Browsing by Subject "Plant height"

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The importance of Fusarium head blight resistance in the cereal breeding industry: Case studies from Germany and Austria
(2023) Miedaner, Thomas; Flamm, Clemens; Oberforster, Michael
Fusarium head blight (FHB) resistance in wheat and triticale has a high priority in the European Union because of the strict guidelines for the major mycotoxins deoxynivalenol (DON) and zearalenone (ZON) and the admission policy of the regulatory authorities. Potentially 70% of the arable land in Germany and about 60% in Austria can be affected by Fusarium. Although epidemics occur only in some years and/or some regions, DON and ZON are detected every year in varying amounts in wheat, rye and maize. Despite a high significance of FHB resistance in breeding companies, as validated by a recent survey, breeding progress in wheat is basically absent for FHB resistance in both countries. The main reasons are the complex inheritance of FHB resistance and the high proportions of the dwarfing allele Rht‐D1b in high‐yielding varieties promoting susceptibility. Despite this, some varieties with high FHB resistance (score 2–3 on the 1–9 scale) have been released that account, however, only for 11% and 18% of the multiplication area in Germany and Austria, respectively. For triticale, an official testing system for FHB resistance in terms of DON content exists in Germany and Austria, but not for the other cereals. Susceptibility to maize ear rot has been described in Austria, but not in Germany. Additionally, a testing system for stalk rot resistance in both countries should be established.
Markergestützte Vererbungsanalyse der Pollenfertilitätsrestauration bei Winterroggen (Secale cereale L.)
(2001) Wolf, Markus; Geiger, Hartwig H.
In rye (Secale cereale L.) as in a number of other crossfertilized crops, hybrid breeding allows a targeted use of heterosis for improving yield and yield stability. The creation of hybrids in outbred rye requires an efficient system of pollination control because of the monoclinous inflorescence. In commercial seed production, mostly the Pampa (P-) Cytoplasma is used, which induces cytoplasmatic male sterility (CMS). Restoration of pollen fertility is achieved by means of pollinator lines carrying nuclear dominant restorer genes. To obtain information about the number, localization, and efficacy of the restorer genes, molecular marker based inheritance analysis in rye was performed. The results were compared to already localized restorer sources in rye and other species. Ninety-two marker loci were mapped by RFLP technique, which covered a genome-length of 845 cM. QTL (quantitative trait loci) analysis revealed a major gene on the short arm of chromosome 1R. Two RFLP markers, psr596 and bcd1124, were linked with a distance of about 0.3 cM to this major gene. Moreover, two modifying minor genes on chromosome arms 3RL and 5RL were detected. One of these minor genes showed epistatic interaction with the above mentioned major gene.
Remote sensing of maize plant height at different growth stages using UAV-based digital surface models (DSM)
(2022) Oehme, Leon Hinrich; Reineke, Alice-Jacqueline; Weiß, Thea Mi; Würschum, Tobias; He, Xiongkui; Müller, Joachim
Plant height of maize is related to lodging resistance and yield and is highly heritable but also polygenic, and thus is an important trait in maize breeding. Various manual methods exist to determine the plant height of maize, yet they are labor-intensive and time consuming. Therefore, we established digital surface models (DSM) based on RGB-images captured by an unmanned aerial vehicle (UAV) at five different dates throughout the growth period to rapidly estimate plant height of 400 maize genotypes. The UAV-based estimation of plant height (PHUAV) was compared to the manual measurement from the ground to the highest leaf (PHL), to the tip of the manually straightened highest leaf (PHS) and, on the final date, to the top of the tassel (PHT). The best results were obtained for estimating both PHL (0.44 ≤ R2 ≤ 0.51) and PHS (0.50 ≤ R2 ≤ 0.61) from 39 to 68 days after sowing (DAS). After calibration the mean absolute percentage error (MAPE) between PHUAV and PHS was in a range from 12.07% to 19.62%. It is recommended to apply UAV-based maize height estimation from 0.2 m average plant height to maturity before the plants start to senesce and change the leaf color.