Genetic Variation, Heritability, and Diversity Analysis of Upland Rice (Oryza sativa L.) Genotypes Based on Quantitative Traits

Upland rice is important for sustainable crop production to meet future food demands. The expansion in area of irrigated rice faces limitations due to water scarcity resulting from climate change. Therefore, this research aimed to identify potential genotypes and suitable traits of upland rice germplasm for breeding programmes. Forty-three genotypes were evaluated in a randomised complete block design with three replications. All genotypes exhibited a wide and significant variation for 22 traits. The highest phenotypic and genotypic coefficient of variation was recorded for the number of filled grains/panicle and yields/plant (g). The highest heritability was found for photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO 2 , and number of filled grains/panicle and yields/plant (g). Cluster analysis based on 22 traits grouped the 43 rice genotypes into five clusters. Cluster II was the largest and consisted of 20 genotypes mostly originating from the Philippines. The first four principle components of 22 traits accounted for about 72% of the total variation and indicated a wide variation among the genotypes. The selected best trait of the number of filled grains/panicle and yields/plant (g), which showed high heritability and high genetic advance, could be used as a selection criterion for hybridisation programmes in the future

Interaction of plant growth regulators and reactive oxygen species to regulate petal senescence in wallflowers (Erysimum linifolium)

Background In many species floral senescence is coordinated by ethylene. Endogenous levels rise, and exogenous application accelerates senescence. Furthermore, floral senescence is often associated with increased reactive oxygen species, and is delayed by exogenously applied cytokinin. However, how these processes are linked remains largely unresolved. Erysimum linifolium (wallflower) provides an excellent model for understanding these interactions due to its easily staged flowers and close taxonomic relationship to Arabidopsis. This has facilitated microarray analysis of gene expression during petal senescence and provided gene markers for following the effects of treatments on different regulatory pathways. Results In detached Erysimum linifolium (wallflower) flowers ethylene production peaks in open flowers. Furthermore senescence is delayed by treatments with the ethylene signalling inhibitor silver thiosulphate, and accelerated with ethylene released by 2-chloroethylphosphonic acid. Both treatments with exogenous cytokinin, or 6-methyl purine (which is an inhibitor of cytokinin oxidase), delay petal senescence. However, treatment with cytokinin also increases ethylene biosynthesis. Despite the similar effects on senescence, transcript abundance of gene markers is affected differentially by the treatments. A significant rise in transcript abundance of WLS73 (a putative aminocyclopropanecarboxylate oxidase) was abolished by cytokinin or 6-methyl purine treatments. In contrast, WFSAG12 transcript (a senescence marker) continued to accumulate significantly, albeit at a reduced rate. Silver thiosulphate suppressed the increase in transcript abundance both of WFSAG12 and WLS73. Activity of reactive oxygen species scavenging enzymes changed during senescence. Treatments that increased cytokinin levels, or inhibited ethylene action, reduced accumulation of hydrogen peroxide. Furthermore, although auxin levels rose with senescence, treatments that delayed early senescence did not affect transcript abundance of WPS46, an auxin-induced gene. Conclusions A model for the interaction between cytokinins, ethylene, reactive oxygen species and auxin in the regulation of floral senescence in wallflowers is proposed. The combined increase in ethylene and reduction in cytokinin triggers the initiation of senescence and these two plant growth regulators directly or indirectly result in increased reactive oxygen species levels. A fall in conjugated auxin and/or the total auxin pool eventually triggers abscission

Genetic Variation, Heritability, and Diversity Analysis of Upland Rice (Oryza sativa L.) Genotypes Based on Quantitative Traits

Upland rice is important for sustainable crop production to meet future food demands. The expansion in area of irrigated rice faces limitations due to water scarcity resulting from climate change. Therefore, this research aimed to identify potential genotypes and suitable traits of upland rice germplasm for breeding programmes. Forty-three genotypes were evaluated in a randomised complete block design with three replications. All genotypes exhibited a wide and significant variation for 22 traits. The highest phenotypic and genotypic coefficient of variation was recorded for the number of filled grains/panicle and yields/plant (g). The highest heritability was found for photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO and number of filled grains/panicle and yields/plant (g). Cluster analysis based on 22 traits grouped the 43 rice genotypes into five clusters. Cluster II was the largest and consisted of 20 genotypes mostly originating from the Philippines. The first four principle components of 22 traits accounted for about 72% of the total variation and indicated a wide variation among the genotypes. The selected best trait of the number of filled grains/panicle and yields/plant (g), which showed high heritability and high genetic advance, could be used as a selection criterion for hybridisation programmes in the futur

Lowe’s Otter Civet Cynogale lowei does not exist

Lowe’s Otter Civet Cynogale lowei is known from only one specimen, which was collected in the winter of 1926-27 in northern Vietnam. It has been considered to be a global priority for small carnivore conservation. Its taxonomic status – a species or a highly disjunct subspecies of Otter Civet C. bennettii – has been debated. This study assessed the taxonomic validity of Lowe’s Otter Civet through three principal methods: (i) a gross morphological comparison of tropical Asian otters, Otter Civet and ‘Specimen 1927.12.1.93’ (the Lowe’s Otter Civet holotype), (ii) microscopic hair analysis from museum specimens of tropical Asian otters, Otter Civet and Specimen 1927.12.1.93 and (iii) DNA analysis of genetic material extracted from Specimen 1927.12.1.93, which was then compared with sequences from tropical Asian otters and Otter Civet. All methods indicated that the specimen is a juvenile Eurasian Otter Lutra lutra. The IUCN SSC Small Carnivore Specialist Group, conservation donors and practitioners should all immediately disregard ’Lowe’s Otter Civet’ as a priority, to ensure that the limited resources for conservation are not wasted

Virtual reality prototype of a linear accelerator simulator for oncological radiotherapy training

Learning to operate medical equipment is one of the essential skills for providing efficient treatment to patients. One of the current problems faced by many medical institutions is the lack or shortage of specialized infrastructure for medical practitioners to conduct hands-on training. Medical equipment is mostly used for patients, limiting training time drastically. Virtual simulation can help alleviate this problem by providing the virtual embodiment of the medical facility in an affordable manner. This paper reports the current results of an ongoing project aimed at providing virtual reality-based technical training on various medical equipment to radiophysicist trainees. In particular, we introduce a virtual reality (VR) prototype of a linear accelerator simulator for oncological radiotherapy training. The paper discusses the main challenges and features of the VR prototype, including the system design and implementation. A key factor for trainees’ access and usability is the user interface, particularly tailored in our prototype to provide a powerful and versatile yet friendly user interaction

The first complete mitochondrial genome data of geoffroy's rousette, rousettus amplexicaudatus originating from Malaysia

The increasing interest in understanding the evolutionary relationship between members of the Pteropodidae family has been greatly aided by genomic data from the Old World fruit bats. Here we present the complete mitogenome of Geoffroy’s rousette, Rousettus amplexicaudatus found in Peninsular Malaysia. The mitogenome constructed is 16,511bp in length containing 37 genes; 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and a D-loop region. The overall base composition is estimated to be 32.28% for A, 25.64% for T, 14.09% for G and 27.98% for C, indicating a slightly AT rich feature (57.93%). A phylogenetic and BLASTn analysis against other available mitogenomes showed Malaysian R. amplexicaudatus matched 98% similarity to the same species in Cambodia and Vietnam. However, it differed considerably (92.53% similarity) with the same species in the Philippines. This suggests flexibility in Rousettus sp. with regards to adapting to mesic and dry habitats, ability for long-distance dispersal and remarkably precise lingual echolocation thus supporting its wide-range distribution and colonization. Further taxonomical and mitogenomic comparatives are required in resolving the evolutionary relationship between Rousettus spp

Molecular identification and phylogenetic analysis of a Callosciurus notatus complete mitogenome from Peninsular Malaysia

The mitogenome of a plantain squirrel, Callosciurus notatus, collected from Bukit Tarek Forest Reserve (Extension), Selangor, Malaysia was sequenced using BGISEQ-500RS technology. The 16,582 bp mitogenome consists of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and 1 control region. A phylogenetic and BLASTn analysis against other available datasets showed that the mitogenome matched with 99.49% similarity to a previously published C. notatus mitogenome from Peninsular Malaysia. However, it also diverged by nearly 8% (92.24% match) from a second previously published mitogenome for the same species, sampled in East Kalimantan, Indonesia. This suggests a difference in landscape features between both localities might affect its genetic connectivity

Exploring floral senescence without a model – the rich rewards of diversity

Floral senescence does not follow the same pattern in all flowering species. Flowers can be broadly divided between those in which petals abscise while still turgid and those in which petals wilt and may or may not abscise. Furthermore, flower senescence can also be divided into a further two groups. In one group of species ethylene is produced by the flowers as the senescence progresses, and acts as a major regulator of this process. In another group ethylene is not produced, or only at very low levels and does not act as a major senescence regulator. Broadly most species that show rapid abscission without wilting are ethylene sensitive whereas those that wilt are generally ethylene insensitive, although the demarcations are not absolute. Many monocotyledonous flowers including lilies, as well as most Asteraceae are ethylene insensitive, while ethylene sensitive species include orchids, carnations petunia and Brassicaceae including Arabidopsis. Given these major differences it has been difficult to find a suitable model to study floral senescence. However new tools such as transcriptomic analyses are offering new approaches to investigate common and divergent regulatory mechanisms. In the obvious model, Arabidopsis, senescence proceeds rapidly and within 48 h petals are abscised with only moderate wilting. Some progress has been made in identifying genes regulating ethylene-regulated senescence in Arabidopsis flowers, and some of these genes may also regulate senescence progression in other ethylene sensitive species. Abscission signals also appear to be shared across different floral senescence groups. A comparison of two lily genotypes that have contrasting senescence programmes identified genes related to abscission previously identified in Arabidopsis. However the regulation of senescence in ethylene-insensitive species remains problematic. Recent transcriptomic studies in lily and other species reveal families of transcription factors that may be involved. A further complexity in floral senescence is offered by composite flowers. A transcriptomic analysis of Dahlias is comparing senescence between florets and the whole inflorescence

An expanded mammal mitogenome dataset from Southeast Asia

Southeast (SE) Asia is 1 of the most biodiverse regions in the world, and it holds approximately 20% of all mammal species. Despite this, the majority of SE Asia's genetic diversity is still poorly characterized. The growing interest in using environmental DNA to assess and monitor SE Asian species, in particular threatened mammals—has created the urgent need to expand the available reference database of mitochondrial barcode and complete mitogenome sequences. We have partially addressed this need by generating 72 new mitogenome sequences reconstructed from DNA isolated from a range of historical and modern tissue samples. Approximately 55 gigabases of raw sequence were generated. From this data, we assembled 72 complete mitogenome sequences, with an average depth of coverage of ×102.9 and ×55.2 for modern samples and historical samples, respectively. This dataset represents 52 species, of which 30 species had no previous mitogenome data available. The mitogenomes were geotagged to their sampling location, where known, to display a detailed geographical distribution of the species. Our new database of 52 taxa will strongly enhance the utility of environmental DNA approaches for monitoring mammals in SE Asia as it greatly increases the likelihoods that identification of metabarcoding sequencing reads can be assigned to reference sequences. This magnifies the confidence in species detections and thus allows more robust surveys and monitoring programmes of SE Asia's threatened mammal biodiversity. The extensive collections of historical samples from SE Asia in western and SE Asian museums should serve as additional valuable material to further enrich this reference database