3种甘蓝型油菜雄性不育系花药发育的细胞学研究

采用石蜡制片方法，对3种甘蓝型油菜雄性不育系及其恢复系的小孢子发生和花粉发育过程进行比较解剖学观察，以确定其花粉败育的时期和细胞学特点。研究结果表明：波里马雄性不育系花药发育受阻于孢原细胞分化期，雄蕊不能分化形成花粉囊。S43A雄性不育系花粉败育的时期发生在小孢子四分体至单核花粉期，败育的特点为小孢子细胞质液泡化，逐渐变形解体，不能进行有丝分裂形成二胞花粉，同时绒毡层细胞过度液泡化，并提早解体死亡。G022A不育系的花药在小孢子发生的不同阶段均出现败育现象，最早的败育表现为花粉母细胞的退化解体；有些因花粉母细胞减数分裂异常不能形成小孢子四分体；还有的因小孢子在四分体中不能正常释放而败育，并伴随着绒毡层细胞的畸形化、异常生长等现象。     

水稻光周期诱导质变在茎蘖间传导的研究——Ⅰ.植株部分短日处理和两段抽穗试验

本研究结果表明:水稻光周期诱导质变在主茎与分蘖间及分蘖之间均不能够互相传导;造成两段抽穗现象的原因,初步认为是由两批穗的穗分化始期的差异所致,而与幼穗分化进度无关。     

Restriction of DNA replication to the reductive phase of the metabolic cycle protects genome integrity

When prototrophic yeast cells are cultured under nutrient-limited conditions that mimic growth in the wild, rather than in the high-glucose solutions used in most laboratory studies, they exhibit a robustly periodic metabolic cycle. Over a cycle of 4 to 5 hours, yeast cells rhythmically alternate between glycolysis and respiration. The cell division cycle is tightly constrained to the reductive phase of this yeast metabolic cycle, with DNA replication taking place only during the glycolytic phase. We show that cell cycle mutants impeded in metabolic cycle-directed restriction of cell division exhibit substantial increases in spontaneous mutation rate. In addition, disruption of the gene encoding a DNA checkpoint kinase that couples the cell division cycle to the circadian cycle abolishes synchrony of the metabolic and cell cycles. Thus, circadian, metabolic, and cell division cycles may be coordinated similarly as an evolutionarily conserved means of preserving genome integrity.     

板粟插穗愈伤组织及不定根的细胞组织学研究

板栗扦插不易生根,用HL—43生根剂处理扦插板栗嫩枝,进行愈伤组织及不定根形成的细胞组织学研究,结果证明:其插穗愈伤组织及不定根的形成,需经过诱导起动,分裂分化及器官形成三个阶段。不定根的形成可以产生在插入苗床的枝段各个部位,以基部1—3节最多,主要由维管形成层细胞或韧皮部薄壁细胞分裂产生。愈伤组织只在剪口处发生,并停留在此阶段,仅有少数愈伤组织形成不定根。     

新化合物苦皮藤素Ⅱ,Ⅲ,Ⅳ的分离和结构鉴定简报

以叶碟定量载毒饲虫的方法追踪活性,经3次硅胶柱层析及反相高效液相色谱半制备,从杀虫植物苦皮藤(Celastrus angulatus,Max.)根皮的石油醚提取物中分离出3个对粘虫(Mythimnaseparata)幼虫具有强烈毒杀作用和麻醉作用的化合物B,D,T.利用高分辨质谱及核磁共振波谱鉴定了3个化合物的分子结构,结果说明,这些化合物都属于二氢沉香呋喃倍半萜酯类,其中B和T为一对异构体,不同之处在于C—9位的苯甲酰氧基的构型,B为χ构型,T为β构型。经文献检索,这3个化合物都是从未报道过的新化合物,分别命名为苦皮藤素Ⅱ,Ⅲ,Ⅳ。     

我国推行农业标准化的发展对策初探

推行农业标准化,是我国应对加入WTO、实施农业结构调整的一项基础性工作,直接关系到农业市场化、产业化、集约化、现代化的实现。应针对我国农业标准化发展的现状,积极借鉴发达国家的经验,健全和完善农业标准化五大体系。     

南昌链霉菌(Streptomyces nanchangensis)固体种子培养的研究

本研究进行了南昌链霉菌孢子培养基和培养条件的筛选。筛选到的培养基和培养条件,使南昌链霉菌每支斜面孢子达5亿多,是高氏培养基产孢量的7.5倍,培养时间缩短了7～10天。同时初步探讨了南昌链霉菌在固体培养基上孢子的消长变化及对摇瓶发酵产素的影响,发现该菌在固体培养基上能周期性地产生多代孢子;摇瓶发酵,接种第一代孢子南昌霉素 A 产量最多,接种第二代孢子则高效杀虫组分 B 的效价最高。     

油桐数量性状的主成分分析及分类

对湖南泸溪葡萄桐在鄂南栽培条件下的１０个表型性状进行了主成分分析一分类。结果表明，前５个主成分的累计贡献率达８０．９％。根据主成分的因子负荷量及其主要指标组合，将１０个生物学性状分为３类，分别称之为冠形因子，花序因子，枝梢因子。主成分分析说明了这３类因子对油桐的作用。     

药用植物淫羊藿克隆构型对异质性生境的响应

通过研究异质性生境中淫羊藿克隆构型,初步分析环境因子对淫羊藿克隆生长的影响及克隆构型可塑性对异质性生境的响应。结果表明:生境中相对光强、土壤含水量和土壤有机质含量对淫羊藿的克隆生长影响较大,土壤pH值对其影响较小。建立了淫羊藿克隆构型可塑性特征与环境因子的关系方程。淫羊藿以地下根茎为克隆器官进行克隆生长,在异质性生境中有着较强的克隆构型可塑性。保护淫羊藿地下根茎,以及生境中适当的光照、水分和养分有利于淫羊藿的克隆生长。     

Distribution of Potato virus Y in potato plant organs, tissues, and cells

The distribution of Potato virus Y (PVY) in the systemically infected potato (Solanum tuberosum) plants of the highly susceptible cultivar Igor was investigated. Virus presence and accumulation was analyzed in different plant organs and tissues using real-time polymerase chain reaction and transmission electron microscopy (TEM) negative staining methods. To get a complete insight into the location of viral RNA within the tissue, in situ hybridization was developed and optimized for the detection of PVY RNA at the cellular level. PVY was shown to accumulate in all studied leaf and stem tissues, in shoot tips, roots, and tubers; however, the level of virus accumulation was specific for each organ or tissue. The highest amounts of viral RNA and viral particles were found in symptomatic leaves and stem. By observing cell ultrastructure with TEM, viral cytoplasmic inclusion bodies were localized in close vicinity to the epidermis and in trichomes. Our results show that viral RNA, viral particles, and cytoplasmic inclusion bodies colocalize within the same type of cells or in close vicinity.