BTA2 regulates tiller angle and the shoot gravity response through controlling auxin content and distribution in rice.

Tiller angle is a key agricultural trait that establishes plant architecture, which in turn strongly affects grain yield by influencing planting density in rice. The shoot gravity response plays a crucial role in the regulation of tiller angle in rice, but the underlying molecular mechanism is largely unknown. Here, we report the identification of the BIG TILLER ANGLE2 (BTA2), which regulates tiller angle by controlling the shoot gravity response in rice. Loss-of-function mutation of BTA2 dramatically reduced auxin content and affected auxin distribution in rice shoot base, leading to impaired gravitropism and therefore a big tiller angle. BTA2 interacted with AUXIN RESPONSE FACTOR7 (ARF7) to modulate rice tiller angle through the gravity signaling pathway. The BTA2 protein was highly conserved during evolution. Sequence variation in the BTA2 promoter of indica cultivars harboring a less expressed BTA2 allele caused lower BTA2 expression in shoot base and thus wide tiller angle during rice domestication. Overexpression of BTA2 significantly increased grain yield in the elite rice cultivar Huanghuazhan under appropriate dense planting conditions. Our findings thus uncovered the BTA2-ARF7 module that regulates tiller angle by mediating the shoot gravity response. Our work offers a target for genetic manipulation of plant architecture and valuable information for crop improvement by producing the ideal plant type.

Decompressive Bone Flap Replacement (Decompressive Cranioplasty): A Novel Technique for Intracranial Hypertension-Initial Experience and Outcome.

BACKGROUND: Intracranial hypertension is a life-threatening condition that can be treated by decompressive craniectomy (DC), which involves removing a part of the skull and intracranial lesions. However, DC has many complications and requires a second surgery to repair the skull. Decompressive bone flap replacement (DBFR) or decompressive cranioplasty is a novel technique that replaces the bone flap with a titanium mesh, providing both decompression and skull integrity. METHODS: The materials and methods of DBFR are described in detail. A three-dimensional titanium mesh is fabricated based on the computed tomography (CT) data of previous DC patients. An appropriate titanium mesh is selected based on the preoperative and intraoperative assessments. After removing the intracranial lesions, the titanium mesh is fixed over the bone window. RESULTS: We successfully performed DBFR in three emergent cases. The postoperative CT scan showed adequate decompression in all cases. No reoperation for skull repair was needed, and there were no surgical complications. The cosmetic outcome was excellent. There were no relevant complications in the operative area. CONCLUSIONS: DBFR may be a safe and effective alternative to DC in a specific subgroup of patients, in whom complete removal of the bone flap is feasible. DBFR can reduce intracranial pressure while maintaining the integrity of the skull cavity, eliminating the need for additional surgery for skull repair. Possible improvements for DBFR in the future are suggested, such as using a greater curvature of the titanium mesh or a modified DBFR with a hinged titanium mesh.

Integrating genome-wide association study into genomic selection for the prediction of agronomic traits in rice (Oryza sativa L.).

Accurately identifying varieties with targeted agronomic traits was thought to contribute to genetic selection and accelerate rice breeding progress. Genomic selection (GS) is a promising technique that uses markers covering the whole genome to predict the genomic-estimated breeding values (GEBV), with the ability to select before phenotypes are measured. To choose the appropriate GS models for breeding work, we analyzed the predictability of nine agronomic traits measured from a population of 459 diverse rice varieties. By the comparison of eight representative GS models, we found that the prediction accuracies ranged from 0.407 to 0.896, with reproducing kernel Hilbert space (RKHS) having the highest predictive ability in most traits. Further results demonstrated the predictivity of GS is altered by several factors. Moreover, we assessed the method of integrating genome-wide association study (GWAS) into various GS models. The predictabilities of GS combined peak-associated markers generated from six different GWAS models were significantly different; a recommendation of Mixed Linear Model (MLM)-RKHS was given for the GWAS-GS-integrated prediction. Finally, based on the above result, we experimented with applying the P-values obtained from optimal GWAS models into ridge regression best linear unbiased prediction (rrBLUP), which benefited the low predictive traits in rice. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-023-01423-y.

Unveiling the Genetic Basis Underlying Rice Anther Culturability via Segregation Distortion Analysis in Doubled Haploid Population.

Anther culture (AC) is a valuable technique in rice breeding. However, the genetic mechanisms underlying anther culturability remain elusive, which has hindered its widespread adoption in rice breeding programs. During AC, microspores carrying favorable alleles for AC are selectively regenerated, leading to segregation distortion (SD) of chromosomal regions linked to these alleles in the doubled haploid (DH) population. Using the AC method, a DH population was generated from the japonica hybrid rice Shenyou 26. A genetic map consisting of 470 SNPs was constructed using this DH population, and SD analysis was performed at both the single- and two-locus levels to dissect the genetic basis underlying anther culturability. Five segregation distortion loci (SDLs) potentially linked to anther culturability were identified. Among these, SDL5 exhibited an overrepresentation of alleles from the female parent, while SDL1.1, SDL1.2, SDL2, and SDL7 displayed an overrepresentation of alleles from the male parent. Furthermore, six pairs of epistatic interactions (EPIs) that influenced two-locus SDs in the DH population were discovered. A cluster of genetic loci, associated with EPI-1, EPI-3, EPI-4, and EPI-5, overlapped with SDL1.1, indicating that the SDL1.1 locus may play a role in regulating anther culturability via both additive and epistatic mechanisms. These findings provide valuable insights into the genetic control of anther culturability in rice and lay the foundation for future research focused on identifying the causal genes associated with anther culturability.

Genomic selection analysis of morphological and adaptation traits in Chinese indigenous dog breeds.

The significant morphological differences and abundant germplasm resources of Chinese indigenous dog breeds can be attributed to the diverse geographical environment, including plateaus, mountains, and a long history of raising dogs. The combination of both natural and artificial selection during the past several thousand years has led to hundreds of dog breeds with distinct morphological traits and environmental adaptations. China is one of the earliest countries to domesticate dogs and there are more than 50 ancient indigenous dog breeds. In this study, the run of homozygosity (ROH) and proportion of the autosomal genome covered by ROHs (FROH) were calculated for 10 dog breeds that are the most representative Chinese indigenous dogs based on 170K SNP microarray. The results of FROH showed that the Chuandong hound dogs (HCSSC) have the highest level of inbreeding among the tested breeds. The inbreeding in HCSSC occurred more recently than the Liangshan dogs (SCLSQ) dogs because of more numbers of long ROHs in HCSSC dogs, and the former also have higher inbreeding degree. In addition, there are significant differences in the inbreeding degree among different subpopulations of the same breed, such as the Thin dogs from Shaanxi and Shandong province. To explore genome-wide selection signatures among different breeds, including coat color, ear shape, and altitude adaptability, we performed genome selection analyses of FST and cross population extended haplotype homozygosity (XP-EHH). For the coat color, the FST analysis between Xiasi dogs (XSGZ) and HCSSC dogs was performed and identified multiple genes involved in coat color, hair follicle, and bone development, including MC1R, KITLG, SOX5, RSPO2, and TBX15. For the plateau adaptability, we performed FST and XP-EHH analyses between dogs from Tibet (Tibetan Mastiffs and Nyingchi dogs) and plain regions (Guangxi Biwei dogs GXBWQ and Guandong Sharpei dogs). The results showed the EPAS1 gene in dogs from Tibet undergo strong selection. Multiple genes identified for selection signals based on different usage of dogs. Furthermore, the results of ear shape analyses showed that MSRB3 was likely to be the main gene causing the drop ear of domestic dogs. Our study provides new insights into further understanding of Chinese indigenous dogs.

An Approach for Plant Leaf Image Segmentation Based on YOLOV8 and the Improved DEEPLABV3.

Accurate plant leaf image segmentation provides an effective basis for automatic leaf area estimation, species identification, and plant disease and pest monitoring. In this paper, based on our previous publicly available leaf dataset, an approach that fuses YOLOv8 and improved DeepLabv3+ is proposed for precise image segmentation of individual leaves. First, the leaf object detection algorithm-based YOLOv8 was introduced to reduce the interference of backgrounds on the second stage leaf segmentation task. Then, an improved DeepLabv3+ leaf segmentation method was proposed to more efficiently capture bar leaves and slender petioles. Densely connected atrous spatial pyramid pooling (DenseASPP) was used to replace the ASPP module, and the strip pooling (SP) strategy was simultaneously inserted, which enabled the backbone network to effectively capture long distance dependencies. The experimental results show that our proposed method, which combines YOLOv8 and the improved DeepLabv3+, achieves a 90.8% mean intersection over the union (mIoU) value for leaf segmentation on our public leaf dataset. When compared with the fully convolutional neural network (FCN), lite-reduced atrous spatial pyramid pooling (LR-ASPP), pyramid scene parsing network (PSPnet), U-Net, DeepLabv3, and DeepLabv3+, the proposed method improves the mIoU of leaves by 8.2, 8.4, 3.7, 4.6, 4.4, and 2.5 percentage points, respectively. Experimental results show that the performance of our method is significantly improved compared with the classical segmentation methods. The proposed method can thus effectively support the development of smart agroforestry.

LG5, a Novel Allele of EUI1, Regulates Grain Size and Flag Leaf Angle in Rice.

Grain size and flag leaf angle are two important traits that determining grain yield in rice. However, the mechanisms regulating these two traits remain largely unknown. In this study, a rice long grain 5 (lg5) mutant with a large flag leaf angle was identified, and map-based cloning revealed that a single base substitution followed by a 2 bp insertion in the LOC_Os05g40384 gene resulted in larger grains, a larger flag leaf angle, and higher plant height than the wild type. Sequence analysis revealed that lg5 is a novel allele of elongated uppermost internode-1 (EUI1), which encodes a cytochrome P450 protein. Functional complementation and overexpression tests showed that LG5 can rescue the bigger grain size and larger flag leaf angle in the Xiushui11 (XS) background. Knockdown of the LG5 transcription level by RNA interference resulted in elevated grain size and flag leaf angle in the Nipponbare (NIP) background. Morphological and cellular analyses suggested that LG5 regulated grain size and flag leaf angle by promoting cell expansion and cell proliferation. Our results provided new insight into the functions of EUI1 in rice, especially in regulating grain size and flag leaf angle, indicating a potential target for the improvement of rice breeding.

Exploring the Pathogenesis of Atlanto-Occipital Instability in Chiari Malformation With Type II Basilar Invagination: A Systematic Morphological Study.

BACKGROUND: Our previous study suggested that atlanto-occipital instability (AOI) is common in patients with type II basilar invagination (II-BI). OBJECTIVE: To further understand the pathogenesis of AOI in Chiari malformations (CM) and CM + II-BI through systematic measurements of the bone structure surrounding the craniocervical junction. METHODS: Computed tomography data from 185 adults (80 controls, 63 CM, and 42 CM + II-BI) were collected, and geometric models were established for parameter measurement. Canonical correlation analysis was used to evaluate the morphological and positional relationships of the atlanto-occipital joint (AOJ). RESULTS: Among the 3 groups, the length and height of the condyle and superior portion of the lateral masses of the atlas (C1-LM) were smallest in CM + II-BI cases; the AOJ had the shallowest depth and the lowest curvature in the same group. AOJs were divided into 3 morphological types: type I, the typical ball-and-socket joint, mainly in the control group (100%); type II, the shallower joint, mainly in the CM group (92.9%); and type III, the abnormal flat-tilt joint, mainly in the CM + II-BI group (89.3%). Kinematic computed tomography revealed AOI in all III-AOJs (100%) and some II-AOJs (1.5%) but not in type I-AOJs (0%). Morphological parameters of the superior portion of C1-LM positively correlated with those of C0 and the clivus and significantly correlated with AOI. CONCLUSION: Dysplasia of the condyle and superior portion of C1-LM exists in both CM and II-BI cases yet is more obvious in type II-BI. Unstable movement caused by AOJ deformation is another pathogenic factor in patients with CM + II-BI.

Progesterone Promotes In Vitro Maturation of Domestic Dog Oocytes Leading to Successful Live Births.

Gene-edited dogs are promising models for biomedical research because they have hundreds of genetic diseases that are similar to humans. A common method for producing gene-edited dogs is assisted reproductive technology (ART) using in vivo oocytes or embryos, but it is much more inefficient and has a higher cost. ART for dogs has lagged mostly because of the lack of an efficient in vitro maturation system. Because early maturation of canine oocytes occurs in follicles with extremely high concentrations of progesterone (P4), we hypothesize that P4 has an important role during maturation. In this study, we obtained ovaries of female dogs and collected cumulus−oocyte complexes, which were cultured in vitro in microdrops containing different P4 concentrations (0, 10, 40, 100 or 200 µg/mL). We found that 40 µg/mL P4 produced the highest oocyte maturation rate (29.7% ± 7.1%, p < 0.05). We also evaluated the quality of in vitro matured oocytes by in vitro fertilization and single-cell RNA sequencing, and both indicated an improvement in oocyte developmental potential. In conclusion, we successfully obtained the first live dogs using in vitro matured oocytes by adding P4 to optimize the in vitro maturation system of canine oocytes, and established a new and low-cost method to produce dogs via in vitro maturation and in vitro fertilization.

Genomic insight into genetic changes and shaping of major inbred rice cultivars in China.

The annual planting area of major inbred rice (Oryza sativa) cultivars reach more than half of the total annual planting area of inbred rice cultivars in China. However, how the major inbred rice cultivars changed during decades of genetic improvement and why they can be prevalently cultivated in China remains unclear. Here, we investigated the underlying genetic changes of major inbred cultivars and the contributions of landraces and introduced cultivars during the improvement by resequencing a collection of 439 rice accessions including major inbred cultivars, landraces, and introduced cultivars. The results showed that landraces were the main genetic contribution sources of major inbred Xian (Indica) cultivars, while introduced cultivars were that of major inbred Geng (Japonica) cultivars. Selection scans and haplotype frequency analysis shed light on the reflections of some well-known genes in rice improvement, and breeders had different preferences for the Xian's and Geng's breeding. Six candidate regions associated with agronomic traits were identified by genome-wide association mapping, five of which were under positive selection in rice improvement. Our study provides a comprehensive insight into the development of major inbred rice cultivars and lays the foundation for genomics-based breeding in rice.

A new mathematical mixed effect model was used for analysing the influencing factors of hypoglycaemia of newborns from women with gestational diabetes mellitus.

A mathematical mixed effect model was established to analyse the factors of neonatal hypoglycaemia of gestational diabetes mellitus (GDM). 229 cases of GDM patients were enrolled in this study. The data were analysed by logarithmic transformation of non-normal distribution. Furthermore, the mathematical model was used to analyse influencing factors of hypoglycaemia of neonatal from women with GDM. The results showed that the blood glucose distribution level had a trend of increasing with time, which indicates that it is necessary to strengthen blood glucose intervention of newborns from GDM maternal and provides a data for the timely detection of hypoglycaemia in GDM newborns. Furthermore, we successfully established the GDM newborn blood glucose level mixed mathematical model. From this model, we calculated the GDM newborn blood glucose normal confidence interval based on mixed factors. The results indicate that the minimum value of blood glucose level in GDM newborns did not exceed the risk level 2.2 mmol/L. We concluded that the mathematical mixed effect model is successfully established, from which the change discipline of blood glucose level of newborn from GDM parturient are found. Impact statementWhat is already known on this subject? The morbidity of gestational diabetes mellitus (GDM) in China has been increased. However, the clinical data is difficult to be collected and the data that is used for statistics is not enough, which makes it difficult to understand the neonatal hypoglycaemia of GDM more clearly.What do the results of this study add? In this study, we successfully established a mathematical mixed effect model of neonatal hypoglycaemia of women with GDM, which can investigate the influence factor of hypoglycaemia of newborn from women with GDM to find the discipline of blood glucose level of newborn from GDM parturient via mathematical model.What are the implications of these findings for clinical practice and/or further research? Our research helps to better understand and improve the health problem of pregnant women with GDM and their newborn babies.

Gene prediction of aging-related diseases based on DNN and Mashup.

BACKGROUND: At present, the bioinformatics research on the relationship between aging-related diseases and genes is mainly through the establishment of a machine learning multi-label model to classify each gene. Most of the existing methods for predicting pathogenic genes mainly rely on specific types of gene features, or directly encode multiple features with different dimensions, use the same encoder to concatenate and predict the final results, which will be subject to many limitations in the applicability of the algorithm. Possible shortcomings of the above include: incomplete coverage of gene features by a single type of biomics data, overfitting of small dimensional datasets by a single encoder, or underfitting of larger dimensional datasets. METHODS: We use the known gene disease association data and gene descriptors, such as gene ontology terms (GO), protein interaction data (PPI), PathDIP, Kyoto Encyclopedia of genes and genomes Genes (KEGG), etc, as input for deep learning to predict the association between genes and diseases. Our innovation is to use Mashup algorithm to reduce the dimensionality of PPI, GO and other large biological networks, and add new pathway data in KEGG database, and then combine a variety of biological information sources through modular Deep Neural Network (DNN) to predict the genes related to aging diseases. RESULT AND CONCLUSION: The results show that our algorithm is more effective than the standard neural network algorithm (the Area Under the ROC curve from 0.8795 to 0.9153), gradient enhanced tree classifier and logistic regression classifier. In this paper, we firstly use DNN to learn the similar genes associated with the known diseases from the complex multi-dimensional feature space, and then provide the evidence that the assumed genes are associated with a certain disease.

Genome-Wide Association Study of Rice Rooting Ability at the Seedling Stage.

BACKGROUND: Rice rooting ability is a complex agronomical trait that displays heterosis and plays an important role in rice growth and production. Only a few quantitative trait loci (QTLs) have been identified by bi-parental population. More genes or QTLs are required to dissect the genetic architecture of rice rooting ability. RESULTS: To characterize the genetic basis for rice rooting ability, we used a natural rice population, genotyped by a 90 K single nucleotide polymorphism (SNP) array, to identify the loci associated with rooting-related traits through the genome-wide association study (GWAS). Population structure analysis divided the natural population into two subgroups: indica and japonica. We measured four traits for evaluating rice rooting ability, namely root growth ability (RGA), maximum root length (MRL), root length (RL), and root number (RN). Using the association study in three panels consisting of one for the full population, one for indica, and one for japonica, 24 SNPs associated with rooting ability-related traits were identified. Through comparison of the relative expression levels and DNA sequences between germplasm with extreme phenotypes, results showed that LOC_Os05g11810 had non-synonymous variations at the coding region, which may cause differences in root number, and that the expression levels of LOC_Os04g09900 and LOC_Os04g10060 are closely associated with root length variation. CONCLUSIONS: Through evaluation of the rice rooting ability-related traits and the association mapping, we provided useful information for understanding the genetic basis of rice rooting ability and also identified some candidate genes and molecular markers for rice root breeding.

Deep Learning-Based Human Activity Real-Time Recognition for Pedestrian Navigation.

Several pedestrian navigation solutions have been proposed to date, and most of them are based on smartphones. Real-time recognition of pedestrian mode and smartphone posture is a key issue in navigation. Traditional ML (Machine Learning) classification methods have drawbacks, such as insufficient recognition accuracy and poor timing. This paper presents a real-time recognition scheme for comprehensive human activities, and this scheme combines deep learning algorithms and MEMS (Micro-Electro-Mechanical System) sensors' measurements. In this study, we performed four main experiments, namely pedestrian motion mode recognition, smartphone posture recognition, real-time comprehensive pedestrian activity recognition, and pedestrian navigation. In the procedure of recognition, we designed and trained deep learning models using LSTM (Long Short-Term Memory) and CNN (Convolutional Neural Network) networks based on Tensorflow framework. The accuracy of traditional ML classification methods was also used for comparison. Test results show that the accuracy of motion mode recognition was improved from 89 . 9 % , which was the highest accuracy and obtained by SVM (Support Vector Machine), to 90 . 74 % (LSTM) and 91 . 92 % (CNN); the accuracy of smartphone posture recognition was improved from 81 . 60 % , which is the highest accuracy and obtained by NN (Neural Network), to 93 . 69 % (LSTM) and 95 . 55 % (CNN). We give a model transformation procedure based on the trained CNN network model, and then obtain the converted . t f l i t e model, which can be run in Android devices for real-time recognition. Real-time recognition experiments were performed in multiple scenes, a recognition model trained by the CNN network was deployed in a Huawei Mate20 smartphone, and the five most used pedestrian activities were designed and verified. The overall accuracy was up to 89 . 39 % . Overall, the improvement of recognition capability based on deep learning algorithms was significant. Therefore, the solution was helpful to recognize comprehensive pedestrian activities during navigation. On the basis of the trained model, a navigation test was performed; mean bias was reduced by more than 1.1 m. Accordingly, the positioning accuracy was improved obviously, which is meaningful to apply DL in the area of pedestrian navigation to make improvements.

Genetic Diversity and Signatures of Selection in 15 Chinese Indigenous Dog Breeds Revealed by Genome-Wide SNPs.

There are dozens of recognized indigenous dog breeds in China. However, these breeds have not had extensive studies to describe their population structure, genomic linkage disequilibrium (LD) patterns, and selection signatures. Here, we systematically surveyed the genomes of 157 unrelated dogs that were from 15 diverse Chinese dog breeds. Canine 170K SNP chips were used to compare the genomic structures of Chinese and Western dogs. The genotyping data of 170K SNP chips in Western dogs were downloaded from the LUPA (a European initiative of canine genome project) database. Chinese indigenous dogs had lower LD and shorter accumulative runs of homozygosity (ROH) in the genome. The genetic distances between individuals within each Chinese breed were larger than those within Western breeds. Chinese indigenous and Western dog breeds were clearly differentiated into two separate clades revealed by the PCA and NJ-tree. We found evidence for historical introgression of Western dogs into Chinese Kazakhstan shepherd and Mongolia Xi dogs. We suggested that Greenland sledge dog, Papillon, and European Eurasier have Chinese dog lineages. Selection sweep analysis identified genome-wide selection signatures of each Chinese breed and three breed groups. We highlighted several genes including EPAS1 and DNAH9 that show signatures of natural selection in Qinghai-Tibetan plateau dogs and are likely important for genetic adaptation to high altitude. Comparison of our findings with previous reports suggested RBP7, NMNAT1, SLC2A5, and H6PD that exhibit signatures of natural selection in Chinese mountain hounds as promising candidate genes for the traits of endurance and night vision, and NOL8, KRT9, RORB, and CAMTA1 that show signals of selection in Xi dogs might be candidate genes influencing dog running speed. The results about genomic and population structures, and selection signatures of Chinese dog breeds reinforce the conclusion that Chinese indigenous dogs with great variations of phenotypes are important resources for identifying genes responsible for complex traits.

Using titanium mesh to replace the bone flap during decompressive craniectomy: A medical hypothesis.

Decompressive craniectomy (DC) plays a significant role in treating refractory intracranial hypertension. During this surgical procedure, part of the skull is removed and the underlying dura mater is open, which can effectively release intracranial pressure. However, in some cases, the decision whether or not to remove the bone flap relies on the surgeon's personal experience. Positive decisions are usually made to avoid massive postoperative cerebral edema and infarction, which can lead to overtreatment. The procedure is related to many side-effects, which may affect the recovery of neurological function. Patients who have survived have to be anesthetized and undergo secondary cranioplasty 3 or 6 months later. Despite its technical simplicity, complications associated with cranioplasty are hard to ignore. Therefore, there is a need for a new surgical procedure combining decompressive craniectomy and cranioplasty. Acute expansion of the skin flap is limited, and the compensatory capacity of the skull after DC depends on the volume of the bone flap at the early stage. The titanium mesh is thin and strong, does not take up extra space provided by bone flap. Therefore, we put forward the concept of Decompressive Bone Flap Replacement. During this procedure, neurosurgeons resect the massive bone flap, open the dura mater, remove the hematoma in a similar manner to a standard craniotomy and then use titanium mesh shaped appropriately to replace the bone flap. Compared with traditional DC, it can ensure the integrity of the skull without affecting the effect of decompression. This paper presents 2 cases of DC and reviews the literature sustaining our hypothesis.

[Investigation on Babesia in ticks infested on police dogs in selected areas of China].

399 tick specimens were collected from the body surface of police dogs in Chongqing municipality, provinces of Fujian, Guangdong, Hainan, Guangxi, Hebei, Henan, Shanxi, Jiangsu and Zhejiang. Nested-PCR and sequence testing were taken to investigate the prevalence of Babesia sp. in ticks. The results showed that Babesia vogeli was found in ticks infested on the body surface of police dogs, with a positive rate of 5.3%. The prevalence in Chongqing, Guangdong, Guangxi, Hainan and Zhejiang was 4/16, 3.6% (1/28), 12.5%(11/88), 3.3% (4/121) and 1/15, respectively. It suggested that there was a certain rate of infected ticks infested on the body suriface of police dogs, which contributed to the potential threat to staff. The prevention and control measures should be strengthened.

[Effects of different irrigation treatments on photosynthesis of Tieguanyin tea plants].

By using chlorophyll fluorescence kinetics technique, the effects of different irrigation intervals, i.e., 5 d (T1), 10 d (T2), 15 d (T3), 20 d (T4), and 25 d (T5), on the photosynthesis of 2-year Tieguanyin tea plants were investigated in the field, with no irrigation as the control. The results showed that the leaf water potential and chlorophyll content decreased with increasing irrigation interval, while the net photosynthesis (P) increased first and decreased then, reaching its highest value (15.55, micromol x m(-2) x s(-1)) in treatment T2. The ratio of the variable to maximal fluorescence (F(v)/F(m)), the variable fluorescence quenching (deltaF(v)), and the variable fluorescence quenching rate (deltaF(v)/F(o)) all got the highest in treatment T2, being 0.844, 342.5, and 4.03, respectively. The initial fluorescence (F(o)) decreased with increasing irrigation interval, while a reverse changing trend of F(o) was observed in the control, demonstrating that PS II reaction center was damaged by drought stress. In conclusion, irrigating per 10 d was favorable to the photosynthetic electron transport and CO2 assimilation of the tea plants, which would enhance their photosynthesis efficiency.

[Genetic polymorphism of eleven canine STR loci].

OBJECTIVE: To investigate the polymorphism of 11 canine STR loci. METHODS: A fluorescent multiplex system with 11 STR loci (PEZ1, PEZ2, PEZ3, PEZ5, PEZ6, PEZ8, PEZ12, FH2010, FH2054, FH2132 and FH2611) was constructed independently and performed to amplify 105 samples from dogs. The character of these loci was analyzed with the PCR data. RESULTS: The distributions of genotypes and allele frequencies of 11 STR loci were obtained. The total power of discrimination for the 11 loci in canine population was 0.9999999 and the cumulative probability of exclusion was 0.9330621. The observed heterozygosity and polymorphism information content (PIC) were 0.502 and 0.640, respectively. CONCLUSION: Each of the eleven canine STR loci has a high genetic polymorphism and can be applied for the parentage testing and individual identification. The fluorescent multiplex system is a reliable method in forensic application.

[Melanocortin 1 receptor (MC1R) gene phylogenetic tree and canine coat colors].

Canines were domesticated approximately 10,000 years ago. The various environmental conditions and selective breeding resulted in abundant diversity of coat colors in domestic canines. Many canine coat colors are affected by melanocortin 1 receptor (MC1R). MC1R genes are homologous among different species. This article reviews the studies on MC1R polymorphism in the domestic canine. We also constructed a phylogenetic tree of MC1R genes by comparing the canine gene with those from nine representative mammalian species. Results show the gene phylogenetic tree accorded with Taxonomy of the ten mammals in the main.