Project description:Parthenocarpy—the production of seedless fruits without fertilization—is very useful for fruit cultivation. Among pear cultivars (Japanese, Chinese, and European pears and their interspecific hybrids) subjected to flower emasculation and left unpollinated, only some of the European pears had a stable and high degree of fruit set and fruit enlargement. Almost all the enlarged fruits formed no seeds. Comparison of fruits produced by using emasculation without pollination or with self-pollination ruled out the possibility of stenospermocarpy in these parthenocarpic pears. The results suggested that the abovementioned characteristics were inherited maternally by the next generation and that it should be possible to introduce parthenocarpy into Japanese pears. Neither Chinese nor Japanese pears treated with emasculation and no pollination showed consistently stable fruit set or fruit enlargement. In Chinese pears, these characteristics varied greatly from year to year, and in Japanese pears they were stable but weak. Although in each cultivar highly parthenocarpic fruits weighed slightly less than cross-pollinated ones, the cortexes of the emasculated fruits were enlarged and the fruits were not greatly inferior to those of cross-pollinated ones. By using a customized pear cDNA microarray, we compared the gene expression profiles of highly and weakly parthenocarpic cultivars before flowering. Expression of several phenylpropanoid-related genes and photosystem-related genes differed significantly between the two groups. Some of these genes were contained in the chloroplast genome. These results showed the unique mechanism of genetic parthenocarpy in pome fruits as opposed to non-pome fruits. The gene expression profiles between high and low parthenocarpy group before flowering were compared.
Project description:Parthenocarpy—the production of seedless fruits without fertilization—is very useful for fruit cultivation. Among pear cultivars (Japanese, Chinese, and European pears and their interspecific hybrids) subjected to flower emasculation and left unpollinated, only some of the European pears had a stable and high degree of fruit set and fruit enlargement. Almost all the enlarged fruits formed no seeds. Comparison of fruits produced by using emasculation without pollination or with self-pollination ruled out the possibility of stenospermocarpy in these parthenocarpic pears. The results suggested that the abovementioned characteristics were inherited maternally by the next generation and that it should be possible to introduce parthenocarpy into Japanese pears. Neither Chinese nor Japanese pears treated with emasculation and no pollination showed consistently stable fruit set or fruit enlargement. In Chinese pears, these characteristics varied greatly from year to year, and in Japanese pears they were stable but weak. Although in each cultivar highly parthenocarpic fruits weighed slightly less than cross-pollinated ones, the cortexes of the emasculated fruits were enlarged and the fruits were not greatly inferior to those of cross-pollinated ones. By using a customized pear cDNA microarray, we compared the gene expression profiles of highly and weakly parthenocarpic cultivars before flowering. Expression of several phenylpropanoid-related genes and photosystem-related genes differed significantly between the two groups. Some of these genes were contained in the chloroplast genome. These results showed the unique mechanism of genetic parthenocarpy in pome fruits as opposed to non-pome fruits. Overall design: The gene expression profiles between high and low parthenocarpy group before flowering were compared.
Project description:The volume of publicly available data in biomedicine is constantly increasing. However, these data are stored in different formats and on different platforms. Integrating these data will enable us to facilitate the pace of medical discoveries by providing scientists with a unified view of this diverse information. Under the auspices of the National Center for Biomedical Ontology (NCBO), we have developed the Resource Index-a growing, large-scale ontology-based index of more than twenty heterogeneous biomedical resources. The resources come from a variety of repositories maintained by organizations from around the world. We use a set of over 200 publicly available ontologies contributed by researchers in various domains to annotate the elements in these resources. We use the semantics that the ontologies encode, such as different properties of classes, the class hierarchies, and the mappings between ontologies, in order to improve the search experience for the Resource Index user. Our user interface enables scientists to search the multiple resources quickly and efficiently using domain terms, without even being aware that there is semantics "under the hood."
Project description:Rye (Secale cereale L.) is a cereal crop of major importance in many parts of Europe and rye breeders are presently very concerned with the restrict pool of rye genetic resources available. Such narrowing of rye genetic diversity results from the presence of "Petkus" pool in most modern rye varieties as well as "Petkus" × "Carsten" heterotic pool in hybrid rye breeding programs. Previous studies on rye's genetic diversity revealed moreover a common genetic background on landraces (ex situ) and cultivars, regardless of breeding level or geographical origin. Thus evaluation of in situ populations is of utmost importance to unveil "on farm" diversity, which is largely undervalued. Here, we perform the first comprehensive assessment of rye's genetic diversity and population structuring using cultivars, ex situ landraces along a comprehensive sampling of in situ accessions from Portugal, through a molecular-directed analysis using SSRs markers. Rye genetic diversity and population structure analysis does not present any geographical trend but disclosed marked differences between genetic backgrounds of in situ accessions and those of cultivars/ex situ collections. Such genetic distinctiveness of in situ accessions highlights their unexplored potential as new genetic resources, which can be used to boost rye breeding strategies and the production of new varieties. Overall, our study successfully demonstrates the high prospective impact of comparing genetic diversity and structure of cultivars, ex situ, and in situ samples in ascertaining the status of plant genetic resources (PGR).
Project description:The Chinese chestnut (Castanea mollissima Bl.) was introduced into Japan about 100 years ago. Since then, a number of Chinese chestnut cultivars and Japanese-Chinese hybrid cultivars have been selected by farmers and plant breeders, but little information has been available about their origins and genetic relationships. A classification based on simple sequence repeat markers was conducted using 230 cultivars including Japanese chestnut (Castanea crenata Sieb. et Zucc.) cultivars originated in Japan, Japanese-Chinese hybrid cultivars, and Chinese chestnut cultivars originated in both Japan and China. First, a search for synonyms (cultivars with identical genotypes) revealed 23 synonym groups among the Chinese chestnut cultivars, and all but one cultivar from each synonym group was omitted from further analyses. Second, genetic structure analysis showed a clear division between Japanese and Chinese chestnut, and most of the Japanese and Chinese cultivars had a simple genetic structure corresponding to the expected species. On the other hand, most Japanese-Chinese hybrid cultivars had admixed genetic structure. Through a combination of parentage and chloroplast haplotype analyses, 16 of the 18 hybrid cultivars in this study were inferred to have parent-offspring relationships with other cultivars originated in Japan. Finally, Bayesian clustering and chloroplast haplotype analysis showed that the 116 Chinese chestnut cultivars could be divided into two groups: one originated in the Hebei region of China and the other originated in the Jiangsu and Anhui regions of China. The Chinese chestnut cultivars selected in Japan showed various patterns of genetic structure including Hebei origin, Jiangsu or Anhui origin, and admixed. The chestnut cultivar genetic classifications obtained in this study will be useful for both Japanese and Chinese chestnut breeding programs.
Project description:Members of the genus Paeonia, which consists of globally renowned ornamentals and traditional medicinal plants with a rich history spanning over 1500 years, are widely distributed throughout the Northern Hemisphere. Since 1900, over 2200 new horticultural Paeonia cultivars have been created by the discovery and breeding of wild species. However, information pertaining to Paeonia breeding is considerably fragmented, with fundamental gaps in knowledge, creating a bottleneck in effective breeding strategies. This review systematically introduces Paeonia germplasm resources, including wild species and cultivars, summarizes the breeding strategy and results of each Paeonia cultivar group, and focuses on recent progress in the isolation and functional characterization of structural and regulatory genes related to important horticultural traits. Perspectives pertaining to the resource protection and utilization, breeding and industrialization of Paeonia in the future are also briefly discussed.
Project description:Wild relatives genetically close to cultivars are precious genetic resources for plant breeding. Oryza rufipogon, O. barthii, O. glumaepatula, O. meridionalis and O. longistaminata are such wild species, and are also categorized as AA genome species based on their structural similarities. Chromosome segment substitution lines (CSSLs) are a powerful resource in breeding and genetics, and numerous rice CSSLs have been produced. This study aimed to develop DNA markers for evaluation of CSSLs directly by PCR and subsequent gel electrophoresis. We confirmed that up to 155 of 188 markers developed for detection of japonica-indica INDELs could also detect INDELs between rice cultivars and wild AA-species accessions. Percentages of applicable markers were higher in O. rufipogon accessions (61.7 to 85.6%), and lower in accessions of other four AA species (39.8 to 51.4%). These markers were distributed throughout the rice chromosomes, and will be useful for genotyping of CSSLs and other genetic resources derived from crosses between rice cultivars and closely related wild species.
Project description:BACKGROUND: The impact of diseases such as Phytophthora foot rot and the replacement of unproductive cultivars by high yielding ones has brought about the disappearance of varieties in Piper species, like any other crop. Black pepper (King of spices), is a major spice crop consumed throughout the world. It is widely cultivated across various parts of the world apart from India. The different cultivars may be genetically related and could be a source of valuable genes for disease resistance and an increase in quantity and quality. Even though Western Ghats in India is believed to be the site of origin of this crop, numerous accessions from the NBPGR have not yet been evaluated. Our study aims to investigate the genetic relatedness in major cultivars of black pepper using Amplified Fragment Length Polymorphism. RESULTS: Amplified Fragment Length Polymorphic (AFLP) DNA analysis was performed in thirty popular cultivars of black pepper from National Bureau of Plant Genetic Resources (NBPGR), India. Fingerprint profiles were generated initially with, five different primer combinations, from which three primer pair combinations (EAGC/MCAA, EAGG/MCTA and EAGC/MCTG) gave consistent and scorable banding patterns. From 173 scorable markers, 158(> 90%) were polymorphic which shows there is considerable variation in the available germplasm. The dendrogram derived by unweighted pair group method analysis (UPGMA) grouped the accessions into three major clusters and four diverse cultivars with only 30% similarity. Karimunda, a widely grown and popular cultivar was unique in the fingerprint profiles obtained. CONCLUSION: There are currently few fingerprinting studies using the valuable spice crop black pepper. We found considerable genetic variability among cultivars of black pepper. Fingerprinting analysis with AFLP proved to be an ideal tool for cultivar identification and phylogenetic studies. It shows the high level of polymorphism and the unique characterization of the major cultivars. An extensive range of similarity value between the cultivars was noted (6.01 to 98.13). Further screening of more cultivars will provide valuable information for current breeding programmes.
Project description:Currently, table olives, unlike oil olives, are harvested manually. Shortage of manpower and increasing labor costs are the main incentives to mechanizing the harvesting of table olives. One of the major limiting factors in adopting mechanical harvest of table olives is the injury to fruit during mechanical harvest, which lowers the quality of the final product. In this study, we used the Israeli germplasm collection of olive cultivars at the Volcani Institute to screen the sensitivity of many olive cultivars to browning in response to injury. The browning process after induced mechanical injury was characterized in 106 olive cultivars. The proportional area of brown coloring after injury, compared to the total fruit surface area, ranged from 0 to 83.61%. Fourteen cultivars were found to be resistant to browning and did not show any brown spot 3 h after application of pressure. Among them, there are some cultivars that can serve as table olives. The different response to mechanical damage shown by the cultivars could be mainly due to genetic differences. Mesocarp cells in the fruits of the sensitive cultivars were damaged and missing the cell wall as a result of the applied pressure. The cuticles of resistant cultivars were thicker compared to those of susceptible cultivars. Finally, we showed that the browning process is enzymatic. We suggest cuticle thickness as an indicator of table olive cultivars suitable for mechanical harvest. A shift to browning-resistant cultivars in place of the popular cultivars currently in use will enable the mechanical harvest of table olive without affecting fruit quality.
Project description:Blueberry is a small fruit crop which includes a complex group of different Vaccinium species of various ploidy levels. Commercial blueberries have been grown in Europe most recently, so there is not much information available about their adaptation into new regions. In this work we investigated adaptation to the environmental conditions of northern Spain, in terms of flowering and ripening seasons, of a set of 70 blueberry cultivars including several of the most important cultivated American species (V. corymbosum, V. virgatum, V. macrocarpon and V. uliginosum) in order to identify which types are best-suited in this geographical area of Europe. Most materials showed high chilling requirements for flowering under local conditions, while materials with low-chilling requirements showed problems in the maturation process of the flowers. Most cultivars were early or mid-season while a relative lack of late-season cultivars was observed. GBS was used for the analysis of genetic diversity in this sample of 70 cultivars. A total of 5255 SNP markers were obtained and a cluster analysis revealed three main groups associated with the ploidy level of the species. A Principal Component Analysis revealed a grouping of the V. corymbosum cultivars according to their chilling requirements. A total of 29 SNPs were identified as being highly informative for diversity analysis and potentially useful for cultivar identification and for breeding purposes. The results obtained from this research should contribute to the expansion of this crop, as well as providing data about genetic diversity useful for the preservation of genetic resources or for future breeding programs.