马铃薯晚疫病菌侵染的Solophenyl Flavine荧光染色方法研究

在植物病害研究中,观察寄主植物被病原菌入侵的过程非常重要。Solophenyl Flavine 7GFE染料可附着于菌丝,在波长为330~380 nm的激发光下被激发出蓝色荧光。为了更好的观察寄主植物中病原真菌的侵染情况,本实验以Solophenyl Flavine 7GFE为染剂,对寄主植物中病原真菌的侵染情况进行了观察研究。结果显示,用0.002%(M/V)Solophenyl Flavine 7GFE溶于0.1 mol/L Tris-HCl(p H 8.5)配制的染色液染色5 min的效果最佳;使用95%乙醇溶液替代0.15%三氯乙酸(W/V)酒精溶液∶氯仿(V/V)(4∶1)对寄主植物叶片脱色的方法操作简便、毒害较低;染色时省略了番红预染步骤。将改良的染色方法用于晚疫病菌入侵的马铃薯叶片观察取得了良好的效果。该技术是一种改良的、快速有效、安全无毒的观察真菌菌丝入侵植物的荧光染色方法,也适用于观察其他真菌入侵寄主植物组织的过程。     

Isolation and characterization of polymorphic microsatellite loci in the Chagas’ disease vector Triatoma infestans (Hemiptera: Reduviidae)

Microsatellites were identified and characterized from Triatoma infestans, the principal vector of Chagas’ disease in the Southern Cone of South American countries. Ninety‐three microsatellite loci were isolated from partial genomic libraries, of which 30 were amplified and 10 were selected for genotyping. The degree of intrapopulation variation in these loci was determined using 34 specimens from the locality of Chancaní (Córdoba, Argentina). The number of alleles per locus ranged from five to 19 and the expected heterozygosity ranged from 0.608 to 0.941. The variability of these microsatellite markers provides a valuable molecular tool for population genetic studies in T. infestans.     

Allatotropin expression during the development of the fourth instar larvae of the kissing-bug Triatoma infestans (Klüg)

Allatotropin (AT) is a neuropeptide originally isolated from the brain of Manduca sexta and then characterized in several insect species. It acts as a neurohormone, as well as a neuromodulator. While it was primarily characterized on the basis of its ability to stimulate the secretion of juvenile hormones, it was also found that it acts as a cardioaccelerator and myostimulator. The presence of AT in IV instar larvae of T. infestans was previously described at the level of the Malpighian tubules. In the present study we report the presence of the peptide at the level of the brain, retrocerebral complex, as well as in the anterior midgut and aorta. The presence of AT at the corpora allata suggests that the peptide is acting on the gland during the first days of the moulting cycle. Neural processes at the level of the aorta and the anterior midgut suggests that, like in adults, the hormone is acting as a cardioaccelerator and myostimulator. The peptide was also found in open-type cells of the midgut. Finally the presence of allatotropic neurons in the optical lobe of the brain suggests that as in other species, the peptide is related with the control of circadian rhythms.     

4. Vavilov's Law of Homologous Series—is it relevant to potatoes?

Nikolai Ivanovich Vaviloc publsihed his Law of Homologous Series in 1920, but did not include any ideas oon homologous variation in potatoes. The relevance of this fundamental concept of genetic diversity to potatoes is discussed in relation to disease and post resistance in wild potatoes from mexico and the Andes of South America.