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Severe lodging has recurrently occurred at strong typhoon's hitting in recent climate change. The identification of quantitative trait loci and their responsible genes associated with a strong culm and their pyramiding are important for developing high-yielding varieties with a superior lodging resistance. To evaluate the effects of four strong-culm genes on lodging resistance, the temperate japonica near isogenic line (NIL) with the introgressed SCM1 or SCM2 locus of the indica variety, Habataki and the other NIL with the introgeressed SCM3 or SCM4 locus of the tropical japonica variety, Chugoku 117 were developed. Then, we developed the pyramiding lines with double,triple and quadruple combinations derived from step-by-step crosses among NIL-SCM1–NIL-SCM4. Quadruple pyramiding line (NIL-SCM1 + 2 + 3 + 4) showed the largest culm diameter and the highest culm strength among the combinations and increased spikelet number due to the pleiotropic effects of these genes. Pyramiding of strong culm genes resulted in much increased culm thickness, culm strength and spikelet number due to their additive effect. SCM1 mainly contributed to enhance their pyramiding effect. These results in this study suggest the importance of identifying the combinations of superior alleles of strong culm genes among natural variation and pyramiding these genes for improving high-yielding varieties with a superior lodging resistance. [ABSTRACT FROM AUTHOR]

The on-current of indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) fabricated by solution process with low-temperature post-annealing increases monotonically with the decrease in the Ga content. This trend is different from that of IGZO fabricated by a solution process, which shows the maximum electron mobility at a Ga content of 33%. To clarify its cause, effects of Ga and In contents in solution-processed IGZO post-annealed at a low-temperature on their oxygen deficiency and band structures were investigated with spectroscopic methods such as X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, photoluminescence, and ultraviolet–visible absorption. When the Ga content is low, the oxygen vacancy becomes less abundant. The increase in In content exhibits similar effects on the oxygen vacancy. We have reported that Ga is not oxidized sufficiently at low temperatures, which should cause the generation of oxygen vacancies. By this theory, the above-mentioned decrease in oxygen vacancies can be explained. Furthermore, when these films are actually used as TFT channels, the on-current increases with the decrease in Ga content. From this, in solution-processed IGZO post-annealed at a low temperature, oxygen vacancies mainly act as electron traps that decrease the on-current, rather than acting as donors. In manufacturing flexible devices, even when we decrease the process temperature low enough to suppress the damage to polymer substrates, the devices must maintain good performance. Our results suggest that an optimal metal ratio different from that of a typical vacuum process is necessary to improve the performance of IGZO TFTs fabricated by the low-temperature solution process. [ABSTRACT FROM AUTHOR]