Development and innovation of haploid induction technologies in plants.

Haploid induction is one of the main techniques for breeding new varieties of major crops, and its key steps are improving the haploid induction rate and simplifying the induction procedure. With the development and innovation of plant haploid induction technologies, haploid breeding has been widely used in varietal improvement of important crops, showing the advantages of rapid homozygosity of heterozygous genes, shortening breeding period, and improving breeding efficiency. The combination of haploid breeding with crossing breeding, mutation breeding, reverse breeding, and molecular marker-assisted selection will greatly improve the effectiveness of crop breeding. Haploids and doubled haploids have demonstrated their usefulness in production of genetic populations, characterization of gene functions, and transgenic and cytological studies in plants. In this review, we summarize the progress of haploid induction technologies in view of various haploid induction techniques and applications of haploids and double haploids. In particular, the advances on the haploid induction in several major crops by genome editing were briefly described. Finally, we discuss current issues and future perspectives in this field, so as to promote the application of the haploid induction techniques, especially the techniques of creating haploid inducer lines by genome editing in crop breeding.

[Analysis of effects of arthroscopic treatment for recurrent patellar dislocation by lateral patellar retinacular release outside the synovial bursa of knee joint combined with reconstruction of medial patellofemoral ligament].

OBJECTIVE: To introduce an arthroscopic technique in managing recurrent dislocation of the patella and its clinical results. METHODS: Sixteen patients with recurrent patellar dislocation were reviewed, including 3 males and 13 females. The average age was 17.6 years old (ranged from 14 to 32 years). The patients suffering from patellar sub-luxation averaged 18.5 months (ranged from 6 to 23 months)before operation. These patients were treated with lateral patellar retinacular release outside the synovial bursa of knee joint and medial patellofemoral ligament reconstruction using the semitendinosus tendon free autograft. The Lyshohm scores before and after operation were used to evaluate outcomes at the final follow-up. RESULTS: All the patients were followed up, and the duration ranged from 6 to 48 months, with an average of 12 months. There was no recurrence. The Q angle decreased from (16.4 ± 3.7)° to (10.1 ± 1.4)°; insall index decreased from 1.37 ± 0.25 to 1.28 ± 0.23; congruence angle decreased from (21.3 ± 2.6)° to (5.86 ± 2.23)°; Lysholm score improved from 76.1 ± 5.2 to 89.8 ± 4.1 at 6 months after operation. CONCLUSION: Compared with conventional procedure, arthroscopic surgery for recurrent dislocation of the patella achieves excellent outcomes with minimum invasion.

[Changes of historical Paragonimus metacercaria infection rates of freshwater crabs in Yongjia County].

OBJECTIVE: To understand the changes of Paragonimus metacercaria infection rates of freshwater crabs in Paragonimus endemic areas and explore the causes in Yongjia County, Zhejiang Province, China. METHODS: A field investigation was carried out. The freshwater crabs were collected and the metacercaria were separated from the crabs. The infection rates, infectiosities and infection indexes were calculated and the results were vertically compared with the historical findings. The causes of the changes were discussed. RESULTS: Compared with those in 1980, the average infection rate in original endemic areas decreased from 59.71% to 21.50% (P < 0.05), while the infection density decreased from 1.09/g to 0.23/g (P < 0.05). The infection index decreased obviously. In Hesheng Village, it decreased from 4.05 to 0.01 (P < 0.01), in Wuchi Village, it was from 37.90 to 2.91 (P <0.01), and in Daruoyan Scinic area,it was from 5.85 to 0.03 (P < 0.01). Two endemic areas disappeared but two new endemic areas (Sihai Village and Sunshan Village) were found, and in Sunshan Village, the metacercaria infection rate was 100%, the infection density and infection index were 21.30/g and 3 402.68 respectively, which meant it was a super high endemic focus. CONCLUSION: The Paragonimus metacercaria infection rate in crabs is lower than before in Yongjia County, but some super high epidemic focus of paragonimiasis still exists. Therefore, we still should strengthen the control measures.