Ploidy-dependent effect of prolonged photoperiod on mode of reproduction and photosynthesis in the Ranunculus auricomus complex (Ranunculaceae)

Polyploidy, whole-genome duplication, enhances stress-tolerance to drastic environmental compared to their diploid progenitor by enabling more extensive adaptation as advantages of gene and genome duplication. Polyploidy acts as drivers of evolution and speciation in plants. Polyploidy in angiosperms is an influential factor to trigger apomixis, the reproduction of asexual seeds. Apomixis is usually facultative, which means that both sexual and apomictic seeds can be formed by the same plant. Environmental abiotic stress, e.g., light stress, can change the frequency of apomixis. Photoperiod stress in plants influences flowering, photosynthesis, growth, metabolite profiles, and production of reactive oxygen species (ROS). The light stress creates photodamage due to the inhibition of photosystem II (PSII) repair and alternation in the photosynthetic redox signaling pathways. Apomeiosis, the production of unreduced embryo sacs, versus meiotic development is influenced by ROS scavenging. The excess of ROS in reproductive tissue generates oxidative stress. In the archespor, oxidative stress might lead to DNA double-strand breaks (DSBs) and induction of meiosis as a DNA repair mechanism. Stress-adapted plants are able to maintain the metabolic network in ROS scavenging, including compatible solutes, antioxidants, and stress-responsive proteins. In polyploid plants, the higher stress tolerance reduces oxidative stress. Hence, in facultative apomictic polyploids, lowered stress levels could result in a decrease in proportions of meiotic ovules and favor apomeiotic development. The main aims of this research were to explore with prolonged photoperiods whether polyploidy alters proportions of sexual ovule and sexual seed formation under light stress conditions and to observed the extent of stress effect on photosynthesis in the leaves that appear together with the flower buds. I used three facultative apomictic, pseudogamous cytotypes of the Ranunculus auricomus complex (diploid, tetraploid, and hexaploid). Stress treatments were applied by extended light periods (16.5 h) and control (10 h) in climate growth chambers. Proportions of apomeiotic vs. meiotic development in the ovule were evaluated with clearing methods, and the mode of seed formation was examined by single seed flow cytometric seed screening (ssFCSS). I further studied pollen stainability to understand the effects of pollen quality on seed formation. In basal leaves, I analyzed the effect of extended photoperiod on photosynthesis efficiency as a proxy of stress conditions. The flower buds are covered by green sepals as photosynthetic tissue, and hence we expect the same photosynthetic performance and stress effects as in the basal leaves. Photosynthesis performance was measured by applying an extensive analysis of chlorophyll a fluorescence to record the parameters: PSII maximum efficiency (ɸPSII), the maximum quantum efficiency of PSII photochemistry (QY_max), relative electron transport rate (rETR), fluorescence induction curve (IC) of non-photochemical quenching (NPQ), and fast fluorescence transient curve (OJIP curve). Results revealed that under extended photoperiod, all cytotypes produced significantly more sexual ovules than in the controls, with the strongest effects on diploids. The stress treatment affected neither the frequency of seed set nor the proportion of sexual seeds nor pollen quality. Prolonged photoperiod did not enhance the photosynthesis efficiency (QY_max and ɸPSII) of three cytotypes of R. auricomus. Among cytotypes, diploids were the most sensitive to the extended photoperiod compared to polyploids as indicated by the alternation of non-photochemical quenching parameters (NPQ, qE, NPQE, and qN), specific energy flux parameters (ABS/RC, DI0/RC, and TR0/RC), and performance index on absorption basis (PI_Abs). In tetraploids, the fraction of light excess was quenched into photochemistry (qP), but another fraction exceeded the capacity of photon trapping (TR0/RC), hence dissipated as non-photochemical quenching (qL). The hexaploids presented a variation of photosynthesis performance among two clones which might relate to different habitats. These findings confirm our hypothesis that megasporogenesis is triggered by light stress treatments. Comparisons of cytotypes support the hypothesis that ovule development in polyploid plants is less sensitive to prolonged photoperiods and responds to a lesser extent with sexual ovule formation. Polyploids may better buffer environmental stress, which releases the potential for aposporous ovule development from somatic cells, and may facilitate the establishment of apomictic seed formation. The photosynthesis performance of R. auricomus relates to the mode of ovule formation, as diploids showed the highest sensitivity to prolonged photoperiod concomitant to the highest proportions of sexual ovules, followed by tetraploids. Hexaploids, however, exhibited a very large variance in the proportions of sexual ovules, which we also observed here in photosynthesis performance. I suppose that this variation is mostly referable to two different ecotypes2021-07-3

Tree Ferns of C. contaminans and C. orientalis from Biosite Erek-erek Geoforest of Ijen Geopark, Banyuwangi

The tree ferns abundant in the ecotourism area of the geoforest erek-erek biosite is represented as ancient plants. However, species list and their composition as diversity richness data is still lacking the in the conservation area. The aims of of this study was to determine the tree ferns and provide the description of the species. Observations on the morphological characters of plants were carried out directly in the field of tree ferns habitat at the Ijen geopark, Banyuwangi, while other morphological and anatomical determinations were conducted in laboratory. The tree ferns identified in the erek-erek forest were two species i.e., Cyathea contaminans and Cyathea orientalis. The main distinguishing characteristics of these species are: stem height, stem surface, attachment of the remaining petiole, scale color, crozier size, indusium and spore shape. This article also provides descriptions of the species and the information regarding conspicuous characters that can be used for species determination in the field. We also propose further conservation efforts to preserve the tree ferns in their habitat

Ephypitic Ferns (Pteridophyta) from Raung Mount Banyuwangi, East Java Indonesia

An investigation of epiphytic Pteridophytes diversity at Mount Raung, Banyuwangi, East Java Province, Indonesia, was carried out in 7 February 2015. As many as 11 Pteridophytes from 3 families had been identified based on their morphological chracteristic. Among them, four species of Family Aspleniaceae, including Asplenium confusum Tardieu & Ching, Asplenium nidus L., Asplenium salignum Blume, and Asplenium tenerumoides S.B.Andrews. Polypodiaceae include Leptochilus wrightii (Hooker & Baker) X. C. Zhang, Microsorum punctatum (L.) Copel., Pyrrosia bicolor ( Kaulf. ) Ching, and Schellolepis percussa (Cav.) Pic.Serm. Vittariaceae include Antrophyum formosanum Hieron., Vittaria ensiformis Sw., and Vittaria lineata (L.) Sm. which is the smallest specimen with less than 10 cm long.Keywords: Mount Raung, Pteridophyta, Epiphytic, Families.

Distribusi Lamun di Zona Intertidal Tanjung Bilik Taman Nasional Baluran Menggunakan Metode GIS (Geographic Information System)

Zona intertidal merupakan wilayah perairan laut yang masih dipengaruhi oleh pasang surut air laut. Salah satu keanekaragaman hayati yang terdapat di zona intertidal adalah lamun. Salah satu tanjung yang memiliki padang lamun adalah Tanjung Bilik Taman Nasional Baluran. Tujuan dari penelitian ini adalah mengetahui distribusi lamun di Zona Intertidal Tanjung Bilik Taman Nasional Baluran dengan menggunakan metode GIS (Geographic Information System). Metode pengambilan data yang digunakan yaitu metode jelajah. Data koordinat habitat lamun dipetakan menggunakan program arcGIS 10. Berdasarkan penelitian yang telah dilakukan ditemukan empat jenis lamun dengan urutan dari distribusi terluas, yaitu Thalassia hemprichii, Enhalus acoroides, Halophila minor, dan Halodule pinifolia. Thalassia hemprichii dan Enhalus acoroides memiliki pola distribusi acak. Halophila minor dan Halodule pinifolia memiliki pola distribusi mengelompok. Kata Kunci: Distribusi, Lamun, Zona Intertidal, Tanjung Bili

BRYOPHYTES OF MOUNT PATUHA, WEST JAVA, INDONESIA

GRADSTEIN, R. et al. 2010. Bryophytes of Mount Patuha, West Java, Indonesia. Reinwardtia 13(2): 107-123. - This paper presents the results of a two-day survey of the bryophyte flora of Mt. Patuha and its surroundings near Bandung, West Java, carried out in the framework of the 5th regional training course on bryophyte and lichen diversity and conservation organized by SEAMEO BIOTROP, Bogor, in July 2009. A total of 159 bryophyte species were identified, including 98 mosses, 60 liverworts, and 1 hornwort, representing almost 1/6 of the total bryophyte flora of Java. Three moss species, Bryohumbertia subcomosa (Dix.) J.-P. Frahm, Fissidens gymnogynus Besch. and F. polypodioides Hedw., and one liverwort, Lejeunea pectinella Mizut., are new additions to the Javanese flora. The bryophyte diversity of Mt. Patuha is well representative of the Malesian flora and is rich in uncommon species. However, the relatively poor representation of shade epiphytes and commonness of sun epiphytes and generalists reflect disturbance of the forest by anthropogenic activities. Careful attention should be given to conservation of the remaining natural forest in order to prevent further losses of the rich bryophyte diversity of the area

Polyploidy Improves Photosynthesis Regulation within the Ranunculus auricomus Complex (Ranunculaceae)

Polyploidy has substantially contributed to successful plant evolution, and is often connected to a higher resilience to environmental stress. We test the hypothesis that polyploids tolerate light stress better than diploids. The Ranunculus auricomus complex comprises diploid (2x), tetraploid (4x), and hexaploid (6x) cytotypes, the former of which occur in shaded habitats and the latter more in open, sun-exposed habitats in Central Europe. In this study, we experimentally explored the effects of ploidy and photoperiod extension on the efficiency of photosystem II in the three cytotypes in climate growth chambers. Quantum yields and various coefficients that can be calculated from light curve, Kautsky curve, and fluorescent transient OJIP experiments provided support for the hypothesis that, in comparison to diploids, the improved regulation of excess light by more efficient photochemical and non-chemical quenching in polyploids might have facilitated the adaptation to unshaded habitats. We suggest how lower stress levels in reproductive tissues of polyploids might have favored asexual reproduction

Data from: Population genetic structure and reproductive strategy of the introduced grass Centotheca lappacea in tropical land-use systems in Sumatra

Intensive transformation of lowland rainforest into oil palm and rubber monocultures is the most common land-use practice in Sumatra (Indonesia), accompanied by invasion of weeds. In the Jambi province, Centotheca lappacea is one of the most abundant alien grass species in plantations and in jungle rubber (an extensively used agroforest), but largely missing in natural rainforests. Here, we investigated putative genetic differentiation and signatures for adaptation in the introduced area. We studied reproductive mode and ploidy level as putative factors for invasiveness of the species. We sampled 19 populations in oil palm and rubber monocultures and in jungle rubber in two regions (Bukit Duabelas and Harapan). Amplified fragment length polymorphisms (AFLP) revealed a high diversity of individual genotypes and only a weak differentiation among populations (FST = 0.173) and between the two regions (FST = 0.065). There was no significant genetic differentiation between the three land-use systems. The metapopulation of C. lappacea consists of five genetic partitions with high levels of admixture; all partitions appeared in both regions, but with different proportions. Within the Bukit Duabelas region we observed significant isolation-by-distance. Nine AFLP loci (5.3% of all loci) were under natural diversifying selection. All studied populations of C. lappacea were diploid, outcrossing and self-incompatible, without any hints of apomixis. The estimated residence time of c. 100 years coincides with the onset of rubber and oil palm planting in Sumatra. In the colonization process, the species is already in a phase of establishment, which may be enhanced by efficient selection acting on a highly diverse gene pool. In the land-use systems, seed dispersal might be enhanced by adhesive spikelets. At present, the abundance of established populations in intensively managed land-use systems might provide opportunities for rapid dispersal of C. lappacea across rural landscapes in Sumatra, while the invasion potential in rainforest ecosystems appears to be moderate as long as they remain undisturbed

Data from: Population genetic structure and reproductive strategy of the introduced grass Centotheca lappacea in tropical land-use systems in Sumatra

Intensive transformation of lowland rainforest into oil palm and rubber monocultures is the most common land-use practice in Sumatra (Indonesia), accompanied by invasion of weeds. In the Jambi province, Centotheca lappacea is one of the most abundant alien grass species in plantations and in jungle rubber (an extensively used agroforest), but largely missing in natural rainforests. Here, we investigated putative genetic differentiation and signatures for adaptation in the introduced area. We studied reproductive mode and ploidy level as putative factors for invasiveness of the species. We sampled 19 populations in oil palm and rubber monocultures and in jungle rubber in two regions (Bukit Duabelas and Harapan). Amplified fragment length polymorphisms (AFLP) revealed a high diversity of individual genotypes and only a weak differentiation among populations (FST = 0.173) and between the two regions (FST = 0.065). There was no significant genetic differentiation between the three land-use systems. The metapopulation of C. lappacea consists of five genetic partitions with high levels of admixture; all partitions appeared in both regions, but with different proportions. Within the Bukit Duabelas region we observed significant isolation-by-distance. Nine AFLP loci (5.3% of all loci) were under natural diversifying selection. All studied populations of C. lappacea were diploid, outcrossing and self-incompatible, without any hints of apomixis. The estimated residence time of c. 100 years coincides with the onset of rubber and oil palm planting in Sumatra. In the colonization process, the species is already in a phase of establishment, which may be enhanced by efficient selection acting on a highly diverse gene pool. In the land-use systems, seed dispersal might be enhanced by adhesive spikelets. At present, the abundance of established populations in intensively managed land-use systems might provide opportunities for rapid dispersal of C. lappacea across rural landscapes in Sumatra, while the invasion potential in rainforest ecosystems appears to be moderate as long as they remain undisturbed

AFLP matrix for Centotheca lappacea

AFLP matrix for Centotheca lappace