarpoides and R. baltica, by the presence of microphyllous branches and by the shape of its leaf lobules.

Local adaptation to an altitudinal gradient: The interplay between mean phenotypic trait variation and phenotypic plasticity in Mimulus laciniatus

Organisms can adapt to environmental heterogeneity through two mechanisms: (1) expression of population genetic variation or (2) phenotypic plasticity. In this study we investigated whether patterns of variation in both trait means and phenotypic plasticity along elevational and latitudinal clines in a North American endemic plant, Mimulus laciniatus, were consistent with local adaptation. We grew inbred lines of M. laciniatus from across the species’ range in two common gardens varying in day length to measure mean and plastic trait expression in several traits previously shown to be involved in adaptation to M. laciniatus’s rocky outcrop microhabitat: flowering time, size-related traits, and leaf shape. We tested for phenotypic plasticity and GxE, examined correlations between the mean phenotype and plasticity, and tested for a relationship between trait variation and population elevation and latitude. We did not find a strong correlation between mean and plastic trait expression at the individual genotype level suggesting that they operate under independent genetic controls. We identified multiple traits that show patterns consistent with local adaptation to elevation: critical photoperiod, flowering time, flower size, mean leaf lobing, and leaf lobing plasticity. These trends occur along multiple geographically independent altitudinal clines indicating that selection is a more likely cause of this pattern than gene flow among nearby populations with similar trait values. We also found that population variation in mean leaf lobing is associated with latitude. Our results indicate that both having more highly lobed leaves and greater leaf shape plasticity may be adaptive at high elevation within M. laciniatus. Our data strongly suggest that traits known to be under divergent selection between M. laciniatus and close relative Mimulus guttatus are also under locally varying selection within M. laciniatus.

Preliminary Exploration of Physiology and Genetic Basis Underlying High Yield in Indica–Japonica Hybrid Rice

The utilization of heterosis is of great significance in improving rice yield. To explore the physiological and genetic basis for high yield in indica–japonica hybrid rice, Zheyou18 (z18) and Yongyou12 (y12) were used as materials and compared with indica hybrid rice, Zheyou12 (z12); japonica hybrid rice, Liangyoupeijiu (LYPJ); and the conventional lines zhe04B (04B) and zhehui818 (h818) under seedling growth vigor, functional leaf morphology, chlorophyll content, yield component, panicle trait, and InDel heterosis analysis. Z18 and y12 showed the largest increase in plant height 6 d and 9 d after germination; the root dry weight of z18 was 31.2% and 42.0% higher than its parents on the 12th d. The length of functional leaves ranked in the middle, while the width was the largest, resulting in z18 and y12 having the largest leaf area. Yield components showed that z18 and y12 had the highest number of primary branches, spikelets, and grains, and grain yield, which was 58.1 g in z18, increased by 29.8% and 8.7%, respectively, in comparison with h818 and LYPJ. The InDel genetic distance was significantly positively correlated with single spike weight, with r reaching 0.771, making it the only consistent and most correlated among the seven traits. Therefore, we speculated that as the InDel genetic distance expands, heterosis mainly manifests in the increase in single spike weight. This study comprehensively explored the physiological mechanism of yield improvement in indica–japonica-hybrid rice and used InDel genetic distances to study the genetic basis of heterosis, which will be helpful for future rice yield improvement.

Does local soil factor drive functional leaf trait variation? A test on Neilingding Island, South China.

Leaf traits were affected by soil factors and displayed varietal differences in forest. However, few examples have been reported on the Island ecosystems. We comprehensively investigated 9 leaf traits (leaf length, leaf width, leaf area, SLA, leaf fresh weight, leaf C content, leaf N content, leaf K content, leaf C:N ratio) of 54 main subtropical woody species and soil parameters (soil pH, total C content, total N content, total K content, available N content, available P content, available K content and soil moisture) in Neilingding Island, Shenzhen, southern China. Intra-and interspecific variation of leaf traits were measured and their correlations with soil parameters were explored. The interspecific variations of leaf C:N ratio, leaf N content and leaf fresh weight were higher than their intraspecific variations. The intraspecific variation of leaf K content was larger than that of interspecific one, accounting for 80.69% of the total variance. Positive correlations were found among intraspecific coefficients of variations in leaf morphological traits. The correlation analysis between the variation of intraspecific traits and the variation of soil parameters showed that changes in soil factors affected leaf morphology and stoichiometry. The interaction between soil moisture and soil available P content was the key factor on intraspecific variations of leaf traits including leaf area, leaf fresh weight, leaf C and leaf K content. We concluded that leaf traits of plants in the island were tightly related to soil parameters. Soil parameters, especially soil moisture and available P content, affected plant leaf morphology and stoichiometry at the local scale.