Leaf Base Research Articles

Effect of Different Intensities of Leaf Removal on Tomato Development and Yield

Defoliation (leaf removal or pruning) is a common practice in tomato production that makes crops more manageable, prevents conditions conducive to fungal attack and increases the exposure of the fruit to light, especially in winter conditions. The intensity and frequency of leaf removal on commercial farms often vary according to workforce availability criteria, which makes it difficult to determine their effect on tomato crop yields. It would be reasonable to think that a reduction in leaf area influences radiation interception and, therefore, the production of assimilates and biomass. However, in intensive production systems with a high leaf area index (LAI), leaf pruning can increase radiation interception, either by reducing competition between productive and vegetative organs or by increasing radiation use efficiency. This study was therefore designed to assess the effect of different intensities and frequencies of basal leaf removal on dry matter production and partitioning between the different organs of the plant, and thus on tomato crop productivity. A series of trials were conducted over three consecutive seasons, with a trial conducted per season: (a) Trial 1: leaf removal control—LRC (with leaves removed from the base to two leaves below the truss close to harvest, T0) was compared with LR1 (leaf removal from the base to two leaves below the truss above T0, i.e., T1) and LR2 (two trusses above T0 (T2)); (b) Trial 2: LRC compared with LR2 and LR4 (four trusses above T0 (T4)), carried out at two frequencies; and (c) Trial 3: LRC compared with an intense leaf removal treatment (LRI) whereby between 10 and 12 leaves were left on each stem. LAI saturation values under our conditions were found to be around 2.0. No significant differences in yield were found between the control and treatments LR1, LR2 and LR4, with a reduction in the number of leaves of up to 35% and LAI values during harvest above 2.0. The intense leaf removal treatment (LRI), which reduced the number of leaves by 47% and the LAI value from 2.8 to 1.5 compared to the control, resulted in a 15% reduction in dry biomass and a 17% decrease in fruit yield.

An integrative taxonomic revision of the Chaerophyllum hirsutum complex (Apiaceae) using morphological and molecular markers

Background and aims – Chaerophyllum hirsutum represents a complex of taxa with varying treatments and ranks across floras. Using both morphometric and molecular markers, we assessed the robustness of C. hirsutum, C. elegans, C. villarsii, and C. villarsii var. cicutariiforme. Material and methods – Ten morphometric variables and two ratios were calculated. Based on the sequencing of six plastomes, the rps16 intron was selected as the more variable region and sequenced on a broader sampling. Additionally, we also sequenced the nrDNA internal transcribed spacer 2 (ITS2) using Illumina technology to obtain intra-individual allelic diversity. Key results – Morphologically, the most easily differentiated taxon was C. elegans, especially using the number of subterminal umbels. The distinction between C. hirsutum and C. villarsii was rather clinal, but is mainly based on the degree of carpophore division. Finally, C. villarsii var. cicutariiforme was less easily distinguishable from the three others, but partly using the carpophore length and the total length of basal leaf blade. The cpDNArps16 clearly distinguished C. elegans from the three other taxa of the complex, which rather showed a geographical pattern of cpDNA diversity. The nrDNA ITS2 partially distinguished C. villarsii from the other taxa, without distinction of C. elegans. Conclusions – The present study supports the species differentiation of C. elegans based on both morphology and chloroplast genome. Furthermore, C. villarsii var. villarsii and C. villarsii var. cicutariiforme could potentially be recognized as distinct varieties within C. hirsutum. This will need to be confirmed by future studies using a larger sampling size and more comprehensive markers, covering a broader portion of the nuclear genome.

Drepananthus khaosoi sp. nov. (Annonaceae) from southern Thailand, with molecular phylogenetic reconstructions

Drepananthus khaosoi sp. nov., a new species from southern Thailand is described and illustrated. It is morphologically most similar to D. ridleyi, especially in the very narrow and elongated petals, but differs in leaf blade size, leaf base, monocarp shape and appearance, monocarp width, length of monocarp stipe, pericarp thickness and seed arrangement. Molecular phylogenetic analyses using chloroplast DNA regions (matK and rbcL exons; trnL intron; atpB-rbcL, psbA-trnH and trnL-trnF intergenic spacers) and including 18 Drepananthus species confirm the monophyly of Drepananthus, but the relationships within the genus are largely unresolved, including a failure to elucidate a sister group of D. khaosoi. The conservation status of the new species is provisionally assessed as Critically Endangered.

Salvia tainingensis, a neglected new species of Lamiaceae from Fujian Province, China

A species could not be known to the world of science if it not be discovered and described, considerable number of new species are neglected due to the plant itself and some other external restricted factors. On the basis of morphological and molecular evidences, a new species previously identified as Salvia scapiformis is now described and illustrated as Salvia tainingensis, named after Taining County in Fujian Province, where it was discovered. S. tainingensis does not closely resemble S. scapiformis, but is more similar to Salvia glabrifolia and Salvia daiguii, which were once identified as S. scapiformis, in terms of leaf shape, apex, base, corolla color, and connective length. However, it can be easily distinguished from the latter two by its thinly leathery leaves, serrate leaf margins, densely villous or glabrescent leaf abaxial, and the X-shaped arrangement of connective and filament.

Three new species of Boesenbergia (Zingiberaceae) from Sabah, Malaysia.

Three new species of Boesenbergia, B.bosuangii sp. nov., B.ganaensis sp. nov. and B.gokusingii sp. nov. were discovered in Sabah, Malaysia. Boesenbergiabosuangii is similar to B.stenophylla R.M.Sm. in the narrowly ovate lamina but differs in the shape of the bract and the calyx. Boesenbergiaganaensis is closely allied to B.burttiana R.M.Sm. but differs in the absence of a ligule, the longer petiole, the obtuse leaf base, the acute leaf apex, the bilobed calyx and the anther dehiscing by pores. Finally, B.gokusingii is similar to B.variegata R.M.Sm., by the single leafy shoot but differs in having an unequal, ovate lamina, a cordate leaf base, an acute leaf apex and the anther dehiscing by pores. The three new species are described and illustrated in detail. With the addition of these new species, there are in total 13 species with one variety in Sabah.

The complete chloroplast genome of Calyptothecium philippinense Broth. (Pterobryaceae, Hypnales)

The genus Calyptothecium, currently comprising ca. 30 species worldwide, is the largest genus within the family Pterobryaceae. However, a comprehensive taxonomic revision of this genus is lacking. Calyptothecium philippinense Broth. 1899, a moss species widely found in the tropical regions of Asia, is characterized by the unique rugose leaves and large auriculate leaf bases. In this study, we sequenced the complete chloroplast genome (CPG) of C. philippinense using the Illumina NovaSeq 6000 platform. The length of the CPG of C. philippinense was determined to be 124,513 bp, with an AT content of 74%. The CPG of C. philippinense exhibited a standard quadripartite structure, consisting of one small single-copy (SSC) region (18,541 bp), one large single-copy region (LSC) (87,222 bp), and two inverted repeat (IR) regions (9375 bp each). A total of 126 genes from the CPG of C. philippinense were annotated, including 82 protein-coding genes, eight ribosomal RNA genes, and 36 transfer RNA genes. Phylogenetic analysis based on the CPGs of 25 bryophyte taxa revealed that the three Pterobryaceae species C. philippinense, Calyptothecium hookeri (Mitt.) Broth. and Pterobryopsis orientalis (Müll. Hal.) M. Fleisch. formed a robust clade. The findings could facilitate more accurate classification and help elucidate evolutionary relationships within Calyptothecium.

The Carboniferous Gondwanan lycophyte Bumbudendron, revisited

The type material of Bumbudendron is reviewed in the light of current knowledge about fossil lycophytes. The bark is characterized having cushions with an infrafoliar bladder and a ligule. The variation in leaf bases and leaf scars and their presence may not only depend on the plant’s age or position on the stem, but also the plant’s preservation. The diagnosis of the genus is emended to include the presence of a ligule and a ligule pit in sterile and fertile leaves, the presence or absence of a preserved leaf scar, and variations in size and shape of the cushions resulting from preservation. Bumbudendron nitidum is here regarded as a synonym of B. millanii, the latter name having priority. In this concept, genus Bumbudendron comprises five species: B. paganzianum and B. millanii (Carboniferous of Argentina and Brazil), B. versiforme (Carboniferous and Lower Permian of Argentina and Uruguay), B. patagonicum (Permian of Argentina), and B. peruvianum (Lower Carboniferous of Peru). A review of the species of lycophytes from India, Niger, Ghana, and Egypt is suggested to determine whether they are assignable to Bumbudendron, and thus to define the geographic range of this genus.

Integrating genetic analysis of germplasm wealth for enhanced selection and improvement in olive (Olea europaea L.): insights from leaves.

High-throughput next-generation sequencing of 161 olive germplas. 33 samples were selected as core olive germplasm and Fingerprints were constructed. After GWAS analysis of olive leaf shape, 14 candidate genes were localized. Olive (Olea europaea L.) has been introduced to China since the 1960s. After a prolonged period of variation and domestication, there is a lack of comprehensive research on its genetics. The olive oil directly extracted from Olea europaea L. is recognized as 'liquid gold', nevertheless, people constantly overlook the valuable wealth of olive leaves. High-throughput next-generation sequencing was performed on 161 olive germplasm to analyze the kinship, genetic structure and diversity of olives, and the core germplasm of olives were selected and fingerprints were constructed. Meanwhile, Genome-wide association analysis (GWAS) was performed to locate the gene for regulating olive leaf shape. Herein, the results parsed that most of the Chinese olive germplasm was more closely related to the Italian germplasm. A wealth of hybridized germplasm possessed high genetic diversity and had the potential to be used as superior parental material for olive germplasm. A total of 33 samples were selected and characterized as core germplasm of olive and Fingerprints were also constructed. A total of 14 candidate genes were localized after GWAS analysis of four olive leaf shape phenotypes, including leaf shape, leaf curvature shape, leaf tip and leaf base shape. Collectively, this study revealed the genetic basis of olives in China and also succeeded in constructing the core germplasm that stands for the genetic diversity of olives, which can contributeto the scientific and effective collection and preservation of olive germplasm resources, and provide a scientific basis for the in-depth excavation and utilization of genes regulating olive leaf shape.

Helichrysum emodi (Gnaphalieae: Asteraceae), a new species from the Indian Himalaya

Helichrysum emodi (Gnaphalieae: Asteraceae) is described as new to science from Madhmaheshwar valley of Uttarakhand, India. Morphologically it resembles H. cutchicum and H. kashgaricum, but differs from these two species in having broad, sub-cordate to semi-amplexicaule leaf base with obtuse apex, shape of phyllaries, and absence of female florets, respectively. A detailed morphological description and illustration of H. emodi, together with pollen and habitat photographs and a key to the species of Helichrysum occurring in India are provided for the species identification.

Photosynthetic Performance and Heterogeneous Anatomical Structure in Prunus humilis under Saline–Alkaline Stress

Prunus (P.) humilis is a small woody shrub that has been widely planted in northern China due to its high nutritional value and resistance to environmental abiotic stress. However, little information about the responses of photosynthetic performance and the anatomical structure of P. humilis to saline–alkaline stress (SAS) under field conditions is available. Here, we investigated the behavior of the photosynthetic apparatus of P. humilis by measuring the chlorophyll fluorescence parameters under moderate (MS) and severe (SS) saline–alkaline stress and analyzing their relationship to leaf anatomical traits. The results showed that SAS significantly decreased the net photosynthetic rate (An) but increased the substomatal CO2 concentration (Ci). The maximum photochemical quantum yield of PSII (Fv/Fm) and the efficient quantum yield of PSII [Y(II)] decreased under MS and SS conditions, and this decrease was greater in the distal (tip) than in the proximal (base) leaf. Compared to the leaf tip, the base of P. humilis leaves seemed to have a stronger ability to cope with MS, as was made evident by the increased quantum yield of regulated energy dissipation in PSII [Y(NPQ)] and decreased excitation pressure (1-qP). Under MS and SS conditions, the shapes of the chlorophyll a fluorescence transient (OJIP) changed markedly, accompanied by decreased PSII acceptor-side and donor-side activities. The palisade–spongy tissue ratio (PT/ST) increased significantly with increasing stress and showed a significant correlation with the chlorophyll fluorescence parameters in the leaf base. These results suggested that the activity of PSII electron transfer in the upper leaf position tended to be more sensitive to saline–alkaline stress, and a chlorophyll fluorescence analysis proved to be a good technique to monitor impacts of saline–alkaline stress on photosynthetic function, which may reflect the non-uniformity of leaf anatomy. In addition, among the anatomical structure parameters, the palisade–spongy tissue ratio (PT/ST) can be used as a sensitive indicator to reflect the non-uniform of photosynthetic function and leaf anatomy under stress.

A developmental gradient reveals biosynthetic pathways to eukaryotic toxins in monocot geophytes

Numerous eukaryotic toxins that accumulate in geophytic plants are valuable in the clinic, yet their biosynthetic pathways have remained elusive. A notable example is the >150 Amaryllidaceae alkaloids (AmAs), including galantamine, an FDA-approved treatment for Alzheimer's disease. We show that while AmAs accumulate to high levels in many daffodil tissues, biosynthesis is localized to nascent, growing tissue at the leaf base. A similar trend is found in the production of steroidal alkaloids (e.g., cyclopamine) in corn lily. This model of active biosynthesis enabled the elucidation of a complete set of biosynthetic genes that can be used to produce AmAs. Taken together, our work sheds light on the developmental and enzymatic logic of diverse alkaloid biosynthesis in daffodils. More broadly, it suggests a paradigm for biosynthesis regulation in monocot geophytes, where plants are protected from herbivory through active charging of newly formed cells with eukaryotic toxins that persist as above-ground tissue develops.

Stable Air Retention under Water on Artificial Salvinia Surfaces Enabled by the Air Spring Effect: The Importance of Geometrical and Surface‐Energy Barriers, and of the Air Spring Height

AbstractSuperhydrophobic surfaces that can remain dry under water have a high potential as nontoxic antifouling coatings or for drag‐reducing ship coatings. The Salvinia effect leads to impressive stable air layers on underwater submerged floating plants Salvinia, decisively determined by the hydrophilic tips of the otherwise hydrophobic Salvinia hairs (Salvinia paradox). The water adheres to these hydrophilic tips, stabilizing the water–air interface. An even more important contribution to the stability of the air layer is provided by the air spring, which is formed by the air volume bound by the hydrophilic leaf edge and the leaf base. Using an artificial Salvinia model with hydrophobic pillars (syn‐trichomes), how the stability against pressure changes in water depends on the height of the artificial hair is systematically shown: a reduction of the air spring height from 3 mm to 300 µm increases the stability against negative pressure by 500% from 72 to 380 mbar. Thicker air layers react much more strongly when subjected to overpressure (1000 mbar). It is also shown that the presence of a boundary is essential for the function of the air spring: removing the limiting hydrophilic edge around the hydrophobic air spring reduces the stability against negative pressure by 300%.

Phenotypic plasticity of water-related traits reveals boundaries to the adaptive capacity of a dominant European grass species under increased drought

The intensification of droughts due to climate change is a global concern, and many plant species face increasing water deficits. Understanding the role of phenotypic plasticity in plant adaptation to these changing conditions is crucial. This research focuses on Bromopsis erecta, a dominant perennial grass in European and Mediterranean grasslands, to predict its potential adaptation to climate change. We assessed plants from shallow and deep soils (i.e., with contrasting water reserves) of a Mediterranean rangeland in southern France, and tested the effect of six years of experimentally increased summer drought compared to the ambient conditions on plant traits, survival and abundance. In both field and common garden experiments, we measured water-related traits, including static traits under non-limiting water conditions, and dynamic traits, such as rates of trait variation during drought. Trait plasticity was determined as a reaction norm to increasing soil water stress and was tested against changes in B. erecta abundance over the past decade, including the study period. Trait plasticity was detected only for leaf dry matter content (LDMC), revealing that the resource strategy of B. erecta became more conservative over less than a decade with higher LDMC and leaf thickness according to the plant economic spectrum. No plasticity was found for osmotic potential or specific leaf area. The variability of other traits was ascribed to the possible lagging effect of previous water stress and was associated more with soil depth than with previous summer drought intensity. The abundance decline of B. erecta, which dropped from 20 % to around 5 % in shallow soils, was not associated with the plasticity of LDMC but was positively correlated with variations in leaf base membrane damage, meaning unexpectedly, that plants exposed to the most severe summer drought also had the most sensitive leaf base membranes, a possible sign of maladaptive trait plasticity in the population. This key trait response reveals boundaries to the adaptive capacity of this perennial grass to survive pluri-annual drought.

Phosphorus deficiency promotes root:shoot ratio and carbon accumulation via modulating sucrose utilization in maize

Phosphorus deficiency usually promotes root:shoot ratio and sugar accumulation. However, how the allocation and utilization of carbon assimilates are regulated by phosphorus deficiency remains unclear. To understand how phosphorus deficiency affects the allocation and utilization of carbon assimilates, we systematically investigated the fixation and utilization of carbon, along with its diurnal and spatial patterns, in hydroponically grown maize seedlings under low phosphorus treatment. Under low phosphorus, sucrolytic activity was slightly inhibited by 12.0% in the root but dramatically inhibited by 38.8% in the shoot, corresponding to the promoted hexose/sucrose ratio and biomass in the root. Results point to a stable utilization of sucrose in the root facilitating competition for more assimilates, while increasing root:shoot ratio. Moreover, starch and sucrose accumulated in the leaves under low phosphorus. Spatially, starch and sucrose were oppositely distributed, starch mainly in the leaf tip, and sucrose mainly in the leaf base and sheath. Evidence of sucrose getting stuck in leaf base and sheath suggests that carbon accumulation is not attributed to carbon assimilation or export disturbance, but may be due to poor carbon utilization in the sinks. These findings improve the understanding of how low phosphorus regulates carbon allocation between shoot and root for acclimation to stress, and highlight the importance of improving carbon utilization in sinks to deal with phosphorus deficiency.

Pharmacognostic, physicochemical and phytochemical profiles of Euclea divinorum (Ebenaceae)

Background: Euclea divinorum, belonging to the family Ebeneceae, has extensive traditional medicinal use in Africa. However, it lacks sufficient published data on its pharmacognostic, physicochemical, and phytochemical properties. Aims and Objectives: Thus, this study aimed at comprehensively evaluating the pharmacognostic, physicochemical, and phytochemical properties of E. divinorum using established techniques. Materials and Methods: The evaluation included assessing organoleptic properties, macroscopy, and microscopy of leaves, stems, and roots. Various physicochemical parameters, such as loss on drying and extractive values via hot and cold maceration, were determined. Phytochemical screening was also conducted on root aqueous extracts. Results and Conclusion: Results revealed specific characteristics of E. divinorum leaves, including light green coloration, distinct odor, and bitterness. Macroscopic examination highlighted opposite phyllotaxy, simple leaf types with lamina length range of 71.09 - 93.89 mm and a width range of 6.05 - 17.59 mm, obtuse leaf apexes, cuneate leaf bases, entire leaf margins, and smooth leaf surfaces. Venation displayed a reticulate pattern, with the midrib prominently visible on the lower surface. Microscopic analysis of the lower leaf epidermis showed an average of stomatal density of 3.75±0.67, epidermal density of 35.75±2.16 and stomatal index of 10.47±1.11. Microscopic examination of the leaf lamina across the midrib revealed cortical parenchymal cells containing calcium oxalate crystals, lignified xylem, and non-lignified phloem. Stem cross-sections displayed single-layered cells comprising the epidermis, secondary phloem, secondary xylem, and pith. Similar structures were observed in root cross-sections. The plant's moisture content was found to be 44.8±1.962%, with water and alcohol-soluble extractive values of 7.27±0.17 and 1.13±0.05 g/100g, respectively, through cold maceration, and 14.77±0.28 and 11.43±0.39 g/100g, respectively through hot maceration. The total ash content was measured at 3.03± 0.103%. Phytochemical screening detected various compounds, with anthraquinone glycosides, coumarine glycosides, saponin glycosides, flavonoids, proteins, and tannins being abundant. Alkaloids, cardiac glycosides, and steroids were absent. This research contributes to standardizing E. divinorum, aiding in its identification, preventing adulteration, and ensuring therapeutic efficacy.

Tank formation transforms nitrogen metabolism of an epiphytic bromeliad and its phyllosphere bacteria.

Up to half of tropical forest plant species grow on other plants. Lacking access to soils, vascular epiphytes have unique adaptations for mineral nutrition. Among the most distinctive is the tank growth form of certain large bromeliads, which absorb nutrients that are cycled by complex microbial communities in water trapped among their overlapping leaf bases. However, tanks form only after years of growth by juvenile plants, which must acquire nutrients differently. Understanding how nutrient dynamics change during tank bromeliad development can provide key insights into the role of microorganisms in the maintenance of tropical forest biodiversity. We evaluated variations in plant morphology, growth, foliar nitrogen physiology, and phyllosphere bacterial communities along a size gradient spanning the transition to tank formation in the threatened species Tillandsia utriculata. Sequential morphological and growth phases coincided with the transition to tank formation when the longest leaf on plants was between 14 and 19 cm. Before this point, foliar ammonium concentrations were very high, but after, leaf segments absorbed significantly more nitrate. Leaf-surface bacterial communities tracked ontogenetic changes in plant morphology and nitrogen metabolism, with less-diverse communities in tankless plants distinguished by a high proportion of taxa implicated in ureolysis, nitrogen fixation, and methanotrophy, whereas nitrate reduction characterized communities on individuals that could form a tank. Coupled changes in plant morphology, physiology, and microbiome function facilitate the transition between alternative nutritional modes in tank bromeliads. Comparing bromeliads across life stages and habitats may illuminate how nitrogen-use varies across scales.

Morphological variation within Solanum campylacanthum (Solanaceae) in Uganda and its relationship with S. cerasiferum

This is a morphological study of 108 accessions of Solanum campylacanthum and 10 accessions of Solanum cerasiferum. The aim was to assess the morphological variations that occur within the S. campylacanthum species in Uganda and evaluate the morphological differences between S. campylacanthum and S. cerasiferum. Fourteen quantitative and eleven qualitative vegetative characters were measured and analysis done by phenetics method. Cluster (UPGMA) and box plot analyses were done in PAST program version 4.03. Prickle density and leaf tip angles are reported for the first time as being useful in the intraspecific delimitation of S. campylacanthum. The distinction between S. cerasiferum and S. campylacanthum can only be based on leaf base shapes, which is, attenuate and oblique respectively.

Evaluation of the Impact of Chemical Mutagens on the Phenological and Biochemical Characteristics of Two Varieties of Soybean (Glycine max L.).

Mutagenic effectiveness and efficiency are the most important factors determining the success of mutation breeding, a coherent tool for quickly enhancing diversity in crops. This study was carried out at Lovely Professional University's agricultural research farm in Punjab, India, during the year 2023. The experimental design followed a randomized complete block design (RCBD) with three replications. The experiment aimed to assess the effect of three chemical mutagens, sodium azide (SA), ethyl methyl sulphonates (EMSs), and methyl methane sulfonate (MMS), at three different concentrations (0.2%, 0.4%, and 0.6%), in SL958 and SL744 soybean varieties to select the mutant exhibiting the highest yield. The data were collected and analysed using a two-way ANOVA test through SPSS software (version 22), and the means were separated using Duncan's multiple range test (DMRT) at the 5% level of significance. Between the two varieties, the highest seed germination percentage (76.0% seedlings/plot) was recorded in SL958 (0.4% SA), while the lowest (30.33% seedlings/plot) was observed in 0.6% MMS as compared to the control (53% and 76% in SL744 and SL958 at 10 days after sowing, respectively). Several weeks after sowing, the average plant height was observed to be higher (37.84 ± 1.32 cm) in SL958 (0.4% SA) and lower (20.58 ± 0.30 cm) in SL744 (0.6% SA), as compared to the controls (SL958: 26.09 ± 0.62 cm and SL744: 27.48 ± 0.74 cm). The average leaf count was the highest (234.33 ± 3.09 tetrafoliate leaves/plant) in SL958 (0.4% SA) while it was the lowest (87 leaves/plant) in 0.6% MMS as compared to the control (SL744 180.00 ± 1.63 and SL958 160.73 ± 1.05). The highest total leaf areas recorded in the SL958 and SL744 M1plants were 3625.8 ± 1.43 cm2 and 2311.03 ± 3.65 cm2, respectively. Seeds of the SL958 variety treated with 0.4% SA resulted in the development of tetrafoliate leaves with a broad leaf base and the maximum yield (277.55 ± 1.37 pods/plant) compared to the narrow pentafoliate leaves obtained through the treatment with EMS. Meanwhile, in the SL744 variety, the same treatment led to tetrafoliate leaves with a comparatively lower yield of 206.54 ± 23.47 pods/plant as compared to the control (SL744 164.33 ± 8.58 and SL958 229.86 ± 0.96). The highest protein content (47.04 ± 0.87% TSP) was recorded in the SL958 (0.4% SA) M2 seeds followed by a content of 46.14 ± 0.64% TSP in the SL744 (0.4% SA) M2 seeds, whereas the lowest content (38.13 ± 0.81% TSP) was found in SL958 (0.6% MMS). Similar observations were recorded for the lipid and fibre content. The 0.4% SA treatment in SL958 proved to be efficient in generating the highest leaf area (tetrafoliate leaves) and a reasonable yield of M1 (the first generation after mutation) plants.

Inheritance pattern of Qualitative traits, Genetic analysis and association of yield attributes in F2 populations of Rice (Oryza sativa)

Understanding the extent of genetic variability within the segregating generations is crucial for identifying superior segregants with high yield and better market acceptability. Thus, the present study was carried out to quantify the extent of genetic variation available in the segregating population of rice. Three crosses, viz., CO 55 × IC 457996, CO 55 × IC 464685, and CO 55 × IC 115439 were evaluated using a non-randomized experimental design for six yield attributing and two physical grain quality traits in F2 generation. The inheritance pattern of basal leaf sheath colour and grain colour in CO 55 × IC 115439 indicate digenic complementary gene interaction (9:7), whereas grain colour in CO 55 × IC 464685 exhibits inhibitory gene action (13:3). The positively skewed nature of productive tillers per plant and single-plant yield in the F2 segregants emphasizes the need for intensive selection to facilitate rapid improvement due to the influence of complementary gene action. Moderate to high GCV with high heritability and GAM for traits such as plant height, productive tillers per plant, hundred seed weight, grain width, and single-plant yield in the F2 segregants underscore the prevalence of additive gene action and thus provide the most effective condition for simple phenotypic selection. Moreover, productive tillers per plant and single-plant yield showed a strong positive association in all the crosses. Therefore, productive tillers per plant can be considered an indicator trait when selecting high-yielding segregants for grain yield improvement.

New discoveries for the genus Miconia (Melastomataceae): a new species for the brazilian Atlantic Forest

We describe Miconia leonorae, a new species exclusive to eastern Brazil, mainly from the evergreen forests of the Atlantic Forest Domain. This species can be distinguished from a wider circumscription of Miconia lepidota. It is classified as Miconia supersect. Discolores sect. Multispicatae and can be distinguished from similar species by features such as an acute leaf base and apex, light brown to gray abaxial leaf blade indumentum with lepidote-stellate trichomes (becoming glabrescent on mature leaves), cylindrical, scorpioid inflorescences with basal branches only bifid or trifid, and an androecium with isomorphic stamens.