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Paeonia jishanensis is endemic in China, and has been proven to be one of the most important ancestral species of cultivated tree peonies. Wild P. jishanensis has been over-exploited and becomes quite rare in China. The wild peony of P. jishanensis was used as an experimental material to sequence the chloroplast genome (cpDNA) by high-throughput sequencing (NCBI accession number: MG991935). The cpDNA of P. jishanensis is a typical quadripartite structure with a length of 152,628 bp, including a large single-copy (LSC) region of 84,292 bp and a small single-copy (SSC) region of 17,044 bp separated by a pair of identical inverted repeat regions (IRs) of 25,646 bp each. The cpDNA contains 112 genes, including 78 protein-coding genes, 30 transfer RNA genes, and 4 ribosomal RNA genes. The result of phylogenomic analysis supports the difference of tree peony from the herbaceous peony.

Background The chloroplast (cp) genome is useful in plant systematics, genetic diversity analysis, molecular identification and divergence dating. The genus Gentiana contains 362 species, but there are only two valuable complete cp genomes. The purpose of this study is to report the characterization of complete cp genome of G. lawrencei var. farreri, which is endemic to the Qinghai-Tibetan Plateau (QTP). Methods Using high throughput sequencing technology, we got the complete nucleotide sequence of the G. lawrencei var. farreri cp genome. The comparison analysis including genome difference and gene divergence was performed with its congeneric species G. straminea. The simple sequence repeats (SSRs) and phylogenetics were studied as well. Results The cp genome of G. lawrencei var. farreri is a circular molecule of 138,750 bp, containing a pair of 24,653 bp inverted repeats which are separated by small and large single-copy regions of 11,365 and 78,082 bp, respectively. The cp genome contains 130 known genes, including 85 protein coding genes (PCGs), eight ribosomal RNA genes and 37 tRNA genes. Comparative analyses indicated that G. lawrencei var. farreri is 10,241 bp shorter than its congeneric species G. straminea. Four large gaps were detected that are responsible for 85% of the total sequence loss. Further detailed analyses revealed that 10 PCGs were included in the four gaps that encode nine NADH dehydrogenase subunits. The cp gene content, order and orientation are similar to those of its congeneric species, but with some variation among the PCGs. Three genes, ndhB, ndhF and clpP, have high nonsynonymous to synonymous values. There are 34 SSRs in the G. lawrencei var. farreri cp genome, of which 25 are mononucleotide repeats: no dinucleotide repeats were detected. Comparison with the G. straminea cp genome indicated that five SSRs have length polymorphisms and 23 SSRs are species-specific. The phylogenetic analysis of 48 PCGs from 12 Gentianales taxa cp genomes clearly identified three clades, which indicated the potential of cp genomes in phylogenetics. Discussion The “missing” sequence of G. lawrencei var. farreri mainly consistent of ndh genes which could be dispensable under chilling-stressed conditions in the QTP. The complete cp genome sequence of G. lawrencei var. farreri provides intragenic information that will contribute to genetic and phylogenetic research in the Gentianaceae.

Chinese jujube (Ziziphus jujuba Mill. [Rhamnaceae]), native to China, is a major dried fruit crop in Asia. Although many simple sequence repeat (SSR) markers are available for phylogenetic analysis of jujube cultivars, few of these are validated on the level of jujube populations. In this study, we first examined the abundance of jujube SSRs with repeated unit lengths of 1–6 base pairs, and compared their distribution with those in Arabidopsis thaliana. We identified 280,596 SSRs in the assembled genome of jujube. The density of SSRs in jujube was 872.60 loci/Mb, which was much higher than in A. thaliana (221.78 loci/Mb). (A+ T)-rich repeats were dominant in the jujube genome. We then randomly selected 100 SSRs in the jujube genome with long repeats and used them to successfully design 70 primer pairs. After screening using a series of criteria, a set of 20 fluorescently labeled primer pairs was further selected and screened for polymorphisms among three jujube populations. The average number of alleles per locus was 12.8. Among the three populations, mean observed and expected heterozygosities ranged from 0.858 to 0.967 and 0.578 to 0.844, respectively. After testing in three populations, all SSRs loci were in Hardy-Weinberg equilibrium (HWE) in at least one population. Finally, removing high null allele frequency loci and linked loci, a set of 17 unlinked loci was in HWE. These markers will facilitate the study of jujube genetic structure and help elucidate the evolutionary history of this important fruit crop.

In this work, the intentional insertion of slots in metal gate (MG) is introduced to solve the dishing issue for the double-diffused drain MOSFET (DDDMOSFET) fabrication. For traditional DDDMOSFET, the gate oxide layer in slots will be reserved to improve the device reliability, which requires an additional photomask to screen the gate/slot regions during the following sidewall formation and source/drain (S/D) implantation. This makes the process more complicated with increased cost. Without that additional photomask, it is proposed that the removal of gate oxide layer in slots can directly allow the floating S/D formation and the followed Ni silicidation there. It is demonstrated that such a novel process can not only relieve the MG dishing issue but can also effectively result in ~16% higher ON current and comparable OFF current for both N- and P-DDDMOSFETs without threshold voltage shift after applying electrical stress on gates. It is also revealed that the floating silicided S/Ds in slots have negligible influence on device breakdown characteristics. By saving one photomask, this work proposes a novel solution for the effective integration of core devices with very small feature sizes and high-voltage (HV) devices with large feature sizes in the same die, which is a common challenge for display driver chip fabrication using high- ${k}$ /MG (HK/MG) technology. [ABSTRACT FROM AUTHOR]

In this work, the influence of TiAl gate electrode fabricated by atomic layer deposition (ALD) and physical vapor deposition (PVD) on threshold voltage ($\text{V}_{\text {t}}$) for metal-gated NMOSFETs is respectively investigated. Compared to ALD TiAl, the 200 mV lower $\text{V}_{\text {t}}$ for PVD TiAl is demonstrated and attributed to the oxidation of TiAl with a strong segregation of Ti near TiAl/TaN interface. It is further revealed that by changing the thickness of the first layer ALD TiAl film, the multi- $\text{V}_{\text {t}}$ can be easily obtained within a range of 200 mV using an ALD TiAl /PVD TiAl double layer gate electrode. [ABSTRACT FROM AUTHOR]