大豆重复序列的克隆,特性分析及在染色体上的定位

从大豆栽培品种Ｕｎｉｏｎ（Ｇ．ｍａｘ）基因组ｐＵＣ１８质粒文库中,以基因组ＤＮＡ为探针,筛选出一个重复序列家族。序列分析表明,此重复序列的重复单位为９１ｂｐ,拷贝数约为１０￣５,其序列约占基因组ＤＮＡ的０．９％。基因组ＤＮＡ不同限制酶片段Ｓｏｕｔｈｅｒｎ杂交分析和染色体原位杂交分析表明此重复序列主要以串联方式集中分布在Ｍ２和Ｍ１１号染色体的臂上,而另外一些则散布于整个Ｍ１２和Ｓｍ７号染色体上。以该序列为探针片大豆属不同亚属１３个种的１８个品系的Ｓｏｕｔｈｅｒｎ杂交结果表明,此重复序列为Ｓｏｊａ亚属所特有。这一Ｓｏｉａ亚属特异重复序列的发现,从另一个角度支持应把Ｓｏｊａ亚属的３个种Ｇ．ｓｏｊａ、Ｇ．ｇｒａｃｉｌｌｉｓ、Ｇ．ｍａｘ划分为一个种的观点。     

Establishment of loop-mediated isothermal amplification (LAMP) for rapid detection of Brucella spp. and application to milk and blood samples

Brucella spp. are facultative intracellular bacteria that infect humans and animals. In this study, the loop-mediated isothermal amplification (LAMP) was used to detect the Brucella-specific gene omp25. Reaction conditions were optimized as temperature 65°C, reaction time 60 min, Mg(2+) concentration 8.0 mmol/L, polymerase content Bst DNA, 0.5 μL, deoxyribonucleotide concentration 1.6 mmol/L, and inner/outer primer ratio 1:8. The LAMP method was evaluated with 4 Brucella species and 29 non-Brucella bacteria species. Positive reactions were observed on all the 4 Brucella species but not on any non-Brucella species. The limit of detection of the LAMP method was 3.81 CFU Brucella spp. Using the LAMP method, 7 of 110 raw milk samples and 5 of 59 sheep blood samples were detected positive of Brucella spp. Results indicated that LAMP is a fast, specific, sensitive, inexpensive, and suitable method for diagnosis of Brucella spp. infection.     

Isolation and mapping of bacterial artificial chromosome (BAC) clone containing telomere-associated sequence

Ｔｅｌｏｍｅｒｅｓａｒｅｔｈｅｅｎｄｓｏｆｔｈｅｅｕｋａｒｙｏｔｉｃｃｈｒｏｍｏｓｏｍｅｓａｎｄｃｏｎｓｉｓｔｏｆｔａｎｄｅｍｌｙｓｈｏｒｔｒｅｐｅａｔｓｅｑｕｅｎｃｅｓｗｈｉｃｈａｒｅｄｅｓｃｒｉｂｅｄｂｙｔｈｅｃｏｎｓｅｎｓｕｓ[ｄ(Ｔ/Ａ)14ｄＧ18]ｎｉｎｍｏｓｔｏｒｇａｎｉｓｍｓ.ＴｈｅｔｅｌｏｍｅｒｉｃｒｅｐｅａｔｓｏｆＡｒａｂｉｄｏｐｓｉｓ,[ＴＴＴＡＧＧＧ]ｎ,ｗｅｒｅｃｌｏｎｅｄｉｎ1988[1].Ｇａｎａｌｅｔａｌ.[2]ｒｅｐｏｒｔｅｄｔｈｅｔｏｍａｔｏｔｅｌｏｍｅｒｅｓｅｑｕｅｎｃｅ,[ＴＴ(Ｔ/Ａ…     

Comparative study of QTLs for agronomic traits of riceOriza sativa L.) between salt stress and nonstress environment

Genotype-by-environment interactions (GxE) are commonly observed for quantitative traits. In the present study, a doubled haploid (DH) population and its genetic linkage map were used to comparatively study QTLs in salt stress and nonstress environments. A total of 24 QTLs were detected for five agronomic traits, which were distributed on all the chromosomes except 9 and 11. Under the salt stress, nine (37.5%) QTLs were detected, including one for 1 000-grain weight (GW), two for heading date (HD), one for plant height (PH), two for grains per panicle (GPP), and three for effective tillers (ET), while in the nonstress environment, 17 QTLs (70.8%) were detected, including five for GW, six for HD, three for PH, two for GPP, and one for ET. Two QTLs (8.3%) were consistently detected in both environments. One was identified on chromosome 4 for HD and the other on Chr.6 for GPP. Furthermore, three regions carrying multiple QTLs were identified on chromosomes 1, 4 and 8 respectively. For example, on chromosome 8, three QTLs for HD, GW and PH, respectively were identified between RG885-GA408 in nonstress environment, but not in the stress environment. The comparative study of QTLs detected in extremely different (salt stress and nonstress) environments revealed that there existed several QTLs for important agronomic traits on chromosome 8 which were affected significantly by salt stress.