QTL mapping and transcriptome analysis identify candidate genes regulating pericarp thickness in sweet corn.

BACKGROUND: In recent years, the planting area of sweet corn in China has expanded rapidly. Some new varieties with high yields and good adaptabilities have emerged. However, the improvement of edible quality traits, especially through the development of varieties with thin pericarp thickness, has not been achieved to date. Pericarp thickness is a complex trait that is the key factor determining the edible quality of sweet corn. Genetic mapping combined with transcriptome analysis was used to identify candidate genes controlling pericarp thickness. RESULTS: To identify novel quantitative trait loci (QTLs) for pericarp thickness, a sweet corn BC4F3 population of 148 lines was developed using the two sweet corn lines M03 (recurrent parent) and M08 (donor parent). Additionally, a high-density genetic linkage map containing 3876 specific length amplified fragment (SLAF) tags was constructed and used for mapping QTLs for pericarp thickness. Interestingly, 14 QTLs for pericarp thickness were detected, and one stable QTL (qPT10-5) was detected across multiple years, which explained 7.78-35.38% of the phenotypic variation located on chromosome 10 (144,631,242-145,532,401). Forty-two candidate genes were found within the target region of qPT10-5. Moreover, of these 42 genes, five genes (GRMZM2G143402, GRMZM2G143389, GRMZM2G143352, GRMZM6G287947, and AC234202.1_FG004) were differentially expressed between the two parents, as revealed by transcriptome analysis. According to the gene annotation information, three genes might be considered candidates for pericarp thickness. GRMZM2G143352 and GRMZM2G143402 have been annotated as AUX/IAA transcription factor and ZIM transcription factor, respectively, while GRMZM2G143389 has been annotated as FATTY ACID EXPORT 2, chloroplastic. CONCLUSIONS: This study identified a major QTL and candidate genes that could accelerate breeding for the thin pericarp thickness variety of sweet corn, and these results established the basis for map-based cloning and further functional research.

Robotic mobile and mirror milling of large-scale complex structures.

Robotization, miniaturization and portability have become the new development trend of milling equipment for large-scale complex structures, and the robotic mobile and mirror milling technology has reached remarkable progress in practical production.

PneuNet: deep learning for COVID-19 pneumonia diagnosis on chest X-ray image analysis using Vision Transformer.

A long-standing challenge in pneumonia diagnosis is recognizing the pathological lung texture, especially the ground-glass appearance pathological texture. One main difficulty lies in precisely extracting and recognizing the pathological features. The patients, especially those with mild symptoms, show very little difference in lung texture, neither conventional computer vision methods nor convolutional neural networks perform well on pneumonia diagnosis based on chest X-ray (CXR) images. In the meanwhile, the Coronavirus Disease 2019 (COVID-19) pandemic continues wreaking havoc around the world, where quick and accurate diagnosis backed by CXR images is in high demand. Rather than simply recognizing the patterns, extracting feature maps from the original CXR image is what we need in the classification process. Thus, we propose a Vision Transformer (VIT)-based model called PneuNet to make an accurate diagnosis backed by channel-based attention through X-ray images of the lung, where multi-head attention is applied on channel patches rather than feature patches. The techniques presented in this paper are oriented toward the medical application of deep neural networks and VIT. Extensive experiment results show that our method can reach 94.96% accuracy in the three-categories classification problem on the test set, which outperforms previous deep learning models.

Two sesquiterpene pyridine alkaloids and a triterpenoid saponin from the root barks of Tripterygium hypoglaucum.

Two new sesquiterpene pyridine alkaloids hypoglaunines E (1) and F (2) and a new triterpenoid saponin hypoglaside A (3), together with a known diterpenoid glucoside11-O-ß-D-glucopyranosyl neotriptophenolide (4) and two known triterpenoids 23-noroxopristimerol(5) and 2,3-dihydroxy-6-oxo-D:A-froedo-24 nor-1,3,5(10),7-oleanatetraen-29-oic acid (6), have been isolated from the root barks of Tripterygiumhypoglaucum. Their structures were elucidated by NMR spectroscopy and MS analysis.Compounds 1­3 were screened for their cytotoxic activities against five cancer celllines, but all of them were inactive.

[Study on chemical constituents from the root bark of Tripterygium hypoglaucum].

OBJECTIVE: To study the chemical constituents of the root bark of Tripterygium hypoglaucum. METHODS: Column chromatography was used to separate the chemical constituents. The structures were determined by application of spectroscopic (NMR, MS) and chemical methods. RESULTS: Eleven compounds were isolated and identified as 4'-0-(-) methylepigallocatechin (1),3,4-dimethoxyphenyl-beta-D-glucopyranoside (2), 3,4,5-trimethoxyphenyl-f-D-glucopyranoside (3), (2R,3R)-3,5,7,3',5'-pentahydroxyflavan (4), 2-O-deacetyleuonine (5), tripfordine C (6), peritassine A (7) hypoglaunine C (8), wilfortrine (9), wilforgine (10) and wilfordine (11). CONCLUSION: Compounds 1-6 are isolated from this plant for the first time.

[Preparation and in vitro release characteristics of pulsed-release tablets of Apocynum venetum].

OBJECTIVE: Using Apocynum venetum as a model drug to prepare pulsed-release tablets based on diffusion, swelling, osmotic pressure mechanism and to evaluate the release characteristics. METHOD: The pulsatile release tablets were prepared by film coating methods using HPMC E5 and Eudragit The effect of formulation on pulsatile release of A. venetum was investigated. RESULT: The pulsed-release tablet was prepared by a swelling layer coating which contains HPMC E5 and a controlled-release membrane containning Eudragit. The delayed release time of the tablets was (5.0 +/- 0.5) h. CONCLUSION: The pulsatile release characteristics of A. venetum pulsatile release tablets were confirmed in vitro.

Construction of High-Density Genetic Map and Identification of QTLs Associated with Seed Vigor after Exposure to Artificial Aging Conditions in Sweet Corn Using SLAF-seq.

Seed vigor is a key factor that determines the quality of seeds, which is of great significance for agricultural production, with the potential to promote growth and productivity. However, the underlying molecular mechanisms and genetic basis for seed vigor remain unknown. High-density genetic linkage mapping is an effective method for genomic study and quantitative trait loci (QTL) mapping. In this study, a high-density genetic map was constructed from a 148 BC4F3 population cross between 'M03' and 'M08' strains based on specific-locus amplified fragment (SLAF) sequencing. The constructed high-density genetic linkage map (HDGM) included 3876 SNP markers on ten chromosomes covering 2413.25 cM in length, with a mean distance between markers of 0.62 cM. QTL analysis was performed on four sweet corn germination traits that are related to seed vigor under artificial aging conditions. A total of 18 QTLs were identified in two seasons. Interestingly, a stable QTL was detected in two seasons on chromosome 10-termed qGR10-within an interval of 1.37 Mb. Within this interval, combined with gene annotation, we found four candidate genes (GRMZM2G074309, GRMZM2G117319, GRMZM2G465812, and GRMZM2G343519) which may be related to seed vigor after artificial aging.