We report here the complete genome sequence of “Candidatus Liberibacter asiaticus” (strain Guangxi-1). The 1,268,237-bp genome with a 36.5% G+C content comprises 1,141 open reading frames, 44 tRNAs, and 3 complete rRNAs in a circular chromosome.

Real-time detection of fruits in orchard environments is one of crucial techniques for many precision agriculture applications, including yield estimation and automatic harvesting. Due to the complex conditions, such as different growth periods and occlusion among leaves and fruits, detecting fruits in natural environments is a considerable challenge. A rapid citrus recognition method by improving the state-of-the-art You Only Look Once version 4 (YOLOv4) detector is proposed in this paper. Kinect V2 camera was used to collect RGB images of citrus trees. The Canopy algorithm and the K-Means++ algorithm were then used to automatically select the number and size of the prior frames from these RGB images. An improved YOLOv4 network structure was proposed to better detect smaller citrus under complex backgrounds. Finally, the trained network model was used for sparse training, pruning unimportant channels or network layers in the network, and fine-tuning the parameters of the pruned model to restore some of the recognition accuracy. The experimental results show that the improved YOLOv4 detector works well for detecting different growth periods of citrus in a natural environment, with an average increase in accuracy of 3.15% (from 92.89% to 96.04%). This result is superior to the original YOLOv4, YOLOv3, and Faster R-CNN. The average detection time of this model is 0.06 s per frame at 1920 × 1080 resolution. The proposed method is suitable for the rapid detection of the type and location of citrus in natural environments and can be applied to the application of citrus picking and yield evaluation in actual orchards.

Self-incompatibility (SI) substantially restricts the yield and quality of citrus. Therefore, breeding and analyzing self-compatible germplasm is of great theoretical and practical significance for citrus. Here, we focus on the mechanism of a self-compatibility mutation in ‘Guiyou No. 1’ pummelo (Citrus maxima), which is a spontaneous mutant of ‘Shatian’ pummelo (Citrus maxima, self-incompatibility). The rate of fruit set and the growth of pollen tubes in the pistil confirmed that a spontaneous mutation in the pistil is responsible for the self-compatibility of ‘Guiyou No. 1’. Segregation ratios of the S genotype in F1 progeny, expression analysis, and western blotting validated that the reduced levels of S2-RNase mRNA contribute to the loss of SI in ‘Guiyou No. 1’. Furthermore, we report a phased assembly of the ‘Guiyou No. 1’ pummelo genome and obtained two complete and well-annotated S haplotypes. Coupled with an analysis of SV variations, methylation levels, and gene expression, we identified a candidate gene (CgHB40), that may influence the regulation of the S2-RNase promoter. Our data provide evidence that a mutation that affects the pistil led to the loss of SI in ‘Guiyou No. 1’ by influencing a poorly understood mechanism that affects transcriptional regulation. This work significantly advances our understanding of the genetic basis of the SI system in citrus and provides information on the regulation of S-RNase genes.

Background: With the continuous improvement of human living standards, more and more dental patients are requiring oral implant restoration treatment. However, there is still controversy regarding the influence of risk factors such as osteoporosis, radiotherapy, diabetes, and smoking on the failure of oral implants. This study aimed to explore the correlation between risk factors and failure of oral implant restoration treatment. Methods:The databases of China National Knowledge Infrastructure (CNKI), Baidu Academic, Weipu, Wanfang, PubMed, EBSCO, Medline, Web of knowledge, Ovid, and the Cochrane Library were searched.The search strategies included: subject terms related to research results such as survival, osseointegration, failure, removal, replacement, and loss; related to risk factors: osteoporosis, head and neck cancer, diabetes, and smoking; and oral implantology as a keyword.Results: Thirty-two articles were included in meta-analysis, there was a high heterogeneity between radiotherapy and dental implant failure (I 2 =71.6%, P=0.000), and there was an obvious correlation between radiotherapy and dental implant failure [relative risk (RR) =2.09, 95% confidential interval (CI): 1.68-2.61].There was heterogeneity between diabetes and oral implant failure in the included articles (I 2 =59.6%, P=0.084). There was no remarkable correlation between osteoporosis and dental implant failure (RR =1.19, 95% CI: 0.81-1.74). There was a high heterogeneity between smoking and dental implant failure in the included articles (I 2 =33.8%, P=0.092), showing obvious correlation (RR =1.80, 95% CI: 1.53-2.11).Discussion: The results of meta-analysis confirmed that radiotherapy and smoking were greatly associated with oral implant failure.

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