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991.
甘蓝型油菜DH系在不同生态区SPAD值的差异分析   总被引:2,自引:0,他引:2  
以甘蓝型油菜纯合双单倍体(DH)为材料,研究不同生态环境下油菜叶绿素SPAD值的变化状况,揭示叶绿素含量遗传表现规律,创制更高叶绿素含量种质资源,以期为油菜高光效育种奠定方法和理论基础。选取了170份甘蓝型油菜DH系,连续3年分别种植在冬油菜区(陕西大荔)和春油菜区(甘肃张掖)。结果表明:无论是不同遗传背景的DH系、还是同一亲本下的不同DH系材料,油菜DH系叶绿素含量在田间既表现出遗传稳定性,又容易受到外界环境影响,即在相似的生态条件下,同一区域即便不同年份的各DH系材料,叶绿素SPAD值的表现基本一致,但在不同生态区,油菜DH系的SPAD值差异很大。通过对油菜DH系亲本和DH系叶绿素SPAD值频数分布分析,叶绿素含量连续3年在2个生态环境具有广泛的连续分布,并且服从正态或者近似于正态分布,以及超亲分离的特点。这些都表明油菜叶绿素含量是一个典型的数量性状,受到多对基因的控制。  相似文献   
992.
GGE叠图法─分析品种×环境互作模式的理想方法   总被引:6,自引:1,他引:6  
本文介绍一种分析作物区域试验结果的方法-GGE叠图法。首先,将原始产量数据减去各地 点的平均产量,由此形成的数据集只含品种主效应G和品种-环境互作效应GE,合称为GGE。对GGE 作单值分解,并以第一和第二主成分近似之。按照第一和第二主成分值将各品种和各地点放到一个平 面图上即形成GGE叠图。借助于辅助线,可以直观回答以下问题:(1)什么是某一特定环境下最好的 品种;(2)什么是某一特定品种最适合的环境;(3)任意两品种在各环境下的表现如何;(4)试验中品 种×环境互作的总体模式是怎样的;(5)什么是高产、稳产品种;(6)什么是有利于筛选高产、稳产品 种的环境。  相似文献   
993.
Summary To investigate genetic regulation of blossom-end scar size in tomato (Lycopersicon esculentum Mill.), a half diallel cross including 10 parents was grown under warm fall conditions in Bradenton, Florida, and cool winter conditions in Hazeva, Israel. The parents were a random sample representing all available fresh market tomato breeding lines commercially grown under subtropical field conditions. A randomized, complete block design with three replications was used and the blossom-end scar index (BSI), a measure for scar size relative to truit size, was measured on 40 and 25 fruits per plot in Bradenton and Hazeva, respectively. Analysis of variance for BSI indicated highly significant (P=0.001) variation among parents and among F1's in both environments. In Bradenton and Hazeva both, the difference in average BSI between parents and F1's was not significant suggesting insignificant overall dominance effects. Further partitioning of variation within F1's indicated that general combining ability (GCA) effects were highly significant in both environments, whereas specific combining ability (SCA) effects were significant at P=0.001 in Bradenton, but only at P=0.05 in Hazeva. Estimated variance components for GCA and SCA effects indicated that BSI inherited mainly additively in both environments. Analysis combined over environments indicated that variation in sensitivity to environments was 5-fold higher among parents than among F1's. The genotype x environment variance component was not large enough to justify testing over more than one environment for population improvement purposes and early testing of hybrids. Evaluation of inbred lines, however, may have to be done in more than one environment, especially for Suncoast-derived material. Under temperatures in Hazeva, genotype differences were more pronounced and heritabilities higher than under high temperatures in Bradenton. The estimated overall single plot heritability was 0.63. Breeding lines with a pointed blossom-end morphology (e.g. NC 8276 and NC 140 in this study) generally had small blossom-end scars, and intercrossing of these lines or crossing with non-pointed, moderately smooth breeding lines generally resulted in smooth hybrids.  相似文献   
994.
贮藏环境乙烯对不同低温下库尔勒香梨果实品质的影响   总被引:1,自引:0,他引:1  
以新疆库尔勒香梨为试材,研究其在-1℃和2℃下不同乙烯浓度(0,自发气调,100μL/L)环境中果实外观色泽和内在品质等的变化规律。结果表明,与环境中的乙烯相比,温度对贮藏期间的果实品质影响较大;贮藏于-1℃的果实果皮颜色保持较好,硬度较高,腐烂率较低,而贮藏于2℃的果实品质则相对较差;相同温度条件下,处于自发气调环境中的果实腐烂率较低,果柄保鲜指数较高,但不同乙烯浓度处理对库尔勒香梨果实的硬度、可溶性固形物含量、可滴定酸(TA)含量以及VC含量等品质指标的影响无明显规律性。  相似文献   
995.
Migration for the reason of zoological environment is the measure for solving the crisis of zoological environment. Nowadays, governments play the chief role in the Migration for the reason of zoological environment, but the migration themselves do not have the freedom to decide whether migrate or not. Because the activity of migration is related to the restraint of economy, culture, law, etc. It is the object of migration that protect the zoological environment and improve the welfare of habitant, which must be concerned when constructing the systems of migration. This paper proves the possibility of contracting for migration based on the methodology of the cost-income analysis. On the other hand, it also argues for changing the mode of migration from that controlled by governments to being decided by habitant themselves.  相似文献   
996.
Herbicide-tolerant crops in agriculture: oilseed rape as a case study   总被引:3,自引:0,他引:3  
Oilseed rape has been modified extensively by conventional breeding for the production of varieties useful for human consumption (blended vegetable oil and margarine) and industrial processes (rubber additives and high‐temperature lubricants). Because much is now known about its genetic and biochemical composition, it has been an obvious choice for genetic modification and is now at the forefront of the commercial development of genetically modified (GM) or transgenic crops. Around the world, the increase in commercial plantings of all transgenic crops has been rapid. In 1996, 1.7 million hectares were planted, but by 1998 this figure had jumped to 27.8 million ha. The area in the year 2001 is likely to be about 50 million ha. With the possible introduction of transgenic varieties into European agriculture, it is essential that the associated farming practices employed are appropriate for their growth, both from a commercial and an environmental viewpoint. Some of the first transgenic crops are those carrying agronomic traits, e.g. herbicide tolerance transgenes. However, before full commercialization occurs, important agronomic and environmental questions need to be answered. How are these new crops to be incorporated into existing cropping practices? How will this change the current herbicide use profile for a given crop? Do herbicide‐tolerant varieties enhance or impede integrated pest management schemes? What is the likely uptake of such crops in agriculture? What are the ecological implications of their introduction? Are there effective measures to control the spread of transgenes to wild relatives? This paper addresses these questions, with special emphasis on oilseed rape production in the UK, but includes examples from other crops and countries where appropriate.  相似文献   
997.
The environment ethic deals with the research on relation between human beings and the nature. The residential environment ethic is a detail study of environment ethic, which studies the relation between human beings and residential environment. The residential environment ethic presents the human duty to care about and protect residential environment and actually to protect human beings themselves. But the residential environment is facing many dangers, such as city pollution and indoor air pollution, which are closely related to building materials. So, one of the ways for improving the residential environment quality is to use green building materials.  相似文献   
998.
Genetic evaluation aims to identify genotypes with high empirical breeding values (EBVs) for selection as parents. In this study, 2157 potato genotypes were evaluated for tuber yield using 8 years of early‐stage trial data collected from a potato breeding programme. Using linear mixed models, spatial parameters to target greater control of localised spatial heterogeneity within trials were estimated and variance models to account for across‐trial genetic heterogeneity were tested. When spatial components improved model fit, correlations of errors were mostly small and negative for marketable tuber yield (MTY) and total tuber yield (TTY), suggesting the presence of interplot competition in some years. For the analysis of multi‐environment trials, a variance model with a simple correlation structure (with heterogeneous variances) was the most favourable variance structure fitted for TTY and PTY (per cent marketable yield). There was very little difference in model fit when comparing a factor analytic structure of order 2 (FA2) with either FA1 or simple correlation structures for MTY, indicating that simple variance models may be preferable for early‐stage genetic evaluation of potato yield.  相似文献   
999.
In the common bean crop in Brazil, the requirement of the value for cultivation and use trials is that these experiments must be conducted over two years in three locations per region. Information in regard to the necessary number of years to ensure precision in cultivar recommendation and the influence of evaluated years in the estimation of the GE interaction are still scarce. Using grain yield of five check varieties assessed over 11 years in three sowing seasons per year, the aims of this study are as follows: to measure the relative contribution of the GE interaction, evaluating the implication of the number of years in the estimates of the GE interaction, and infer how many years are needed to ensure precision in cultivar recommendation. For instances, analysis of variance was carried out involving all environments and also combinations of years. The results showed that the GE interaction was greater than all other cross‐effects involving lines. The use of at least two years allows good coincidence in cultivar recommendation compared to the whole period. Increasing the evaluation time is a good strategy, especially when it is difficult to grow three different sowing seasons.  相似文献   
1000.
分析了朱鹮自然保护区的自然环境、生产环境和社会人文环境,以及朱鹮自然保护区发展有机产品的可行性。进一步论述了朱鹮保护区有机产品产业环境的构成,在此基础上建立了朱鹮保护区有机产品产业环境的评价体系:目标层、项目层、评价因素层和指标层;政策体系:国家法律体系、政府行政体系、民俗民约体系;评价监控管理体系:国家法律、政府行政、经济活动方面和管理过程方面,并对这一评价体系的应用前景进行了展望。保护朱鹮自然保护区有机产品产业环境是一项长期艰巨的任务。建立朱鹮自然保护区有机产品产业环境评价体系具有广阔的应用前景,主要体现:能为有机产品产业提供有效的管理方法;可供政府管理、监控、指导产业发展,以及能为投资决策提供依据。  相似文献   
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