Resistenzzüchtung in Dresden-Pillnitz - Der Apfel

The Institute of Fruit Breeding has a long tradition in breeding resistant apple cultivars. Systematic resistance breeding started in the 1930 ties in Müncheberg. Material developed in Müncheberg was transferred in the 1970 ties to the Institute for Fruit Research, the antecessor of the Institute of Fruit Breeding. Based on this material, a couple of multiple resistant cultivars were generated. The time schedule for combining biotic and abiotic resistant traits which demonstrates the long-lasting period necessary for systematic resistance breeding is given. An overview of resistant cultivars of Dresden-Pillnitz and the respective resistant traits is presented. This assortment of cultivars was developed to provide a resistant cultivar for each ripening group and every application in fruit growing. Modern resistance breeding is focused on quality and combination of different resistance genes for each pathogene to achieve durable resistance. Selection is facilitated by genetic markers. Likewise the look for new resistance genes, the analyses of genetics and the development of basic material are main areas of interest. Practical approaches in apple breeding to reach these aims are reported

Turnip mosaic potyvirus probably first spread to Eurasian brassica crops from wild orchids about 1000 years ago

Turnip mosaic potyvirus (TuMV) is probably the most widespread and damaging virus that infects cultivated brassicas worldwide. Previous work has indicated that the virus originated in western Eurasia, with all of its closest relatives being viruses of monocotyledonous plants. Here we report that we have identified a sister lineage of TuMV-like potyviruses (TuMV-OM) from European orchids. The isolates of TuMV-OM form a monophyletic sister lineage to the brassica-infecting TuMVs (TuMV-BIs), and are nested within a clade of monocotyledon-infecting viruses. Extensive host-range tests showed that all of the TuMV-OMs are biologically similar to, but distinct from, TuMV-BIs and do not readily infect brassicas. We conclude that it is more likely that TuMV evolved from a TuMV-OM-like ancestor than the reverse. We did Bayesian coalescent analyses using a combination of novel and published sequence data from four TuMV genes [helper component-proteinase protein (HC-Pro), protein 3(P3), nuclear inclusion b protein (NIb), and coat protein (CP)]. Three genes (HC-Pro, P3, and NIb), but not the CP gene, gave results indicating that the TuMV-BI viruses diverged from TuMV-OMs around 1000 years ago. Only 150 years later, the four lineages of the present global population of TuMV-BIs diverged from one another. These dates are congruent with historical records of the spread of agriculture in Western Europe. From about 1200 years ago, there was a warming of the climate, and agriculture and the human population of the region greatly increased. Farming replaced woodlands, fostering viruses and aphid vectors that could invade the crops, which included several brassica cultivars and weeds. Later, starting 500 years ago, inter-continental maritime trade probably spread the TuMV-BIs to the remainder of the world

Diversity of banana streak-inducing viruses in Nigeria and Ghana: Twice as many sources detected by immunoelectron microscopy (IEM) than by TAS-ELISA or IC-PCR

Our previous study had shown that some Musa leaf samples with Banana streak symptoms tested negative for Banana streak virus (BSV) in triple antibody-sandwich ELISA (TAS-ELISA). Therefore, in this study 63 additional Musa leaf samples were tested for BSV by TAS-ELISA, immunoelectron microscopy (IEM) and immunocapture polymerase chain reaction (IC-PCR). Sensitivity tests by sap dilution end-point analyses indicated that IC-PCR was considerably more sensitive than IEM fordetecting typical BSV, while IEM proved to be of similar sensitivity as TAS-ELISA. However, when leaf samples of Musa plants, obtained from different farmers’ fields in Nigeria and Ghana and some Nigeriansources maintained in the greenhouse were screened for BSV, more than twice as many samples revealed BSV-like particles by IEM than were detected by TAS-ELISA or IC-PCR. Of the 51 leaf samplesthat were BSV positive in all tests taken together, 48 were positive by IEM, 25 by IC-PCR and only 19 by TAS-ELISA. Upon IEM examination, typical bacilliform BSV-like particles were clearly recognized although in very diverse concentrations. Bacilliform particles deviating in length from the main particle populations or showing an angularly bent morphology were found. Occasionally, in certain samples and with certain antisera the IEM decoration tests revealed mixtures of strongly decorated and weaklydecorated BSV-like particles or bacilliform particles which did not at all react with the antibodies available. This proved, the occurrence, besides the presence of typical BSV, of diverse populations of BSV-like viruses in West Afric

Unmasking motherhood : a poststructuralist study of motherhood and its meanings for women

The intention of the following paper is to explore from a poststructuralist perspective the reasons why women choose to have children and the consequences resulting from this choice. Interviews were conducted with women who were mothers, and a selection of contemporary feminist literature, some related to motherhood and some to poststructuralist feminist theory, reviewed, in order to develop an understanding of the subject positions available to women in the discourses of motherhood. Two paradoxical and contradictory discourses of motherhood emerge, which are described in the concluding chapter of the paper

Facing infant cuteness: How nurturing care motivation and oxytocin system gene methylation are associated with responses to baby schema features

Baby schema features are a specific set of physical features—including chubby cheeks, large, low-set eyes, and a large, round head—that have evolutionary adaptive value in their ability to trigger nurturant care. In this study among nulliparous women (N = 81; M age = 23.60, SD = 0.44), we examined how sensitivity to these baby schema features differs based on individual variations in nurturant care motivation and oxytocin system gene methylation. We integrated subjective ratings with measures of facial expressions and electroencephalography (EEG) in response to infant faces that were manipulated to contain more or less pronounced baby schema features. Linear mixed effects analyses demonstrated that infants with more pronounced baby schema features were rated as cuter and participants indicated greater motivation to take care of them. Furthermore, infants with more pronounced baby schema features elicited stronger smiling responses and enhanced P2 and LPP amplitudes compared to infants with less pronounced baby schema features. Importantly, individual differences significantly predicted baby schema effects. Specifically, women with low OXTR methylation and high nurturance motivation showed enhanced differentiation in automatic neurophysiological responses to infants with high and low levels of baby schema features. These findings highlight the importance of considering individual differences in continued research to further understand the complexities of sensitivity to child cues, including facial features, which will improve our understanding of the intricate neurobiological system that forms the basis of caregiving behavior