Shock Wave Propagation and Flame Kernel Morphology in Laser-Induced Plasma Ignition of CH4/O2/N2 Mixture

The application of laser ignition in the aerospace field has promising prospects. Based on the constant volume combustion chamber, the laser ignition of CH4/O2/N2 mixture with different initial pressure, different laser energy, different equivalence ratio and different oxygen content has been carried out. The development characteristics of the flame kernel and shock wave under different conditions are analyzed. In addition, the Taylor model and Jones model are also used to simulate the development process of the shock wave, and a new modified model is proposed based on the Jones model. The experimental results show that under pure oxygen conditions, the chemical reaction rate of the mixture is too fast, which makes it difficult for the flame kernel to form the ring and third-lobe structure. However, the ring structure is easier to form with the pressure and laser energy degraded; the flame kernel morphology is easier to maintain at a rich equivalence ratio, which is caused by the influence of the movement of hot air flow and a clearer boundary between the ring and the third-lobe. The decrease of the initial pressure or the increase of the laser energy leads to the increase in shock wave velocity, while the change of the equivalence ratio and oxygen content has less influence on the shock wave.

Variability in Nutritional Composition, Kernel Morphology and Cooking Quality of Selected Rice in Xingan Meng from Northeast China

Paddy rice cultivation expanded in Northeast China, and Xingan Meng of Inner Mongolia is an emerging area of rice production area. The goals of this study: i) to investigate varietal differences in levels of nutritional quality, kernel morphology and cooking quality and ii) to identify clusters of rice samples from Xingan Meng, northeast part of China. Research was conducted in Xingan Meng, China during the 2019 rice-growing season. The nutritional quality (energy, protein, carbohydrate, lipid, amylose, ash, Ca, Na, Fe, Zn, Mn), cooking quality (alkali spreading value, gel consistency) and kernel morphology (length, width, length width ratio, chalky rice percentage, chalky rice degree) were analysed. Significant difference were found across all traits. The largest variation was found for Mn, followed by Ca, Fe and Zn content. Four principal components were found that accounted for 95.14% of overall variability. Cluster analysis sorted the rice sample into four clusters based on nutritional quality, kernel morphology, and cooking quality. The findings of this study can support to demonstrate the quality of rice from Xingan Meng, northeast part of China.

Molecular mapping of quantitative trait loci for kernel morphology traits in a non-1BL.1RS×1BL.1RS wheat cross

The improvement of kernel morphology traits is an important goal in common wheat (Triticum aestivum L.) breeding programs because of their close relationship with grain yield and milling quality. The aim of this study was to map quantitative trait loci (QTL) for kernel morphology traits using 240 recombinant inbred lines derived from a cross between the non-1BL.1RS translocation cv. PH 82-2 and the 1BL.1RS translocation cv. Neixiang 188, grown in six environments in China. Inclusive composite interval mapping identified 71 main-effect QTL on 16 chromosomes for seven kernel morphology traits measured by digital imaging, viz. kernel length, width, perimeter, area, shape factor, factor form-density and width/length ratio. Each of these loci explained from 2.6 to 28.2% of the phenotypic variation. Eight QTL clusters conferring the largest effects on kernel weight and kernel morphology traits were detected on chromosomes 1BL.1RS (2), 2A, 4A, 4B, 6B, 6D and 7A. Fourteen epistatic QTL were identified for all kernel morphology traits except kernel width/length ratio, involving 24 main-effect QTL distributed on 13 chromosomes, and explaining 2.5–8.3% of the phenotypic variance. Five loci, viz. Sec-1 on 1BL.1RS, Glu-B1 on 1BL, Xcfe53 on 2A, Xwmc238 on 4B, and Xbarc174 on 7A, were detected consistently across environments, and their linked DNA markers may be used for marker-assisted selection in breeding for improved wheat kernel traits and grain yield.