水稻温敏型两用核不育系繁殖存在的问题及解决办法

水稻两用核不育系冷水串灌繁殖和海南冬繁存在安全性差、产量不高不稳、种子质量差等问题,已严重影响到两系法杂交水稻的健康发展.利用全国740个气象站点近50 a的历史气象资料,根据水稻两用核不育系育性敏感期可育和抽穗扬花期安全对温度的要求,运用计算机处理技术,研制出不同不育起点温度水稻两用核不育系最佳繁殖基地和时段的计算机决策系统,根据该系统筛选出不育起点温度为22℃的水稻两用核不育系最佳繁殖基地为云南省保山市,最佳育性敏感始期为8月3日.2010年在云南省保山市对不育起点温度为22℃的C815S进行了大面积繁殖,获得8.44 t/hm2的高产.介绍了在低纬度高海拔地区繁殖水稻两用核不育系所具有的优势和应注意的事项.     

籼型水稻温敏核不育系宣69S海南异地冬繁高产技术研究

宣69S是安徽省宣城市农业科学研究所于2002年育成的籼型温敏核不育系？该不育系在海南三亚地区异地冬繁，其生育期长短受年度间温度高低影响，繁殖产量受育性转换敏感期高温或抽穗扬花期低温影响。从基地选择、适期播种、培育壮秧、合理稀植、科学水肥管理、病虫害防治、严格除杂等方面探讨了其高产繁殖技术。     

培矮64S和K1405S春季冷灌繁殖技术探讨

培矮６４Ｓ和Ｋ１４０５Ｓ分别是湖南杂交水稻研究中心和广西农科院新育成的低温敏核不育系，均已通过省级鉴定。低温敏核不育系的繁殖是比较困难的，首先是育性转换临界温度较低，与生物学下限温度幅差小，育性恢复后易遭到致害温度的影响，结实率不高。其次是适宜正常开花结实的温度高于育性转换临界温度，繁殖需要的前低后高的气温模式在自然条件下是较难找到的。第三是育性转换温度较低，繁殖期间气温略为偏高不育花粉增加，影响结实。为了探讨低温敏核不育系的繁殖技术，加快该不育系的开发应用，笔者在１９９７年对该不育系进行了认真…     

光温条件对北方粳稻光温敏核不育系LY156S育性转换的影响及其育性鉴定技术探讨

通过对不育系应用区域气象条件的分析,选择不同光温条件处理北方粳稻光温敏核不育系LY156S,研究光温变化对其育性转换的影响及育性鉴定方法。结果表明,在不育系制种区域辽宁盘锦,2011—2017年的7—8月日平均温度大于23℃,最低温度为20℃,低于23℃的天数较少,适合临界温度为21℃左右的两系不育系制种;在不育系繁殖地区海南三亚,2011—2017年冬季低于20℃天数较少,且比较分散,较适合两系不育系繁种。在长日照14.5h低温处理下,不育系的抽穗期滞后,22和21℃处理下育性没有恢复,但20和19℃处理花粉不育度降低到82.36%和78.45%,育性发生了转换。在日照长度为11.5和12.5 h条件下,22和24℃处理的育性均得到恢复;在日照长度为13.5 h条件下22和24℃处理的花粉不育度仍都大于99.5%,育性没有恢复。为提高北方粳稻光温敏核不育系应用的安全性,北方粳稻光温敏核不育系育性鉴定在《水稻光、温敏雄性核不育系育性鉴定规程》(NY/T 1215—2006)的基础上,可将14.5 h长日照条件下的处理温度降至21℃,11.5、12.5和13.5 h等短日照条件下的处理温度降低至22℃,以提高不育系的育性鉴定准确性与应用价值。     

优质水稻低温敏核不育系潭农S的选育与应用

潭农S是用株1S与中鉴100杂交转育而成的水稻低温敏核不育系。该不育系早熟性好,分蘖力强,植株矮壮,穗大粒多,株叶型好,稻米品质优,配组优势强。不育起点温度22℃以下,不育期不育株率和花粉不育度均为100%,表现为典败或无花粉型败育,可育期自交结实率42%左右。开花习性好,柱头外露率高,制种产量高,2007年2月通过湖南省农作物品种审定。     

两系法杂交水稻研究和应用中若干问题的思与行

指出了当前我国两系法杂交水稻研究和应用中面临的主要问题,即两系法杂交水稻体系中不育系的称谓和分类不规范,生产上利用的水稻两用核不育系育性温光反应特性研究不清楚,水稻两用核不育系繁殖和两系法杂交稻制种基地选择不当等。针对当前情形,结合多年育种实践,提出了解决这些问题的对策及措施。建议将水稻两用核不育系分为长光高温不育型、高温不育型、短光低温不育型、低温不育型等四种类型。提出了水稻光温不育机理设想,即水稻光温敏核不育系育性转换是主效不育基因与其位置相近的发育感光基因或(和)发育感温基因相互作用的结果,微效不育基因可影响两用核不育系的不育起点温度。只有深入研究光温敏型不育系育性的光温组合效应,且获得具体的光温指标,才能更好地指导两系法杂交水稻制种和不育系繁殖。提出了水稻两用核不育系育性光温特性的鉴定方法以及两系法杂交稻种子生产应根据不育系育性温光特性和历史气象资料来合理安排基地和时段。     

水稻温敏核不育系株1S及其衍生系育性对低温的敏感性差异比较研究

以株1S及其9份衍生温敏核不育系为材料,并以大面积应用的温敏核不育系Y58S(CK1)、广占63-4S(CK2)为对照,在育性转换敏感期分别设置17.0、18.0、18.5、20.0、21.5、23.0和23.5℃共7个日均温冷水处理8 d,研究不同温敏核不育系育性对低温的敏感性差异。结果表明,湘陵628S、隆科638S、晶4155S和隆臻36S的不育起点温度低于23.0℃,华玮338S、华悦468S、华炫302S、腾晖191S、振湘S和Y58S的不育起点温度在23.0～23.5℃之间,广占63-4S的不育起点温度高于23.5℃;12份温敏核不育系的最佳繁殖温度均为日均温21.5℃;隆科638S、晶4155S、隆臻36S、华玮338S、华悦468S、华炫302S和Y58S的生理不育温度接近17.0℃,株1S、湘陵628S和广占63-4S生理不育温度在17.0～18.0℃之间,腾晖191S和振湘S的生理不育温度高于18.0℃;隆科638S、晶4155S、隆臻36S、华玮338S、华悦468S、华炫302S和Y58S在育性转换敏感期耐低温能力强,可繁性好。本研究为温敏核不育系的繁殖及杂交稻安全制种提供了指导。     

两系杂交早稻苗头组合海南早春大棚增温制种技术研究

以276S/R1019为材料,在两用不育系育性敏感期采用塑料棚增温处理,促使两用不育系育性转换,探索两系杂交早稻苗头组合海南早春少量制种可行性。结果表明:在海南三亚腾桥2月中下旬,棚区内日平均温度增至23.0~26.5℃,比同期自然温度提高3.5~4.1℃,达到了温敏不育系276S表达完全不育的温度条件;经育性敏感期26 d增温处理,镜检花粉不育度为99.1%~100%,套袋自交结实率为0.044%,异交结实率为26.4%,可以实现两系杂交早稻苗头组合海南早春少量制种。     

广东省实用型水稻低温敏核不育系选育技术

根据广东省的生态条件和耕作制度,确定了广东省应以选育起点温度＜23.5℃的低温敏型两用核不育系为主的育种方向,总结了一套"广州-乳源-三亚"穿梭育种的低温敏核不育系选育程序,可使不育系选育进程每年增加2个世代,并据此选育出GD-1S等一批低温敏核不育系.     

萍乡显性核不育水稻临界温度值及其温度敏感期的研究

利用人工气候箱研究了萍乡显性核不育水稻临界温度值及其温度敏感期。试验结果表明高温诱导萍乡显性核不育水稻纯合不育株和杂合不育株育性转换的临界值均为27℃～ 28℃, 说明高温诱导萍乡显性核不育水稻育性转换不存在显性不育基因的剂量效应; 萍乡显性核不育水稻育性转换温度敏感期在花粉母细胞形成期至减数分裂期, 即抽穗前18～ 12 d;同时, 讨论了该不育材料的实际应用问题。     

Factors in the Reduction in Grain Number in Winter Wheat by Early-Sowing in Yamaguchi

Abstract

Grain number per spike of wheat is lower in early sowing than in the conventional standard cultivation in Yamaguchi, Prefecture, Japan. Components of the grain number per spike in five cultivars were analyzed with respect to temperature during the spike development period throughout three growing seasons 2001/2002, 2002/2003 and 2003/2004 to find the cause of the problem of early sowing cultivation. The plants sown in early-October and late-November were called the early sown group and the standard group, respectively, in the following. Three of the five cultivars, Hokushin, Akitakko and Nanbukomugi, showed a strong winter habit, which requires very cold temperatures for spike differentiation. The other two cultivars, Iwainodaichi and Airakomugi, had a moderate winter habit. Grain number per spike and grain yield were decreased by early-sowing (compare with the standard group) in almost all cultivars throughout the three growing seasons. The three cultivars which had a strong winter habit had fewer spikelets per spike in the early-sown group than in the standard group. The other two cultivars which had a moderate winter habit had fewer grains per spikelet in the early-sown group. The higher the temperature during the spikelet formation phase, which is from flag leaf initiation to terminal spikelet initiation, the higher the number of spikelets per spike in the standard group. The spikelet number per spike in the early-sown group increased with the increase in productive tillers under fertile conditions. Such conditions also increased the grain number per spike.     

Allelopathy in Agroecosystems in Spain

Summary

This paper reviews the effects of allelopathic interactions in agroecosystems in Spain on plant physiological activity and their ecological advantages. The phenological stage of growth of donor plants and the effective allelochemicals in the soil solution while studying the role of phenolic compounds were highlighting. Finally possible future prospects and conclusions regarding weed control by allelochemi-cals under integrated crop management strategies are discussed.     

我国干热区甘蔗抗旱植蔗主要问题研讨

我国干热蔗区是我国甘蔗糖业的重要生产基地,蔗区光热资源丰富,唯降水分布不均成为植蔗生产的主要限制因子;根据蔗区植蔗特点和甘蔗需水规律,苗期抗旱是干热蔗区抗旱植蔗的关键,保证较多的总苗数和足够的生长量是苗期抗旱植蔗需解决的关键技术难题,制定相应的苗期抗旱植蔗栽培技术措施是解决该难题的重要保障;该观点为我国干热蔗区植蔗生产、甘蔗引育种提供理论和技术支持。     

Diurnal changes in net photosynthetic rate in potato in two environments

Summary Diurnal changes in net photosynthetic rate were measured in a furrow-irrigated potato crop and in a riverbed crop where the water table was always maintained at 20–28 cm from the soil surface. In the irrigated crop, the photosynthetic rate during mid-afternoon was about half the peak rate observed at noon. This reduction was accompanied by a near tripling of stomatal resistance, a 45% reduction in transpiration, and a 5-fold increase in the difference between leaf and air temperatures. No such changes were observed in the riverbed crop where the photosynthetic rate remained nearly constant at about 0.9 mg m⁻² s⁻¹ between 9 a.m. and 4 p.m. Tuber yield in the riverbed crop was about 30% higher than in the irrigated crop.     

棉花体细胞无性系变异的研究进展

体细胞无性系变异是一种重要的细胞工程育种技术,其应用于棉花育种的前提是建立高效的组织培养诱导再生植株体系.本文简要综述了棉花离体诱导植株再生研究的现状,重点讨论了棉花体细胞无性系变异的表现、利用方法及机理,提出了当前研究存在的问题并对今后的研究进行了展望.     

2009年中国稻米市场分析及2010年展望

以翔实的资料对2009年中国稻米生产、消费、进出口、供求平衡、库存、价格走势、购销政策和国际稻米供求等情况进行了全面地分析,对影响2010年稻米市场价格走势的各种因素进行了深入研究,并在此基础上对2010年我国稻米市场价格走势进行了预测,结论是我国稻米价格仍呈上行趋势。     

Advances in Variable Rate Technology Application in Potato in The Netherlands

Precision agriculture is a farming management concept based on observing, measuring and responding to inter- and intra-field variability in crops. In this paper, we focus on responding to intra-field variability in potato crops and analyse variable rate applications (VRAs). We made an overview of potential VRAs in potato crop management in The Netherlands. We identified 13 potential VRAs in potato, ranging from soil tillage to planting to crop care to selective harvest. We ranked them on availability of ‘proof of concept’ and on-farm test results. For five VRAs, we found test results allowing to make a cost-benefit assessment. These five VRAs were as follows: planting, soil herbicide weed control, N side dress, late blight control and haulm killing. They use one of two types of spatial data: soil maps or biomass index maps. Data on costs and savings of the VRAs showed that the investments in VRAs will pay off under practical conditions in The Netherlands. Savings on pesticide use and N-fertilizer use with the VRAs were on average about 25%, which benefits the environment too. We foresee a slow but gradual adoption of VRAs in potato production. More VRAs will become available given ongoing R&D. The perspectives of VRAs in potatoes are discussed.     

我国高粱育种研究进展

对我国高粱育种的主要途径和研究方向进行了概述,针对目前高粱产量徘徊现象,提出了高粱超高产育种设想,并对其技术路线进行了探讨。