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The study investigated the effect of albedo and flavedo extracts of grapefruit and pomelo on storage stability of turkey patties during refrigerated storage. Five different types of products were developed depending on the addition of extracts viz. control (C), albedo and flavedo extract of grapefruit (GA and GF), and albedo and flavedo extract of pomelo (PA and PF). The products were stored for 10 days and evaluated for lipid and protein oxidation, pH, colour and sensory properties. The extracts improved the lipid oxidative stability by decreasing (P < 0.05) the TBARS values of the samples compared to control group. No effect of the extract treatments (P > 0.05) was observed on pH and colour values of the products (a* and b*). The lowest TBARS values were found for the products containing GF (0.78 mg MA/kg) on day 4. The treatments showed a significant impact on flavour of the products and the highest scores were obtained for PA containing products. [ABSTRACT FROM AUTHOR]

Delayed greening of young leaves is an unusual phenomenon of plants in nature. Citrus are mostly evergreen tree species. Here, a natural mutant of "Guanxi" pummelo (Citrus maxima), which shows yellow leaves at the young stage, was characterized to identify the genes underlying the trait of delayed leaf greening in plants. A segregating population with this mutant as the seed parent and a normal genotype as the pollen parent was generated. Two DNA pools respectively from the leaves of segregating seedlings with extreme phenotypes of normal leaf greening and delayed leaf greening were collected for sequencing. Bulked segregant analysis (BSA) and InDel marker analysis demonstrated that the delayed leaf greening trait is governed by a 0.3 Mb candidate region on chromosome 6. Gene expression analysis further identified a key candidate gene (Citrus Delayed Greening gene 1, CDG1) in the 0.3 Mb region, which showed significantly differential expression between the genotypes with delayed and normal leaf greening phenotypes. There was a 67 bp InDel region difference in the CDG1 promoter and the InDel region contains a TATA-box element. Confocal laser-scanning microscopy revealed that the CDG1-GFP fusion protein signals were co-localized with the chloroplast signals in the protoplasts. Overexpression of CDG1 in tobacco and Arabidopsis led to the phenotype of delayed leaf greening. These results suggest that the CDG1 gene is involved in controlling the delayed leaf greening phenotype with important functions in chloroplast development. [ABSTRACT FROM AUTHOR]

Gametophytic self-incompatibility, one of the key characters for production of seedless citrus, is known in pummelo [Citrus maxima (Burm.) Merr.], mandarin (C. reticulata Blanco) and their hybrid cultivars. The allelic variation in Citrus was reported for the self-incompatibility gene (S). However, S allele frequencies and S genotypes of self-incompatible and semi-self-incompatible Citrus cultivars were known only in a few S alleles. In the present study, S3 and S11 alleles were examined with homozygous S1 seedlings (S3S3 and S11S11) of self-incompatible Clementine mandarin (C. clementina hort. ex Tanaka; S3S11) a putative hybrid between self-compatible 'Mediterranean' mandarin (C. deliciosa Ten.) and self-compatible sweet orange [C. sinensis (L.) Osbeck]. One-hundred-forty-six Citrus accessions, including 43 pummelo accessions, were pollinated with each of the homozygous S1 seedlings (S3S3 and S11S11). Pollen tube arrest in the styles of their pollinated pistils indicated that 25 accessions, including Clementine, have an S3 allele each and 18 accessions, including Clementine, have an S11 allele each. Frequency of accessions with S3 allele was 17.7% (25 of 141 accessions examined) and S3 allele frequency was 11.8% (25 of 212 alleles excluding Sf self-compatible allele). Frequency of accessions with S11 allele was 13.2% (18 of 136 accessions examined) and S11 allele frequency was 8.8% (18 of 205 alleles excluding Sf allele). Pummelo accessions have S3 and S11 alleles with the frequencies of 12.2% and 33.3% respectively, suggesting that the two alleles originated from pummelo. Clementine shared S3 allele with two navel oranges, ten common oranges and two tangors, but not with three blood oranges. In the three blood oranges, it was suggested that stylar part mutation (S3sm) resulting in cross compatibility with S3 pollen occurred in their common ancestor. Clementine shared S11 allele with two tangors but did not share it with 'Mediterranean' mandarin. The present result for S3 and S11 alleles in Citrus accessions suggests that the two S alleles expanded their distribution in Citrus plants including sweet orange along with stylar part mutation for S3 allele during long history of cultivation. [ABSTRACT FROM AUTHOR]

Thirty-seven chloroplast molecular markers were used to evaluate the genetic diversity and infer the phylogenetic relationship of 24 Algerian Citrus accessions from the Institut Technique de l′Arboriculture Fruitière et de la Vigne germplasm bank. The reliability and consistence of the clustering distribution was further asserted including 5 Spanish accessions from the Instituto Valenciano de Investigaciones Agrarias. The accessions were positioned on a phylogenetic tree of the genus Citrus based on previous analyses of the whole sequence of citrus chloroplast. Algerian accessions clustered into two main clades mostly differentiated by the occurrence of either mandarin or pummelo chloroplast types. All 7 mandarins analyzed were grouped in the same clade while the other cluster subdivided in 4 groups, included 1 lumia, 3 lemons, 2 grapefruits and 11 sweet oranges. Algerian grapefruit accessions were grouped together with the pummelos in a single cluster while all sweet oranges formed an independent and homogenous clade. Interestingly, the lemons studied were clustered in 3 different subclusters while Citrus lumia genotype was isolated in a different group. These results suggest that in contrast to the studied Algerian mandarins or sweet oranges, that share all the same mandarin or sweet orange chloroplast haplotype, the high diversity of current lemon accessions is at least partially correlated with the identity of different pummelo progenitors which evolved from a common ancestor. In addition, the data indicate that Citrus lumia is a new type of citrus chloroplast that appears to be phylogenetically related to the chloroplasts of the pummelo and micrantha group. [ABSTRACT FROM AUTHOR]

Pummelo ( Citrus maxima) is one of the basic species of Citrus. It has been cultivated for about 4000 years in China, and therefore, there are abundant germplasm during the long time of culture. However, there is still a lack of a detailed study of the genetic characteristics of pummelo population. In this study, genetic diversity and population structure among 274 pummelo accessions collected in China were analyzed using 31 nuclear simple sequence repeat (nSSR) markers. The observed heterozygosity was calculated as 0.325 and genetic differentiation Fst as 0.077. Genetic structure analysis divided the whole germplasm into three subpopulations, Pop-a, Pop-b, and Pop-c. Pop-a was composed of accessions mostly from Southeast China, Pop-b was composed of accessions from the central region of South China, and Pop-c was composed of accessions from Southwest China. Meanwhile, the analysis of principal coordinate analysis and neighbor-join tree supported the viewpoint of three subpopulations, and then the possible dispersal routes of pummelos in China were proposed. This study provides an insight into the genetic diversity, facilitates future genome-wide association studies, and promotes the breeding program of pummelo as well. [ABSTRACT FROM AUTHOR]

Vis/NIR spectroscopy was used in combination with pattern recognition methods to identify cultivars of pummelo ( Citrus grandis (L.) Osbeck). A total of 240 leaf samples, 60 for each of the four cultivars were analyzed by Vis/NIR spectroscopy. Soft independent modeling of class analogy (SIMCA), partial least square discriminant analysis (PLS-DA), back propagation neural network (BPNN) and least squares support vector machine (LS-SVM) were applied to the spectral data. The first 8 principal components extracted by principal component analysis were used as inputs in building the BPNN and the LS-SVM models. The results showed that a 97.92 % of discrimination accuracy was achieved for both the BPNN and the LS-SVM models when used to identify samples of the validation set, indicating that the performance of the two models was acceptable. Comparatively, the results of the PLS-DA and the SIMCA models were unacceptable because they had lower discrimination accuracy. The overall results demonstrated that use of Vis/NIR spectroscopy coupled with the use of BPNN and LS-SVM could achieve an accurate identification of pummelo cultivars. [ABSTRACT FROM AUTHOR]

Pectinase and naringinase were investigated for improving the production of pummelo juice by increasing the juice yield and eliminating juice bitterness. Compared to a control, the enzymatic treatment significantly ( p<0.05) increased the juice yield, soluble pectin and total soluble solid (TSS) contents, and the clarity, while decreasing the concentrations of the bitter chemicals naringin, limonin, and nomilin. A combined processing treatment of peeling and enzymatic hydrolyses using 5U/g of pectinase and 0.4 U/g of naringinase at 50oC for 60 min resulted in a juice yield of 42.3%, a TSS content of 11.4oBx, a titrable acidity (TA) of 0.96%, a vitamin C concentration of 38.4 mg/100 mL, and concentrations of naringin, limonin, and nomilin of 42.4 μg/mL, 33.5 μg/mL, and 13.3 μg/mL, respectively. The enzymatic method was effective and practical for production of high quantity pummelo juice. [ABSTRACT FROM AUTHOR]

In the light of the serious economic crisis of 1997 and Agenda 21, as proposed in the United Nations Conference on Environment and Development in 1992, the Thai government has increased commitments to sustainable agricultural development. This paper examines how local Thai farmers are interacting with the policy imperatives of sustainable agriculture, focusing on the adoption of sustainable practices and farmer livelihoods. Two pummelo producing communities in Chaiyaphum province, Northeast Thailand were chosen as examples and compared: one, located in the highlands, focused on sales for local and domestic markets and the other, located in the lowlands, included sales for export. Both were involved in the implementation of Q-GAP, a public policy for good agricultural practices. The pummelo producers discursively sought the best combination of conventional and sustainable farming practices by balancing the benefits and risks concerning labour requirements, commercial results, financial risks associated with credit loans and investment and ecological sustainability. [ABSTRACT FROM AUTHOR]

Pummelo ( Citrus grandis) is one of the most important species found in the genus Citrus and one of the ancestors of sweet oranges. We used flower buds at different developmental stages to construct the first cDNA library for this species. A total of 3,758 EST sequences were generated from the cDNA library and clustered into 2,228 unigenes, comprising 451 contigs and 1,777 singletons. Among these unigene sequences, 1,266 have significant homology to the non-redundant protein database, from which 891 were assigned to one or more gene ontology categories. Functional categorization of the annotated unigenes showed that 760 genes were involved in molecular function, 1,189 in biological processes and 1,154 in cellular component categorization. Homologs of genes regulating many aspects of flower development were also identified, including those for organ development, cell-cycle control and cell and tissue differentiation. The majority of these genes (e.g., embryo relatives, YABBY-like, MAD Box, SKP-like and SRNAs) are the first representatives in Citrus, providing an opportunity to explore the cause of self incompatibility and embryo development in Citrus. Patterns of transcript accumulation were characterized by real-time qPCR for 13 of these genes. Many potential molecular markers were also identified in this EST data set; 212 Simple Sequences Repeats (SSRs), 717 transposon elements and 115 candidate single nucleotide polymorphisms (SNPs) were found. An assessment of a set of 212 SSR primer pairs on 16 citrus genotypes showed polymorphism with 122 (57.82%) markers. Similarly, a set of eight contigs were used to confirm in silico predicated SNPs in a set of five genotypes using wet lab experiments, three contigs were generated as scorable and sequenceable amplicons and no PCR amplicons were obtained from five contigs. The outcome of this study could aid in the discovery of genes involved in reproductive developments. Identified candidate genes can be experimentally tested for their functions in various important processes. SSR, SNP and transposon element-containing data sets may facilitate marker development and can be used for citrus molecular breeding, linkage map construction, evolutionary, phylogenetic and population genetic studies. [ABSTRACT FROM AUTHOR]

F-box proteins are a large family of eukaryotic proteins that contained a conserved motif of approximately 40 amino acids. They play an important role in the processing of degradation of cellular regulatory proteins. In this study we isolated a full-length of cDNA encoding a putative F-box protein from Citrus grandis Osbeck CV 'Zigui shatian' pummelo and designated as CgF- box. The cDNA sequence of CgF- box was 920 bp containing a 585 bp open reading frame encoding a precursor protein of 194 amino acid residues. The deduced protein comprised a conserved F-box domain at the position from the 40th to 84th amino acids. Cluster analysis suggested that CgF- box was more closely related to the grape F-Box protein. Southern hybridization verified CgF- box existed in the genome as multiple copies. The expression analysis revealed that the expression level of CgF- box gene remarkably increases during the flower developmental process of 'Zigui shatian' pummelo, such as high level of expression was noted in style, petal and anther, on the other hand low level of expression was found in ovary and leaf. For further verifying the different expression in different tissue of this gene, in situ hybridization was conducted, strong expression signal could be observed in the style, stigma and anther, low even no signal was observed in ovary. According to their findings we can conclude that CgF- box was not only involved in flower maturation, but also showed different roles in different tissue. [ABSTRACT FROM AUTHOR]

'Zigui shatian' pummelo ( Citrus grandis Osbeck) is one nature mutant from 'Shatian' pummelo, which showed self-compatibility, because self-pollen tubes were not arrested in the style, moreover abnormal post-zygotic development in ovary caused seed abortion in the cultivar. Herein we constructed a cDNA library from flowers of 'Zigui shatian' pummelo and identified one RNase gene fragment. The full length of cDNA sequence of this gene, with an open reading frame of 834 bp, was isolated by 5′-RACE method. The gene, named as CgSL2, contained five conserved regions and two histidine residues essential for RNase activity. Phylogenetic analysis indicated that CgSL2 was mostly similar to AhSL28, an S-like RNase from Antirrhinum. Southern hybridization verified CgSL2 existed in the genome as multiple copies. qRT-PCR and RT-PCR analysis showed that the expression of CgSL2 was not tissue-specific. The expression of CgSL2 was down-regulated during senescence of stem, petal, style and stamen, whereas up-regulated during ovary senescence. Further in situ hybridization of CgSL2 in the ovary during the balloon stage to anthesis stage also showed that it dramatically increased in mature flower, consistent with qRT-PCR and RT-PCR results. These findings suggested that CgSL2 might play an important role during ovary senescence. [ABSTRACT FROM AUTHOR]

'Shatian' pummelo ( Citrus grandis Osbeck), one of the main citrus cultivars in China, is self-incompatible, and its pollen tubes are believed to be arrested in style after self-pollination.We have characterized one 'Shatian' pummelo mutant, named 'Zigui shatian' pummelo. The mutant pummelo had identical DNA ploidy level, morphology (leaf shape, stoma size and density, pollen shape and size) and developmental progress of pistil and male organs to that of the common 'Shatian' pummelo. However, unlike the common 'Shatian' pummelo, 'Zigui shatian' is self-compatible since its pollen tubes can self-pollinate allowing for successful fertilization. Histological analyses of 'Shatian' pummelo further verified abnormal post-zygotic development which led to seed abortion. Simple sequence repeats (SSR) analysis revealed polymorphism in 1 of the 120 primers screened showing that 'Zigui shatian' and 'Shatian' pummelo are different at the DNA level. Taken together, these data suggested mutant 'Zigui shatian' pummelo might be derived from 'Shatian' pummelo with self-sterility by self-incongruity after self-fertilization. [ABSTRACT FROM AUTHOR]

The main purpose of this work was to investigate the effect of pummelo juice on the pharmacokinetics of sildenafil after oral administration. This was a comparative, randomized, two-period, two-treatment, two-sequence, single dose, crossover study investigating the effect of pummelo juice on the pharmacokinetics of sildenafil citrate tablets (equivalent to 50 mg sildenafil) in healthy male participants under fasting conditions compared with water as a control. Six healthy normal adult males were administered 50 mg sildenafil with pummelo juice or water at two different periods in a crossover study. Study results showed that pummelo juice reduced the rate and extent of sildenafil bioavailability to around 60% [maximum plasma concentration (Cmax); from 212.44 ng/ml to 134.07 ng/ml, 90% confidence interval (90% CI) 44.70–89.11, and area under the plasma concentration time curve from zero to infinity (AUC∞); from 564.51 ng.hr/ml to 336.87 ng.hr/ml, 90% CI 39.17–90.92]. This interaction was opposite to that expected and is speculated to be due to either an effect on transporters or a physicochemical interaction between sildenafil and some components of the juice. Patients should be advised not to drink pummelo juice before or immediately after taking sildenafil. [ABSTRACT FROM AUTHOR]