共查询到17条相似文献，搜索用时 125 毫秒
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通过对两系稻制种气候风险的数学定义,根据江西省125万地形数据和各气象台站40a气候资料及气候要素与海拔高度的关系,运用地理信息系统的空间分析方法,对两系稻制种基地的气候风险进行了区划,找出了最佳制种地理区域和不同品种最小气候风险下的最佳播种期. 相似文献
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两系杂交稻制种生产对气候生态条件有严格要求,确定制种生产基地时应当先对当地的气候生态适宜性进行科学地诊断与评估。该文系统地分析了气候生态条件对两系杂交稻制种生产的特定影响,提出了制种生产上应注重的两段气候生态安全期概念,研究了两段安全期的诊断评估方法,研制出了两系杂交稻种子生产时空择优气候服务系统,并据此确定了湖南全省两系杂交稻种子生产的适宜区域与时段。2000年初,湖南省有关部门采纳了此项建议,进一步规范了全省的两系制种生产管理。 相似文献
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根据两系杂交水稻制种对气象条件的要求，利用广西80多站的气象资料，统计分析了广西各地两系统杂交水稻制种的安全期，提出了广西杂交水稻安全制种应注意的一些气候问题。 相似文献
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广西两系杂交稻制种安全期气候分析 总被引：1，自引：0，他引：1
根据两系杂交水稻制种对气象条件的要求 ,利用广西 80多站的气象资料 ,统计分析了广西各地两系杂交水稻制种的安全期 ,提出了广西杂交水稻安全制种应注意的一些气候问题 相似文献
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永州市两系杂交水稻制种气象条件分析研究 总被引：2，自引：0，他引：2
通过对农田与气象站同步观测气象数据的对比分析和对永州市历史气象资料的统计分析,掌握了农田小气候气象因子变化和调节规律,总结出永州市两系杂交水稻制种育性转换和抽穗扬花“两个安全期”最佳安排时段,为回避或减少制种的气象灾害风险、提高制种的产量和质量等工作提供了科学气象理论依据,具有现实指导意义。 相似文献
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研究两系杂交稻的首要不育系———培矮64S制种的气候适应性, 一方面可为两系杂交稻的生产提供决策参考, 另一方面也可为其它不育系的研究提供借鉴。分析气候适应性时, 首先利用播种—抽穗天数及其对应的气象资料, 建立发育期模型; 然后利用自交结实率资料及其对应的气象资料建立育性量化模型, 并求出育性转换的光温指标; 最后将我国稻区35个站点42年 (1951~1992年) 的气象资料代入发育期模型, 求出各站点的可能出穗持续期 (最早出穗期—最晚出穗期的历期), 对比育性转换的光温指标, 确定培矮64S在80%、90%和95%保证率下连续不育 (可育) 的初、终日, 将连续不育期作为生产杂交稻种子的季节, 将连续可育期作为繁殖培矮64S的季节。结果显示:培矮64S仅能在海南岛及云贵高原中低海拔地区自交繁殖; 而在东北、云贵高原以外的稻区, 培矮64S均可用于生产两系杂交稻的种子, 各稻区制种季节的长短、起止日期与种植地的纬度、海拔高度相关。 相似文献
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“两系”法杂交水稻示范推广是我国水稻生产中又一革命性的发展 ,它具有稻米品质好、增产潜力大的显著特点。“两系”杂交稻不育系的不育性 ,既受细胞核不育基因的控制 ,又受气候条件的影响 ,因此既要选择一个最佳扬花授粉期 ,又要选择一个安全的育性转换期。前者是制种稳产高产的前提 ,后者是制种成败的关键。１水稻“两系”法制种的概念水稻“两系”法制种是利用不育系在某种特定光温条件下的雄性不育特性 ,与恢复系配制生产杂交水稻种子。同时又利用它在一定条件下表现为雄性可育能自交结实的特性 ,繁殖不育系种子。它具有一系两用、种子… 相似文献
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发挥山区农业气候资源优势 攻克两系杂交稻制种难关 总被引：2，自引：0，他引：2
本文围绕提高两系杂交稻制种这个问题，根据其不育系育性转换期以及现有不育系的温敏型，从农业气象角度出发，提出攻克两系杂交水稻制种难关的技术措施。抓好“三防”，按“四佳”选择制种基地，无疑将使两系杂交稻制种产量和杂一代的纯度得到有效的提高。 相似文献
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针对两系杂交稻制种易遇夏季低温危害制种纯度的技术瓶颈,为正确采用以水调温预防技术,本文依据热量平衡原理,建立了制种稻田的水热传输多层模型。经实测资料检验,模型稳定、可靠。对模型输入不同灌水参数的计算结果表明:20 cm气温(不育系敏感期的幼穗高度)随着净辐射通量、灌水深度、进水及出水口水温的升高而增加,增温幅度受这些因子的综合影响。要合理的利用水资源必须考虑多种因子的相互作用。对育性的实测表明,以水调温对防御夏季低温,提高制种纯度效果良好。 相似文献
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水稻气候生产力的数值模拟及其应用 总被引：8，自引：0，他引：8
在水稻气候生产力数值模拟的基础上,利用杂交水稻种植区１８省１６５站３０年逐旬光温整编资料,模拟并分析了早、中、晚稻气候生产力的空间分布规律及其气象原因;利用模糊聚类分析,进一步对我国水稻种植区域作了气候生态类型区划,结果早季稻划分为七个类型区,中季稻和晚季稻可划分为六个类型区。 相似文献
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两系法杂交稻65396在我国一季稻区的制种播差期决策 总被引：1，自引：0，他引：1
以具有超高产水平的两系杂交稻 6 5 396 (培矮 6 4 s× E32 )为研究对象 ,在分析母本不育系培矮 6 4 s用作单季稻区域制种时的稳定不育期的季节和持续期的基础上 ,用生育期模型分析了培矮 6 4 s与 E32在南方一季稻区制种时的播差期及其变化规律。研究得到的两系法杂交稻制种技术的气象学方法可供其他熟制地区应用。 相似文献
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两优培九关键期的气象指标与气候适应性分析 总被引：8，自引：2，他引：8
以两系法杂交稻两优倍九在南京和镇江两地的分期播种资料为基础，选出与产量密切相关的5个高产关键期，用回归统计分析方法组建气象响应模型，得出各高产关键期的最适气象条件值。以此为依据，用1951－1992年江苏省赣榆、徐州、高邮、南京、常州、溧阳、苏州等7个地区的气象资料，在高产关键期预测的基础上，计算了4种茬口各产量构成因素的气候值并与最适气候值进行比较，提出了相应的高产技术措施。 相似文献
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Under global warming, the risk of heat injury for crops increases, which leads to increasing instability in agricultural production. In this study, based on phenological observation data and yield data during 1981-2011 and daily meteorological data during 1961-2011 in the middle and lower reaches of the Yangtze River (MLRYR), the risk of heat injury for single-cropping rice in this area and its response to climate change were assessed and analyzed. The risk was decomposed into such elements as hazard, exposure, vulnerability, and disaster prevention/mitigation capacity, in accordance with natural disaster risk assessment theory and the formation mechanisms of agrometeorological disasters.First, a hazard assessment model was established to identify spatiotemporal variations of the heat injury in the MLRYR during 1961-2011, and the relationship between heat injury hazard and air temperature was analyzed to identify the response of hazard to climate change. It was found that the heat injury hazard of single-cropping rice was positively correlated with the mean and maximum temperatures during the rice heading period of 20 days, with the hazard increasing sharply when the mean temperature exceeded 26.5°C and the maximum temperature exceeded 31°C. Then, exposure, vulnerability, and disaster prevention/mitigation capacity were also quantitatively examined. The results show that vulnerability and hazard were the two most important factors in the heat injury risk assessment for single-cropping rice at most stations in the MLRYR.The risk assessment considering only the first three natural elements produced high-risk values (> 0.46) mainly in the northeast of the study area. By adding the regional capability in disaster prevention/mitigation into account, the risk assessment produced high-risk values in a much smaller area in the northeast but some-what larger areas in the southwest of the study domain. In general, the risk of heat injury differed greatly within the MLRYR. Particular rice varieties should be adopted for specific regions, according to the local risk features quantified by this study. Under the warming climate, the risk of heat injury for single-cropping rice is likely to continue to increase. 相似文献
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Despite decades of research and interventions, crop yields for smallholder farmers across sub-Saharan Africa are dramatically lower than in developed countries. Attempts to address low yields of staple crops in Africa since the Green Revolution through policies and investments in advanced seed cultivars have had mixed results. Numerous countries have heartily embraced and promoted hybrid cultivars through government subsidy programs and investments in research and seed multiplication. One possible explanation for why these programs have not resulted in more significant yield improvements is the challenge faced by farmers to select cultivars that are suited to their local environmental conditions. The question of what seeds farmers choose is exceptionally complex as it is often affected by local seed availability, the availability of information on seed performance, and the transfer of that information to farmers. At the foundation of this choice are farmers’ perceptions of different seed varieties coupled with their perceptions of climate variability. We examine seed choice in Zambia, a country with decades of hybrid maize seed development and supporting policies. We demonstrate how input subsidy programs and seed market liberalization have led to choice overload and a discontinuity in information exchange between farmers and seed companies. The decision making environment is further complicated by the heterogeneity in growing conditions and its variable impact on seed performance, which complicates characterization of seed duration at the farm level. Perceptions and biases related to climate variability effect seed choice, and potentially lead farmers to make risk averse decisions, which ultimately depress maize yields. 相似文献