Acuminata Var Research Articles

The Combined Effect of Lemon Peel Extract and Calcium Chloride on the Physical and Biochemical Quality Parameters of the Dessert Banana (Musa acuminata var. Dwarf Cavendish) Fruit

The dessert banana is a popular fruit worldwide, but its ripening process is greatly accelerated by high temperatures, which eventually leads to an unpleasant taste and the appearance of spots on the skin of the fruits. To slow down the ripening of bananas, expensive strategies are used, which are usually not practical for conventional farmers in less developed countries. In this study, we try to find a less costly alternative. Therefore, the effects of coatings of lemon peel extract (2.5%, 5%, and 10%), calcium chloride (4%), and glycerol (2%) on the shelf life and postharvest quality of the banana fruit (Cavendish) stored at 19–22 °C and 40–60% relative humidity were investigated. Treatment with a mixture of 2.5% lemon peel extract and 2% glycerol resulted in an extension of the shelf life of the dessert banana by up to 6 days and no detectable fungal infestation. The coating solution is an effective alternative to extend the shelf life and reduce quality losses in bananas.

LCYB GENE EXPRESSION AND MORPHOPHYSIOLOGICAL TRAITS OF MUSA ACUMINATA CULTIVARS

Banana (Musa acuminata) is a tropical fruit plant vigorously growing in Southeast Asia, particularly Indonesia. Despite its prevalence in different Musa acuminata cultivars, the LCYB gene expression and morphological and physiological traits remain unexplored. Therefore, the presented study sought to examine the manifestation of the LCYB gene and analyze various morphophysiological features. The promising research focused on probing the five cultivars of banana, specifically M. acuminata var. breviformis, M. acuminata var. tomentosa, M. acuminata var. malaccensis (Ridl.), M. acuminata var. microcarpa (Becc.), and M. acuminata var. rutilifers. The morphological observations revealed these cultivars have no prominent distinctions in stem size, fruit characteristics, banana blossom, and leaf traits. Remarkably, cultivar Rutilifers showed the highest carotenoid and total chlorophyll content levels. Inversely, the banana cultivars Breviformis and Microcarpa exhibited comparatively lower contents of physiological parameters than the other cultivars. Likewise, by analyzing the LCYB gene expression, it was evident that the cultivar Tomentosa displayed the superior level, followed by the cultivar Malaccensis. Conversely, the cultivar Microcarpa exhibited the lowest LCYB gene expression. To summarize the results, the applicable study enunciated a significant relationship between the LCYB gene expression and the chlorophyll and carotenoid contents across the various banana cultivars.

20th-Century hurricanes leave long-lasting legacies on tropical forest height and the abundance of a dominant wind-resistant palm.

Projected increases in hurricane intensity under a warming climate will have profound effects on many forest ecosystems. One key challenge is to disentangle the effects of wind damage from the myriad factors that influence forest structure and species distributions over large spatial scales. Here, we employ a novel machine learning framework with high-resolution aerial photos, and LiDAR collected over 115 km2 of El Yunque National Forest in Puerto Rico to examine the effects of topographic exposure to two hurricanes, Hugo (1989) and Georges (1998), and several landscape-scale environmental factors on the current forest height and abundance of a dominant, wind-resistant species, the palm Prestoea acuminata var. montana. Model predictions show that the average density of the palm was 32% greater while the canopy height was 20% shorter in forests exposed to the two storms relative to unexposed areas. Our results demonstrate that hurricanes have lasting effects on forest canopy height and composition, suggesting the expected increase in hurricane severity with a warming climate will alter coastal forests in the North Atlantic.

First report of Fusarium kalimantanense causing Fusarium wilt on banana tree in Brazil.

Banana (Musa spp.) is the second most-consumed fruit in Brazil, the fourth-largest producer globally, with 7 million tons in 2021 (IBGE 2021). Studies about the morphological and pathogenic characteristics revealed that the etiology of Fusarium wilt in banana cultivars in Brazil had been related to the Fusarium oxysporum f. sp. cubense (Foc) (E.F. Smith) Snyder and Hansen species (Costa et al. 2015; Cordeiro et al. 2016; Araújo et al. 2017). Phylogenetic studies have shown the existence of distinct genetic lineages for Foc, which has come to be called the Fusarium oxysporum Species Complex (FOSC) (O'Donnell et al. 1998; Maryani et al. 2019). Symptoms of Fusarium wilt were observed in banana trees at the headquarters of Embrapa Roraima (02°45'26.89"N and 60°43'52.78"W), Roraima-Brazil, in 2016. Samples were collected and sterilized with 70% ethanol for 30 s, followed by 3% NaClO for 1 min, rinsed three times in sterile distilled water, seeded on potato dextrose agar (PDA), and incubated at 25 °C for three days. Two isolates obtained from a pure culture (LPPC130) were submitted to the morphological characterization by Leslie and Summerell (2006) protocol. The fungal colony showed vinaceous color, progressing to livid red (Rayner 1970), with a mean diameter of 41 mm (± 0.1) at three days of incubation in a PDA culture medium. The fungus produced abundant macroconidia in spezieller nährstoffarmer agar (SNA) culture medium containing clove leaf (CLA) after 14 days of incubation at 25 °C. The sporodochium conidia presented a falcate shape, moderately curved, with 3 to 5 septa and dimensions ranging from 38.8 (48.0) 56.2 x 3.5 (4.4) 6.0 µm (n=50). The conidia of the aerial mycelium presented ovoid to ellipsoid shape, slightly curved, aseptic, measuring 6.0 (12.0) 18.0 x 2.8 (3.3) 5.0 µm (n=50). The genomic DNA of the isolate was extracted (Murray and Thompson 1980), and fragments of the elongation factor 1-α (TEF1) and RNA Polymerase II (RPB2) gene regions were amplified and sequenced in both directions (O'Donnell et al. 1998; O'Donnell et al. 2010) (GenBank accession numbers: Seq1 OL802918 and Seq2 OL802919). Multiple alignments of the combined dataset of the isolates and representative sequences obtained from GenBank were submitted to phylogenetic analysis with 1,000 bootstrap replicates. The micromorphological characteristics together to phylogenetic inference on the TEF1 and RPB2 genes, allowed a robust analysis, generating 42 more parsimonious trees and making it possible to identify the LPPC130 isolate as Fusarium kalimantanense, a species belonging to the F. oxysporum species complex (FOSC), with 100% bootstrap support (Maryani et al. 2019). The pathogenicity of the isolate was evaluated in five micropropagated seedlings of banana cv. Silk 75 days old, grown in pots with 5 kg of sterile formulation of sand and soil, in 1:1. Seedlings were inoculated by wounding the roots and depositing a suspension of conidia and chlamydospores at 105 spores mL-1. The inoculating of the isolate in 35 micropropagated seedlings of banana was based on Koch's postulates. The seedlings were transplanted into plastic bags (2 kg of sterile formulation: sandy soil and substrate, in 2:1) and inoculated with 10 mL of the chlamydospore suspension (107 CFU mL-1) at transplanting, and after 30 days of transplanting. Seedlings treated only with water were used as control. Evaluation of the symptoms of the disease was carried out 90 days after inoculation, and revealed that the isolate (LPPC130) was pathogenic by inducing the same symptoms of Fusarium wilt. F. kalimantanense was first reported associated with the pseudostems of Musa acuminata var. Pisang Ambon, and proved to be non-pathogenic to cv. Gros Michel and the bananas of the Cavendish group (Maryani et al. 2019). In Brazil, this fungus was recently associated with the Fusarium rot on melon fruits (Araújo et al. 2021); however, this is the first report of its pathogenicity in banana trees cv. Silk.

α-Glucosidase inhibitive diarylheptanoids from Ottelia acuminata var. acuminata, a traditional vegetable of Bai Nationality in Yunnan

Diabetes is an urgent health issue characterized by ethnic and regional variations, and is inseparable from the different dietary habits. It is worthy to note that the incidence of diabetes in Bai nationality has been reported to be much lower than Han in China. As a daily vegetable of Bai, the phytochemical and antidiabetic study of Ottelia acuminata var. acuminata had not been carried out. In this study, 41 metabolites with diverse diarylheptanoid (six new ones, Otteacumienes A–F), flavone, sesquiterpenoid, coumarin, lignan, polyacetylene, and alkaloid skeletons were characterized from O. acuminata var. acuminata. Among them, the racemic nature of 3 was characterized by chiral resolution and calculated ECD methods. The biological study revealed diarylheptanoids showed significant α-glucosidase inhibitory activities with 5 as the most effective one (60-fold stronger than acarbose). Molecular docking studies indicated that these structures have different binding cavities with acarbose. This study demonstrated that O. acuminata var. acuminata might correlated with the low incidence diabetes of Bai and the diarylheptanoids may have potential therapeutic value for diabetes mellitus.Graphical

Morphological Characterization and Seed Germination Study of Wild Banana <i>Musa acuminata</i> var. <i>flava</i> (Ridl.) Nasution

Wild bananas provide important genetic materials for further banana improvement, therefore they need to be conserved and studied. This study aimed to describe morphological characteristics of plant and seed and also to study the seed germination of wild banana M. acuminata var. flava (Ridl.) Nasution. The morphological characteristics were observed descriptively by referring to the descriptor for banana. The internal and external morphology of the seeds were observed using a digital microscope. The germination testing was carried out by a completely randomized design, using fresh seeds extracted from a bunch of fruits with two ripeness levels i.e. fully-ripe (yellow peel) and under-ripe (green-yellow peel). The data resulted was then analyzed using an independent t-test. The results showed that M. acuminata var. flava is characterized as a perennial herb; pseudostem height ≥3 m; male bud like a top with prominent green-yellow bracts; fruit curved and tasted mild-sweet when ripe. The seed is angular with wrinkled surface, and dark brown-black color when ripe. The longitudinal section showed parts of the seeds comprising the seed coat, outer and inner integument, embryo, endosperm, chalazal mass, micropyle cap and channel. The seeds are classified as orthodox, with hypogeal type and gradual germination pattern. The seeds extracted from fully-ripe fruit germinated faster with higher germination percentage and growth variables (root number and plant height). Thus, it is suggested to use physiologically mature seeds (seeds from fully-ripe fruits) which should be separated from the seeds of under-ripe fruits to lower the heterogeneity.

Mechanisms of Chitosan Nanoparticles in the Regulation of Cold Stress Resistance in Banana Plants.

Exposure of banana plants, one of the most important tropical and subtropical plants, to low temperatures causes a severe drop in productivity, as they are sensitive to cold and do not have a strong defense system against chilling. Therefore, this study aimed to improve the growth and resistance to cold stress of banana plants using foliar treatments of chitosan nanoparticles (CH-NPs). CH-NPs produced by nanotechnology have been used to enhance tolerance and plant growth under different abiotic stresses, e.g., salinity and drought; however, there is little information available about their effects on banana plants under cold stress. In this study, banana plants were sprayed with four concentrations of CH-NPs—i.e., 0, 100, 200, and 400 mg L−1 of deionized water—and a group that had not been cold stressed or undergone CH-NP treatment was used as control. Banana plants (Musa acuminata var. Baxi) were grown in a growth chamber and exposed to cold stress (5 °C for 72 h). Foliar application of CH-NPs caused significant increases (p < 0.05) in most of the growth parameters and in the nutrient content of the banana plants. Spraying banana plants with CH-NPs (400 mg L−1) increased the fresh and dry weights by 14 and 41%, respectively, compared to the control. A positive correlation was found between the foliar application of CH-NPs, on the one hand, and photosynthesis pigments and antioxidant enzyme activities on the other. Spraying banana plants with CH-NPs decreased malondialdehyde (MDA) and reactive oxygen species (ROS), i.e., hydrogen peroxide (H2O2), hydroxyl radicals (•OH), and superoxide anions (O2•−). CH-NPs (400 mg L−1) decreased MDA, H2O2, •OH, and O2•− by 33, 33, 40, and 48%, respectively, compared to the unsprayed plants. We hypothesize that CH-NPs increase the efficiency of banana plants in the face of cold stress by reducing the accumulation of reactive oxygen species and, in consequence, the degree of oxidative stress. The accumulation of osmoprotectants (soluble carbohydrates, proline, and amino acids) contributed to enhancing the cold stress tolerance in the banana plants. Foliar application of CH-NPs can be used as a sustainable and economically feasible approach to achieving cold stress tolerance.

Glyphochloa acuminata (Hack.) Clayton var. laevis (Poaceae): a new variety from central Western Ghats of Karnataka, India

This communication describes a new variety of Glyphochloa acuminata var. laevis from the lateritic plateau of central Western Ghats of Karnataka, southern India.

Hydropriming Improves Germination and Plant Recovery During Embryo Rescue of Wild Banana Musa acuminata var. tomentosa

Wild bananas are believed to have genes for resistance to biotic and abiotic stress in nature, making them potential genetic resources for creating superior varieties. Wild banana seeds, such as Musa acuminata var. tomentosa are generally difficult to germinate in vivo, so that in vitro embryo culture technique is needed. This study aimed to increase embryo germination and regeneration of wild banana M. acuminata var. tomentosa by soaking the seeds as hydropriming. The treatment comprised of soaking the seeds in sterile distilled water for four periods of time: 0 (control), 1, 4, and 7 days. A total of 45 embryos for each treatment were planted on petri dishes containing MS + 0.5 mg/L BA + 1 mg/L biotin + 1 mg/L proline. The results showed that hydropriming increased the rate of embryo germination and regeneration. Seeds soaked for 1, 4, and 7 days successfully resulted in embryo germination percentages of 87%, 62%, and 62%, respectively, while the control unsoaked seeds germinated with a lower percentage of 42%. One-day soaking treatment was the most optimal treatment to increase the rate of germination and regeneration as well as obtained the best vigor as demonstrated by the highest average height of plantlets, number of leaves, and roots than other treatments. Thus, 1-day seed hydropriming is the best treatment for embryo rescue and regeneration of wild banana M. acuminata var. tomentosa

O gênero Pinnularia Ehrenberg (Bacillariophyceae) em um lago de inundação do rio Tapajós (Lago Verde, Santarém, Pará, Brasil)

This study aimed to carry out a taxonomic inventory of the genus Pinnularia in Verde Lake, a floodplain lake located on the right bank of the Tapajós River, in the Protection Area of Alter do Chão in Santarém. Samplings were carried out monthly using a plankton net (20 μm) at four different stations, including limnetic and littoral zones, from July 2016 to June 2017. A total of 41 taxa, of which 29 species and 12 varieties were described, commented and illustrated with light microscopy and/or scanning electron microscopy micrographs. Pinnularia acuminata var. novazealandica Krammer, P. divergens var. media Krammer, P. graciloides var. rumrichae Krammer, P. parallela var. parallela Brun, P. percuneata var. percuneata Krammer and P. tumescens Metzeltin &amp; Krammer are the first records for the Brazilian Amazon and 21 are documented for the first time for Pará State.

O gênero Pinnularia Ehrenberg (Bacillariophyceae) em um lago de inundação do rio Tapajós (Lago Verde, Santarém, Pará, Brasil)

This study aimed to carry out a taxonomic inventory of the genus Pinnularia in Verde Lake, a floodplain lake located on the right bank of the Tapajós River, in the Protection Area of Alter do Chão in Santarém. Samplings were carried out monthly using a plankton net (20 μm) at four different stations, including limnetic and littoral zones, from July 2016 to June 2017. A total of 41 taxa, of which 29 species and 12 varieties were described, commented and illustrated with light microscopy and/or scanning electron microscopy micrographs. Pinnularia acuminata var. novazealandica Krammer, P. divergens var. media Krammer, P. graciloides var. rumrichae Krammer, P. parallela var. parallela Brun, P. percuneata var. percuneata Krammer and P. tumescens Metzeltin &amp; Krammer are the first records for the Brazilian Amazon and 21 are documented for the first time for Pará State.

Chromosome diversity and karyotype asymmetry analysis in four cultivated triploid and three diploid wild genotypes of Musa from North-East India

Ploidy and karyotype asymmetry of four cultivated Musa acuminata var. Luwaobi, var. Masung Tabi, var. Gopi and var. Poitrish Kola (2n = 3x = 33) and three wild seeded M. acuminata var. Ram Kola, Musa balbisiana var. Blung Thali and Musa laterita (2n = 2x = 22) were reported for the first time from North East India. The predominance of median constricted chromosomes was found as compared to sub-median constricted chromosome in all genotypes. The average chromosome length varied from 1.55 μm in var. Luwaobi to 1.92 μm in var. Ram Kola. Symmetric karyotype was recorded in the wild as compared to the cultivated Musa genotypes. Out of the twelve inter- and intra-chromosomal asymmetry indices studied, intra-chromosomal asymmetry index (A1) versus inter-chromosomal asymmetry index (A2), relative variation in the centromeric index (CVCI) versus relative variation in chromosome length (CVCL) and heterogeneity of chromosome length (AI) versus dispersion index were found most reliable to assess chromosome asymmetry. Most symmetric karyotype was found in var. Poitrish Kola of Tripura and most asymmetric karyotype was found in var. Luwaobi of Manipur among cultivated genotypes. Genotype var. Ram Kola showed more karyotype asymmetry among the wild Musa as compared to var. Blung Thali of Tripura and M. laterita of Sikkim. Phylogenetic tree obtained from chromosome characters revealed that var. Ram Kola has ancestral karyotype and was found to be distantly related from the others. Two wild seeded genotypes M. balbisiana var. Blung Thali and M. laterita were found to have close relationship with AB genome suggesting the phylogenetic ancestry with AA or AAA genotypes.

Haplotype network analysis of wild banana relatives Ensete glaucum, Musa acuminata and Musa balbisiana based on cpDNA rbcL sequences in ex-situ collection

Conservation and genetic assessment of wild banana relatives is important for future breeding purposes. Haplotype network analysis was conducted to wild banana relatives comprised Ensete glaucum, Musa acuminata and Musa balbisianausing rbcL gene sequences. Sequences characterization showed high conservation level (91%), low indels (1.83%), and low parsimony informatives (3.51%). However, it was powerfull to separate the dataset at families, genera and species level; and moderately to separate at intraspecies level of wild bananas. Haplotype and nucleotide diversity of wild bananas were high. At intraspecies level, both M. acuminata and M. balbisiana showed high haplotype diversity but low nucelotide diversity among haplotypes; M. acuminata has higher value than M. balbisiana. No haplotype and nucleotide diversity in E. glaucum. Wild bananas were separated into seven haplotypes, with four haplogroups. Mutational pathway revealed that E. glaucum haplotype became root; and was closely related to M. balbisiana than M. acuminata. M. acuminata var. malaccensis haplotype became root within all M. acuminata varieties, and each haplotype differed by single point mutation.

The complete chloroplast genome of Musa acuminata var. chinensis

Musa acuminata var. chinensis is one of the most important wild banana species native to China which has huge potential breeding value by its cold tolerance and disease resistance. In this study, we first reported the complete chloroplast genome of M. acuminata var. chinensis and explore its phylogenetic position using a maximum likelihood phylogenetic tree. The chloroplast genome of M. acuminata var. chinensis is 170,402 bp in length and the overall GC content of the whole genome is 36.8%. It consisting of a pair of inverted repeat (IR, 35,320 bp) regions, a large single-copy (LSC, 88,870 bp) and a small single-copy (SSC, 10,900 bp). The chloroplast genome contained 112 genes, including 79 protein-coding genes, 29 tRNA genes, and 4 rRNA ribosomal genes. The most genes occur as a single copy, while 23 gene species occur in double copies. Phylogenetic analysis of 7 selected chloroplast genomes revealed that M. acuminata var. chinensis was closely related to M. acuminata ssp. malaccensis. The complete chloroplast genome of M. acuminata var. chinensis will greatly enhance precious gene resources for banana breeding programs in the future.

Effect of Hexanal as a Post-harvest Treatment to Extend the Shelf-life of Banana Fruits (Musa acuminata var. Sweet Banana) in Kenya

The short shelf-life of fruits in the tropics continues to be a pressing problem for farmers and other value chain actors. Hexanal is a naturally occurring compound that has received attention as a novel postharvest compound preservative. This study was conducted to determine the effect of hexanal on enhancing the postharvest shelf-life and quality of ‘sweet banana’ fruits. Two hexanal concentrations (2% and 3%) were applied as either a pre-harvest spray or a post-harvest dip. Fruits were obtained from two different agro ecological zones of Kenya (AEZs II and IV). The treated fruits were kept under ambient room conditions of 25 ± 1°C and RH 60 ± 5% to ripen. Hexanal treatment maintained the fruits quality and prolonged the shelf-life by 6 days in the dipped fruits, 6 and 3 days in the sprayed fruits from the drier AEZ IV and colder AEZ II respectively compared to the untreated controls. Hexanal treatments significantly (P = .05) delayed or reduced the rate of most of the physicochemical parameters analysed irrespective of the concentration and mode of application used. Fruit firmness was significantly (P = .05) maintained up to day 6 and 9 of storage in the treated fruits compared to the controls which softened drastically as from day 3 and 6 in the sprayed and dipped fruits respectively. Hexanal treatment delayed ethylene and respiratory peaks by 3 days in both modes of application and significantly delayed progression of other ripening related changes such as 0Brix, titratable acidity, simple sugars and vitamin C. Sensory evaluation showed no significant differences in the various quality attributes analysed between the hexanal treated and control fruits. The results of this study indicate that, use of hexanal is a potential technology that could be adopted by banana farmers to enhance post-harvest shelf-life without compromising on quality.

- Diversity wild banana species (Musa spp.) in Sulawesi, Indonesia

Abstract. Hastuti, Purnomo, Sumardi I, Daryono BS. 2019. Diversity wild banana species (Musa spp.) in Sulawesi, Indonesia. Biodiversitas 20: 824-832. Indonesia is known as one of the centers of banana diversity in the world. There are 70 species of wild banana in the genus of Musa, 12 of them it was found in Indonesia. Sulawesi was located in the Wallace Line, which is a meeting between the Sunda and Sahul exposures, and has many endemic species, some of which are wild banana species. However, studies on wild banana in Sulawesi are still limited. This study focuses on species of wild bananas found in Sulawesi. Purposive sampling was used to select banana example from wild, cultivated area, residential areas and research garden. Observation was carried out in the field as well as using a collection herbarium and living specimens. The observation was done by observing the characteristics of the sample according to the guidance on Descriptor for Banana. Identification was done by matching the sample with herbarium and relevant references. The results showed that there were four species of wild bananas found on the island of Sulawesi. These are Musa balbisiana Colla, Musa acuminata Colla var. zebrina (v.Houtte) Nasution, Musa acuminata Colla var. banksii (F.Muell.) N.W Simmonds, Musa acuminata Colla var. lutraensis, Musa acuminata Colla var. sigiensis, Musa acuminata Colla ssp. microcarpa Becc., Musa borneensis Becc. and Musa textilis Nee. Four wild banana accessions had never been reported before. These were Musa acuminata var. zebrina, Musa acuminata var. lutraensis, Musa acuminata var. siginenesis and Musa borneensis.

GENETIC VARIATION OF WILD Musa acuminata COLLA FROM INDONESIA

Indonesia is the center of origin and diversity of Musa acuminata Colla, one of the progenitors of cultivated bananas today. However, the genetic variation of wild M. acuminata has not been studied extensively, thus this study aimed to assess the genetic variation of the Indonesian wild M. acuminata based on 10 RAPD (Random Amplified Polymorphic DNA) and 10 ISSR (Inter Simple Sequence Repeats) markers. The genetic properties of 17 populations of wild M. acuminata were analyzed by Popgene 1.32 based on Nei’s unbiased measures of genetic identity and genetic distance. Of the 443 DNA bands produced, 425 (95.94%) were polymorphic. Cluster analysis of the combined data of RAPD and ISSR produced a dendrogram which separated the population of M. acuminata (A genome) from M. balbisiana (B genome), but not from M. schizocarpa (S genome). Nei’s genetic distance of the 17 populations of wild M. acuminata ranged from 0.3676 to 0.1634. The highest genetic distance was observed between M. acuminata var rutilifes (from East Java) and M. acuminata var sumatrana (from West Sumatra). The percentages of polymorphic loci among the 17 populations of M. acuminata ranged from 9.93% to 39.73%. Nei’s gene diversity (h) ranged from 0.041 to 0.1418. M. acuminata var malaccensis population was the most diverse among the researched 17 M. acuminata. The high level of genetic diversity of the wild M. acuminata from Indonesia emphasizes the need for conservation and preservation of the natural population and its use in the banana breeding program.

The Analysis of Leaf Traits of Eight Ottelia Populations and Their Potential Ecosystem Functions in Karst Freshwaters in China.

Submerged macrophytes play a structuring role in the shallow freshwater ecosystem by increasing the heterogeneous state in freshwaters. The macrophytes in genus Ottelia were featured for their broad leaves, which might consequently produce specialized functions that differed from other submerged species. To explore the potential ecological role of Ottelia, a field investigation was conducted on leaf traits in eight populations of Ottelia ranging from the southwestern Yunnan–Guizhou plateau to the southern Hainan island in China covering a distance of >1,700 km. The eight populations included all the extant Ottelia species and varieties in China except the well-documented O. alismoides. Carbon-related traits [bicarbonate usage, photosynthetic characteristics, capability of Crassulacean acid metabolism (CAM)], pigment content and parameters of chlorophyll fluorescence, morphology and mass of the leaves were determined. The different populations showed distinct functional traits of mature leaves; O. acuminata var. songmingensis had the thickest and longest leaf with CaCO3 precipitation on the both sides of the leaf, and O. cordata showed putative CAM activity with the highest diel acidity changes 12.5 μequiv g-1 FW. Our results indicated an important role of Ottelia populations in carbon cycling as the dominant species in karst freshwaters in China.

The complete chloroplast genome of Ottelia acuminata var. songmingensis, an Endangered aquatic macrophyte in China

Ottelia acuminata var. songmingensis is an Endangered freshwater submerged macrophyte occupying only a portion of a stream ca. 300 meters long in Songming County of the Yunnan Province, China. Here, we report and characterize the complete chloroplast genome sequence of O. acuminata var. songmingensis to provide genomic resources useful for promoting its conservation. The complete chloroplast genome is 157,645 bp in length, consisting of a pair of inverted repeat (IR) regions (24,973 bp), a small single copy (SSC) region (20,055 bp), and a large single copy (LSC) region (87,644 bp). The chloroplast genome contained 116 genes, including 71 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The overall GC content of the whole genome is 36.6%. Phylogenetic analysis of 19 selected chloroplast genomes revealed that O. acuminata var. songmingensis was closely related to Elodea canadensis of Hydrocharitaceae.

Characterization of the complete chloroplast genome of an endangered aquatic macrophyte, Ottelia cordata (Hydrocharitaceae)

Ottelia cordata (Wallich) Dandy (Hydrocharitaceae) is an endangered aquatic macrophyte. The complete chloroplast genome sequence of O. cordata was generated by de novo assembly using whole genome next-generation sequencing. The complete chloroplast genome was 157,879 bp in length and constructed out of four parts – a large single-copy (LSC) region of 87,672 bp, a small single-copy (SSC) region of 20,265 bp, and two inverted repeat (IRa and IRb) regions of 24,971 bp each. The genome annotation predicted a total of 117 genes, including 72 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic analysis of 20 selected chloroplast genomes revealed that sampled species of Hydrocharitaceae formed a monophyletic clade, in which O. cordata and O. acuminata var. songmingensis formed a sister clade to Elodea canadensis.