A mitochondrial DNA polymorphism in honeybees (Apis mellifera L.)

Summary Mitochondrial DNA (mtDNA), isolated from worker honeybee larvae, was digested by each of seven 6-base restriction enzymes. Only one enzyme (BglII) showed a mtDNA difference between the three tested races (Apis mellifera carcia, A. m. ligustica, A.m. caucasica). BothA.m. carnica andA.m. ligustica showed the same pattern, differing fromA.m. caucasica. The degree of fragment pattern similarity revealed that there is only a small level of mtDNA variation between the three races tested. This is in line with previous investigations of enzyme polymorphisms.     

大白菜雄性不育系和保持系花药的几种同工酶分析

本文分析了大白菜品种“早皇白”雄性不育系及同型保持系花药三种同工酶谱,不育系均少于保持系.细胞色素氧化酶显示,不育系为3条,保持系为7条;过氧化物酶谱不育系为3条,保侍系为8条;脂酶、不育系为4条,保持系为7条.     

四川山矾的小孢子囊和雄配子体的发育

四川山矾（Symplocos setchumensis Brand)的孢原细胞由1－2列细胞组成，花药壁层的发育为双子叶植物型，初生造孢细胞分裂2－3次形成次生造孢细菌，同一花药室内小孢子母细胞的减数分裂是同步的，绒毡层属腺质绒毡层，直到花粉成熟时还可见到残留的绒毡层细胞。     

秀丽白虾繁殖生物学研究Ⅰ.雄性生殖系统的结构与发育

利用组织学方法对秀丽白虾（ Ｅｘｏｐａｌａｅｍ ｏｎ ｍ ｏｄｅｓｔｕｓ） 雄性生殖系统的结构及发育进行研究,结果表明：秀丽白虾雄性生殖系统由精巢、输精管和雄性生殖孔组成．精巢由许多生精小管组成,生发区位于小管一侧,不同区段的生精小管内精子发生不同步．精巢的发育有季节性：１２ 月～次年２月为精原细胞增殖期,３月～４ 月为精母细胞形成期,５月～８月为精子形成期,９月～１１月精巢退化,越年虾死亡．输精管可分为前、中、后、末四部分,各部管壁上皮构成有所不同,繁殖季节后,上皮细胞分泌活动明显减弱。     

对少年男篮运动员训练时负荷强度的探讨

对少年男篮运动员负荷强度的安排必须考虑其生理特点,阶段训练目标和专项供能特征等因素,本研究在学期、假期两阶段,对北体师少年男篮运动员训练和比赛中血乳酸、心率等指标进行了测试.以探索少年男篮运动员负荷强度安排的合理性.     

水稻光温敏核不育系不育性表达的同步性研究

以农垦５８Ｓ、７００１Ｓ、５０４７Ｓ、Ｗ６１５４Ｓ、ＫＳ９、培矮６４Ｓ、安农１Ｓ和５４６０Ｓ８个不同类型的水稻光温敏核不育系为材料，在广州（２３°０８′Ｎ）盛夏７月～８月份对各不育系的不育性表达进行了系统的比较研究，并对育性转换的同步性进行了观察。结果表明，不育性表达的同步性以安农１Ｓ和７００１Ｓ较好，群体不育性整齐，其他６个不育系的不育性表达的同步性较差，株间、株内穗间、穗内颖花间的花粉育性差异显著或极显著。连续单株套袋对降低株间、株内颖花间的花粉育性差异效果不大。遗传纯合的不育系单株间、株内颖花间的育性转换是不完全同步的。不育同步性可作为评价光温敏核不育系优劣的一个重要指标     

构树雄花序的营养成分

构树幼嫩的雄花序是徐州地区民间食用的一种野生蔬菜，营养成分分析结果显示，100g干燥的雄花序含有β－胡萝卜素3.09mg，维生素C267.71mg，粗脂肪8.82g，总碳水化合物58.83g，粗蛋白20.51g，氨基酸总量16.73g，其中人体必需的氨基酸含量达35.5%。     

Sequence analysis of the gene correlated with cytoplasmic male sterility (CMS) in rape-seed (Brassica napus) Polima and Shaan 2A

orf224 is a CMS-related mitochondrial gene discovered in Polima cytoplasm. Shaan 2A CMS line is the parent of the first rapeseed hybrid cultivar Qinyou No. 2that has been grown in many regions of China. In this work,genomic DNA of Polima CMS line and Shaan 2A CMS line were used as templates, two primers of specific oligonucleoamplification fragments were cloned into pGEM-T Easy vectors and DNA sequences were determined. The CMSassociated gene, orf224-1 present in Shaan 2A CMS line, has a sequence highly homologous to the orf224 of the Polima CMS line, except for one nucleotide at position +398. There were only one base (AAC→AGC) and one amino acid (Asn →Ser) differences between the two. The homologies of the two sequences in nucleotide and. amino acid were 99.9 % and 99.6%, respectively. It is concluded that orf224 in Polima CMS line and orf224-1 of Shaan 2A CMS line are the allele at the same locus in mitochondria.``