杂种大花万寿菊试管苗繁殖

利用组织培养技术繁殖引进的杂种大花万寿菊获得成功,在诱导侧芽时,利用６－卞基腺嘌呤（６－ＢＡ２．５ｍｇ／Ｌ）和玉米素（ＺＴ２．５ｍｇ／Ｌ）ＺＴ对侧芽的诱导效果好于６－ＢＡ,诱导生根的培养基分别为（１）１／２ＭＳ;（２）１／２ＭＳ＋ＮＡＡ０．５ｍｇ／Ｌ;（３）１／２ＭＳ＋ＮＡＡ１ｍｇ／Ｌ;（４）１／２ＭＳ＋ＩＢＡ０．５ｍｇ／Ｌ;（５）１／２ＭＳ＋ＩＢＡ１ｍｇ／Ｌ．ＩＢＡ可以促进万行区形成不定根,质量     

不同光谱能量分布对冬青试管苗生长的影响

 采用发光二极管(Light-Emitting Diode,LED)调制光质和光量,研究光谱能量分布对冬青试管苗生长的影响,以荧光灯为对照。结果表明：红光LED处理下试管苗的干样质量、生根率、根冠比和根长指标最高;而蓝光LED处理下则最低。绿光LED有利于叶片质量增加。单色红光LED导致试管苗徒长,根系活力和移栽成活率最低,最高值出现在复合光质LED组合中。与荧光灯相比,在能效、干样质量、碳水化合物含量以及SOD和CAT抗氧化酶活性指标上,复合光质LED具有明显优势,有利于培育壮苗并、提高移栽成活率并降低能耗成本。     

不同光源处理对非洲菊组培苗生长的影响

以非洲菊瑞扣为材料,普通荧光灯为对照,研究发光二极管(LED)和冷阴极荧光灯(CCFL)处理对其组培苗生长的影响。结果表明:在红光/蓝光=7/3(光质比)的情况下,LED光源处理下,组培苗地下部、整株鲜质量,叶绿素a、叶绿素b、总叶绿素含量,可溶性蛋白含量及根系活力均高于其他处理;LED和CCFL光源处理下,组培苗叶长显著高于对照;在根长方面,CCFL光源处理下出现最大值,LED次之,均显著高于对照;LED和对照处理下,根数、地上部鲜质量、地下部干质量均显著高于CCFL处理;CCFL处理下,叶片下表皮气孔面积显著大于其他处理,在气孔密度方面,LED处理略显优势。综合比较,LED光源是用于非洲菊组织培养的最佳光源。     

铁皮石斛组培苗生根条件优化研究

以铁皮石斛无菌幼苗为材料,在不同生根培养基中添加不同配比的生长调节物质、香蕉汁、马铃薯汁以及活性炭,研究其对铁皮石斛组培苗生根效果的影响。研究结果表明,生根培养基为：1/2 MS＋6-BA 0.2 mg/L＋10.0%香蕉汁＋10.0%马铃薯汁＋NAA 0.4 mg/L＋2.0%蔗糖＋0.04%活性炭,生根条件为光照强度2 000 lx、琼脂用量7.0 g/L、培养基pH为5.8是最适宜条件。     

利用浸苗法将野生天麻总DNA导入马铃薯的初步研究

采用浸苗法将野生天麻总DNA导入马铃薯试管苗,研究野生天麻总DNA对马铃薯的转化,分析马铃薯转化植株中野生天麻的药用成分。结果表明：（1）在200株转化的马铃薯中有21株的紫外扫描图谱与正常对照组有显著差异,且在220nm有明显吸收峰。（2）通过薄层层析法（TLC）检测出3株转基因马铃薯表达野生天麻的有效药用成分天麻素。     

PEG处理葡萄试管苗生理反应及叶片组织形态研究

应用不同浓度的聚乙二醇(PEG10000)处理红地球葡萄生根试管苗,在造成一定程度水分亏缺的情况下,观察葡萄试管苗的生理反应和植株生长、叶片形态解剖结构的变化。结果表明:在PEG处理下,葡萄生长发育迟滞,植株节间变短,株高变矮,但发根数量增加,根变长;新生叶片与对照比,叶片小而皱缩,气孔指数降低,上皮细胞排列更紧凑;同时葡萄试管苗脯氨酸的积累和内源ABA迅速增加。说明在一定强度的水分胁迫下,葡萄试管苗叶片的发育向增强其耐旱能力的方向进行,其渗透调节物质的积累是葡萄试管苗对长期水分胁迫的生理反应。     

马铃薯脱毒试管苗二次结薯的产量试验

为解决生产中存在的马铃薯脱毒试管苗生产成本高、生产微型薯繁殖系数低、造成微型薯价格居高不下的难题,本研究选用两个马铃薯品种(抗疫白和润者),在防虫温室收获完微型薯后,把植株再移栽到网棚,株行距20 cm×60 cm,继续使其结薯,进行二次收获。结果其产量远高于第一次收获生产微型薯的产量,因此大大提高了种薯生产效率。     

四倍体酸枣组培苗移栽研究

以四倍体酸枣生根组培苗为试材,研究炼苗天数、基质种类、空气相对湿度、组培苗高度、根条数及移栽时间对组培苗移栽成活率和生长的影响。结果表明：移栽应在4月底至6月进行,在此时期选择高度大于5 cm,根7条以上的组培苗,经炼苗3天,移栽至纯蛭石或珍珠岩与土（1:1）或蛭石与土（1:1）中,移栽前期保持空气相对湿度在90%以上,移栽成活率可达70%以上。     

Discussion on Calculation Pattern of Concrete Filled Steel Tube with Dumbbell shaped Section

Based on the structural feature of dumbbell shaped section of concrete filled steel tube (CFST), a combined spatial beam element is presented. In this structure, two steel tubes, two core concretes, one web and the concrete in web cavity are firstly considered as general spatial beam elements, then they are assembled into a spatial combined beam element according to the plane hypothesis and transformation matrix formed from master and slave nodes. A FORTRAN program for CFST arch with dumbbell shaped section has been developed, and the numerical example shows that the steel tubes and core concretes bear mainly the axial forces with small moments, thus, a modified formula for lattice column method to calculate axial forces of the upper and lower limbs of CFST with dumbbell shaped section is deduced. Comparison of the results from the modified formula with those from an example indicates that the modified formula gives relatively accurate results.      

Efficient elimination of sweetpotato little leaf phytoplasma from sweetpotato by cryotherapy of shoot tips

Shoot tips with 3–4 leaf primordia were excised from in vitro -grown sweetpotato plants ( Ipomoea batatas ) infected with little leaf phytoplasma ( Candidatus Phytoplasma aurantifolia) and subjected to cryotherapy. All plants regenerated from the cryo-treated shoot tips were free of phytoplasma, whereas shoot tip culture or dehydration of shoot tips without subsequent cryotherapy resulted in phytoplasma-free plants at a frequency of only 7–10%. Histological and ultrastructural studies with light and transmission electron microscopy, respectively, indicated that cryotherapy was lethal to all cells except those in the apical dome of the meristem and the two youngest leaf primordia. These surviving parts of the shoot tip contained vascular tissue and sieve elements, but electron microscopy showed no phytoplasma in them. In contrast, an abundance of phytoplasma was found in sieve elements located at the lower, non-surviving parts of the shoot tip 1·0 or 1·5 mm from the apical dome. In the greenhouse, the plants in which phytoplasmas were not detected were healthy-looking, grew vigorously and were readily distinguished from the infected plants that exhibited little leaf and chlorosis symptoms, proliferation of axillary shoots and roots, stunting, and heavily reduced number and size of storage roots. In this study efficient elimination of phytoplasma and production of pathogen-tested plant stocks were achieved with the novel cryotherapy-based approach. The proposed advantage of the technique is that it can be simultaneously used for long-term storage of plant germplasm and for production of pathogen-free plants.