Chromosomal locations of the maize (Zea mays L.) HtP and rt genes that confer resistance to Exserohilum turcicum

We used 125 microsatellite markers to genotype the maize (Zea mays L.) near isogenic lines (NIL) L30HtPHtPRtRt and L30htphtpRtRt and the L40htphtprtrt line which contrast regarding the presence of the recently described dominant HtP and the recessive rt genes that confer resistance to Exserohilum turcicum. Five microsatellite markers revealed polymorphisms between the NIL and were considered candidate linked markers for the HtP resistance gene. Linkage was confirmed by bulked segregant sample (BSS) analysis of 32 susceptible and 34 resistant plants from a BC1F1 population derived from the cross (L30HtPHtPRtRt x L40htphtprtrt) x L40htphtprtrt. The bnlg198 and dupssr25 markers, both located on maize chromosome 2L (bin 2.08), were polymorphic between bulks. Linkage distances were estimated based on co-segregation data of the 32 susceptible plants and indicated distances of 28.7 centimorgans (cM) between HtP and bnlg198 and 23.5 cM between HtP and dupssr25. The same set of susceptible plants was also genotyped with markers polymorphic between L30HtPHtPRtRt and L40htphtprtrt in order to find markers linked to the rt gene. Marker bnlg197, from chromosome 3L (bin 3.06), was found linked to rt at a distance of 9.7 cM. This is the first report on the chromosomal locations of these newly described genes

Analyzing the influence of correlation length in permeability on convective systems in heterogeneous aquifers using entropy production

Hydrothermal convection in porous geothermal reservoir systems can be seen as a double-edged sword. On the one hand, regions of upflow in convective systems can increase the geothermal energy potential of the reservoir; on the other hand, convection introduces uncertainty, because it can be difficult to locate these regions of upflow. Several predictive criteria, such as the Rayleigh number, exist to estimate whether convection might occur under certain conditions. As such, it is of interest which factors influence locations of upwelling regions and how these factors can be determined. We use the thermodynamic measure entropy production to describe the influence of spatially heterogeneous permeability on a hydrothermal convection pattern in a 2D model of a hot sedimentary aquifer system in the Perth Basin, Western Australia. To this end, we set up a Monte Carlo study with multiple ensembles. Each ensemble contains several hundred realizations of spatially heterogeneous permeability. The ensembles only differ in the horizontal spatial continuity (i.e., correlation length) of permeability. The entropy production of the simulated ensembles shows that the convection patterns in our models drastically change with the introduction and increase of a finite, lateral correlation length in permeability. An initial decrease of the average entropy production number with increasing lateral correlation length shows that fewer ensemble members show convection. When neglecting the purely conductive ensembles in our analysis, no significant change in the number of convection cells is seen for lateral correlation lengths larger than 2000 m. The result suggests that the strength of convective heat transfer is not sensitive to changes in lateral correlation length beyond a specific factor. It does, however, change strongly compared to simulations with a homogeneous permeability field. As such, while the uncertainty in spatial continuity of permeability may not strongly influence the convective heat transfer, our findings show that it is important to consider spatial heterogeneity and continuity of permeability when simulating convective heat transfer in an aquifer.ISSN:2195-970