Genome assembly and analysis of Lactuca virosa: implications for lettuce breeding.

Lettuce (Lactuca sativa L.) is a leafy vegetable crop with ongoing breeding efforts related to quality, resilience, and innovative production systems. To breed resilient and resistant lettuce in the future, valuable genetic variation found in close relatives could be further exploited.

The genome of Lactuca saligna, a wild relative of lettuce, provides insight into non-host resistance to the downy mildew Bremia lactucae.

Lactuca saligna L. is a wild relative of cultivated lettuce (Lactuca sativa L.), with which it is partially interfertile.

Patterns of Transmission Ratio Distortion in Interspecific Lettuce Hybrids Reveal a Sex-Independent Gametophytic Barrier.

Interspecific crosses can result in progeny with reduced vitality or fertility due to genetic incompatibilities between species, a phenomenon known as hybrid incompatibility (HI). HI is often caused by a bias against deleterious allele combinations, which results in transmission ratio distortion (TRD). Here, we determined the genome-wide distribution of HI between wild lettuce, , and cultivated lettuce, , in a set of backcross inbred lines (BILs) with single introgression segments from introgressed into a genetic background.

Bidirectional backcrosses between wild and cultivated lettuce identify loci involved in nonhost resistance to downy mildew.

The nonhost resistance of wild lettuce to lettuce downy mildew seems explained by four components of a putative set of epistatic genes. The commonplace observation that plants are immune to most potential pathogens is known as nonhost resistance (NHR). The genetic basis of NHR is poorly understood.

Effector-mediated discovery of a novel resistance gene against Bremia lactucae in a nonhost lettuce species.

Candidate effectors from lettuce downy mildew (Bremia lactucae) enable high-throughput germplasm screening for the presence of resistance (R) genes. The nonhost species Lactuca saligna comprises a source of B. lactucae R genes that has hardly been exploited in lettuce breeding.

Effects of stacked quantitative resistances to downy mildew in lettuce do not simply add up.

In a stacking study of eight resistance QTLs in lettuce against downy mildew, only three out of ten double combinations showed an increased resistance effect under field conditions. Complete race nonspecific resistance to lettuce downy mildew, as observed for the nonhost wild lettuce species Lactuca saligna, is desired in lettuce cultivation. Genetic dissection of L.

Fine mapping quantitative resistances to downy mildew in lettuce revealed multiple sub-QTLs with plant stage dependent effects reducing or even promoting the infection.

Three regions with quantitative resistance to downy mildew of non-host and wild lettuce species, Lactuca saligna , disintegrate into seventeen sub-QTLs with plant-stage-dependent effects, reducing or even promoting the infection. Previous studies on the genetic dissection of the complete resistance of wild lettuce, Lactuca saligna, to downy mildew revealed 15 introgression regions that conferred plant stage dependent quantitative resistances (QTLs). Three backcross inbred lines (BILs), carrying an individual 30-50 cM long introgression segment from L.

Specific in planta recognition of two GKLR proteins of the downy mildew Bremia lactucae revealed in a large effector screen in lettuce.

Breeding lettuce (Lactuca sativa) for resistance to the downy mildew pathogen Bremia lactucae is mainly achieved by introgression of dominant downy mildew resistance (Dm) genes. New Bremia races quickly render Dm genes ineffective, possibly by mutation of recognized host-translocated effectors or by suppression of effector-triggered immunity. We have previously identified 34 potential RXLR(-like) effector proteins of B.

Assessing the impacts of livestock production on biodiversity in rangeland ecosystems.

Biodiversity in rangelands is decreasing, due to intense utilization for livestock production and conversion of rangeland into cropland; yet the outlook of rangeland biodiversity has not been considered in view of future global demand for food. Here we assess the impact of future livestock production on the global rangelands area and their biodiversity. First we formalized existing knowledge about livestock grazing impacts on biodiversity, expressed in mean species abundance (MSA) of the original rangeland native species assemblages, through metaanalysis of peer-reviewed literature.

Rin4 causes hybrid necrosis and race-specific resistance in an interspecific lettuce hybrid.

Some inter- and intraspecific crosses may result in reduced viability or sterility in the offspring, often due to genetic incompatibilities resulting from interactions between two or more loci. Hybrid necrosis is a postzygotic genetic incompatibility that is phenotypically manifested as necrotic lesions on the plant. We observed hybrid necrosis in interspecific lettuce (Lactuca sativa and Lactuca saligna) hybrids that correlated with resistance to downy mildew.

Three combined quantitative trait loci from nonhost Lactuca saligna are sufficient to provide complete resistance of lettuce against Bremia lactucae.

The nonhost resistance of wild lettuce (Lactuca saligna) to downy mildew (Bremia lactucae) is based on at least 15 quantitative trait loci (QTL), each effective at one or more plant developmental stages. We used QTL pyramiding (stacking) to determine how many of these QTL from L. saligna are sufficient to impart complete resistance towards B.

Nitrogen and phosphorus retention in surface waters: an inter-comparison of predictions by catchment models of different complexity.

Nitrogen and phosphorus retention estimates in streams and standing water bodies were compared for four European catchments by a series of catchment-scale modelling tools of different complexity, ranging from a simple, equilibrium input-output type to dynamic, physical-based models: source apportionment, MONERIS, EveNFlow, TRK, SWAT, and NL-CAT. The four catchments represent diverse climate, hydrology, and nutrient loads from diffuse and point sources in Norway, the UK, Italy, and the Czech Republic. The models' retention values varied largely, with tendencies towards higher scatters for phosphorus than for nitrogen, and for catchments with lakes (Vansjø-Hobøl, Zelivka) compared to mostly or entirely lakeless catchments (Ouse or Enza, respectively).

Efficient QTL detection for nonhost resistance in wild lettuce: backcross inbred lines versus F(2) population.

In plants, several population types [F(2), recombinant inbred lines, backcross inbred lines (BILs), etc.] are used for quantitative trait locus (QTL) analyses. However, dissection of the trait of interest and subsequent confirmation by introgression of QTLs for breeding purposes has not been as successful as that predicted from theoretical calculations.

A high-density, integrated genetic linkage map of lettuce (Lactuca spp.).

An integrated map for lettuce comprising of 2,744 markers was developed from seven intra- and inter-specific mapping populations. A total of 560 markers that segregated in two or more populations were used to align the individual maps. 2,073 AFLP, 152 RFLP, 130 SSR, and 360 RAPD as well as 29 other markers were assigned to nine chromosomal linkage groups that spanned a total of 1,505 cM and ranged from 136 to 238 cM.

The development of lettuce backcross inbred lines (BILs) for exploitation of the Lactuca saligna (wild lettuce) germplasm.

Backcross inbred lines (BILs) were developed in which chromosome segments of Lactuca saligna (wild lettuce) were introgressed into L. sativa (lettuce). These lines were developed by four to five backcrosses and one generation of selfing.

Lactuca saligna, a non-host for lettuce downy mildew ( Bremia lactucae), harbors a new race-specific Dm gene and three QTLs for resistance.

Lactuca sativa (lettuce) is susceptible to Bremia lactucae (downy mildew). In cultivated and wild Lactuca species, Dm genes have been identified that confer race-specific resistance. However, these genes were soon rendered ineffective by adaptation of the pathogen.

Distribution of ifosfamide and metabolites between plasma and erythrocytes.

The distribution of ifosfamide (IF) and its metabolites 2-dechloroethylifosfamide (2DCE), 3-dechloroethylifosfamide (3DCE), 4-hydroxyifosfamide (4OHIF) and ifosforamide mustard (IFM) between plasma and erythrocytes was examined in vitro and in vivo. In vitro distribution was investigated by incubating blood with various concentrations of IF and its metabolites. In vivo distribution of IF, 2DCE, 3DCE and 4OHIF was determined in 7 patients receiving 9 g/m(2)/72 h intravenous continuous IF infusion.

Determination of ifosfamide, 2- and 3-dechloroethyifosfamide using gas chromatography with nitrogen-phosphorus or mass spectrometry detection.

A comparison was made between methods for determining ifosfamide (IF), 2- (2DCE) and 3-dechloroethylifosfamide (3DCE) using gas chromatography with nitrogen-phosphorus detection (GC-NPD) versus positive ion electron-impact ion-trap mass spectrometry (GC-MS2). Sample pretreatment involved liquid-liquid extraction with ethyl acetate after adding trofosfamide as internal standard and alkalinization. The GC-NPD was linear, specific, and sensitive for all analytes in the range of 0.

Improved Performance of Transgenic Fructan-Accumulating Tobacco under Drought Stress.

Fructans are polyfructose molecules produced by approximately 15% of the flowering plant species. It is possible that, in addition to being a storage carbohydrate, fructans have other physiological roles. Owing to their solubility they may help plants survive periods of osmotic stress induced by drought or cold.

Thinking about mind and matter from biology.

In biology, man is an object of research; therefore the question might be asked whether inspirations can go from biological data to the reflections on the mind-matter relation in man. The social aspect of man, as treated by sociobiology, is left out of consideration. The knowledge that man is mind, or has a mind, is no result of biological research.

[The animal in the environment of man(author's transl)].

An analysis of the content of the terms "man", "animal" and "environment" provides the framework within which the difference between animals and man is defined. Animals have their place in the environment of man. Man has the ethical duty of giving them full value.

The biological and philosophical definitions of life.

A distinction must be made between various levels of thought. For a definition of life the formulation on the level of natural sciences, i.e.