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Abstract The cultivated peanut (Arachis hypogaea L.) is an important oil crop but has a narrow genetic diversity. Molecular markers can be used to probe the genetic diversity of various germplasm. In this study, the restriction site associated DNA (RAD) approach was utilized to sequence 31 accessions of Taiwanese peanut germplasm, leading to the identification of a total of 17,610 single nucleotide polymorphisms (SNPs). When we grouped these 31 accessions into two subsets according to origin, we found that the “global” subset (n = 17) was more genetically diverse than the “local” subset (n = 14). Concerning botanical varieties, the var. fastigiata subset had greater genetic diversity than the other two subsets of var. vulgaris and var. hypogaea, suggesting that novel genetic resources should be introduced into breeding programs to enhance genetic diversity. Principal component analysis (PCA) of genotyping data separated the 31 accessions into three clusters largely according to the botanical varieties, consistent with the PCA result for 282 accessions genotyped by 14 kompetitive allele-specific PCR (KASP) markers developed in this study. The SNP markers identified in this work not only revealed the genetic relationship and population structure of current germplasm in Taiwan, but also offer an efficient tool for breeding and further genetic applications.

Sorghum (Sorghum bicolor) exhibits drought resistance and environmental adaptability, making it a crucial cereal crop for semi-arid regions. It has a wide range of uses, including as food, feed, brooms, alcohol production, and bioethanol. In particular, Taiwan imports nearly 50,000 tons of sorghum annually, primarily for the production of sorghum liquor. However, the ideal raw material for high-quality sorghum liquor is waxy sorghum, and not all sorghum varieties imported or promoted in Taiwan are of this waxy type. Consequently, there is a shortage of sufficient waxy sorghum raw materials to meet the demands of the Taiwan market. The occurrence of waxy sorghum (wx) is caused by the mutation of granule-bound starch synthase I (GBBS I), and there are currently several known types of mutants, carrying different wxa, wxb, and wxc waxy alleles. Among them, wxc is a novel mutation type, and in native sorghum in Taiwan, individuals with the waxy allele wxc have been found. The three-line method is a commonly used breeding strategy, which simplifies the process of emasculation to obtain hybrid F1 offspring. In this study, imported sorghum variety Liangnuo No.1 (with male sterility), native glutinous sorghum variety SB6 from Taiwan (carrying the wxc waxy allele), and sorghum reference genome variety BTx623 were used as research materials. The goal was to use the three-line method to produce waxy sorghums, including the male sterile line (A-line), male sterile maintenance line (B-line), and fertility-restoring line (R-line). The breeding results showed that by using backcross breeding, molecular-assisted selection, and traditional field selection methods, high-quality three-line materials (A-, B-, R-lines, named CNA1, CNB1 CNR1, respectively) and F1 hybrid (CNH1) with favorable agronomic traits and yield quality were successfully obtained.

We analyze 214 freshly laid eggs belonging to 16 species across three orders of Class Reptilia. Using mechanical compression tests, we measure each egg’s absolute stiffness (K, unit: N m−1) and relative stiffness (C number). The effective Young’s modulus, E, was obtained by combining experimental and numerical methods. The mineral (CaCO3) content was measured by acid–base titration, the microstructures by scanning electron microscopy (SEM), and the crystallography by electron backscatter diffraction (EBSD). We find that the C number of reptilian eggs is, on average, higher than that of bird eggs, indicating that reptilian eggs are stiffer with respect to the egg mass than birds. However, Young’s moduli of the reptilian eggshells (32.85 ± 3.48 GPa) are similar to those of avian eggshells (32.07 ± 5.95 GPa), even though those eggshells have different crystal forms, microstructures, and crystallography. Titration measurement shows that the reptilian eggshells are highly mineralized (>89% for nine Testudines species and 96% for Caiman crocodilus). Comparing the species with aragonite and calcite crystals, we find that calcite shells, including those of the Kwangsi gecko (inner part) and spectacled caiman (outer part), generally have larger grains than the aragonite ones. However, the grain size is not correlated to the effective Young’s modulus. Also, as measured by the C number, the aragonite shells are, on average, stiffer than the calcite ones (except for the Kwangsi gecko), primarily due to their thicker shells.