Comparison of microendoscopic discectomy and open discectomy for single-segment lumbar disc herniation

BACKGROUND Lumbar disc herniation is a common disease.Endoscopic treatment may have more advantages than traditional surgery.AIM To compare the clinical efficacy and safety of microendoscopic discectomy(MED)and open discectomy with lamina nucleus enucleation in the treatment of singlesegment lumbar intervertebral disc herniation.METHODS Ninety-six patients who were operated at our hospital were selected for this study.Patients with single-segment lumbar disc herniation were admitted to the hospital from March 2018 to March 2019 and were randomly divided into the observation group and the control group with 48 cases in each group.The former group underwent lumbar discectomy and the latter underwent laparotomy and nucleus pulpectomy.Surgical effects were compared between the two groups.RESULTS In terms of surgical indicators,the observation group had a longer operation time,shorter postoperative bedtime and hospital stay,less intraoperative blood loss,and smaller incision length than the control group(P<0.05).The excellent recovery rate did not differ significantly between the observation group(93.75%)and the control group(91.67%).Visual analogue scale pain scores were significantly lower in the observation group than in the control group at 1 d,3 d,1 mo,and 6 mo after surgery(P<0.05).The incidence of complications was significantly lower in the observation group than in the control group(6.25%vs 22.92%,P<0.05).CONCLUSION Both MED and open discectomy can effectively improve single-segment lumbar disc herniation,but MED is associated with less trauma,less bleeding,and a lower incidence of complications.

GL9 from Oryza glumaepatula controls grain size and chalkiness in rice

Grain size is a key factor influencing grain yield and appearance quality in rice.We identified twelve quantitative trait loci(QTL)for grain length(GL),nine for grain width(GW),and nine for 1000-kernel weight(TKW)using GLU-SSSLs,which are single-segment substitution lines with Oryza glumaepatula as donor parent and Huajingxian 74(HJX74)as recipient parent.Among the QTL,qGL1-2,qGL1-4,qGL9-2,qGW2-2,qGW9-1 and qTKW9-2 contributed to high grain yield.GL9 was identified as a candidate gene for qGL9-2 by map-based cloning and sequencing,and is a novel allele of GS9.The kernel of NIL-gl9was slenderer and longer than that of HJX74,and the TKW and grain yield per plant of NIL-gl9 were higher than those of HJX74.The proportion of grain chalkiness of NIL-gl9 was much lower than that of HJX74.Thus,gl9 increased grain yield and appearance quality simultaneously.Three pyramid lines,NIL-gs3/gl9,NIL-GW7/gl9 and NIL-gw8/gl9,were developed and the kernel of each was longer than that of the corresponding recipient parent lines.The gl9 allele may be beneficial for breeding rice varieties with high grain yield and good appearance quality.

Identification of Rice QTLs for Important Agronomic Traits with Long-Kernel CSSL-Z741 and Three SSSLs

Rice kernel shape affects kernel quality(appearance) and yield(1000-kernel weight) and therefore is an important agronomic trait, but its inheritance is complicated. We identified a long-kernel rice chromosome segment substitution line(CSSL), Z741, derived from Nipponbare as a recipient and Xihui 18 as a donor parent. Z741 has six substitution segments distributed on rice chromosomes 3, 6, 7, 8 and 12 with an average replacement length of 5.82 Mb. Analysis of a secondary F2 population from a cross between Nipponbare and Z741 identified 20 QTLs for important agronomic traits. The kernel length of Z741 is controlled by a major QTL(qKL3) and a minor QTL(qKL7). Candidate gene prediction and sequencing indicated that qKL3 may be an allele of OsPPKL1, which encodes a protein phosphatase implicated in brassinosteroid signaling, and qKL7 is an unreported QTL. Finally, we validated eight QTLs(qKL3, qKL7, qRLW3-1, qRLW7, qPH3-1, qKWT3, qKWT7 and qNPB6) using three selected singlesegment substitution lines(SSSLs), S1, S2 and S3. Also, we detected five QTLs(qKL6, qKW3, qKW7, qKW6 and qRLW6) in S1, S2 and S3, which were not found in the Nipponbare/Z741 F2 population. However, qNPB3, qNPB7 and qPL3 QTLs were not validated by the three SSSLs in 2019, suggesting that minor QTLs are susceptible to environmental factors. These results lay the foundation for studying the biodiversity of kernal length and molecular breeding of different kernel types.

Fine Mapping of QTLs for Stigma Exsertion Rate from Oryza glaberrima by Chromosome Segment Substitution

Stigma exsertion is an important trait for outcrossing ability in rice.Stigma exsertion rate(SER)of male sterile lines(MSLs)is a key factor affecting F1-seed production in hybrid rice.In this study,seven QTLs for SER were detected on five chromosomes using a set of single-segment substitution lines(SSSLs)derived from O.glaberrima.Three of the QTLs were mapped in the estimated intervals of 92.5–333.0 kb.qSER-5 was located in a substitution segment of 92.5 kb.qS ER-1 b and qS ER-8 b were respectively limited to 333.0 kb and 107.5 kb by secondary substitution mapping.qSER-1 b and qSER-3 had bigger additive effects of 11.5%and 11.9%,respectively,while the other five QTLs had smaller additive effects from 5.7%to 8.6%.Open reading frames were identified in the regions of qS ER-5 and qSER-8 b in O.sativa and O.glaberrima genomes.Fine mapping of the QTLs laid a foundation for the cloning of genes,and QTLs for SER will be used to develop MSLs with strong ability of outcrossing.