Assessing morphological characteristics of elite Cocoa accessions (Theobroma cacao L.) in Makira Island, Solomon Islands

Characterization in Theobroma cacao L. based on the suggested Australian Center for International Agricultural Research(ACIAR) guidelines is observed to be important to encourage fine quality Cocoa production, and to realize remunerative income. Hence, 40 Cocoa accessions collected from fields distributed under different wards of Makira Island of the Solomon Islands were characterize for nine quantitative and qualitative morphological traits. Among the identified Cocoa accessions,Principal Component Analysis (PCA) grouped all the traits into three major Principal Components (PC) accounted 46.2% of total variation. PC axis one accounted for 23.1% of total variation explained by pod weight, pod circumference, cotyledon length, pod length, cotyledon width, pod external thickness, mature pod ridge color (anthocyanin), pod surface texture, pod surface shape and pod shape. The 12.2% of total variation in PC axis two was considerably attributed by the qualitative traits cotyledon color, pod surface texture , mature pod ridge color (anthocyanin), pod surface shape, cotyledon width, pod shape and tree vigor. While, PC axis three accounted for 10.9% of total variation referred to traits pod neck, pod surface shape, pod surface texture, pod length, tree vigor, pod internal thickness, weight of the bean per pod, pod external thickness, number of beans per pod, pod weight and reaction to black pod. Unweighted Pair Group Mean with Arithmetic Average (UPGMA)classified the 40 accessions in to three clusters. Under Cluster 1, 95.5% of identified accessions were grouped by traits such as cotyledon length and cotyledon width, red pods tree. While, Cluster 2 made up of 5% of total number of accessions with traits least pod weight, least pod external thickness, least cotyledon length and red podded trees. A single accession in Cluster 3 characterized by longest pod and constituted only 2.5% of the total accession. The frequency distribution of the nine qualitative traits confirmed that, 90% of identified accessions exhibited pod surface texture as smooth and slightly rough, 97% with pod surface shape as slightly furrowed with medium furrows and 85% with Amelonado pod shape. Most of the identified Cocoa accessions, grouped into three pod apex shapes traits such as Mammelate, Acute and Obtuse,accounting for 44, 25 and 20%, respectively. Of the total accessions studied, 63% had no anthocyanin on the mature pod ridge. Each of 72% measured as the strength of the accessions to withstand Phytophthora palmivora, and vigorous. The Shannon Weaver Diversity Index characterized and suggested that the Cocoa accessions in Makira Island mainly resemble to Amelonado (bulk) type, usually classified as Forasterio variety

Mango Breeding Support

The Mango Breeding Support project provided technical, research and development support to the Queensland-based, Australian Mango Breeding Program to develop and evaluate breeding systems and technologies that improve mango breeding efficiency. Adoption of efficient breeding support technologies will allow breeders to identify genes for desirable plant and fruit traits in parent varieties and incorporate those genes into new hybrid varieties more efficiently and rapidly. The project compared traditional hand pollination methods with DNA marker assisted selection (MAS) open-pollinated methods to identify paternity and found both systems had advantages. Marker assisted paternity identification was not practical in all cases and relied on a greater range of technical skills and resources being available to the breeder. It is expected that MAS will become even more efficient when markers are available for production and quality traits in addition to parental identification. Breeding for anthracnose resistance in mango is in its infancy. This project has identified several accessions in related Mangifera species with potential tolerance to postharvest anthracnose and tested the compatibility of these related species with the common mango and if the tolerance is transferable. The project investigated ways of determining a trees postharvest fruit disease resistance status in seedlings to avoid the up to 6 year wait for trees to crop. Identification of genes and gene markers for plant development, stress response, fruit colour and flavour development was another goal of this project. Twenty five new expressed sequence tag (EST) derived single sequence repeat (SSR) DNA markers were identified and tested across a diverse range of germplasm. These markers were shown to be useful in determining genetic relationships, exploring potential pedigrees and estimating the genetic background of cultivated accessions of M. indica. They are the first reported EST-SSR markers suitable to cross-amplify in five wild Mangifera species. The technologies that have been shown to be more efficient have been incorporated in to the Australian Mango Breeding Project. Other technologies being researched that are not yet fully developed to the stage where they can be adopted in a working breeding program are being progressed in other related research projects

Mango germplasm screening for the identification of sources of tolerance to anthracnose

Colletotrichum species are one of the most common causes of postharvest fruit rot in mango in Australia, particularly in the tropical region of north Queensland, and can result in significant losses if not managed. The research aims were to identify sources of anthracnose tolerance and to determine if host material other than fruit could improve or fast track the screening process and result in improved breeding efficiency. Access to the Australian National Mango Genebank (ANMG) collection enabled fruit screening of more than 100 Mangifera indica cultivars or Mangifera species for tolerance to anthracnose by artificial inoculation with Colletotrichum asianum over a period of 14 years. Mean lesion diameters were compared with those on a known susceptible M. indica cultivar Kensington Pride (KP) and a tolerant M. laurina cultivar Lombok. Inoculation of leaf discs and entire leaves was evaluated in the laboratory and the field as alternative assays for tolerance to anthracnose and was assessed by presence/absence of disease. Screening of fruit has shown that anthracnose tolerance within the mango germplasm is highly variable and needs to be assessed over multiple years. None of the alternative laboratory bioassays provided consistent or reliable data. The in-field artificial inoculation of immature leaf flush was successful but was not deemed suitable for adoption due to practical restraints. While resistance to anthracnose in fruit has not yet been identified, some cultivars and Mangifera spp. showed promise for inclusion as parents in future breeding programs

Text messaging and brief phone calls for weight loss in overweight and obese English- and Spanish-speaking adults: A 1-year, parallel-group, randomized controlled trial.

BACKGROUND:Weight loss interventions based solely on text messaging (short message service [SMS]) have been shown to be modestly effective for short periods of time and in some populations, but limited evidence is available for positive longer-term outcomes and for efficacy in Hispanic populations. Also, little is known about the comparative efficacy of weight loss interventions that use SMS coupled with brief, technology-mediated contact with health coaches, an important issue when considering the scalability and cost of interventions. We examined the efficacy of a 1-year intervention designed to reduce weight among overweight and obese English- and Spanish-speaking adults via SMS alone (ConTxt) or in combination with brief, monthly health-coaching calls. ConTxt offered 2-4 SMS/day that were personalized, tailored, and interactive. Content was theory- and evidence-based and focused on reducing energy intake and increasing energy expenditure. Monthly health-coaching calls (5-10 minutes' duration) focused on goal-setting, identifying barriers to achieving goals, and self-monitoring. METHODS AND FINDINGS:English- and Spanish-speaking adults were recruited from October 2011 to March 2013. A total of 298 overweight (body mass index [BMI] 27.0 to 39.9 kg/m2) adults (aged 21-60 years; 77% female; 41% Hispanic; 21% primarily Spanish speaking; 44% college graduates or higher; 22% unemployed) were randomly assigned (1:1) to receive either ConTxt only (n = 101), ConTxt plus health-coaching calls (n = 96), or standard print materials on weight reduction (control group, n = 101). We used computer-based permuted-block randomization with block sizes of three or six, stratified by sex and Spanish-speaking status. Participants, study staff, and investigators were masked until the intervention was assigned. The primary outcome was objectively measured percent of weight loss from baseline at 12 months. Differences between groups were evaluated using linear mixed-effects regression within an intention-to-treat framework. A total of 261 (87.2%) and 253 (84.9%) participants completed 6- and 12-month visits, respectively. Loss to follow-up did not differ by study group. Mean (95% confidence intervals [CIs]) percent weight loss at 12 months was -0.61 (-1.99 to 0.77) in the control group, -1.68 (-3.08 to -0.27) in ConTxt only, and -3.63 (-5.05 to -2.81) in ConTxt plus health-coaching calls. At 12 months, mean (95% CI) percent weight loss, adjusted for baseline BMI, was significantly different between ConTxt plus health-coaching calls and the control group (-3.0 [-4.99 to -1.04], p = 0.003) but not between the ConTxt-only and the control group (-1.07 [-3.05 to 0.92], p = 0.291). Differences between ConTxt plus health-coaching calls and ConTxt only were not significant (-1.95 [-3.96 to 0.06], p = 0.057). These findings were consistent across other weight-related secondary outcomes, including changes in absolute weight, BMI, and percent body fat at 12 months. Exploratory subgroup analyses suggested that Spanish speakers responded more favorably to ConTxt plus health-coaching calls than English speakers (Spanish contrast: -7.90 [-11.94 to -3.86], p < 0.001; English contrast: -1.82 [-4.03 to 0.39], p = 0.107). Limitations include the unblinded delivery of the intervention and recruitment of a predominantly female sample from a single site. CONCLUSIONS:A 1-year intervention that delivered theory- and evidence-based weight loss content via daily personalized, tailored, and interactive SMS was most effective when combined with brief, monthly phone calls. TRIAL REGISTRATION:ClinicalTrials.gov NCT01171586

The influence of genetic structure on phenotypic diversity in the Australian mango (Mangifera indica) gene pool

Genomic selection is a promising breeding technique for tree crops to accelerate the development of new cultivars. However, factors such as genetic structure can create spurious associations between genotype and phenotype due to the shared history between populations with different trait values. Genetic structure can therefore reduce the accuracy of the genotype to phenotype map, a fundamental requirement of genomic selection models. Here, we employed 272 single nucleotide polymorphisms from 208 Mangifera indica accessions to explore whether the genetic structure of the Australian mango gene pool explained variation in trunk circumference, fruit blush colour and intensity. Multiple population genetic analyses indicate the presence of four genetic clusters and show that the most genetically differentiated cluster contains accessions imported from Southeast Asia (mainly those from Thailand). We find that genetic structure was strongly associated with three traits: trunk circumference, fruit blush colour and intensity in M. indica. This suggests that the history of these accessions could drive spurious associations between loci and key mango phenotypes in the Australian mango gene pool. Incorporating such genetic structure in associations between genotype and phenotype can improve the accuracy of genomic selection, which can assist the future development of new cultivars. © 2022, The Author(s)

The influence of genetic structure on phenotypic diversity in the Australian mango (Mangifera indica) gene pool

Genomic selection is a promising breeding technique for tree crops to accelerate the development of new cultivars. However, factors such as genetic structure can create spurious associations between genotype and phenotype due to the shared history between populations with different trait values. Genetic structure can therefore reduce the accuracy of the genotype to phenotype map, a fundamental requirement of genomic selection models. Here, we employed 272 single nucleotide polymorphisms from 208 Mangifera indica accessions to explore whether the genetic structure of the Australian mango gene pool explained variation in trunk circumference, fruit blush colour and intensity. Multiple population genetic analyses indicate the presence of four genetic clusters and show that the most genetically differentiated cluster contains accessions imported from Southeast Asia (mainly those from Thailand). We find that genetic structure was strongly associated with three traits: trunk circumference, fruit blush colour and intensity in M. indica. This suggests that the history of these accessions could drive spurious associations between loci and key mango phenotypes in the Australian mango gene pool. Incorporating such genetic structure in associations between genotype and phenotype can improve the accuracy of genomic selection, which can assist the future development of new cultivars. © 2022, The Author(s)

Promotor insertion leads to polyembryony in mango – a case of convergent evolution with citrus

Sexual reproduction in plants is the main pathway for creating new genetic combinations in modern agriculture. In heterozygous plants, after the identification of a plant with desired traits, vegetative propagation (cloning) is the primary path to create genetically uniform plants. Another natural plant mechanism that creates genetically uniform plants (clones) is apomixis. In fruit crops like citrus and mango, sporophytic apomixis results in polyembryony, where seeds contain multiple embryos, one is sexually originated and the others are vegetative clones of the parent mother tree. Utilizing the mango genome and genetic analysis of a diverse germplasm collection, we identified MiRWP as the gene that causes polyembryony in mango. There is a strong correlation between a specific insertion in the gene’s promoter region and altered expression in flowers and developing fruitlets, inducing multiple embryos. The MiRWP gene is an ortholog of CitRWP that causes polyembryony in citrus. Based on the data, we speculate that promoter insertion events, which occurred independently in citrus and mango, induced nucellar embryogenesis. The results suggest convergent evolution of polyembryony in the two species. Further work is required to demonstrate the utility of these genes (mango and citrus) in other biological systems as a tool for the clonal production of other crops

The ‘Tommy Atkins’ mango genome reveals candidate genes for fruit quality

Mango, Mangifera indica L., an important tropical fruit crop, is grown for its sweet and aromatic fruits. Past improvement of this species has predominantly relied on chance seedlings derived from over 1000 cultivars in the Indian sub-continent with a large variation for fruit size, yield, biotic and abiotic stress resistance, and fruit quality among other traits. Historically, mango has been an orphan crop with very limited molecular information. Only recently have molecular and genomics-based analyses enabled the creation of linkage maps, transcriptomes, and diversity analysis of large collections. Additionally, the combined analysis of genomic and phenotypic information is poised to improve mango breeding efficiency

Introductory programming: a systematic literature review

As computing becomes a mainstream discipline embedded in the school curriculum and acts as an enabler for an increasing range of academic disciplines in higher education, the literature on introductory programming is growing. Although there have been several reviews that focus on specific aspects of introductory programming, there has been no broad overview of the literature exploring recent trends across the breadth of introductory programming. This paper is the report of an ITiCSE working group that conducted a systematic review in order to gain an overview of the introductory programming literature. Partitioning the literature into papers addressing the student, teaching, the curriculum, and assessment, we explore trends, highlight advances in knowledge over the past 15 years, and indicate possible directions for future research

CXCR4 involvement in neurodegenerative diseases

Neurodegenerative diseases likely share common underlying pathobiology. Although prior work has identified susceptibility loci associated with various dementias, few, if any, studies have systematically evaluated shared genetic risk across several neurodegenerative diseases. Using genome-wide association data from large studies (total n = 82,337 cases and controls), we utilized a previously validated approach to identify genetic overlap and reveal common pathways between progressive supranuclear palsy (PSP), frontotemporal dementia (FTD), Parkinson's disease (PD) and Alzheimer's disease (AD). In addition to the MAPT H1 haplotype, we identified a variant near the chemokine receptor CXCR4 that was jointly associated with increased risk for PSP and PD. Using bioinformatics tools, we found strong physical interactions between CXCR4 and four microglia related genes, namely CXCL12, TLR2, RALB, and CCR5. Evaluating gene expression from post-mortem brain tissue, we found that expression of CXCR4 and microglial genes functionally related to CXCR4 was dysregulated across a number of neurodegenerative diseases. Furthermore, in a mouse model of tauopathy, expression of CXCR4 and functionally associated genes was significantly altered in regions of the mouse brain that accumulate neurofibrillary tangles most robustly. Beyond MAPT, we show dysregulation of CXCR4 expression in PSP, PD, and FTD brains, and mouse models of tau pathology. Our multi-modal findings suggest that abnormal signaling across a 'network' of microglial genes may contribute to neurodegeneration and may have potential implications for clinical trials targeting immune dysfunction in patients with neurodegenerative diseases