植物叶发育分子遗传机制的研究进展

植物的叶发育是由复杂的调控网络相互作用而进行调控的。植物叶发育的基本过程可以分为叶原基的起始发育、叶片极性的建立、叶片大小以及叶形的调控,本文主要从以上4个过程对叶发育分子遗传机制进行了阐述。     

初配日龄对母猪产仔性能的影响

根据某猪场淘汰的203头母猪的生产记录,对不同初配日龄母猪的头胎产仔数、产仔胎数及产仔总数进行统计分析。结果表明,240～269日龄的初配母猪头胎产活仔数最少,270～299日龄的初配母猪平均产仔胎数最少,300～329日龄的初配母猪平均产仔胎数和产活仔总数最高,210～239日龄的初配母猪平均产仔胎数最低。从最佳经济效益来看,母猪的最佳初配日龄为210～239日龄。     

Osmolarity,cell volume and proliferation in nasopharyngeal carcinoma cells

AIM: To investigate the relationship between osmolarity, cell volume and cell proliferation in nasopharyngeal carcinoma cells. METHODS: MTT method was applied to detect the proliferation ability of the poorly-differentiated nasopharyngeal carcinoma cell (CNE-2Z) under various osmolarity conditions. The flow cytometry was used to analyse cell cycle distribution. Cell volume was obtained by the image analysis of living cells and cell viability was determined by the trypan blue assay. RESULTS: Cultivation of cells under the hypertonic conditions of 370 and 440 mOsmol/L increased cell volume by 8.7% and 27.8% and facilitated cell proliferation by 22.2% and 33.9%, respectively. However, hypotonic incubation of cells with osmolarity of 160 and 230 mOsmol/L decreased cell volume by 12.8% and 4.1% and inhibited cell proliferation by 34.0% and 15.6%, respectively. Cell volume was positively correlated with cell proliferation rate. Long-term cultivation of cells under anisotonic conditions did not significantly alter cell cycle distribution, but hypotonic cultivation decreased cell viability. CONCLUSION: Proliferation of nasopharyngeal carcinoma cells was closely correlated with the osmolarity of culture medium and cell volume. Hypotonic cultivation may inhibit cell proliferation by decreasing cell volume to facilitate cell death mechanisms.     

种瓣及密度对大蒜产量的影响

采用二次正交通用旋转设计，进行了种辩大小与种植密度对大蒜产量影响的研究，建立了大蒜产量与种植密度及种瓣大小间的二元二次数学模型。通过模型解析得出，种植密度对产量的影响大于种瓣大小，但密度对单株产量的贡献为负值。通过计算机模拟试验，得出本试验条件下，获得３００００ｋｇ／ｈｍ２以上产量的种植密度为５２．９５～６３．４５万株／ｈｍ２、种瓣大小为４．９～７．０ｇ;;单株产量大于５０ｇ的种植密度为３４．０５～４．５５万株／ｈｍ２、种瓣大小４．９～７．０ｇ。     

肉用西门塔尔牛改良云南黄牛的效果初报

对云南黄牛、西门塔尔与云南黄牛的杂交牛（西本杂）体尺体重进行了测定,结果西本牛与本地牛体尺体重都有了显著提高（P＜0．01）。西本杂牛的初生、6、12、18、24月龄体重比同龄本地牛分别高出82％、18％、69％、50％、78％。     

“难分离有机磷杀虫剂对”的毛细管气相色谱法分析研究

研究了用3种大口径毛细管柱分析由有机磷杀虫剂组成的“难分离有机磷对”。HP－1大口径毛细管柱只能分离由甲基对硫磷和其它有机磷杀虫剂组成的“有机磷对”；QF－1大口径毛细管柱能够分离部分“有机磷对”；阿皮松L固定液大口径毛细管柱能完全分离马拉硫磷和水胺硫磷组成的“有机磷对”。     

流动沙丘表面输沙率的理论计算方程

本文研究流动沙丘表面上输沙率的理论计算，得出输沙率是风速的二次函数且与沙丘表面沙粒平均粒度的１．４３次方成反比的新结论。     

Fusarium moniliforme secretes four endopolygalacturonases derived from a single gene product

Extracellular endopolygalacturonase, purified from the pathogenic fungus Fusarium moniliforme, consists of four molecular forms (38, 41·5, 45, and 48·5 kDa, respectively. Three forms (38, 41·5, and 45 kDa) were purified to homogencity by FPLC on a Mono S column followed by electroelution after SDS-PAGE. The N-terminal amino acid sequences of each of the three forms, and of a mixture containing all four forms were shown to be identical to that predicted from the nucleotide sequence of the endopolygalacturonase gene previously cloned from F. moniliforme. Enzymatic deglycosylation experiments revealed the presence of N-linked, high mannose oligosaccharide side-chains on all four forms of endo polygalacturonase. Hydrogen fluoride catalysed chemical deglycosylation of the polygalacturonase mixture yielded a single polypeptide with an apparent molecular mass of 36·2 kDa. Southern blot analysis, carried out at high stringency with an endopolygalacturonase-specific probe on genomic DNA digested with three different restriction enzymes, showed a single hybridizing restriction fragment in all three digests. A single 2·0 Mb chromosome hybridized with the endo polygalacturonase-specific probe, as shown by Southern blot analysis of F. moniliforme chromosomes separated by CHEF electrophoresis. Northern blot analysis revealed only one mRNA species 1350 nt encoding endo polygalacturonase. These data indicate that a single gene encodes the endopolygalacturonases of F. moniliforme.     

体细胞克隆牛0～12月龄生长的测定研究

通过对5头体细胞克隆母犊牛及其同期自然繁殖出生的荷斯坦母犊牛初生期、6月龄、12月龄的体重、体尺指标测定,初步分析了其生长发育速度的变化规律。结果表明:(1)克隆牛初生重53.67±7.00kg,明显高于自繁奶牛(P<0.01),6月龄体重141.00±16.49kg,明显低于自繁奶牛(P<0.01),12月龄体重302.80±32.17kg,与自繁奶牛基本相当;(2)克隆牛0～6月龄期间平均日增重0.70±0.11kg明显低于自繁奶牛(P<0.01),6～12月龄期间平均日增重0.90±0.12kg,与自繁奶牛基本相当(P>0.05),0～12月龄期间平均日增重0.70±0.11kg,与自繁奶牛基本相当(P>0.05);(3)克隆牛初生体尺指标明显大于自繁奶牛(P<0.01),6月龄体尺指标明显小于自繁奶牛(P<0.01),12月龄体尺指标与自繁奶牛相当(P>0.05);(4)克隆牛0～6月龄期间体尺平均增长明显低于自繁奶牛(P<0.01),6～12月龄期间体尺平均增长明显高于自繁奶牛(P<0.01),0～12月龄期间体尺平均增长明显低于自繁奶牛(P<0.01)。     

Genome-wide Association Study on Alive Litter Size Trait in Bama Xiang Pigs

In order to identify the molecular markers related to alive litter size of Bama Xiang pigs,the genome-wide association study (GWAS) was used to map and screen the candidate genes affecting the alive litter size trait.Ear tissue samples of 297 Bama Xiang pigs with multiple parity records were collected,and DNA was extracted and genotyped by porcine 50K SNP beadchip.After quality control and genotype imputation,the alive litter size of Bama Xiang pigs were GWAS by Tassel.The results showed that the average number born alive per litter of Bama Xiang pigs increased gradually with the increasing of parity in the range of 1-9 parities.A total of 32 816 SNPs were obtained after quality control and filtration.8 SNPs related to alive litter size of Bama Xiang pigs were screened by genome-wide association analysis,which were significant at genome or chromosome level.Based on the enrichment analysis of the coding genes in the region between 500 kb upstream and downstream of the associated significant SNP loci,and the QTL regions and gene functions related to porcine reproductive traits,4 genes (CAPZB,MSH3,CITED2 and HSD17B7) were finally identified to be candidate genes related to alive litter size of Bama Xiang pigs.