Spotted-Leaf Mutants of Rice(Oryza sativa)

Many rice spotted-leaf(spl) mutants are ideal sources for understanding the mechanisms involved in blast resistance,bacterial blight resistance and programmed cell death in plants.The genetic controls of 50 spotted-leaf mutants in rice have been characterized and a few spotted-leaf genes have been isolated as well.This article reviews the origin,genetic modes,isolation and characterization of spotted-leaf genes responsible for their phenotypes,and their resistance responses to main rice diseases.     

Australian Oryza: Utility and Conservation

Australian Oryza are an understudied and underexploited genetic resource for rice improvement. Four species are indigenous: Oryza rufipogon, Oryza meridionalis, Oryza australiensis are widespread across northern Australia, whereas Oryza officinalis is known from two localities only. Molecular analysis of these wild populations is required to better define the distinctness of the taxa and the extent of any gene flow between them and rice. Limited collections of these wild populations are held in seed and DNA banks. These species have potential for domestication in some cases but also have many traits of potential value in the improvement of domesticated rice. Stress tolerance (biotic and abiotic) and grain quality characteristics in these populations may be useful.     

稻田高产节水灌溉方式的研究

 1984～1988年在中国水稻研究所实验场排水与其它农业措施相结合，采用节水灌溉措施和高产灌溉制度，综合考虑对田面水、土壤水、地下水和雨水的统一管理利用和合理调节控制，通过大田、小区、测坑试验和生产实践，提出了适合当地条件的节水高产灌排方式、地下水埋深度和排水量。这种水综合运用，既可节约灌溉用水量，减少灌水次数，还可降低排涝水量，减轻排涝能耗费用。     

杂交水稻新组合D优448

D优448是用D62A与成恢448配组育成的优质、高产杂交中、晚籼新组合,2001年4月通过四川省农作物品种审定委员会审定.     

澳大利亚畜牧业概况

澳大利亚现有绵羊 1 2 3亿只 ,牛 2 60 0万头 ,草食动物养殖规模化程度很高。畜牧业成功之路在于引进欧洲及地中海草种 ,人工种植牧草 ,以及改良或引进生产性能优良的动物品种。动物活体及其产品出口是促进畜牧业稳步发展的重要因素     

优质多抗高产高效北方粳稻新品种选育报告

在综合研究水稻优质、多抗、高产、高效的生理基础、生态条件和关键性状遗传特性的基础上,采用“多元杂交,混系结合,株型理想,优化选择”方法,选出了优质、多抗、高产、高效的理想稻新品种。其中沈农8718、沈稻7号通过国家审定熏沈稻4号、沈稻5号等通过辽宁省审定。新品种的产量超过对照品种。经检测熏7个品种的米质达到国家优质稻米一级或二级标准熏其余达到三级标准。新品种各性状组配合理熏抗病性、耐寒性、耐旱性较好。采用的优化育种方法熏实现了育种目标。     

Long-term phosphorus fertilisation increased the diversity of the total bacterial community and the phoD phosphorus mineraliser group in pasture soils

Fertilisers, especially nitrogen (N) and phosphorus (P) supplies, are frequently used in agricultural soil management to attain high crop yields. However, the intensive application of these chemical inputs can decrease the quality of agricultural soils and increase the probability of environmental pollution. In this study, the impact of P fertilisation on the diversity of the soil bacterial community was assessed. For this, a culture-independent approach targeting 16 rRNA and phoD genes was used on DNA extracted from pasture soils subjected to three different P fertilisation regimes for a long-term (42 years). As alkaline phosphomonoesterase (ALP) is necessary for mineralisation of organic P, an inverse relationship between the level of potential ALP activity and soil available P was expected. Indeed, a lower ALP activity was observed in soil subjected to higher chemical P fertiliser input. Analysis of the prevalence of three divergent families of ALP (PhoA, PhoD and PhoX) in metagenomic datasets revealed that PhoD is the most frequent ALP in soil samples and was selected as the most representative ALP possessed by the soil bacterial communities. Diversity of the phoD phosphorus mineraliser group, as well as the total bacterial community, was both increased in response to long-term P fertilisation. Specifically, phosphorus fertilisation decreased the relative abundance of certain taxa, including Acidobacteria and Pseudomonas fluorescens. In conclusion, this study shows that P fertilisation affects the microbial diversity of soil ecosystems, which might potentially modulate the soil biogeochemical cycle.     

一种简便高效的PCR辅助选择技术在杂交水稻转Xa21基因育种中的应用

介绍了一种在杂交水稻转Xa21基因育种中使用的PCR分子标记辅助选择技术.该技术结合测交和半粒种子法可以快速准确地筛选出转Xa21基因纯合株系和转[ WTBX〗Xa21基因杂交稻,大大提高育种效率,对培育抗白叶枯病杂交稻具有重要的应用价值.