影响番茄花芽分化及产生畸形果的因素分析

番茄苗期花芽分化异常易形成畸形花,而畸形花是形成畸形果的主要原因。畸形果会严重影响番茄的外观和口感,从而影响其经济效益。为此,对影响番茄花芽分化的外部和内在因素及花芽分化与畸形果形成的关系进行了综述。     

江苏地方山羊不同地域群体间的遗传分化

在采用多座位电泳法检测江苏地方山羊群体结构基因座遗传变异的基础上,分析群体间的遗传分化水平并探讨了影响群体遗传分化的主要因素。结果显示,4个山羊群体间的遗传分化系数在0.0067~0.0368之间,平均仅为0.0177,说明群体间的遗传分化水平很低,遗传变异绝大部分存在于群体内;不同地域山羊群体的分布符合地理隔离模式,而且群体间的基因流十分通畅;亲缘关系的模糊聚类结果与已知的品种史也是吻合的。据此可认为,大而通畅的基因流是江苏4个地方山羊群体间遗传分化水平很低的主要原因,而生境异质性则是引起群体发生轻微遗传分化的原因。     

抗生素对水生植物小对叶外植体分化的影响

[目的]研究小对叶对常用的抗生素的敏感性。[方法]将培养2周的小对叶无菌苗叶片切成0.5 cm×0.5 cm的小块,在添加不同浓度梯度的卡那霉素、潮霉素、壮观霉素和氯霉素4种抗生素的MS1培养基上进行培养,诱导其分化出芽,研究了4种抗生素对小对叶外植体分化的影响。[结果]一定浓度的抗生素对小对叶离体叶片的分化均具有抑制作用;确定了4种抗生素作为小对叶遗传转化研究的筛选标记的适宜浓度:卡那霉素为15 mg/L,潮霉素为10 mg/L,壮观霉素为60 mg/L,氯霉素为20 mg/L;小对叶对4种抗生素的敏感程度为:潮霉素>卡那霉素>氯霉素>壮观霉素。[结论]在进行遗传转化之前,对待转化材料进行抗生素敏感性测定是建立小对叶遗传转化系统的必然条件。     

中国落叶松-杨栅锈菌生理小种鉴定

对来自全国7个省市一定地域、不同年份、不同批次的15个落叶松-杨栅锈菌菌系 进行了 鉴别寄主反应型测定以及潜育期、产孢量观察,进一步明确了落叶松-杨栅锈菌在我国的 生理小种 分化。结果表明,15个菌系中的13个分别属于4个生理小种,Th 053 、Sb和Cj 052 归1号生理小种 CMLP 1 ,Ts 06 、Gl 051 、Hb 05ˉ1 和Sb 052 归2号生理小种CMLP 2 ,Qh 063 、Gl 052 、Hdao和Sb 051 归3号生理 小种CMLP 3 ,Bq和Qh 061 归5号生理小种CMLP 5 ,By 05ˉ3 和Zs暂单独划为1个致病类型。     

红小豆花芽分化与结实率的研究

2006-2007年对红小豆花芽分化与结实率进行了研究。结果表明:红小豆的营养生长和生殖生长并进时间长,花芽分化从出苗后6 d左右开始分化,分化时间长,分化小花多。小花分化进程与主茎叶片数之间具有同伸性。分枝和主茎不同叶位小花分化时期相互重叠,不同节位相同花位和同一节位不同花位小花分化有规律的进行。同一花序节位上的小花存在高节位滞育的问题,各节位小花脱落严重。     

京水菜花芽分化的形态解剖学研究

采用实体解剖和石蜡连续切片的方法对京水菜花芽分化过程进行了形态学上的观察研究。结果表明,京水菜花芽分化可分为花序分化期和花器官分化期。花序分化期生长点分化各级花枝,花枝形成后其上的花芽进入花器官分化期。花器官分化期由花萼分化期、花瓣分化期、雄蕊分化期、雌蕊分化期组成。     

A comparison of genetic diversity and differentiation in five Chinese pines using cpSSR and AFLP markers

Gene diversity and genetic differentiation in five Chinese pines, Pinus henryi, P. tabulaeformis, P. yunnanensis, P. taiwanensis and P. massoniana, were compared using amplified fragment length polymorphism (AFLP) and simple chloroplast sequence repeat (cpSSR). High genetic differentiation and median gene diversity with cpSSR markers were found both at population and species level, while median differentiation and higher gene diversity in AFLP data. Measures of subdivision that consider similarity between haplotypes offered better information on the geographic structure of plants than the standard subdivisions. Among several methods analyzed in AFLPs, the square root method provided downwardly biased estimates of the genetic parameters, while the Lynch and Milligan method over-estimated genetic diversity due to a small sample size. The Bayesian statistic was the most accurate and popular method for these dominant species and its value of species differentiation (θ ^B = 0.1035) was close to the parameter given by analysis of molecular variance (AMOVA). __________ Translated from Acta Botanica Boreali-Occidentalia Sinica, 2007, 27(12): 2385–2392 [译自: 西北植物学报]     

Genetic diversity of Lithocarpus harlandii populations in three forest communities with different succession stages

By using random amplified polymorphic DNA (RAPD) technique, this paper studied the genetic diversity and genetic differentiation of Lithocarpus harlandii populations in three forest communities (coniferous forest, coniferous and broad-leaved mixed forest, and evergreen broad-leaved forest) with different succession stages in Tiantai Mountain in Zhejiang Province. The results showed that a total of 173 repetitive loci were produced in 60 individuals of L. harlandii by 12 random primers, among which, 152 loci were polymorphic, and the total percentage of polymorphic loci was 87.86%. The average percentage of polymorphic loci of the populations was 65.32%, and their total genetic diversity estimated by Shannon information index was 0.4529, with an average of 0.3458, while that judged from Nei’s index was 0.3004, with an average of 0.2320. The percentage of polymorphic loci, Shannon information index, and Nei’s index of the populations were in the sequence of coniferous forest community > coniferous and broad-leaved mixed forest community > evergreen broad-leaved forest community. Analysis of molecular variance (AMOVA) showed that 72.85% of genetic variance was found within the populations, and 27.15% of genetic variance resided among the populations. The coefficient of gene diferentiation was 0.2277, and the gene flow was 1.6949. The genetic structure of L. harlandii was influenced not only by the biological characteristics of this species, but also by the microenvironment of different communities. The mean of genetic identity among three populations of L. harlandii was 0.8662, and the mean of their genetic distance was 0.1442. The genetic similarity between coniferous and broad-leaved mixed forest community and evergreen broad-leaved forest community was the highest, while that between evergreen broad-leaved forest community and coniferous forest community was the lowest. The unweighted pair group method with arithmeticmean (UPGMA) cluster analysis based on Nei’s genetic distance showed that conierous and broad-leaved mixed forest community first gathered with evergreen broad-leaved forest community, and then with coniferous forest community. __________ Translated from Chinese Journal of Ecology, 2007, 26(4): 509–514 [译自: 生态学杂志]     

山白树属雄蕊数目和形态的变异及其系统学意义？

该文利用扫描电镜法（SEM）研究了山白树属雄蕊的形态学特征,主要观察结果如下：多数情况下,雄蕊为5枚,其成熟花药有背腹之分,花药侧面纵向延伸的缝线在两端发生分叉;此外,还观察到4枚及6枚雄蕊的情况,有的雄蕊的花药在形态上没有背腹之分,呈四方柱状或扁平状,其侧面纵向延伸的缝线在两端不发生分又或者仅在基部的一侧发生分叉。研究结果,山白树属雄蕊在形态分化上处于不稳定的过渡阶段,表现出和“高等金缕梅类”的联系。     

m6A甲基化酶相关基因在牛骨骼肌生成中的表达

【目的】近年来,RNA m⁶A甲基化修饰在肌肉发育中的作用不断被发现,通过探究m⁶A甲基化酶相关基因,包括METTL3,METTL14,WTAP,FTO和ALKBH5,在牛肌肉组织以及骨骼肌卫星细胞(skeletal muscle satellite cells, SMSCs)增殖和分化过程中的表达,同时分析体外成肌分化过程中m⁶A甲基化水平的变化,为阐明m⁶A修饰在骨骼肌发育中的作用及机制提供参考。【方法】使用实时荧光定量PCR(RT-qPCR)技术检测m⁶A甲基化酶相关基因在新生和成年牛不同部位骨骼肌中的表达。随后在秦川牛肉用新品系背最长肌中分离SMSCs,通过生长曲线、免疫荧光和RT-qPCR技术验证SMSCs的增殖和成肌分化功能,使用RT-qPCR检测m⁶A甲基化酶相关基因在SMSCs增殖期24、36、48、60、72 h和分化第0、2、4、6、8天中的时序表达谱。最后利用LC-MS/MS和Dot blot技术检测SMSCs分化过程中m^6...