荔枝基因枪转化及其GUS瞬时表达研究

以幼胚来源的荔枝EC作为受体材料,采用基因枪轰击的方法将外源gus基因转入荔枝,并对不同条件下的GUS瞬时表达进行了详细研究。结果表明:在其它参数不变的条件下,轰击距离、真空度、可裂膜片压力、金粉用量、质粒DNA用量等理化参数显著影响GUS瞬时表达;渗透处理可显著促进GUS瞬时表达。因此,荔枝EC基因枪转化的适宜条件为在轰击距离6 cm、真空度84.66 k Pa、可裂膜片压力7 584.23 k Pa、轰击1次的情况下,每次轰击用1μg质粒DNA包裹600μg金粉对事先用0.25 mol/L前处理4 h的荔枝EC轰击,并在轰击后渗透处理20 h。另外,经50 mg/L潮霉素筛选得到荔枝抗性愈伤组织,并通过体胚发生途径获再生植株,且GUS染色显示获得了稳定表达GUS蛋白的细胞系和植株。     

林地土壤对沙棘人工更新的影响

黄土高原地区沙棘林地土壤的含磷量,对沙棘人工更新后代的生长有重大影响,高的土壤含磷量和低的pH值,对沙棘生长有促进作用;沙棘幼苗的生长与林地上沙棘林的年龄关系不大。因此在黄土高原地区培育沙棘人工林应重视施用磷肥。     

木（木继）与（木继）木叶绿体超微结构的比较

为探讨红Ji木叶色变化与叶绿体超微结构的关系，对不同叶色时期红Ji木及Ji木叶绿体超微结构进行了比较。结果表明，与Ji木相比，红Ji木叶绿体体积减小，数量有所增多，基粒片层垛叠疏松。不同时色时期，红Ji木叶绿体超微结构发生变化。转绿期间，叶绿体数量减少，体积有所增大，比基粒片层数相应减少。     

小白菜叶片数量增长数学模拟

通过田间试验,对小白菜花叶病寄主生长动态进行了数学分析。结果表明,小白菜生长过程符合一般种群增长动态过程,逻辑斯谛曲线拟合效果很好,即使在利用四点式平均值法估计环境容纳量和线性化方法估计其它两参数的情况下,非线性决定系数多在0.99以上,仅一例为0.97。对全部6次田间试验数据拟合的植株平均叶数m与有效积温ST的关系方程为: m=18.94/[1+exp(2.0676-2.7346×10~(-3)ST)] 群体内各植株叶数的标准差Se与平均叶数m的关系方程为: In(Se)=11.7320m-0.1959m~2+18.09261n(m)-20.59071n~2(m)-30.0681 从小白菜生长时间动态方程的拟合效果来看,利用四点式平均值法估计环境容纳量后再用线性化方法来估计其它生长参数的效果,与麦夸尔特法拟合方程的效果差异很小。这表明在实验数据较完整和样本容量较大的情况下,可直接利用前一种方法进行逻辑斯谛曲线拟合。     

荔枝瘤状根结构与VA菌根调查研究

荔枝（Litchi chinensis Sonn.）根尖直径1-1.5mm,长轴方向有根冠,分生区,伸长区和成熟区4个分区,成熟区上有大量的根毛;根尖后部有许多侧根性质的细小瘤状根,瘤状根没有明显分化的伸长区,成熟区上无根毛,但皮层肥厚,维管柱相应对较细,皮层和维管柱一道与根尖的皮层和维管柱有机相连。30d苗龄的根尖和成年结果树根尖2－3cm长根段以及瘤状根上都观察到VA菌根的形成,但侵染率低,土壤中的AM真菌孢子密度也低,认为提高土壤中的AM真菌孢子数量和荔枝根系的VA菌根感染率,将是提高荔枝果实产量和质量的有效生物途径之一。     

萝卜胞质不结球白菜雄性不育系叶片黄化现象的研究

用2个 ogura 萝卜细胞质不结球白菜雄性不育系的衍生株系为母本,99个不结球白菜品种为父本,配组198个测交 F_1代。秋冬栽培期安排田间随机区组试验。试验发现了在 ogura 细胞质背景下不结球白菜叶片的黄化规律,其黄化程度与细胞核基因型、植株生长时期和环境温度有密切关系。方差分析表明,测交 F_1代间、父本间和母本间的平均黄化指数存在极显著差异。试验虽未筛选到叶片完全不黄化的测交组合,但发现有一些组合的黄化很轻微,有进一步研究的价值。试验还发现了几个对 Ogura 胞质黄化敏感性弱的父本好材料,其中绝大多数为青梗品种。文章讨论了进一步改良这类不育材料黄化现象的可行途径。     

月季黑斑病的研究

1986～1988年,以PDA加500 ppm五氯硝基苯的组织分离法和取病斑上分生孢子分离法,分离月季黑斑病菌获得成功,病菌在PDA和燕麦培养基上生长良好,果糖和甘露醇促进孢子发芽率;病菌菌丝生长和产孢温度范围为10～35℃,最适温度22～25℃,最适pH 6;碳源为棉子糖和菊糖,氮源为L-丙氨酸和L-异亮氨酸最好,长沙地区月季黑斑病周年发生,每年5,6月和10月下旬至12月上旬为发病高峰期,采用配制土栽培,在施用2%尿素水或波美5度人粪水时,结合喷施0.1%四硼酸钠或0.1%硫酸锌微肥,既能防病又能提高观赏价值,药剂防治以施用75%百菌清500倍和18%多菌铜300倍液,每隔15～20 d喷1次,连喷2或3次,可控制病害。     

早熟猕猴桃结实期形态变化与营养代谢

猕猴桃品种黄皮５月中旬坐果，６月果实迅速膨大，７月下旬种子发育成形，８月中下旬种子发育成熟，９月中下旬最适采收。此期间果内组织发育、形态变化及密度均已稳定，果重、体积、蛋白质、可溶性糖等数量均达最大值，维生素ｃ含量正由低峰值回升至（１１．４８±０．３５）ｍｇ·ｇ￣（－１）。不同采收期的果实也以９月中旬食用品质较好。确定采收期的相应参考指标是：果内种皮变黑，中果皮为浅绿色，外果皮淡茶褐色，上附橙黄色星状毛，蛋白质积累量（４．７±０．８４）％，可溶性糖含量（８．５±０．２）％，维生素Ｃ（１．４８±０．３５）ｍｇ·ｇ￣（－１），可溶性固形物６．５％～７．５％。     

The genetic diversity of perennial Leymus chinensis originating from China

Leymus chinensis is an economically and ecologically important grass that is widely distributed across eastern areas of the Eurasian steppe. A better knowledge of genetic diversity of L. chinensis could be valuable in the efficient utilization, conservation and management of germplasm collections. Genetic diversity in thirty‐seven morphological characters of 293 accessions was assessed in three successive years. Based on these qualitative and quantitative characters, the genetic diversity indices (Shannon indices) of traits and geographical populations were estimated, and a principal coordinates analysis and a path analysis were undertaken. Compared with the yellow‐green type of L. chinensis, the grey‐green type had significantly (P < 0·05) more genetic diversity. In addition, the path analysis suggested that the combined effects of genetic diversity and vegetative traits could explain 0·206 of the total variance in plant reproductive traits. The highest Shannon genetic diversity index of accessions (H = 2·252) was observed in accessions from the region of longitude of 124–128°E, suggesting the most abundant germplasm of L. chinensis in this region.     

Growth Patterns of Jojoba Male and Female Leaf Callus with Various Ammonium and Nitrate Sources

Abstract

Male and female leaf discs of Jojoba [Simmondsia chinensis (Link) Schneider] were cultured on Murashige and Skoog (MS) media supplemented with various nitrate:ammonium ratio and phytohormones concentrations. For the optimum callus growth, hormonal concentrations were remained equal for both male and female leaf tissues i.e., 0.4 mg L^?1 2,4‐dichlorophenoxyaceticacid, 1.25 mg L^?1 6‐benzyladenine and 0.5 mgL^?1 kinetin. However, a statistically significant difference was observed when Murashige and Skoog media was supplemented with an additional nitrogen source. In female leaf tissue, maximum fresh and dry weights were recorded in Murashige and Skoog media supplemented with an additional source of NO₃ ^?:NH₄ ⁺ (60 mM) whereas in male leaf tissue this addition was inhibitory. This study suggests that nitrogen requirement may be different for optimum callus growth in both male and female leaf tissues.