中国马铃薯主要审定品种系谱分析和细胞质分型研究

通过对中国436个马铃薯审定品种的系谱分析发现,马铃薯祖先亲本中‘疫不加’、‘竹板’、‘工业’、‘兰芽’和‘早玫瑰’应为第1代亲本,而其衍生系如‘男爵’、‘胜利’、‘燕子’、‘白头翁’、‘米拉’、‘多子白’、‘卡它丁’和‘小叶子’应为第2代亲本。在审定的436个品种中,自行选育的379个品种涉及423个亲本,分别来源于国内品种、国内品系、地方品种、新型栽培种、北美资源、欧洲资源、CIP资源和其他,共8类,且其相应的核遗传贡献分别为97.5、107、10.5、16、27.5、71、33和16.5,表明国内品种和国内品系一直是贡献最大的类型,而地方品种主要以母本为主,外来资源如新型栽培种、欧洲资源和北美资源多以父本为主。为进一步验证其准确性,利用多重引物系统,对278份国内育成品种(品系)和330份国外育成品种(品系)进行了细胞质分型。结果表明,T型和D型为主要细胞质类型,所占数量和比例分别为303个(49.8%)和243个(40%),其次为W、A、M和P型,分别为39(6.4%)、15(2.5%)、6(1%)和2(0.3%),但也发现部分育成品种的细胞质类型与其祖先母本不一致,未发现6种类型以外的其他细胞质类型。

Two-dimensional finite element model to study calcium distribution in astrocytes in presence of excess buffer

In this paper a finite element model is developed to study cytosolic calcium concen- tration distribution in astrocytes for a two-dimensional steady-state case in presence of excess buffer. The mathematical model of calcium diffusion in astrocytes leads to a boundary value problem involving elliptical partial differential equation. The model con- sists of reaction-diffusion phenomena, association and dissociation rates and buffer. A point source of calcium is incorporated in the model. Appropriate boundary conditions have been framed. Finite element method is employed to solve the problem. A MATLAB program has been developed for the entire problem and simulated to compute the numer- ical results. The numerical results have been used to plot calcium concentration profiles in astrocytes. The effect of ECTA, BAPTA and aCa influx on calcium concentration distribution in astrocytes is studied with the help of numerical results.