枇杷试管苗2个CAT基因成员的克隆及表达分析

以早钟6号枇杷试管苗叶片为试验材料,采用同源克隆方法从叶片mRNA中分离得到CAT基因的2个成员Ej-CAT1和Ej-CAT2,Ej-CAT1 cDNA序列全长1 738 bp,包括1 479 bp ORF和257 bp 3′-UTR;Ej-CAT2序列全长1 742 bp,包含1 479 bp ORF及261 bp 3′-UTR。2个CAT基因成员的核苷酸序列相似性为98.04%,其开放阅读框推导的氨基酸序列具有97.32%的相似性。生物信息学分析结果表明:2个蛋白均编码492个氨基酸,是亲水蛋白,不含信号肽,不存在螺旋卷曲结构,是非跨膜蛋白,亚细胞定位于过氧化物酶体;Ej-CAT1及Ej-CAT2蛋白分别有18、17个功能位点,22、19个磷酸化位点。CAT基因在枇杷试管苗离体保存过程中不同时期具有不同的表达量,整体趋势呈"W"形状,在离体保存1个月时表达量最高,保存7个月时表达量最低。CAT表达量变化可能跟枇杷试管苗的生长发育模式有关。     

香青兰的离体保存研究

以香青兰为试材,研究不同养分水平培养基,不同浓度甘露醇、多效唑及琼脂对试管苗离体保存的影响.结果表明:1/4MS培养基中试管苗前期存活率较低,但保存时间延长了4个月以上:甘露醇对试管苗的生长有抑制作用,可延长试管苗存活时间4个月；多效唑能促进香青兰试管苗侧芽分化,但对试管苗茎的伸长有明显抑制作用,其中浓度为2.0 mg/L时试管苗存活率最高,保存时间可延长4个月,保存至9个月时,存活率达到50％；MS培养基中附加琼脂浓度8.5～10.5 g/L为香青兰最佳离体保存方法,该条件下香青兰试管苗保存时间明显延长,保存12个月时存活率仍高达85 ％～60％,且试管苗恢复生长后长势良好,其再生后代的形态特征与对照株无差异.     

山药组培快繁条件优化的研究

以漳州云霄毛山药试管苗为试验材料,研究不同的转接材料、培养方式和激素配比对其试管苗快速繁殖的影响。结果表明:以不带微型块茎的茎段最适合试管苗继代增殖的转接材料,液体培养更有利于山药试管苗的增殖和芽苗生长;不同的激素配比继代培养基中以改良MS+TDZ0.1 mg·L~(-1)+NAA0.1mg·L~(-1)组合更适合山药试管苗的快繁,增殖系数为8.56,植株生长健壮。     

甘蔗无根试管苗光合自养生根过程中叶片生理生化特征的变化

甘蔗光合自养生根技术是一种新型的试管苗生根方法,比传统的培养基异养生根法有显著优势。为了揭示甘蔗生根的生理生化机理,为完善其生根技术提供理论依据。本研究以甘蔗栽培品种桂糖44号无根试管苗为材料,喷施ABT2号生根粉溶液后移栽于沙土混合基质中,在普通日光温室进行自养生根。在生根过程中连续采样调查试管苗生根率和生长状态,检测叶片中总叶绿素、碳水化合物(蔗糖、可溶性糖)、三大内源激素(IAA、ABA、CTK)含量和过氧化物酶(POD)活性。结果表明,由于环境改变,试管苗受到环境胁迫,致使叶片先微黄后转绿,7 d后老叶变黄衰老,新叶开始长出,并与日俱增;第一批不定根在处理后第5天突破表皮,至第9天100%的试管苗完成不定根的再生。叶绿素含量先减少后增加而后下降,9 d后跳跃上升;蔗糖、可溶性糖含量先是呈波动上升后急剧下降再跳跃上升;ABA含量和POD活性先上升后下降;IAA和CTK含量则相反,先下降后上升。从试管苗生长状态和生理生化指标变化规律分析,本研究发现甘蔗试管苗光合自养生根过程分为3个阶段,第一阶段在0~7 d,为试管苗适应期;第二阶段在7~9 d,为试管苗异养自养切换期;第三阶段在9~15 d,为试管苗自养能力恢复期,试管苗成功过渡到自养阶段是试管苗获得高存活率的必要条件。     

延长马铃薯种质资源低温保存条件的探究

试管苗离体保存是马铃薯目前应用最广泛的种质资源保存方法,探究延长试管苗继代周期的保存条件可以有效减少风险并降低保存成本。从实验室种质资源库中挑选了6个不同基因型的马铃薯材料,以植株状态、株高和存活率作为指标,探究不同预生根处理、保存温度、培养基蔗糖浓度和继代方式对马铃薯试管苗保存的影响,以探索广泛适用于马铃薯试管苗长期低温保存的条件。不进行预生根处理的试管苗在低温保存的第60 d几乎不生长,随后死亡,说明预生根处理是试管苗低温保存的必要条件。4℃条件下试管苗的生长比7℃更缓慢,在第90 d时的株高明显更小,4个材料的试管苗存活率仅为53.75%,而7℃条件下存活率为100%,说明7℃更适于不同基因型马铃薯种质资源的低温保存。8%蔗糖浓度培养基中的试管苗在第90 d时的株高明显低于4%蔗糖浓度,存活率统计显示4%蔗糖浓度培养基中的试管苗在7℃保存第270 d时全部死亡,8%蔗糖浓度培养基中的试管苗存活率达到61.25%,表明8%蔗糖浓度能明显延长马铃薯试管苗的低温保存时间。由此可见,可以采用8%蔗糖浓度培养基和7℃环境温度用于大部分马铃薯株系的长期低温保存。此外,探究了一种试管苗-组培盒...     

马铃薯试管苗组织培养及微型薯诱导技术的研究

通过加入不同浓度的BA、NAA和KT,以探讨外源激素对马铃薯试管苗生理性状的影响,发现低浓度的外源激素较适合用来进行试管苗的增殖。本试验利用香豆素进行微型薯的诱导,结果表明低浓度的香豆素对提高薯重和大薯率有利,而高浓度有利于提高微型薯的结薯数量。     

马铃薯脱毒苗培养过程中内源激素变化规律研究

在马铃脱毒试管苗培养过程中 ,对其生长发育特性进行观察及对内源激素进行测定 ,结果表明 :在培养的 30d内 ,随着植株高度、数、根长、根数、茎叶干重及根干重的不断增加 ,内源激素也呈现有规律变化 ,ABA在培养至 2 0d达峰值 ,以后均保较高含量水平 ;CTK在培养前 2 0d含量基本不变 ,2 0～ 30d含量剧增 ;而IAA在培养的 30d内 ,含量是不断增加的     

马铃薯试管薯诱导因子研究

以马铃薯栽培品种Favorite、Atltantic和克新 1号脱毒试管苗为材料 ,着重研究了离体条件下外源激素、碳源以及活性炭对试管薯形成和发育的影响。结果表明 :①加入一定浓度的外源激素 ,利于提高试管薯的产量和质量 ,其诱导效应依次为BA >BA +CCC >CCC >无外源激素 ;②诱导试管薯对碳源纯度要求不高 ,食用白糖替代蔗糖完全可能 ;③活性炭能够明显提高试管薯前期的形成和发育。     

马铃薯脱毒试管薯工厂化生产技术及应用研究

研究明确了2倍MS培养基培育健壮母株是提高试管薯的结薯率和单薯重的基础。不同激素与配比对试管薯诱导的效果有很大差异,明确了BA是诱导试管薯的重要激素之一。利用试管薯繁殖原原种较试管苗直接移栽,显著提高了单株块茎数和产量。试验结果证明,直接利用试管薯有利于工厂化生产和原原种的繁殖。     

马铃薯休眠阶段中内源激素变化的研究

实验以早熟马铃薯品种费乌瑞它(Favorita)和中熟品种夏波蒂(Shepody)的脱毒试管苗为材料,诱导结薯,研究离体块茎在休眠与萌芽过程中不同时期的内源激素GA3,KT,IAA和ABA含量的变化。结果表明:①KT,GA3,IAA,三种激素含量随着休眠的解除呈明显上升趋势;②ABA的含量甚微,品种费乌瑞它仅在第一时期及品种夏波蒂仅在第一和第二时期检测出微量,此后均未检出,可见ABA的含量呈下降趋势。     

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.     

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.     

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。     

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.     

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.     

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。     

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。