苎麻抗旱性基因型差异的农艺性状及形态解剖特征

采用大田旱棚、盆栽干旱胁迫及室内渗透胁迫相结合的方法对苎麻代表基因型从地下部形态特征、农艺性状、生物产量和经济产量等方面进行了抗旱性鉴定 ,首次用抗旱指数等指标鉴定出了同类根型苎麻基因型间抗旱性存在差异 ,中根型中也有较深根型抗旱性强的基因型 ;一龄麻、二龄麻抗旱性综合评定为 :圆叶青、沅江黄壳早为抗旱性基因型 ,沅江稀节巴为中抗基因型 ,资兴绿麻和新宁箭杆麻为不抗旱性基因型 ;三龄麻抗旱性综合评定为 :沅江黄壳早 ,沅江稀节巴为抗旱基因型 ,新宁箭杆麻为不抗基因型 ,其它如资兴绿麻、宜章雅麻、宜章绩麻为中抗基因型。与抗旱性弱的基因型比较 ,在干旱胁迫下 ,抗旱性强的基因型地下部体积、干重均较大 ,叶片棚栏组织厚度 /叶片厚度的比值高 ,各项农艺性状和干物质积累下降少 ,抗萎蔫能力较强     

苎麻抗旱性基因型差异的农艺性状及形态解剖特征

采用大田旱棚、盆栽干旱胁迫及室内渗透胁迫相结合的方法对苎麻代表基因型从地下部形态特征、农艺性状、生物产量和经济产量等方面进行了抗旱性鉴定，首次用抗旱指数等指标鉴定出了同类根型苎麻基因型间抗旱性存在差异，中根型中也有较深根型抗旱性强的基因型；一龄麻、二龄麻抗旱性综合评定为：圆叶青、沅江黄壳早为抗旱性基因型，沅江稀节巴为中抗基因型，资兴绿麻和新宁箭杆麻为不抗旱性基因型；三龄麻抗旱性综合评定为：沅江黄壳早，沅江稀节巴为抗旱基因型，新宁箭杆麻为不抗基因型，其它如资兴绿麻、宜章雅麻、宜章绩麻为中抗基因型。与抗旱性弱的基因型比较，在干旱胁迫下，抗旱性强的基因型地下部体积、干重均较大，叶片棚栏组织厚度/叶片厚度的比值高，各项农艺性状和干物质积累下降少，抗萎蔫能力较强。     

苎麻品种抗旱性早期鉴定研究

本文首次用抗旱指数等指标对苎麻基因型抗旱性进行了鉴定。结果表明：圆叶青,沅江黄壳早和沅江稀节巴为抗旱性较强的基因型,抗旱性较弱的基因型包括次兴绿麻和新宁箭杆麻。     

苎麻品种抗旱性早期鉴定研究

本文首次用抗旱指数（ Ｒ Ｉ） 等指标对苎麻基因型抗旱性进行了鉴定。结果表明：圆叶青、沅江黄壳早和沅江稀节巴为抗旱性较强的基因型, 抗旱性较弱的基因型包括资兴绿麻和新宁箭杆麻。苎麻抗旱性早期鉴定的途径和指标的研究结果表明： Ｒ Ｗ Ｃ（ 相对含水量） 、 Ｐ Ｏ Ｄ（ 过氧化物酶） 、 Ｐｒｏｉｎｅ（ 脯氨酸） 与抗旱指数呈正相关, 而 Ｒ Ｐ Ｐ（ 细胞膜透性） 、 Ｍ Ｄ Ａ（ 丙二醛） 则与抗旱指数呈负相关。苎麻扦插（４５ 天） 苗在渗透胁迫４ 小时测定相关生理生化指标,其中 Ｒ Ｗ Ｃ 、 Ｐｒｏｌｉｎｅ 和 Ｐ Ｏ Ｄ 活性与抗旱指数呈正相关,而 Ｒ Ｐ Ｐ 和 Ｍ Ｄ Ａ 则与抗旱指数呈负相关, 采用模糊隶属法用上述五种生理生化指标对１３ 个基因型抗旱性进行了早期鉴定,此法简便有效,准确性高。     

不同基因型苎麻叶片脯氨酸积累差异研究

在干旱胁迫下,苎麻叶片游离脯氨酸积累存在基因型差异。在干旱胁迫较轻时,抗旱性弱的基因型积累游离脯氨酸多于抗旱笥强的基因型,而随着胁迫加强,抗旱性强的基因型游离脯氨酸积累强度大于抗旱性弱的基因型。苎麻幼苗,一龄麻,二龄麻上表现基本一致。     

不同基因型苎麻叶片脯氨酸积累差异研究

在干旱胁迫下，苎麻叶片游离脯氨酸积累存在基因型差异。在干旱胁迫较轻时，抗旱性弱的基因型积累游离脯氨酸多于抗旱性强的基因型，而随着胁迫加强，抗旱性强的基因型游离脯氨酸积累强度大于抗旱性弱的基因型。苎麻幼苗、一龄麻、二龄麻上表现基本一致。复水后，游离脯氨酸积累下降，但下降速度存在基因型差异，抗旱性强的基因型下降快，抗旱性弱的基因型下降较慢。     

苎麻抗旱性基因型差异及其生理生化机理研究

同类根型的苎麻基因型抗旱性存在显著差异。在干旱胁迫下，抗旱性强的基因型叶片相对含水量、水势和细胞膜的稳定性高，苎麻叶片游离脯氨酸积累的过氧化物酶活性对干旱胁迫的反应存在基因型差异，随着干旱胁迫加强，抗旱性强的基因型过氧化物酶活性从低到高，而抗旱性弱的基因型则相反。在干旱胁迫０￣１２天内，抗旱性弱的基因型积累游离脯氨酸多于抗旱性强的基因型，而随着胁迫加强（干旱１２￣２４天），抗旱性强基因型游离脯氨酸     

苎麻抗旱性基因型差异及其生理生化机理研究

同类根型的苎麻基因型抗旱性存在显著差异。在干旱胁迫下，抗旱性强的基因型叶片相对含水量、水势和细胞膜的稳定性高，苎麻叶片游离脯氨酸积累和过氧化物酶活性对干旱胁迫的反应存在基因型差异，随着干旱胁迫加强，抗旱性强的基因型过氧化物酶活性从低到高，而抗旱性弱的基因型则相反。在干旱胁迫0－12天内，抗旱性弱的基因型积累游离脯氨酸多于抗旱性强的基因型，而随着胁迫加强（干旱12－24天），抗旱性强基因型游离脯氨酸积累强度大于抗旱性弱的基因型，这可能是苎麻通过积累游离脯氨酸来抵抗逆境的一种积极反应模式。     

苎麻种质资源抗花叶病鉴定研究

1986—1990年对943份苎麻种质资源进行了田间抗花叶病鉴定,鉴定出无病材料有沅江肉麻、青脚麻、黄壳红等29份;占鉴定材料的3.08%;抗病材料有大叶白、青家麻、龙泉青麻等178份,占鉴定材料的18.88%;其中如红皮小麻、玉山麻等一些种质是具有良好农艺性状的抗源材料,可供生产或育种利用。     

苎麻品种圆叶青不同生育期抗旱性差异研究

采用盆栽干旱胁迫方法对苎麻品种圆叶青不同生育期抗旱性差异进行了研究,结果表明:在干旱胁迫下,苎麻品种圆叶青农艺性状、干物质积累和产量的胁迫指数均以苗期>工艺成熟期>旺长期,旺长期是苎麻品种圆叶青干旱胁迫敏感期。     

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.