野生稻优良基因资源的研究与应用进展

野生稻是栽培稻的野生近缘种,作为重要的基因资源,具有诸多的优良性状,如野生稻对病虫害的抗性、对各种逆境的耐受性以及胞质雄性不育等,已被广泛应用于现代栽培稻的育种改良,成为栽培稻遗传改良的丰富基因源和不可替代的物质基础。本文综述了野生稻优良基因的发掘和种质资源的利用现状,总结了野生稻保护和利用目前存在的问题,并对其在水稻育种中的应用潜力做出了展望。     

野生稻抗性基因的发掘、定位与利用研究进展

野生稻是现代栽培稻的祖先,几万年前古人类就开始将野生稻逐步驯化成现代栽培稻。但在野生稻驯化成栽培稻过程中,约有1/3的等位基因和1/2的基因型丢失了,其中包括抗病、虫、杂草、抗逆境基因和高产优质等大量特异基因。文章综述了近年来在野生稻抗病性(稻瘟病、白叶枯病、细菌性条斑病),抗虫性(稻飞虱、三化螟、稻纵卷叶螟),抗逆境(耐冷性、耐旱性、耐低磷)以及野生稻种质资源在水稻育种上利用的研究进展。     

中国野生稻种质资源利用与保护

野生稻是栽培稻的近缘野生种，可为栽培水稻育种提供重要的抗病、抗虫、耐旱、耐寒等抗逆基因，是水稻品种改良的宝贵基因库。随着工业化、城镇化进程加快及气候环境变化，野生稻居群数量和分布面积正急剧减少，野生稻种质资源的损失难以估量。虽然近年来我国野生稻种质资源利用与保护工作取得积极成效，但仍存在一系列问题。本文系统总结了野生稻种质的优异基因发掘、育种应用以及资源保护方面取得的重要进展，并综合分析目前保护管理中存在的问题，针对性的提出未来野生稻保护与利用的相关建议。     

利用分子育种技术改良水稻稻瘟病抗性

为选育具有稻瘟病持久抗性的水稻新品系提供可利用资源,1993 年以小粒野生稻为外源DNA供体,采用花粉管通道法,将其稻瘟病抗性导入栽培稻24D中。经过4 年连续6 代的选择,成功地将小粒野生稻稻瘟病抗性转移到栽培稻中,获得了9 份苗叶瘟和穗颈瘟均得到改良的抗性材料。因此,利用分子育种技术改良水稻抗病性是可行的。     

海南普通野生稻与栽培稻的营养品质比较

对海南普通野生稻与栽培稻稻米营养品质特征进行了比较分析,结果表明,不同居群普通野生稻蛋白含量都在10%以上,极显著高于栽培稻;不同居群野生稻总淀粉含量变化无规律,但直链淀粉含量都显著低于栽培稻;海南普通野生稻中钙、镁、锌和铁含量普遍显著高于栽培稻,这说明海南普通野生稻含有高蛋白、低直链淀粉和高营养元素的遗传资源。研究结果可为优异野生稻资源挖掘和利用及优质稻育种研究提供参考。     

栽培稻与野生稻杂交花培创新种质的研究

对栽培与野生稻杂交后代进行花药培养，在药得的芬粉植株中，经农艺性状和抗病性鉴定，筛选出一批具有野生稻抗病性强，米质优特性，又具有栽培稻丰产性的稳定品系。研究表明，栽野稻杂交花培育种技术是克服栽野稻杂交后代稳定难，育种周期长和加速野生稻优异资源利用的有效途径。     

利用非洲长雄野生稻改良栽培稻的耐盐性

为了研究水稻的耐盐性，本研究通过测试5个长雄野生稻（Oryza longistaminata）的耐盐性，发现材料E11-9苗期耐盐性显著优于耐盐品种韭菜青。利用长雄野生稻E11-9对亚洲栽培稻海南红米进行耐盐性改良，创制了1个苗期至孕穗期耐盐性明显增强的株系CXZH，表明非洲长雄野生稻E-119在改良亚洲栽培稻耐盐性方面具有实际应用价值。     

对国际热带农业研究所收集的稻属种的柱头外露性状的研究（英文）

 为筛选柱头高度外露的稻种资源用于培育柱头外露率高的新雄性不育系,提高杂交稻制种产量,我们在位于尼日利亚伊巴丹市的国际热带农业研究所对非洲稻种资源,包括二个栽培种、三个野生种及一个杂草类型,共2065份种质进行柱头外露性状的观察。结果表明。每穗柱头外露率高(≥%)的种质的百分数从高到低依次为:斑点野生稻(100%)>长药野生稻(85.7%)>非洲栽培稻(54.9%).>巴蒂野生稻(34.8%)>杂草型 stapfii(20%)>亚洲栽培稻(1%)。在1787份亚洲栽培稻中筛选出18个柱头高度外露的种质可考虑作为培育异交率高的水稻雄性不育系的亲本。本文还分析讨论了柱头外露种质的遗传及其地理分布。     

水稻种质资源遗传多样性保护和利用研究进展

种质资源是作物优良基因的载体,切实保护现有保存种质资源的遗传多样性,努力推进改良创新利用是当前乃至长远种质资源研究工作的主要内容,也是实施农业可持续发展战略的重要举措.本文介绍了我国水稻种质资源面临的濒临灭绝的形势,提出对其保护的重要意义和措施以及野生稻在水稻育种方面应用的情况和对野生稻种质资源利用前景的展望.     

云南药用野生稻的高光效特性

云南药用野生稻由于原生境生态类型的多样性,在长期自然进化中形成了丰富的遗传多样性,具有许多优异性状,是改良和拓宽栽培稻遗传基础的宝贵基因资源。针对药用野生稻生长势强、生物量积累速率快的性状,对云南药用野生稻的光合特性进行了研究。结果发现,与其他两种野生稻和两种栽培稻相比,云南药用野生稻净光合速率较高,特别是羧化效率和光饱和点均为其余品种的2倍以上,具有高光效潜能,为发掘其中的高光效基因提供了依据。     

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.     

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。     

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.     

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。     

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.