显性雄性核不育小麦不育株与育性近等基因系可育株不同器官的蛋白质比较研究

近年来作物杂种优势利用的研究取得了很大的进展，杂交种的应用带来了巨大的经济效益。作物杂种的生产通常借助于雄性不育系。但是某些植物雄性不育形成的分子机理尚未搞清，不育基因的结构与功能以及不育基因在表达过程中一系列的基因与蛋白质的相互作用有待揭晓。 显性雄性核不育小麦（太谷核不育小麦）是我国特有的显性雄性核不育无花粉型材料，其不育性是由显性单基因Ms2控制的。本论文以显性雄性核不育小麦不育株和可育株近基因系为材料，应用单向电泳（SDS－PAGE）和双向电泳（IEF／SDS－PAGE）方法，分析了不育株和可育株不同器官（种子、旗叶、幼穗及花药）的蛋白质组成。通过研究发现两者之间在蛋质组成上存在一些异同点。在胚乳和旗叶中，未发现不育株和可育株两者之间的蛋白质组成存在明显的差异。在外于减数分裂时期的幼穗和花药中，不育株和可育株之间蛋白质组成上有明显差异。与可育株相比，不育株缺少分子量分别为15.8kD、17kD、17．8kD、38kD、81．2kD的5个碱性蛋白质。另外，还发现不育株增加了一个16．2kD的低分子量酸性蛋白质。在某些特定分子量的蛋白质中，虽然两者都存在该蛋白质，但是在含量上有着明显的不同，可育株含量比不育株高。这些蛋白质组成的变化成为不育株的重要特征。本文首次报告了显性雄性核不育小麦不育株与近等基因系可育株不同器官中蛋白质组成的区别。本研究结果在蛋白质水平上证实了花器官是雄性败育基因表达的主要器官，Ms的表达具有较强的时间性和空间性。 本论文还对双向电泳方法进行了一些探讨。

Reproductive biology of male franciscanas (Pontoporia blainvillei) (Mammalia: Cetacea) from Rio Grande do Sul, southern Brazil

The reproductive biology of male franciscanas (Pontoporia blainvillei), based on 121 individuals collected in Rio Grande do Sul State, southern Brazil, was studied. Estimates on age, length, and weight at attainment of sexual maturity are presented. Data on the reproductive seasonality and on the relationship between some testicular characteristics and age, size, and maturity status are provided. Sexual maturity was assessed by histological examination of the testes. Seasonality was determined by changes in relative and total testis weight, and in seminiferous tubule diameters. Testis weight, testicular index of maturity, and seminiferous tubule diameters were reliable indicators of sexual maturity, whereas testis length, age, length, and weight of the dolphin were not. Sexual maturity was estimated to be attained at 3.6 years (CI 95% =2.7–4.5) with the DeMaster method and 3.0 years with the logistic equation. Length and weight at attainment of sexual maturity were 128.2 cm (CI 95%=125.3–131.1 cm) and 26.4 kg (CI 95% =24.7–28.1 kg), respectively. It could not be verified that there was any seasonal change in the testis weight and in the seminiferous tubule diameters in mature males. It is suggested that at least some mature males may remain reproductively active throughout the year. The extremely low relative testis weight indicates that sperm competition does not occur in the species. On the other hand, the absence of secondary sexual characteristics, the reversed sexual size dimorphism, and the small number of scars from intrassexual combats in males reinforce the hypothesis that male combats for female reproductive access may be rare for franciscana. It is hypothesized that P. blainvillei form temporary pairs (one male copulating with only one female) during the reproductive period.