紫外辐射与复合胁迫对植物抗氧化酶系统的影响

植物抗氧化酶系统对UV-B辐射增强与复合胁迫的响应是植物抵御逆境伤害的关键机制之一。结合近年来国内外研究成果,概述了UV-B辐射对植物抗氧化酶基因表达、转录与翻译的影响,植物抗氧化酶系统对UV-B辐射与干旱、臭氧、高温、盐渍、重金属及酸雨复合胁迫的响应,以及CO2、抗坏血酸、α-萘乙酸、硒、激光辐射和稀土等调节因子对UV-B辐射下植物抗氧化酶系统的作用。     

Dam safety management for sustainable farming businesses and catchments

In most countries, owner responsibility exists under Common Law to manage and maintain dams according to current standards. However, farm dam safety in Australia is being flouted and the sustainability of farming businesses compromised because of the potential and severe consequences of dam failure. This paper explores management and policy issues associated with safety of farm dam water storage through a comparison of developments in two Australian states against international benchmarks. Historical review and a longitudinal study over a 12-year period provides the basis for case analysis and demonstrates the application of the benchmarked model policy selection guidelines. Research results show South Australia is lagging international best practice in a number of ways whilst Tasmania provides leadership. The contribution of this paper is a regulatory mix analysis approach, incorporating a cost-effective spillway safety engineering/accounting tool, developed and demonstrated through Australian case studies, that can be applied by any jurisdiction wanting to check and/or improve its farm dam safety management and provide a clearer analysis of the social and environmental costs and threats associated with on-farm dam safety issues.     

Comments on the regulatory gate hypothesis and implications for C-cycling in soil

The paper by Kemmitt et al. [2008. Mineralization of native soil organic matter is not regulated by the size, activity or composition of the soil microbial biomass - a new perspective. Soil Biology and Biochemistry 40, 61-73] proposing the existence of an abiotic regulatory gate that controls the rate-limiting step of stabilised soil organic matter (SOM) mineralization, has initiated a fundamental and far-reaching debate. In this contribution the implications of a functioning abiotic regulatory gate are considered in the context of microbial community diversity and soil carbon cycling. I argue that although the evidence presented in support of the regulatory gate is strong, abiotic routes for SOM-mineralization function in parallel with biologically mediated mechanisms. Evidence is now accumulating that, in the presence of plant-inputs to soil, enhanced microbial mobilisation of SOM into biomass is a quantitatively important and ubiquitous process. I argue that this mineralization of SOM is fuelled by energy-rich substrates and is driven by microbial nutrient-demand. This implies that the mineralization of stabilised SOM and the turnover of C-inputs from current vegetation are intimately linked through the functioning of microbial communities associated with plants. This suggests that the microbial ‘eye of the needle’ is a crucial control-point in determining the carbon balance of soils. Fortunately, there are now excellent methods that allow quantification of SOM- and plant-derived C-fluxes through the members of soil microbial communities, and will also allow quantification of the relative importance of the abiotic and biotic routes of SOM-mineralization.     

常优一号杂粳机插高产形成规律及调控关键技术研究

以杂粳“常优一号”为试验材料,通过丰产示范与专题试验,分析探讨其高产形成规律及其调控关键技术.结果表明,每穗粒数与产量的关系,最为密切,呈极显著正相关,各产量构成要素对产量贡献作用,以每穗粒数的作用最大,其次为有效穗,再次为结实率与千粒重.其直接通径量,每穗粒数高达1.958,分别为有效穗、结实率、千粒重的1.88、3...     

果实糖代谢及调控因子的研究进展

综述了果实中糖的生理功能、种类及积累类型,果实中糖代谢相关酶的作用.糖代谢的调控因子等方面的研究概况.     

光照对绿宝石叶绿素荧光特性的影响

用叶绿素荧光动力学研究不同光照对绿宝石叶绿素荧光特性的影响.结果表明:遮光使绿宝石叶片SPAD值升高4.7%;日光灯使初始荧光下降,最大荧光升高;遮光和自然光照的PSⅡ潜在活性和原初光能转化效率比处理前低,而日光灯处理10 d时二者分别增加9.9%和7.73%;在日光灯处理20 d时PSⅡ量子效率升高61.67%,荧光...     

光照对绿宝石叶绿素荧光特性的影响

用叶绿素荧光动力学研究不同光照对绿宝石叶绿素荧光特性的影响。结果表明：遮光使绿宝石叶片SPAD值升高4.7%;日光灯使初始荧光下降,最大荧光升高;遮光和自然光照的PSⅡ潜在活性和原初光能转化效率比处理前低,而日光灯处理10 d时二者分别增加9.9%和7.73%;在日光灯处理20 d时PSⅡ量子效率升高61.67%,荧光下降比值升高23.16%,光化学猝灭升高12.62%,非光化学猝灭仅为处理前的64.72%。说明日光灯处理可增加绿宝石叶绿体PSⅡ反应中心开放部分的比例,将更多的光能用于推动光合电子传递,从而提高光合电子传递能力,同时叶片的非化学热耗散降低,植物体充分利用所吸收的光能用于光合作用。     

植物诱导型启动子的研究进展

为实现目的基因的高效表达,诱导型启动子的开发和应用成为植物基因工程中的研究热点。在特定生物及非生物环境胁迫下,诱导型启动子能够驱动外源基因实现高效表达,其诱导型是由其上存在的正负调控元件相互作用而决定的。综述了诱导型启动子的种类、启动子序列内部调控元件的类型以及适用于诱导型启动子的研究方法,并对其在植物基因工程中的应用前景进行了展望。