甜樱桃离体叶片再生的研究

利用甜樱桃的无菌苗叶片做外植体,进行离体叶片再生不定芽研究。结果表明:培养基中添加的激素浓度、种类和配比均影响不定芽再生,6-BA和NAA组合诱导甜樱桃离体叶片再生的活性较强;在MS 6-BA3mg/L NAA0.2mg/L GA30.5mg/L AgNO35.0-10.0mg/L培养基上,通过3次继代培养的不定梢的叶片,再生不定芽的频率达6.4%,确定良好的生根培养基为1/2MS IBA 0.7mg/L NAA0.2mg/L 蔗糖20g/L 琼脂7g/L,生根率可达75.1%。     

甘薯叶多酚氧化酶的分离纯化和部分性质研究

经硫酸铵分级沉淀、DEAE-Sepharose离子交换层析、Superdex-200凝胶过滤层析,从甘薯叶中得到多酚氧化酶(PPO)电泳纯制品.酶比活力为50 075.43 U/mg,纯化倍数为597.99,回收率为0.48%,相对分子质量约为6.44×104,最适pH值为6.5,最适温度为35℃,且在25~55℃内较稳定.有机溶剂甲醇、乙醇、异丙醇对多酚氧化酶均有一定抑制作用,其抑制作用由强到弱顺序为异丙醇、乙醇、甲醇.低浓度的抗坏血酸和亚硫酸钠对多酚氧化酶有强烈的抑制作用,柠檬酸次之,EDTA-2Na的抑制效果较弱.     

酶法离心处理对甜橙汁及其超滤的影响

探讨了酶法处理对甜橙汁粘度、果胶等成分的影响,考查了酶法离心处理对提高甜橙汁超滤透液通量和减轻膜污染的效果。试验结果表明,甜橙汁中果胶含量及其粘度随果胶酶浓度的增加而减小,但酶浓度达到0．06％以上时则变化较小。经酶法离心处理的甜橙汁,其营养成分变化较小,但在超滤澄清过程中,可大幅度提高透液通量,明显减轻膜的污染,便于膜的清洗。     

多功能种衣剂防治玉米、高粱病害研究初报

玉米、高粱黑穗病和苗期病害是当前生产上的主要问题，多功能种子包衣剂对上述病害具有显著的防治效果，对玉米丝黑穗病的平均防治效果达８５．１％，对高粱各种黑穗病的平均防治效果达９０．４％，增加保苗１０％以上，且对植株生长具有显著的促进作用，经济效益和社会效益十分显著。     

一个甜橙花斑变异的研究

一个甜橙的花斑变异，其枝、叶、果实表现不同程度的白绿镶嵌的花斑．研究表明，这是由于Ｌ－Ⅱ组织原层发生失绿突变，由此衍生的组织器官，叶绿素的合成受阻，从而产生白化现象，这是一个由核基因控制的白化突变     

甜樱桃砧木根际和非根际解磷细菌研究初报

在甜樱桃砧木落叶期,利用根际和非根际土壤测定分解卵磷脂和溶解磷酸三钙的细菌,发现根际土壤解磷细菌的数量高于非根际土壤,但无论是根际还是非根际土壤,有机磷细菌比无机磷细菌多。根际土壤解磷细菌种类较多,而非根际土壤解磷细菌种类较少。根际土壤的有机磷细菌主要为假单胞菌属,且2种砧木之间根际与非根际解磷细菌种类明显不同。     

水分胁迫下高梁叶片的渗透调节

实验结果表明,高粱抗旱品种“3197B”比不抗旱品种“三尺三”在水分胁迫条件下相对含水量随水势下降缓慢,渗透势下降低。在相对含水量为1.0时,3197B渗透势比三尺三低0.3MPa,即3197B渗透调节能力强,水分胁迫期间,3197B膨压变化比三尺三大,表明3197B的细胞壁弹性低于三尺三。     

抗生素对高粱愈伤组织诱导和生长的影响

用羧苄青霉素等抗生素进行抑菌试验,以羧苄青霉素和头孢霉素的抑菌效果较好.头孢霉素对高梁愈伤组织的毒性表现出比羧苄青霉素大.浓度低于500 mg/L羧苄青霉素对高梁愈伤组织的生长起促进作用;而分化率随着羧苄青霉素浓度的提高而下降.在农杆菌介导高梁遗传转化时,选用羧苄青霉素是合适的,浓度以250 mg/L为宜.高梁愈伤组织对潮霉素的反应比卡那霉素更敏感,高梁不同基因型愈伤组织对卡那霉素和潮霉素的反应在褐化(死亡)率上表现不同.在以潮霉素作为抗性筛选标记时,选择压以50～75 mg/L为宜.     

不同根腐病抗性的甘薯产生呋喃类萜植保素的特性

根据七个甘薯品种抗根腐病特性鉴定的结果,用分光光度法和薄层扫描分光光度法来检测受根腐病菌侵染后甘薯块根组织中呋喃类萜植保素的含量。结果表明,接种根腐病菌后的早期状态中,抗病品种徐薯18侵染组织内积累呋喃类萜植保素的速度较快,且含量较高,而感病品种胜利百号积累呋喃类萜植保素速度则较慢,且含量小。于接种24和48小时后分析各个抗感品种病部的呋喃类萜植保素含量与其对根腐病的抗病性高度相关。据此,建议将接种后产生呋喃类萜植保素的特性作为衡量甘薯品种对根腐病抗性的参考指标。     

Relationships Between Yield Monitor Data and Airborne Multidate Multispectral Digital Imagery for Grain Sorghum

Remote sensing imagery taken during a growing season not only provides spatial and temporal information about crop growth conditions, but also is indicative of crop yield. The objective of this study was to evaluate the relationships between yield monitor data and airborne multidate multispectral digital imagery and to identify optimal time periods for image acquisition. Color-infrared (CIR) digital images were acquired from three grain sorghum fields on five different dates during the 1998 growing season. Yield data were also collected from these fields using a yield monitor. The images and the yield data were georeferenced to a common coordinate system. Four vegetation indices (two band ratios and two normalized differences) were derived from the green, red, and near-infrared (NIR) band images. The image data for the three bands and the four vegetation indices were aggregated to generate reduced-resolution images with a cell size equivalent to the combine's effective cutting width. Correlation analyses showed that grain yield was significantly related to the digital image data for each of the three bands and the four vegetation indices. Multiple regression analyses were also performed to relate grain yield to the three bands and to the three bands plus the four indices for each of the five dates. Images taken around peak vegetative development produced the best relationships with yield and explained approximately 63, 82, and 85% of yield variability for fields 1, 2, and 3, respectively. Yield maps generated from the image data using the regression equations agreed well with those from the yield monitor data. These results demonstrated that airborne digital imagery can be a very useful tool for determining yield patterns before harvest for precision agriculture.