巴西橡胶树HbMyb1基因的原位PCR物理定位

为探讨巴西橡胶树(Hevea brasiliensis)死皮病抗性相关HbMyb1基因的定位,采用所建立的橡胶树染色体原位PCR技术体系进行研究。结果表明,HbMyb1基因初步定位于巴西橡胶树‘热研7-33-97’的第5号染色体长臂上,信号位点到着丝粒的百分距离为15.21,并观察到在巴西橡胶树‘热研7-33-97’叶片细胞核的不同分裂时期均扩增到1~2个信号。同时对染色体标本的制备、保存、预处理等方面进行了探讨。     

水稻半矮秆基因sd-t的染色体定位研究

以籼型标志基因系和ＩＲ３６三体为工具材料,通过杂交研究了籼稻矮秆材料矮泰引－２所携半矮秆基因Ｓｄ－ｔ在染色体上的位置。结果表明,半矮秆基因Ｓｄ－ｔ与标志基因系０１９所携紫果皮基因Ｐｒｐ－ｂ、标志基因系Ｂ３０所携无叶舌基因１ｇ、标志基因系０２７所携灰白壳基因Ｗｈ表现连锁,ｓｄ－ｔ与Ｐｒｐ－ｂ之间的交换值为２．８５％±０．５２％,ｓｄ－ｔ与ｌｇ之间的交换值为２７．９０％±３．８１％,ｓｄ－ｔ与Ｗｈ之间的交换值为３８．６２％±２．９９％。由于Ｐｒｐ－ｂ、ｌｇ、Ｗｈ基因均位于第４染色体上,因而推定ｓｄ－ｔ基因位于第４染色体上,其排列位置可能是Ｐｒｐ－ｂ－ｓｄ－ｔ－ｌｇ－Ｗｈ。     

Alternative Splicing Products of the Gene for a Human Nuclear Actin-related Protein,hArpNβ/Baf53, that Encode a Protein Isoform,hArpNβS,in the Cytoplasm

A human nuclear actin-related protein, hArpNβ/Baf53, is a component of chromatin remodeling and histone acetyltransferase complexes. We identified two alternative splicing products of the gene for hArpNβ/Baf53. They encoded a protein isoform, hArpNβS; and its fusion product with green fluorescent protein was to be found in the cytoplasm, not the nucleus. The isoforms may contribute to functional regulation of these complexes.     

野生稻抗病虫基因的研究与利用

野生稻是宝贵的种质资源,具有丰富的遗传多样性。多项研究表明,野生稻对多种病虫害有较强的抗性。但由于野生稻的远缘杂交存在许多的弊端,因而采用常规杂交技术不能选育出新的抗性品种而未能这到利用野生稻抗性基因的目的。可考虑从野生稻中提取抗性活性成分用于植物源农药的开发研究,但在实际的研究中发现其有效活性成分含量较少和基因遗传连锁障碍等两个问题。基因的分子标记定住技术可解决这两个难点。使野生稻特别是非AA组野生稻的抗病虫基因在植物源农药开发中的利用成为现实。     

小麦条锈菌主要结构中糖基种类的细胞化学定位研究

用8种植物凝集素探针对小麦条锈菌主要结构中的糖基种类进行了细胞化学定位。电镜观察结果表明在菌丝和吸器母细胞壁中存在有α-葡萄糖或α-甘露糖、乙酰胺基葡萄糖、α-半乳糖、α-乙酰半乳糖、岩藻糖和β-连结的糖基,而隔膜中仅含α-葡萄糖或甘露糖和乙酰胺基葡萄糖基;在吸器颈壁中分布有α-葡萄糖或α-甘露糖;尽管吸器体壁中仅含乙酰胺基葡萄糖,而在吸器外间质中存在有半乳糖,乙酰半乳糖,α-葡萄糖或甘露糖等糖基。以上结果表明不同结构所含糖基种类并非一致。     

Mitochondrial location of pyruvate carboxylase in Aspergillus niger

Pyruvate carboxylase has been found in the mitochondrial fraction of two strains of Aspergillus niger along with the marker enzymes of citrate synthase and cytochrome c oxidase. The location of pyruvate carboxylase in A. nidulans was, however, confirmed to be in the cytosolic fraction. The enzyme from the former sources was dependent upon the presence of acetyl-CoA for full activity; the enzyme from A. nidulans was unaffected by the presence or absence of acetyl-CoA.     

Flight behaviour of Encarsia formosa in response to plant and host stimuli

The flight behaviour of Encarsia formosa Gahan (Hymenoptera: Aphelinidae), a parasitoid of Trialeurodes vaporariorum (Westwood) (Homoptera: Aleyrodidae) has been studied in response to the following natural components: bean plant (Phaseolus vulgaris L.) infested with T. vaporariorum (PHC, plant host complex), host damaged bean plant from which whiteflies were removed (HDP, host damaged plant), T. vaporariorum third instar larvae (H, host), uninfested bean plant (P, plant) and T. vaporariorum empty pupal cases (EPC, empty pupal cases). A combination of chemical and visual stimuli is necessary in host location from a distance by E. formosa and seems to deeply affect the dispersal of this parasitoid. The presence of host (PHC, H) or of its parts (EPC) led to a substantial increase of oriented flights suggesting the occurrence of host derived chemicals. At a closer range, a combination of visual and chemical stimuli deriving from all the components of the plant host complex elicited the transition flying-landing and the following landing on the source.