Improving micropropagation of some grape cultivars via boron,calcium and phosphate

BackgroundAn efficient regeneration protocol is a priority for the successful application of plant biotechnology. Grape nodal explants were used to develop a micropropagation protocol for Thompson Seedless and Taify cvs. Explants were cultured on MS medium supplemented with Kinetin or benzylaminopurine (BA) and indolebutyric acid (IBA).ResultsFor both cultivars, axillary buds were grown, only, on a medium enriched with kinetin, moreover, shoot tip necrosis and callus formation were observed on Thompson Seedless cv. cultures grown on a medium with BA. Supplementing the growth medium with 100 mM (boron) B and 2.5 mM (calcium) Ca successfully help overcome these phenomena. The highest regenerated shoot numbers (14 and 6.2 explant⁻¹) for Taify and Thompson Seedless cvs., respectively, were on media supplemented with 13.2 µM BA + 4.9 µM IBA and BA 13.2 µM + 5.8 µM IBA, respectively. Moreover, these media supported the developing shoots to have the heaviest dry weights (1.46 and 0.72 mg explant⁻¹) for Taify and Thompson Seedless cvs., respectively. Thompson Seedless cv. regenerated shoot numbers and their dry weights were significantly increased by increasing the MS medium PO₄⁻ concentration. However, these two parameters were significantly decreased for Taify cv. Developing shoots were elongated and rooted on MS medium enriched with 4.9 µM, IBA 100 mM B and 2.5 mM Ca. Plantlets were acclimatized and successfully transferred to the greenhouse conditions.ConclusionsA novel promising protocol for Thomson Seedless and Taify cvs. micropropagation using single nodes has been developed.How to cite: Al-Aizari AA, Al-Obeed RS, Mohamed MA-H. Improving micropropagation of some grape cultivars via boron, calcium and phosphate. Electron J Biotechnol 2020;49. https://doi.org/10.1016/j.ejbt.2020.10.001     

铜对不同水稻品种种子萌发及根尖分生细胞钙分布的影响

以16个水稻品种为材料,测定了铜对水稻种子萌发相关指标,并观察了根尖有丝分裂及分生区Ca分布的影响。结果表明：（1）0．1mM和0．2mMCuSO4溶液处理对水稻根长的抑制作用大于对芽长的抑制,且对不同品种根长的抑制作用存在明显差异;（2）随着铜处理浓度（25、50、75、100μM）的升高,根尖细胞有丝分裂指数及相对有丝分裂指数皆呈下降趋势;（3）t常生长条件下,水稻根尖分生区细胞中的Ca主要分布在液泡和细胞间隙中,而细胞质、细胞核中分布很少;50μM铜处理下,根尖分生区细胞液泡和胞间的Ca沉淀颗粒明显减少,而胞质及核基质中的Ca沉淀颗粒增多。铜胁迫造成根尖细胞中原有Ca分布的变化可能是引起细胞功能的紊乱,进而影响根系生长的原因之一。     

嘉绍通道长山河特大桥试桩静载试验研究

嘉绍通道长山河特大桥位于嘉兴海宁市扬汇桥村,桥长1061 m。桩径1.8 m,桩长92 m,属于超长钻孔灌注桩。为了测定桩身的抗压极限承载力,对试桩采用自平衡测试法进行了静载试验。基于实测数据,对桩总承载力、桩侧摩阻力、桩端承载力、桩身变形、位移以及承载性能进行了分析,并将桩端承载力实测值和公路桥涵地基基础规范计算值进行了对比。研究表明桩侧摩阻力提供了大部分的承载力;施工工艺对超长桩承载力有很大影响;控制沉降同时也要控制桩身压缩变形。成功地确定了超长钻孔灌注桩的单桩极限承载力以及承载力性能,位移特征,可为类似工程参考。     

RTK技术在露天矿采剥场验收测量中的应用

着重介绍RTK技术在露天矿采剥场验收测量中实际应用,对应用过程中的精度进行分析。结果表明RTK技术具有直观快捷、实时性强、点位误差不积累等优点,大大降低测量人员劳动强度,提高工作效率和测绘成果的质量。     

论国民素质的角锥结构

国民素质包括国民的综合身体素质、科学文化素质和思想道德素质三种素质.三种素质分别由三个互相制约的要素构成三角形结构,三个三角形结构在实践活动的基础上有机结合,相互联系,构成国民综合素质的立体角锥结构.综合身体素质是其他素质的物质载体,科学文化素质是国民适应和改造社会技能的核心,是国民的深层次素质,思想道德素质则是国民素质的灵魂,是国民的高层次素质.三者在实践过程中有机统一构成完整的国民素质.     

Existence and uniqueness for a class of double pyramidal central configurations with a concave pentagonal base

~~bodies involved have masses m1, m2,,m7 respectively (hereinafter, these symbols of masses also denote the relating bodies ) and m5 lies at the geometrical center of the square consisting of positions of masses m1, m2,, m4 , i.e. m1, m2,,m5 form a concave pentagon. The line between m6 and m7 passes through m5 and is perpendicular to the plane containing the concave pentagon. The distance between m5 and m6 is equal to the distance between m5 and m7. Then the position vectors of m1, m2,,m…     

夯扩桩单桩承载力估算公式的修正

分析夯扩机理对各土层扩大头形状和桩端阻力影响 ,提出了对单桩承载力公式和扩大头计算公式的修正 ,并给出常用土层的参考取值     

菊花切花“黄秀凤”茎尖培养加速繁殖的研究

本文报道菊花切花“黄秀凤”茎尖培养和加速繁殖。诱导愈伤组织培养基为MS NAA0.2-1;分化培养基为MS NAA0.2-1 KT0.2-1;芽的增殖培养基为MS GA_31-6 BA0.1-1。研究结果表明,从一块外植体每年可获4.096×10~(15)至5.31×10~(17)株试管苗。移植大田后,成活率达95％以上。     

巧除酸式滴定管尖嘴气泡

介绍用胶皮管捏挤法、仿碱式滴定管法、逆流充液法和双管互相移动法巧妙地除去酸式滴定管尖嘴气泡的方法。     

离体玉米芽尖中酚类物质产生的影响因素

玉米芽尖分生组织培养过程中,酚类物质的产生与培养芽尖的基石莳背景明显相关,培养基的Ｐ迂低或过高均会加剧芽尖的酚类物质产生。蔗糖浓度在２０￣４０％范围内变化和使用活性炭对芽尖产生酚类物质的影响不明显。