94份水稻骨干材料抗稻瘟病基因和恢复基因的分子检测与分析

为明确6个抗稻瘟病基因(Pita、Pi54、Pia、Pib、Pikm、Pikh)和1个恢复基因(Rf1a)在水稻骨干材料及新品系中的基因型和分布情况,从而为今后抗稻瘟病基因和恢复基因的合理利用及分子标记辅助育种提供依据,利用6对扩增条带清晰、稳定的抗稻瘟病基因特异性分子标记对48份水稻品系的基因组DNA进行PCR扩增,利用恢复基因分子标记Rf1a对46份外引及自育恢复系材料进行检测。结果表明,在48份水稻骨干材料及品系中,单个种质携带的抗稻瘟病基因为1~6个,携带4个抗稻瘟病基因的品系最多,占总数的33.33%,其次为携带3个(22.92%)、2个(18.75%)抗稻瘟病基因的品系,携带6个抗稻瘟病基因的种质资源最少(4.17%);6个抗稻瘟病基因在48份水稻种质中的分布差异较大,Pib、Pikh、Pi54在供试粳稻中的分布最广泛,分布频率分别达到77.08%、64.58%、62.50%,其次为Pita、Pikm、Pia,分布频率分别为47.92%、41.67%、33.33%;48份水稻种质共有抗稻瘟病基因组合22个,其中组合Pia+Pi54+Pikh+Pib和组合Pi54+Pikh+Pib的水稻材料数量最多(各6份)。在46份外引及自育恢复系材料中,携带恢复基因Rf1a的占93.48%。通过分子标记手段明确了相关种质的抗稻瘟病基因类型,为抗稻瘟病和恢复系新品系的选育及亲本组配提供了较好的遗传信息。

Identification of the Parentage of Corn Variety Using SSR Markers

[Objective] The study was to explore the molecular interpretation standards on parentage in the seeds of corn variety. [Method] With 16 hybrids and their parents and 202 inbred elites as materials for screening primers, the artificial groups of two standard diad and two standard triad were respectively established as the verification materials. Genomic DNA of seedlings was extracted by using CTAB method. 137 pairs of SSR primers were selected for SSR amplification and product detection, which was used for the parentage identification of maize varieties. [ Result] Twenty pairs of corn primers with high polymorphism information content （ PIC value）, clearly amplified bands and good reproducibility were screened from 137 pairs of corn SSR primers tested. The identification results of using SSR molecular were consistent with the actual situation. [ Conclusion] It is feasible to identify the parentage of maize variety using SSR markers.

A history of low back pain affects pelvis and trunk coordination during a sustained manual materials handling task

Purpose:The purpose of this study was to compare the coordination between the trunk and the pelvis during a sustained asymmetric repetitive lifting task between a group with a history of low back pain(LBP;HBP) and a group with no history of LBP(NBP).Methods:Volunteers lifted a 11-kg box from ankle height in front to a shelf 45° off-center at waist height,and lowered it to the start position at12 cycles/min for 10 min.Lifting side was alternated during the trial.Continuous relative phase was used to calculate coordination between the pelvis and trunk rotation at the beginning(Min 1),middle(Min 5),and end of the bout(Min 9).Results:While there were no main effects for group,a significant interaction between time and group indicated that,in the frontal plane,the NBP group coordination was more anti-phase toward the end of the bout,with no such differences for the HBP group.Analysis of sagittal-axial(bend and twist) coordination revealed the HBP group coordination was more in-phase at the end of the bout over the entire cycle and for the lifting phase alone,with no such differences for the NBP group.Conclusion:Differences between groups demonstrate residual consequences of LBP in an occupational scenario,even though the HBP group was pain-free for >6 months prior to data collection.More in-phase coordination in the HBP group may represent a coordination pattern analogous to'guarded gait' which has been observed in other studies,and may lend insight as to why these individuals are at increased risk for re-injury.

Treatment of osteonecrosis of femoral head with BMSCsseeded bio-derived bone materials combined with rhBMP-2 in rabbits

Objective： To evaluate the effect of autologous bone marrow mesenchymal stem cells （BMSCs） seeded bio-derived bone materials （BBM） combined with recombinant human bone morphogenetic protein-2 （rhBMP-2） in repairing defect of osteonecrosis of femoral head （ONFH）. Methods： Early-stage osteonecrosis in the left hip was induced in 36 adult New Zealand white rabbits （provided by the Animal Center of Guangxi Medical University, Nanning, China） after core decompression and delivery of liquid nitrogen into the femoral head. Then the animals were divided into three groups according to the type of implants for bone repair： 12 rabbits with nothing （Group Ⅰ, the blank control group）, 12 with BBM combined with rhBMP-2 （Group Ⅱ）, and 12 with BMSCs-seeded BBM combined with rhBMP-2 （Group Ⅲ）. At 4, 8, and 12 weeks after surgery, X-ray of the femoral head of every 4 rabbits in each group was taken, and then they were killed and the femoral heads were collected at each time point, respectively. Gross observation was made on the femoral heads. After hematoxylin and eosin staining, Lane-sandhu scores of X-ray and bone densitometry were calculated and the histomorphometric measurements were made for the new bone trabeculae. Results： At 12 weeks after surgery, two femoral heads collapsed in Group Ⅰ, but none in Group Ⅱ or Group Ⅲ. X-ray examination showed that the femoral heads in Group I had defect shadow or collapsed while those in Group II had a low density and those in Group III presented with a normal density. Histologically, the defects of femoral heads were primarily filled with no new bone but fibrous tissues in Group Ⅰ. In contrast, new bone regeneration and fibrous tissues occurred in Group II and only new bone regeneration occurrd in Group Ⅲ. Lane-sandhu scores of X-ray, bone mineral density and rate of new bone in trabecular area in Group Ⅲ were higher significantly than those of the other two groups. Conclusions： Our findings indicate a superior choice of repairing the experimental defect of OFH with BMSCsseeded BBM combined with rhBMP-2.