高温对杂交水稻制种扬花授粉的影响及应对措施

高温对杂交水稻制种扬花授粉影响严重,在实践中,观察到高温天气下杂交水稻制种扬花授粉期亲本的异常特征,并提出了几点针对性的措施。     

谈谈杂交稻制种中提高结实率的几个问题

本文调查分析了杂交稻制种母本异交结实率与割剑叶、喷“九二○”、天气状况、父本花粉量等因素的关系，提出了提高结实率的技术措施，即调准播差期达到花期相遇，选择最佳扬花授粉时段，轻割剑叶，科学施用“九二○”，搞好人工辅助授粉等。     

降低丰源A系列组合种子裂颖率的制种技术探讨

丰源A系列组合种子裂颖率较高.实践表明,选择粘壤土质基地,确保父母本花期花时相遇,安排最佳天气时段扬花授粉,合理施肥,科学管水,适时喷施"九二○",防治好病虫,能有效降低种子裂颖率.     

分宜县1200亩协优辐26春制亩产250公斤

分宜县历年６月底前后，为多晴少雨天气，日均温２８℃，相对温度８０％，有利扬花授粉，辐２６恢复系第一期于４月８日播，二期于 ４月１６日播，母本于４月２３日播，花期相遇良好，获得大面积亩产２５０公斤。     

优质杂交粳稻滇杂31高产制种技术

介绍了杂交粳稻滇杂31的亲本榆密15A和南34的特征特性；提出选择适宜的制种地域和最佳扬花授粉期、合理安排父母本播种差期、培肥父本、增加母本有效穗和颖花数、适时适量喷施“九二○”是滇杂31高产制种的关键技术。     

徐68优201亲本特征特性及高产制种技术要点

介绍了江苏徐淮地区徐州农科所优质高产多抗三系杂交粳稻新品种徐68优201的选育过程及其父母本的特征特性。通过在制种过程中合理安排播期,建立高产群体,定量施肥,定期观察记载生长发育进程并灵活运用合理措施调节花期、选择最佳扬花授粉时间等提高制种产量。     

两系超级杂交稻新组合P88S/0293制种高产原因分析

2004年超级杂交稻新组合P88S/0293在湖南麻阳制种8.07 hm2,平均单产3 223.7 kg/hm2,解决了该组合制种产量低的难题.从技术角度分析了该组合制种高产的5点原因,即育性转换和扬花授粉期间天气较好;花期相遇理想;双亲群体较协调;异交结实率较高;病虫危害损失较轻.     

湘双季稻区气候特点与两系杂产稻秋季制种技术

分析了湘南地区的气候特点与两系杂交稻制种季别的关系,认为湘南双季稻区两系杂交稻制种以发展和制为宜,秋制不育系育性转换敏感期安排以８月上旬为最佳抽穗扬花授粉可安排在８月１６日－９月５日之间,以８月下旬为优,对两系杂交稻秋季制种主要技术进行了总结。     

湘南双季稻区气候特点与两系杂交稻秋季制种技术

分析了湘南地区的气候特点与两系杂交稻制种季别的关系,认为湘南双季稻区两系杂交稻制种以发展秋制为宜。秋制中不育系育性转换敏感期安排以８月上旬为最佳,抽穗扬花授粉期可安排在８月１６日～９月５日之间,以８月下旬为优。对两系杂交稻秋季制种主要技术进行了总结。     

杂交晚稻必须防御秋寒危害

防御秋寒对杂交晚稻的危害很重要，秋寒影响抽穗扬花、授粉受精和灌浆结实，影响根系对养分的吸收。防御低温危害除选用抗寒杂交组合、合理安排播期、育壮秧等基本措施外，在低温侵袭前后及危害期间，还必须采取一些应急措施，如灌水增温、喷面水调温、人工授粉、施草木灰、喷叶面肥、喷“九二○”等。     

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.