Attempts to Produce Alien Addition Lines in Triticum durum

Aneuploid stocks in durum wheat are few, and alien additions are particularly rare. The present contribution describes the results of a program aimed at the addition of alien chromosomes to tetraploid wheat. Aegilops caudata, Ae. longissima and Dasypyrum villosum were used as chromosome donors. The crossing program involved the production of amphidiploids with the wheat cytoplasm and the recurrent crossing with durum wheat pollen. IS monosomic addition (2n= 29) plants were obtained and partly selfed and/or backcrossed to wheat. Two disomic addition (2n = 30) plants, possessing two different Ae. caudata chromosomes, were obtained; unfortunately they were very weak and highly sterile, thus preventing their further propagation. The difficulties experienced during the development of the crossing program are discussed in detail

Statistical Approaches to Analyse Gene Bank Data Using a Lentil Germplasm Collection as a Case Study

Normally in a plant gene bank a large number of accessions per each crop and/ or taxon is stored. During their characterization and preliminary evaluation, several quantitative and qualitative data are recorded and, usually, a wide intra accession variation is observed. Th e management of all this information becomes very difficult without effective statistical methods combining these different types of data. At the Institute of Plant Genetics, CNR, in Bari (Italy) this problem has been tackled by testing many statistical approaches. The present contribution describes one of these approaches, which to date has proven to be highly adequate; a case study describing a lentil germplasm collection has been used for demonstration. A valuable application of this method is the determination of core subsets important to increase the utilization and accessibility of plant genetic resources. In the presented case study a subset of the lentil germplasm collection was chosen to perform molecular analysis based on ISSR markers. The samples were selected on the basis of both morpho-agronomic evaluation and geographical origin. These markers proved to be useful for distinguishing among closely related genotypes and for possibly substantiating the genetic peculiarity of some interesting material

Statistical Approaches to Analyse Gene Bank Data Using a Lentil Germplasm Collection as a Case Study

Normally in a plant gene bank a large number of accessions per each crop and/ or taxon is stored. During their characterization and preliminary evaluation, several quantitative and qualitative data are recorded and, usually, a wide intra accession variation is observed. Th e management of all this information becomes very difficult without effective statistical methods combining these different types of data. At the Institute of Plant Genetics, CNR, in Bari (Italy) this problem has been tackled by testing many statistical approaches. The present contribution describes one of these approaches, which to date has proven to be highly adequate; a case study describing a lentil germplasm collection has been used for demonstration. A valuable application of this method is the determination of core subsets important to increase the utilization and accessibility of plant genetic resources. In the presented case study a subset of the lentil germplasm collection was chosen to perform molecular analysis based on ISSR markers. The samples were selected on the basis of both morpho-agronomic evaluation and geographical origin. These markers proved to be useful for distinguishing among closely related genotypes and for possibly substantiating the genetic peculiarity of some interesting material

The miRNAome of globe artichoke: conserved and novel micro RNAs and target analysis

<p>Abstract</p> <p>Background</p> <p>Plant microRNAs (miRNAs) are involved in post-transcriptional regulatory mechanisms of several processes, including the response to biotic and abiotic stress, often contributing to the adaptive response of the plant to adverse conditions. In addition to conserved miRNAs, found in a wide range of plant species a number of novel species-specific miRNAs, displaying lower levels of expression can be found. Due to low abundance, non conserved miRNAs are difficult to identify and isolate using conventional approaches. Conversely, deep-sequencing of small RNA (sRNA) libraries can detect even poorly expressed miRNAs.</p> <p>No miRNAs from globe artichoke have been described to date. We analyzed the miRNAome from artichoke by deep sequencing four sRNA libraries obtained from NaCl stressed and control leaves and roots.</p> <p>Results</p> <p>Conserved and novel miRNAs were discovered using accepted criteria. The expression level of selected miRNAs was monitored by quantitative real-time PCR. Targets were predicted and validated for their cleavage site. A total of 122 artichoke miRNAs were identified, 98 (25 families) of which were conserved with other plant species, and 24 were novel. Some miRNAs were differentially expressed according to tissue or condition, magnitude of variation after salt stress being more pronounced in roots. Target function was predicted by comparison to <it>Arabidopsis </it>proteins; the 43 targets (23 for novel miRNAs) identified included transcription factors and other genes, most of which involved in the response to various stresses. An unusual cleaved transcript was detected for miR393 target, transport inhibitor response 1.</p> <p>Conclusions</p> <p>The miRNAome from artichoke, including novel miRNAs, was unveiled, providing useful information on the expression in different organs and conditions. New target genes were identified. We suggest that the generation of secondary short-interfering RNAs from miR393 target can be a general rule in the plant kingdom.</p

Chromatin Characterization in Dasypyrum

An open pollinated natural population and an inbred line of Dasypyrum villosum were cytologically examined. Nuclear DNA content, chromosomal distribution of the C-banded heterochromatin and the chromosomal site of action of restriction endonucleases were investigated. The results demonstrate that in D. villosum two classes of heterochromatin exist with different chromosomal location and reacting properties. One fraction of heterochromatin appears to be more affected by individual variation than the other. Preliminary examination of the chromosomal characteristics of D. breviaristatum indicate that the evolution of this latter species involved a more complicated process than the simple duplication of its chromosome number

Karyomorphological analyses and chromatin characterization by banding techniques in Euphorbia characias L. and E. wulfenii Hoppe (= E. veneta Willd.) (Euphorbiaceae)

Abstract Karyomorphological analysis of Euphorbia characias L. using Giemsa and fluorescent techniques revealed a characteristic C-banding pattern. Intraspecific variation in C-banding pattern was observed within of chromosomal complements of some populations of this species. Using fluorochrome Chromomycin A3 (CMA), E. characias exhibit trait patterns of CMA+ bands in intercalary and telomeric regions. Many bands correspond to Giemsa C-band. After the double staining with chromomycin A3/DAPI numerous chromosomes have showed a distribution of rich pattern in basic G-C (CMA+/DAPI-). The present studies indicate that to determine this characteristic C-banding pattern has intervened a deep restructuring of the karyotype. The karyotypes of E. characias and E. wulfenii were indistinguishable with very similar karyomorphologies and banding patterns, and these data suggest that both entities might be geographical biotypes

Heterochromatin distribution in selected taxa of the 42-chromosomes Orchis s. l. (Orchidaceae)

In six 42-chromosomes taxa belonging to genus Orchis s. l. heterochromatin location and distribution and staining properties were analysed by means of C-banding and of the fluorochromes 4'-6-diamino-2-phenylindole-2HCl (DAPI) and Hoechst 33258. Most species could be distinguished on the basis of heterochromatin amounts and distribution. In the species O. mascula and O. provincialis most DAPI-positive sites did not co-localize with C-bands. DAPI revealed bright fluorescence at telomeric or subtelomeric regions of numerous chromosomes of O. mascula and particularly large/bright blocks at the telomeres of O. provincialis. In O. x penzigiana (Orchis mascula ssp. ichnusae x O. provincialis) overall heterochromatin distribution followed that of the parental species. In Neotinea group all DAPI positive bands co-localize with C-bands, but have different distribution in the taxa analysed. Present and literature data indicate a high level of plasticity of heterochromatin organization in Orchis s. l., and suggest evolutionary pathways in agreement with recent molecular data

Chromatin organisation and computer aided karyotyping of Triticum durum Desf. cv. Timilia

Abstract The tribe Triticeae includes three cereal genera Secale, Hordeum and Triticum and because of their economical and agronomical importance, the relationships among species on the tribe have been extensively investigated. The wild wheat relatives are an important source of genetic variation for cultivated species and wheat is an important crop of the mediterranean region. Banding pattern of metaphase chromosomes and nuclear DNA content in root meristematic cells of an old sicilian landrace "Timilia" were determined. Microdensitometric evaluation of nuclear absorption at different thresholds of optical density indicates the organization of chromatin in the interphase nuclei. Chromosome morphometric data, karyotype simmetry, the TF% values and Syi indices were determined. The results are compared with the data of other durum wheat varieties as Capeiti and Simeto

Can High Throughput Phenotyping Help Food Security in the Mediterranean Area?

According to the IPCC 2014 report the Mediterranean region will be affected by strong climatic changes, both in terms of average temperature and of precipitations regime. This area hosts some half a billion people and the impact on food production will be severe. To implement a climate smart agriculture paradigm and a sustainable increase of agricultural productivity different approaches can be deployed. Agriculture alone consumes 70% of the entire water available on the planet, thus the observed reduction of useful rainfall and growing costs for irrigation water may severely constrain food security. In our work we focused on two typical Mediterranean crops: durum wheat, a rainfed crop, and tomato, an irrigated one. In wheat we explored the possibility of identifying genotypes resilient to water stress for future breeding aims, while in tomato we explored the possibility of using biostimulants to increase the plant capacity of using water. In order to achieve these targets, we used high throughput phenotyping (HTP). Two traits were considered: digital biovolume, a measure based on imaging techniques in the RGB domain, and Water Use Efficiency index as calculated semi-automatically on the basis of evaporation measurements resulting in a high throughput, non-destructive, non-invasive approach, as opposed to destructive and time consuming traditional methods. Our results clearly indicate that HTP is able to discriminate genotypes and biostimulant treatments that allow plants to use soil water more efficiently. In addition, these methods based on RGB quality images can easily be scaled to field phenotyping structure USVs or UAVs