Construction of high-density genetic map based on SLAF-seq and QTL analysis of major traits in sweetpotato [Ipomoea batatas (L.) Lam.].

Sweetpotato, Ipomoea batatas (L.) Lam., is an important worldwide crop used as feed, food, and fuel. However, its polyploidy, high heterozygosity and self-incompatibility makes it difficult to study its genetics and genomics. Longest vine length (LVL), yield per plant (YPP), dry matter content (DMC), starch content (SC), soluble sugar content (SSC), and carotenoid content (CC) are some of the major agronomic traits being used to evaluate sweetpotato. However limited research has actually examined how these traits are inherited. Therefore, after selecting 212 F1 from a Xin24 × Yushu10 crossing as the mapping population, this study applied specific-locus amplified fragment sequencing (SLAF-seq), at an average sequencing depth of 26.73 × (parents) and 52.25 × (progeny), to detect single nucleotide polymorphisms (SNPs). This approach generated an integrated genetic map of length 2441.56 cM and a mean distance of 0.51 cM between adjacent markers, encompassing 15 linkage groups (LGs). Based on the linkage map, 26 quantitative trait loci (QTLs), comprising six QTLs for LVL, six QTLs for YPP, ten QTLs for DMC, one QTL for SC, one QTL for SSC, and two QTLs for CC, were identified. Each of these QTLs explained 6.3-10% of the phenotypic variation. It is expected that the findings will be of benefit for marker-assisted breeding and gene cloning of sweetpotato.

[Effectiveness comparison of LARS artificial ligament and autogenous hamstring tendon in one-stage reconstruction of anterior and posterior cruciate ligaments].

OBJECTIVE: To compare the effectiveness of arthroscopic one-stage reconstruction of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) with LARS artificial ligament and autogenous hamstring tendon, respectively. METHODS: A retrospective study was performed on 23 patients with ACL and PCL injuries, who were treated with one-stage reconstruction, between June 2013 and June 2017. The ACL and PCL were reconstructed with LARS artificial ligament in 11 patients (artificial ligament group) and autogenous hamstring tendon in 12 patients (autogenous tendon group). There was no significant difference in gender, age, side of injury, cause of injury, time from injury to operation, and preoperative Lysholm score and International Knee Documentation Committee (IKDC) score between the two groups ( P>0.05). The operation time, the time of recovery of daily activities and preoperative exercise level, the occurrence of surgical-related complications, Lysholm score, IKDC score, and the results of knee stability assessment were recorded and compared between the two groups. RESULTS: The operation time and the time of recovery of daily activities and preoperative exercise level were significantly shorter in artificial ligament group than in autogenous tendon group ( P<0.05). All incisions healed primarily. In autogenous tendon group, the common fibular nerve injury occurred in 1 case and intermuscular vein thrombosis occurred in 1 case. No complication occurred in the remaining patients of the two groups. All the patients were followed up 24-54 months (mean, 36.4 months). At last follow-up, the Lysholm score and IKDC score of the two groups were significantly higher than preoperative scores ( P<0.05). There was no significant difference between the two groups ( P>0.05). The varus and valgus stress tests of the two groups were negative. There was no significant difference in anterior drawer test, posterior drawer test, and Lachman test between the two groups ( P>0.05). CONCLUSION: The effectiveness of arthroscopic one-stage reconstruction of ACL and PCL with LARS artificial ligament or autogenous hamstring tendon was similar. The knee function and stability recover well. But the patients with LARS artificial ligament reconstruction can resume daily activities and return to exercise earlier.

[Two-stage reverse total shoulder arthroplasty for treating postoperative deep infection after internal fixation of proximal humeral fracture].

OBJECTIVE: To summarize the effectiveness of two-stage reverse total shoulder arthroplasty for treating postoperative deep infection after internal fixation of the proximal humeral fracture. METHODS: Between June 2014 and January 2018, 17 patients with deep infection and humeral head necrosis or bone nonunion after internal fixation of proximal humeral fractures were treated. There were 8 males and 9 females, aged from 52 to 78 years (mean, 63.8 years). The infection occurred at 19-66 months after the initial internal fixation (mean, 34.8 months). Microbial culture of joint fluid was positive in 14 cases and negative in 3 cases. The preoperative Constant score, American shoulder and elbow surgeons (ASES) score, and visual analogue scale (VAS) score were 36.41±8.65, 31.06±7.43, and 7.29±0.99, respectively. The preoperative ranges of forward flexion, abduction, external rotation were (45.88±12.46), (42.18±12.31), and (16.76±4.92)°, respectively. The preoperative range of internal rotation was buttock in 9 cases, lumbosacral joint in 3 cases, L 3 in 5 cases. At the first-stage surgery, the thorough debridement was done and the antibiotic-impregnated bone cement spacer was placed after the removal of internal fixation. After the infections disappeared, the two-stage reverse total shoulder arthroplasty was performed. The mean interval between the two procedures was 4.2 months (range, 3.0-6.5 months). RESULTS: All the incisions healed primarily and no complications such as recurrent infection or vascular nerve injury occurred. All patients were followed up 15-32 months (mean, 22.0 months). At last follow-up, the ranges of forward flexion, abduction, and external rotation were (109.00±23.66), (98.53±16.92), (41.41±6.82)°, respectively; and the range of internal rotation was lumbosacral joint in 5 cases, L 3 in 8 cases, T 12 in 4 cases. The range of motion of shoulder joints at last follow-up was significant improved when compared with the preoperative range of motion ( P<0.05). The Constant score (64.88±8.70), ASES score (65.18±8.10), and VAS score (2.94±1.25) were significantly superior to the preoperative scores ( P<0.05). X-ray films showed that no prosthesis loosening occurred. CONCLUSION: Two-stage reverse total shoulder arthroplasty is an effective treatment for the postoperative deep infection after internal fixation of the proximal humeral fracture, which has advantages of low risk of infection recurrence, good shoulder function, and satisfactory short-term effectiveness.