Polyploidy

Effects of polyploidy in allohexaploid wheat (Triticum aestivum L.) have primarily been ascribed to increases in coding sequence variation and potential to acquire new gene functions through mutation of redundant loci. However, regulatory variation that arises through new promoter and transcription factor combinations or epigenetic events may also contribute to the effects of polyploidization. In this study, gene expression was characterized in a synthetic T. aestivum line and the T. turgidum and Aegilops tauschii parents to establish a timeline for such regulatory changes and estimate the frequency of nonadditive expression of homoeologous transcripts in newly formed T. aestivum. Large-scale analysis of nonadditive gene expression was assayed by microarray expression experiments, where synthetic T. aestivum gene expression was compared to additive model values (mid-parent) calculated from parental T. turgidum and Ae. tauschii expression levels. Approximately 16% of genes were estim...

Objective: Investigation of the normal frequency of tetraploid metaphases in semidirect (STC) and cultured (LTC) chorionic villi. Methods: Fifty metaphases in STC- and in LTC-villi slides of 100 women of advanced maternal age were screened for tetraploidy. Results: Up to three tetraploid metaphases were encountered in 27% of the STC-villi preparations; the scores fitted a Poisson distribution. In all LTC-villi preparations tetraploid cells were seen; the scores fitted a log-Gaussian distribution. Conclusions: On the basis of these distributions, we propose a protocol for the management of tetraploid metaphases in chorionic villi, strongly reducing the number of prenatal follow-up investigations.

Polystichum is one of the most diverse genera of ferns, with 360–400 species distributed worldwide. South America harbors ~40 species, clustered in three centres of diversity, namely, the Northern and Central Andes Center (NCC), the Brazilian Center (BC) and the Southern South America Center (SSC). To increase our understanding of the systematic relationships within Polystichum, mitotic chromosomes and spore features were studied in nine species from Argentina and Chile. All species presented the basic number x = 41, with different ploidy levels (2x, 4x and 8x). In general, chromosomes were homogeneous in size (average length 2.50–5.75 µm) and mostly subtelocentric; centromeres were inconspicuous and secondary constrictions were frequently observed. All species presented 64 spores per sporangium, suggesting normal sexual reproduction. Significant differences in spore size were found among species and it was positively correlated with ploidy level. A relationship between sum total ch...

Cannabis sativa is known for the source of therapeutic compounds, gaining great importance since restrictions on its growth and use are gradually reduced throughout the world. Unintended cross-pollination of Cannabis sativa crops is one of the most important threats to cannabinoid production. Therefore, avoiding pollination of female flowers during the production of Cannabis sativa for phytocannabinoids is a priority for growers of this crop, as pollination has been shown to reduce final yield of phytocannabinoids. Polyploid plants possess three or more sets of homologous chromosomes and are sterile. Ploidy manipulation has been used in other crops to improve agronomic traits, reduce fertility and produce sterile plants. A promising approach for cannabis breeding involves the process of polyploidization, in which the number of copies of each chromosome is increased. Polyploidization not only causes seedlessness but also brings other physiological and morphological changes to plants, including the plant architecture. Triploid plants are usually both male and female sterile and seeds are not viable or not present. Seedlessness is a highly desirable characteristic for consumers. Polyploid plants often exhibit altered traits, such as larger cell sizes, increased biomass, and changed morphology, which can have significant implications for cannabis industries. Polyploid cannabis plants offer a host of benefits, and they may help growers to overcome the fertilization issue when it comes to cultivating cannabis on a large scale. The strong polyploidy inducing agents in plants are either chemical (Colchicine, Oryzalin, Caffeine, Trifuralin, or phosphoric amides) or gaseous i.e. Nitrous oxide. Polyploid cannabis could become another option for commercial and small-scale growers looking to produce seedless weed. The research lays important groundwork for the development of improved cannabis strains and novel germplasm for breeding efforts.

Polyploidization is an important mechanism for sympatric speciation in plants. Still, we know little about whether plant polyploidization leads to insect host shifts, and if novel interactions influence habitat and trait selection in plants. We investigated herbivory by the flower bud gall-forming midge Dasineura cardaminis on tetraploids and octoploids of the herb Cardamine pratensis. Gall midges attacked only octoploid plant populations, and a transplantation experiment confirmed this preference. Attack rates were higher in populations that were shaded, highly connected or occurred along stream margins. Within populations, late-flowering individuals with many flowers were most attacked. Galling reduced seed production and significantly influenced phenotypic selection on flower number. Our results suggest that an increase in ploidy may lead to insect host shifts and that plant ploidy explains insect host use. In newly formed plant polyploids, novel interactions may alter habitat preferences and trait selection, and influence the further evolution of cytotypes.

Glioblastoma multiforme (GBM) is the most frequent and aggressive type of primary brain tumours in adults. Despite very intensive treatments including maximal safe neurosurgery, radiation therapy and chemotherapy, the prognosis of GBM patients remains poor with a median overall survival below 18 months. Temozolomide (TMZ)-based chemotherapy is the most common pharmacological treatment in patients with diagnosed GBM. Even if TMZ administration improves patient overall survival, prognosis remains poor and no major therapeutic advance has been accomplished within the past 10 years. This can be related to a lack of knowledge in how the tumour evolves and ultimately escape drug activity, especially in a context of large inter-patient variability. New systems pharmacology approaches combining experimental and mathematical expertise provide interesting perspectives towards the design of safe and efficient TMZ-based therapies against GBM. The present study aims to do so through the concepti...

vi 7. Tak lupa-sahabat Oryzalin‖ Miftah Farid, Alifah Nur Fauziah, dan Hikmatul Maulidina yang selalu membantu lancarnya penelitian. Dan juga M. Farid Annas yang selalu kurepotkan perihal pengamatan. 8. Adik-adik tercinta Lina Hidayatur, Yunita, Humay, dan Maslaha yang senantiasa membantu tanpa pamrih. Kalian The Best. Semangat pejuang oryzalin. Mbak Miftahur Rohmah, Mbak I'anatur Rofiqoh yang tanpa bosan membimbing saya 9. Teman-teman Biologi C dan Genetist'15 yang sudah saya anggap sebagai keluarga. Terimakasih telah menemani selama proses menempuh S1. 10. Semua pihak yang tidak bisa penulis sebutkan satu-persatu yang telah membantu terealisasinya tugas akhir ini. Atas dukungan, motivasi, canda tawa dan nasihatnya, semoga Allah membalas semua kebaikan yang telah diberikan. Semoga karya ini mampu memberikan nilai manfaat khususnya bagi saya dan bagi orang lain. Aamiin. vii MOTTO " ْ ‫َّاس‬ ‫لن‬ ِ ‫ل‬ ْ ‫م‬ ُ ‫ه‬ ُ ‫ع‬ َ ‫ف‬ ْ ‫ن‬ َ ‫ا‬ ْ ‫َّاس‬ ‫الن‬ ُ ‫ر‬ ْ ‫ي‬ َ ‫"خ‬ viii ix PEDOMAN PENGGUNAAN SKRIPSI Skripsi ini tidak dipublikasikan namun terbuka untuk umum dengan ketentuan bahwa hak cipta ada pada penulis. Daftar Pustaka diperkenankan untuk dicatat, tetapi pengutipan hanya dapat dilakukan seizin penulis dan harus disertai kebiasaan ilmiah untuk menyebutkannya.

INDONESIA: Stevia rebaudiana Bertoni merupakan tanaman yang berpotensi dijadikan sebagai pemanis rendah kalori sehingga aman dikonsumsi oleh penderita gangguan metabolisme darah. Kebutuhan akan tanaman ini cukup tinggi, namun belum banyak dikembangkan. Oleh karena itu, perlu dilakukan upaya pemuliaan tanaman melalui induksi poliploidi menggunakan oryzalin, untuk menghasilkan tanaman dengan kromosom berlipat, sel yang lebih besar, karakter morfologi yang lebih baik, dan kandungan biomassa yang meningkat. Penggunaan oryzalin jauh lebih efektif dalam meningkatkan poliploidi tanaman, dengan penggunaan konsentrasi yang rendah (µM). Tujuan dari penelitian ini adalah untuk mengetahui pengaruh kosentrasi oryzalin dan waktu inkubasi terhadap stomata dan karakter morfologi tanaman Stevia rebaudiana Bertoni. Rancangan penelitian yang digunakan adalah Rancangan Acak Kelompok (RAK) dua faktorial, faktor pertama yaitu konsentrasi oryzalin 15, 25, dan 35 µM. Fakor kedua yaitu waktu inkubasi selama...

Background: Sugarcane is the source of sugar in all tropical and subtropical countries and is becoming increasingly important for bio-based fuels. However, its large (10 Gb), polyploid, complex genome has hindered genome based breeding efforts. Here we release the largest and most diverse set of sugarcane genome sequences to date, as part of an ongoing initiative to provide a sugarcane genomic information resource, with the ultimate goal of producing a gold standard genome. Results: Three hundred and seventeen chiefly euchromatic BACs were sequenced. A reference set of one thousand four hundred manually-annotated protein-coding genes was generated. A small RNA collection and a RNA-seq library were used to explore expression patterns and the sRNA landscape. In the sucrose and starch metabolism pathway, 16 non-redundant enzyme-encoding genes were identified. One of the sucrose pathway genes, sucrose-6-phosphate phosphohydrolase, is duplicated in sugarcane and sorghum, but not in rice and maize. A diversity analysis of the s6pp duplication region revealed haplotype-structured sequence composition. Examination of hom(e)ologous loci indicate both sequence structural and sRNA landscape variation. A synteny analysis shows that the sugarcane genome has expanded relative to the sorghum genome, largely due to the presence of transposable elements and uncharacterized intergenic and intronic sequences. Conclusion: This release of sugarcane genomic sequences will advance our understanding of sugarcane genetics and contribute to the development of molecular tools for breeding purposes and gene discovery.

Rhizomatosae is a taxonomic section of the South American genus Arachis, whose diagnostic character is the presence of rhizomes in all its species. This section is of particular evolutionary interest because it has three polyploid (A. pseudovillosa, A. nitida and A. glabrata, 2n = 4x = 40) and only one diploid (A. burkartii, 2n = 2x = 20) species. The phylogenetic relationships of these species as well as the polyploidy nature and the origin of the tetraploids are still controversial. The present study provides an exhaustive analysis of the karyotypes of all rhizomatous species and six closely related diploid species of the sections Erectoides and Procumbentes by cytogenetic mapping of DAPI/CMA heterochromatin bands and 5S and 18-26S rDNA loci. Chromosome banding showed variation in the DAPI heterochromatin distribution pattern, which, together with the number and distribution of rDNA loci, allowed the characterization of all species studied here. The bulk of chromosomal markers sug...

Ferns are the only major lineage of vascular plants not represented by a sequenced nuclear genome. This lack of genome sequence information significantly impedes our ability to understand and reconstruct genome evolution not only in ferns, but across all land plants. Azolla and Ceratopteris are ideal and complementary candidates to be the first ferns to have their nuclear genomes sequenced. They differ dramatically in genome size, life history, and habit, and thus represent the immense diversity of extant ferns. Together, this pair of genomes will facilitate myriad large-scale comparative analyses across ferns and all land plants. Here we review the unique biological characteristics of ferns and describe a number of outstanding questions in plant biology that will benefit from the addition of ferns to the set of taxa with sequenced nuclear genomes. We explain why the fern clade is pivotal for understanding genome evolution across land plants, and we provide a rationale for how knowledge of fern genomes will enable progress in research beyond the ferns themselves.

The present paper represents the macro and micro-characters of the achenes of Carthamus (Asteraceae) species naturally growing in Turkey. A diagnostic identification key, descriptions and images of achenes were given. SEM investigation of seed coat sculpturing revealed 3 distinct types of surface structure: I: Striate, II: Irregularly striate and III: Finely striate. Our research shows that achene morphology is of great value for taxonomist and for plant breeders for identification of Turkish Carthamus species without the need of herbarium specimen.

The article presents the study results of the populations of the relict species Dryopteris filix-mas (L.) Schott on the territory of the Tyubkaragan Peninsula in the Mangistau region, Kazakhstan. Studies have shown that this species is found among the blackberry-grass community's rocks, indicating its adaptation to the specific habitat conditions in this region. The work also presents the morphometric parameters of D. filix-mas, such as shoot length and average leaf size. The data obtained indicate that the studied populations are young and have a high self-renewal capacity. Analysis of the morphometric characteristics of generative individuals showed that the measured parameters are within the typical range for this species, which confirms its good condition and viability. Observations of the population were carried out for two years (2023-2024), which allows us to draw more substantiated conclusions about the dynamics of the D. filix-mas population. Currently, the population is in a satisfactory condition due to the high proportion of generative individuals and maximum density, a positive characteristic of sustainability. The population was found in shaded areas among rocks. Morphometric analysis showed that the length of the leaf blade in adult plants varied from 47 to 52 cm, while the number of spore-bearing leaves reached 4 per plant. The height of the plants ranged from 12 to 17 cm in young plants up to 57 cm in adults. The studied population consists mainly of generative individuals, contributing to its high self-renewability. Genetic analysis based on the chloroplast gene rbcL showed a high level of genetic variability, confirming the population's adaptation to specific conditions of the region. Nevertheless, the state of the population is assessed as threatened with extinction, which raises serious concerns. A factor contributing to this state is the dependence on the preservation of habitats and the sustainability of ecosystems in which this species grows. In this regard, the article recommends continued monitoring and control of the status of D. filix-mas populations to ensure their conservation and avoid potential extinction. These study results highlight the need for an active approach to protecting this relict species and the importance of further research to study the factors affecting the status of populations and the possibility of their restoration in the context of climate change and anthropogenic impact. The recommendation to implement sustainable methods of protection and monitoring will contribute to protecting D. filix-mas and maintaining biological diversity in the region.

Background: With some 700 species, the pantropical Crotalaria is among the angiosperm's largest genera. We sampled 48% of the species from all sections (and representatives of the 15 remaining Crotalarieae genera) for nuclear and plastid DNA markers to infer changes in climate niches, flower morphology, leaf type, and chromosome numbers. Results: Crotalaria is monophyletic and most closely related to African Bolusia (five species) from which it diverged 23 to 30 Ma ago. Ancestral state reconstructions reveal that leaf and flower types are conserved in large clades and that leaf type is uncorrelated to climate as assessed with phylogenetically-informed analyses that related compound vs. simple leaves to the mean values of four Bioclim parameters for 183 species with good occurrence data. Most species occur in open habitats <1000 m alt., and trifoliolate leaves are the ancestral condition, from which unifoliolate and simple leaves each evolved a few times, the former predominantly in humid, the latter mainly in dry climates. Based on chromosome counts for 36% of the 338 sequenced species, most polyploids are tetraploid and belong to a neotropical clade. Conclusions: An unexpected finding of our study is that in Crotalaria, simple leaves predominate in humid climates and compound leaves in dry climates, which points to a different adaptive value of these morphologies, regardless of whether these two leaf types evolved rarely or frequently in our focal group.

QTL mapping experiments yield heterogeneous results due to the use of different genotypes, environments, and sampling variation. Compilation of QTL mapping results yields a more complete picture of the genetic control of a trait and reveals patterns in organization of trait variation. A total of 432 QTL mapped in one diploid and 10 tetraploid interspecific cotton populations were aligned using a reference map and depicted in a CMap resource. Early demonstrations that genes from the non-fiber-producing diploid ancestor contribute to tetraploid lint fiber genetics gain further support from multiple populations and environments and advanced-generation studies detecting QTL of small phenotypic effect. Both tetraploid subgenomes contribute QTL at largely non-homeologous locations, suggesting divergent selection acting on many corresponding genes before and/or after polyploid formation. QTL correspondence across studies was only modest, suggesting that additional QTL for the target traits...

Darwin introduced the concept of the "living fossil" to describe species belonging to lineages that have experienced little evolutionary change, and suggested that species in more slowly evolving lineages are more prone to extinction (1). Recent studies revealed that some living fossils such as the lungfish are indeed evolving more slowly than other vertebrates (2, 3). The reason for the slower rate of evolution in these lineages remains unclear, but the same observations suggest a possible genome size effect on rates of evolution. Genome size (C-value) in vertebrates varies over 200 fold ranging from pufferfish (0.4 pg) to lungfish (132.8 pg) (4). Variation in genome size and architecture is a fundamental cellular adaptation that remains poorly understood (5). C-value is correlated with several allometric traits such as body size and developmental rates in many, but not all, organisms (6, 7). To date, no consensus exists concerning the mechanisms driving genome size evolution or the effect that genome size has on species traits such as evolutionary rates (8-12). In the following we show that: 1) within the same range of divergence times, genetic diversity decreases as genome size increases and 2) average rates of molecular evolution decline with increasing genome size in vertebrates. Together, these observations indicate that genome size is an important factor influencing rates of speciation and extinction. Results and discussion Several investigations have demonstrated that lineages corresponding to species with large genomes tend to be less speciose (9, 13-15). This observation has frequently been interpreted as evidence that large genomes are maladaptive and pose an elevated risk of extinction (13, 14). Consistent with genome size posing a hazard to species survival (12, 16), mutation rates, as measured by the base substitution rate per nucleotide per generation, increase proportionally with genome size (17), and consequently large genomes are expected to be more genetically unstable. Why species with large genomes are more prone to extinction remains unclear, but allometric factors, such as small effective population size, constitute plausible explanations (12). Rates of molecular evolution also frequently correlate positively with taxonomic diversity and rates of macro-evolution (18-20). Mutation rates, however, vary significantly between different taxa (21, 22), which might contribute to the observed differences in evolutionary rates in diverse lineages. Evidence is accumulating, for example, that generation time, which reflects the number of genome duplications during development, has a significant impact on mutation rate (23, 24). A generation time effect, for example, has been proposed to account for the decrease in mutation rate resulting from DNA replication errors as the primate lineage evolved (25). Generation time correlates strongly with genome size (nucleotypic effect) (26, 27), but how genome size and generation time influence evolutionary rates in different species remains an open question (28, 29).

Arachis hypogaea (peanut) is a leading oil and protein-providing crop with a major food source in many countries. It is mostly grown in tropical regions and is largely affected by abiotic and biotic stresses. Cysteine-rich receptor-like kinases (CRKs) is a family of transmembrane proteins that play important roles in regulating stress-signaling and defense mechanisms, enabling plants to tolerate stress conditions. However, almost no information is available regarding this gene family in Arachis hypogaea and its progenitors. This study conducts a pangenome-wide investigation of A. hypogaea and its two progenitors, A. duranensis and A. ipaensis CRK genes (AhCRKs, AdCRKs, and AiCRKs). The gene structure, conserved motif patterns, phylogenetic history, chromosomal distribution, and duplication were studied in detail, showing the intraspecies structural conservation and evolutionary patterns. Promoter cis-elements, protein–protein interactions, GO enrichment, and miRNA targets were also predicted, showing their potential functional conservation. Their expression in salt and drought stresses was also comprehensively studied. The CRKs identified were divided into three groups, phylogenetically. The expansion of this gene family in peanuts was caused by both types of duplication: tandem and segmental. Furthermore, positive as well as negative selection pressure directed the duplication process. The peanut CRK genes were also enriched in hormones, light, development, and stress-related elements. MicroRNA (miRNA) also targeted the AhCRK genes, which suggests the regulatory association of miRNAs in the expression of these genes. Transcriptome datasets showed that AhCRKs have varying expression levels under different abiotic stress conditions. Furthermore, the multi-stress responsiveness of the AhCRK genes was evaluated using a machine learning-based method, Random Forest (RF) classifier. The 3D structures of AhCRKs were also predicted. Our study can be utilized in developing a detailed understanding of the stress regulatory mechanisms of the CRK gene family in peanuts and its further studies to improve the genetic makeup of peanuts to thrive better under stress conditions.

Characterization of microsatellites in the parthenogenetic polyploid snail Melanoides tuberculata revealed an unusual high density of dinucleotide repeats. Multiple banding patterns were obtained at these loci, and interpreted as a consequence of polyploidy. Microsatellite variability was low within, but high between, shell morphotypes. Genotypes were wholly transmitted from mothers to offspring. These results suggest that reproduction is strictly apomictic, and that shell morphotypes are genetic clones.

Effects of polyploidy in allohexaploid wheat (Triticum aestivum L.) have primarily been ascribed to increases in coding sequence variation and potential to acquire new gene functions through mutation of redundant loci. However, regulatory variation that arises through new promoter and transcription factor combinations or epigenetic events may also contribute to the effects of polyploidization. In this study, gene expression was characterized in a synthetic T. aestivum line and the T. turgidum and Aegilops tauschii parents to establish a timeline for such regulatory changes and estimate the frequency of nonadditive expression of homoeologous transcripts in newly formed T. aestivum. Large-scale analysis of nonadditive gene expression was assayed by microarray expression experiments, where synthetic T. aestivum gene expression was compared to additive model values (mid-parent) calculated from parental T. turgidum and Ae. tauschii expression levels. Approximately 16% of genes were estim...

Sisyrinchium is the largest genus of Iridaceae in the Americas and has the greatest amount of cytological data available. This study aimed at investigating how genomes evolved in this genus. Chromosome number, genome size and altitude from species of sect. Viperella were analyzed in a phylogenetic context. Meiotic and pollen analyses were performed to assess reproductive success of natural populations, especially from those polyploid taxa. Character optimizations revealed that the common ancestor of sect. Viperella was probably diploid (2n = 2x =18) with two subsequent polyplodization events. Total DNA content (2C) varied considerably across the phylogeny with larger genomes detected mainly in polyploid species. Altitude also varied across the phylogeny, however no significant relationship was found between DNA content changes and altitude in our data set. All taxa presented regular meiosis and pollen viability (&gt; 87%), except for S. sp. nov. aff. alatum (22.70%), suggesting a re...

d Background and Aims Thymus loscosii (Lamiaceae) is a tetraploid perennial species endemic to the Ebro river basin (north-eastern Spain), which is included in the National Catalogue of Endangered Species. It is a tetraploid species (2n = 54), presumably an autotetraploid originated by the duplication of a 2n = 28 genome and the subsequent loss of two chromosomes. Allozyme electrophoresis was conducted to survey the levels and distribution of genetic diversity and to test the previous autopolyploid hypothesis for its origin. In addition, both in situ and ex situ conservation measures are proposed. d Methods Eight populations were sampled for analysis by standard methods of starch gel electrophoresis, and six putative enzymatic loci were resolved (®ve consistently and one only partially). d Key Results Banding patterns exhibited no evidence of ®xed heterozygosity and showed both balanced and unbalanced heterozygotes. In addition, most individuals showed a pattern consistent with the presence of three or four alleles at a single locus. High levels of genetic variability were found at population level (P = 85 %, A = 3´0, H e = 0´422), in addition to a trend of an excess of heterozygotes. d Conclusions Allozyme data support the hypothesis that T. loscosii is an autotetraploid, and the high number of alleles at some loci may be due to repeated polyploidization events. The high values of genetic variation found in this species agree with those expected for tetraploids. The excess of heterozygotes may be due to some barriers to inbreeding (e.g. occurrence of gynodioecy) and/or selection for heterozygosity.

Origin and rearrangement of ribosomal DNA repeats in natural allotetraploid Nicotiana tabacum are described. Comparative sequence analysis of the intergenic spacer (IGS) regions of Nicotiana tomentosiformis (the paternal diploid progenitor) and Nicotiana sylvestris (the maternal diploid progenitor) showed species-specific molecular features. These markers allowed us to trace the molecular evolution of parental rDNA in the allopolyploid genome of N. tabacum; at least the majority of tobacco rDNA repeats originated from N. tomentosiformis, which endured reconstruction of subrepeated regions in the IGS. We infer that after hybridization of the parental diploid species, rDNA with a longer IGS, donated by N. tomentosiformis, dominated over the rDNA with a shorter IGS from N. sylvestris; the latter was then eliminated from the allopolyploid genome. Thus, repeated sequences in allopolyploid genomes are targets for molecular rearrangement, demonstrating the dynamic nature of allopolyploid genomes.

A new member of the P450 gene family was identified in barley. The P450 gene was a member of the subfamily CYP72A. Northern analysis revealed that various CYP72A39 transcripts were found in four barley cultivars at a very early vegetative stage but no expression was detected at the reproduction stage. This suggested that this P450 gene may be involved in seedling development in barley. Comparison of expression profiles of this gene and “digital expression” databases confirmed that this gene was homologous to ...

Drought is able to cause biomass reduction, disturbance in water relations
as well as in photosynthetic apparatus. Though it has been found that
chemical compounds such as omeprazole showed recently good results by promoting biomass, morphological attributes, relative water content, water potential and photosynthetic efficiency. However, mechanism behind the OMP action under drought is unclear. The present study investigates the effect of 10μM omeprazole on two varieties (D3366Tol and D6619Sens) of Zea mays (maize) subjected to drought after screening. Drought decreased relative water content in both varieties (70% and 62%) while substantially increased osmotic adjustment along with an increase in NPQ and NPQt. However, such effects are different in both varieties. Exogenous application of 10μM OMP increased morphological attributes (shoot /root length, shoot/root biomass, number of leaves, leaf area), improved water relation related parameters (RWC and water potential) influenced photosynthetic parameters
(ɸII, ɸNO, LEF, ECSt, vH+, gH+) under normal and drought conditions in
both varieties (D3366Tol and D6619Sens). This led to increase maize varieties’ growth under drought, such as increase in biomass. These results indicate mitigating effect of omeprazole in D3366Tol and as well as in D6619Sens by increasing morphological, water relations and photosynthetic attributes, reduction in loss of water by boosting water potential of leaf and relative water content (RWC); improving PSII activity when exposed to drought.

Many plant species of great economic value (e.g., potato, wheat, cotton, and sugarcane) are polyploids. Despite the essential roles of autopolyploid plants in human activities, our genetic understanding of these species is still poor. Recent progress in instrumentation and biochemical manipulation has led to the accumulation of an incredible amount of genomic data. In this study, we demonstrate for the first time a successful genetic analysis in a highly polyploid genome (sugarcane) by the quantitative analysis of single-nucleotide polymorphism (SNP) allelic dosage and the application of a new data analysis framework. This study provides a better understanding of autopolyploid genomic structure and is a sound basis for genetic studies. The proposed methods can be employed to analyse the genome of any autopolyploid and will permit the future development of high-quality genetic maps to assist in the assembly of reference genome sequences for polyploid species. C ommon marker systems, such as Amplified Fragment Length Polymorphism (AFLP) and Simple Sequence Repeat (SSR), have been successfully used in the last few decades for several types of genetic studies, including diversity analysis, genetic mapping, quantitative trait locus (QTL) mapping, synteny (co-linearity) definition, co-ancestry estimation, and more. However, most of these applications have been developed in diploid plant species in which the theoretical foundation for analysis and interpretation of the results has already been established. These tools are less developed for autopolyploids, i.e., organisms that have more than two sets of chromosomes of the same type and origin 1. Despite the fact that great progress has been made using marker systems in autotetraploids (e.g., potato), other, more complex polyploid species, such as sugarcane, strawberry, and some forage crops, have not yet fully benefited from molecular marker information. This is because several unrealistic and simplified assumptions need to be made. AFLP and SSR (and even RFLP) do not allow a straightforward estimation of the number of copies of each allele (dosage) at a given polymorphic locus in complex polyploids (species with more than four chromosomes per homology group). For example, in sugarcane, there are approximately 22 linkage maps 2 , and only a few of these maps include loci with high allelic doses. The scenario is similar for QTL studies 3. Some models have attempted to consider the effects of QTL dosage 4,5 , but these models still rely on marker data that are not fully informative. In Saccharomyces cerevisiae,

Background: Sugarcane is the source of sugar in all tropical and subtropical countries and is becoming increasingly important for bio-based fuels. However, its large (10 Gb), polyploid, complex genome has hindered genome based breeding efforts. Here we release the largest and most diverse set of sugarcane genome sequences to date, as part of an ongoing initiative to provide a sugarcane genomic information resource, with the ultimate goal of producing a gold standard genome. Results: Three hundred and seventeen chiefly euchromatic BACs were sequenced. A reference set of one thousand four hundred manually-annotated protein-coding genes was generated. A small RNA collection and a RNA-seq library were used to explore expression patterns and the sRNA landscape. In the sucrose and starch metabolism pathway, 16 non-redundant enzyme-encoding genes were identified. One of the sucrose pathway genes, sucrose-6-phosphate phosphohydrolase, is duplicated in sugarcane and sorghum, but not in rice and maize. A diversity analysis of the s6pp duplication region revealed haplotype-structured sequence composition. Examination of hom(e)ologous loci indicate both sequence structural and sRNA landscape variation. A synteny analysis shows that the sugarcane genome has expanded relative to the sorghum genome, largely due to the presence of transposable elements and uncharacterized intergenic and intronic sequences. Conclusion: This release of sugarcane genomic sequences will advance our understanding of sugarcane genetics and contribute to the development of molecular tools for breeding purposes and gene discovery.

Karyotypes of three microhylid frog species of the Malagasy relict genus Scaphiophryne were studied: Scaphiophryne gottlebei, S. madagascariensis and S. spinosa. The latter two showed a plesiomorphic ranoid karyotype of 2n = 26. In contrast, tetraploidy was demonstrated in S. gottlebei, which constitutes an exceptional state among Malagasy amphibians. A combination of different banding techniques and of rDNA-FISH provided evidence

Karyological and flow cytometric (FCM) analyses were performed on a group of 14 green toads of the Bufo viridis species from seven Eurasian populations. Both approaches gave concordant results concerning the DNA ploidy level. All the populations examined were represented exclusively by diploid or tetraploid specimens, except one, where triploids were found. Results evidenced an interpopulation variability in DNA content against the same ploidy level, as well as an unusually high number of triploids in a particular reproductive place. The origin of polyploidy and the presence and persistence of a high number of triploids in a particular population are discussed.