Analysis of incompatibility barriers during cross-pollinations among Phaseolus L. and other leguminous plants

Plant breeding is intended to seek for ways of realizing a genetic structure adapted to criteria and population needs. In this context, cross-pollinations are for great interest. They offer the means of creating a wide genotypic variability. However, a limited number of species are able to undergo hybridization studies. In Phaseolus L., improvement can be envisioned by either exploiting the primary genetic pool of the species, or the genetic variability of other species. In fact, there are wild or wild-like species more resistant to stresses or diseases than the cultivated ones. The methods of embryo rescues facilitate the interspecific crosses and contribute to exploiting the available genetic diversity within plant germplasm. Difficulties related to obtaining hybrids in grain legumes, and Phaseolus L. in particular, are reported in this research. It is possible to avoid the incompatibility barriers based on their appearance time. When they are pre-zygotic, the use of growth regulators during pollination is recommended. The in vitro explants culture is the most usual method to overcome the post-zygotic barriers. The mechanisms leading to abortion of hybrid embryos, as well as adequate methods to overcome the interspecific incompatibilities should be subjected to further studies.Keywords: Abortion, hybridization, interspecific barriers, Phaseolus L., plant embryos

Optimization of ISSR marker for African edible-seeded Cucurbitaceae species’ genetic diversity analysis

We applied a molecular approach using inter-simple sequence repeat (ISSR) markers on three African edible-seeded cucurbits (Citrullus lanatus L. Matsumura and Nakai, Cucumeropsis mannii L. Naudin and Cucumis melo var. agrestis L. Naudin). To obtain clear and reproducible bands on 1.5% agarose gels, we screened 21 ISSR primers and three parameters (annealing temperature, gel tray, and voltage and running time). The resolution of 11 ISSR markers was performed, with optimal annealing temperature (Ta) varying from 50 to 52°C. The best combination to obtain clear and well-distinguished band patterns was 1.5% agarose gel with a 20-lanes tray (6 mm width) at 80 V for 5 h. Applying the 11 ISSR primers on DNA extracted from an accession of C. lanatus, 66 bands with 4 to 11 bands per primer was observed.Keywords: ISSR, Cucurbits, genetic diversity, molecular markers, optimizatio

Macronutrient composition of three cucurbit species cultivated for seed consumption in Côte d’Ivoire

Dry seeds from three indigenous cucurbits [Citrullus lanatus var. citroides (Thumb.) Matsum. & Nakai.,Cucumeropsis mannii Naudin, and Cucumis melo var. agrestis L.] largely cultivated in Côte d’Ivoire andconsumed as sauce thickeners were analyzed for their proximate composition and compared to a locallandrace of peanut (Arachis hypogae L.). The protein contents were 29.23±1.74, 36±2.17, 29.55±2.09, and24.79±0.44% for C. lanatus, C. mannii, C. melo, and A. hypogaea, respectively. The highest estimates offat content was observed with C. lanatus (56.67±4.90%) followed in decreased order by the peanut(48.17±1.60%), C. mannii (45.89±4.73%), and C. melo (42.67±3.43%). The carbohydrate content for C.lanatus was 9.87±3.52% and C. mannii and C. melo had 13.86±3.64 and 23.18±4.80%, respectively. C.melo was then the highest in carbohydrate content whereas A. hypogaea has the lowest value(6.39±2.66%). The crude fibre contents for C. lanatus, C. mannii, and C. melo averaged 2.87±1.07,2.30±0.85, and 2.94±0.75%, respectively. The three cucurbit species were markedly low in fibre value,compared to the analyzed peanut (17.14±3.82%). As expected on the basis of several published data,ash content of seeds from indigenous cucurbits was generally low: 1.33±0.52% (C. lanatus), 2.50±1.38%(C. mannii), and 1.67±0.82% (C. melo)

Genetic Diversity of Andean Tuber Crop Species in the in situ Microcenter of Huanuco, Peru

peer reviewedAndean tuber crop species oca (Oxalis tuberosa Molina), ulluco (Ullucus tuberosus Caldas), and mashua (Tropaeolum tuberosum Ruiz & Pav.) play major roles in Andean communities. These species show high variability but are threatened with genetic erosion. To study the management of genetic resources of neglected vegetatively propagated crop species, we studied genetic diversity and structure of these species in an in situ diversity microcenter (Huanuco, Peru). A sample of 15 varieties of oca, 15 of ulluco, and 26 of mashua was analyzed with the inter simple sequence repeats (ISSR) molecular markers. Mean genetic distances and global genetic diversities were high for the three species, with higher values for mashua than for oca and ulluco. Assignment technique divided both oca and ulluco samples into two genetic clusters; the mashua sample probably belongs to a single genetic cluster. Inter simple sequence repeats (ISSR) technique showed intravarietal genetic variability for most varieties, suggesting an underestimation of the in situ genetic variability. These results are discussed considering how variation in breeding systems and farmers' practice influenced patterns of genetic diversity. Our findings confirm the hypothesis of a considerable amount of variability found in neglected Andean tubers and are essential to deserve adequate conservation strategies and to maintain genetic resources of neglected Andean tuber crop species under a threat of genetic erosion

Tagungsbericht „Europäische Geschichtskulturen. Nationale Identität, Globalisierung und die Herausforderung des deutsch-italienischen Transfers in der Geschichtswissenschaft (19.-21. Jahrhundert)

none3siReport of the workshop "Europäische Geschichtskulturen. Nationale Identität, Globalisierung und die Herausforderung des deutsch-italienischen Transfers in der Geschichtswissenschaft (19.-21. Jahrhundert)", Menaggio, Villa VigoniopenTeresa Malice, Markus Wurzer, Nicola CamilleriTeresa Malice, Markus Wurzer, Nicola Camiller

Increase in urinary leukotriene LTE(4) levels in acute asthma: correlation with airflow limitation

Background: Leukotrienes play a key role in the pathophysiology of chronic asthma. Activation of leukotriene pathways is accompanied by rises in detectable urinary levels of leukotriene E(4) (LTE(4)). The relationship between urinary LTE(4) levels and factors associated with acute asthma has not been determined. Methods: Adults aged 15–54 years presenting with moderate to severe acute asthma were evaluated at emergency departments in 16 US sites. Forced expiratory volume in 1 second (FEV(1)) was measured during the first 60 minutes after arrival and at specified times until discharge or admission. Urine samples for measurement of LTE(4) levels were obtained either on arrival at the study site and/or before discharge. Patients were seen 2 weeks later for follow up, at which time repeat FEV(1) measurements and urine samples for LTE(4) were obtained. Results: One hundred and eighty four patients were evaluated; LTE(4) results from both the acute and follow up periods were available for analysis in 146. Urinary LTE(4) levels were increased during asthma exacerbations compared with levels obtained 2 weeks later (geometric means 111.7 and 75.6 pg/mg creatinine, respectively, mean percentage change -32.3; 95% confidence interval (CI) for the mean percentage change -39.6 to -24.3, p<0.001). The correlation between improvement in FEV(1) and decline in LTE(4) over the 2 week interval was significant (p<0.001, r = 0.43). Conclusions: Activation of leukotriene pathways in acute asthma is correlated with the degree of airflow obstruction, and resolution of the asthma exacerbation is associated with a reduction in leukotriene levels