镉胁迫对3个品种圭亚那柱花草镉积累和矿质养分吸收的影响

利用不同浓度Cd2+溶液对3个品种圭亚那柱花草[Stylosanthes guianensis(Aublet)Swartz]进行不同程度的胁迫处理,以研究镉胁迫对柱花草生长、镉积累和矿质养分吸收的影响。结果表明:在镉胁迫下,3个品种圭亚那柱花草生长均受到抑制,TPRC2001-18(S.guianensis TPRC2001-18)受抑制作用最强,其次是热研10号(S.guianensis cv.Reyan No.10),而热研2号(S.guianensis cv.Reyan No.2)受抑制最弱。在镉胁迫下3个品种柱花草地上部和地下部镉含量均显著增加;镉浓度在1.0～5.0 mg/kg时,3个品种柱花草地上部镉含量从高到低的顺序为热研2号>热研10号>TPRC2001-18。镉胁迫能干扰柱花草对氮(N)、磷(P)、钾(K)养分的吸收。     

西北地区芝麻抗旱性鉴定研究

为探索西北地区在芝麻生殖生长阶段干旱胁迫条件对资源的影响,为我国抗旱品种改良提供亲本,本试验选择山西省农业科学院经济作物研究所为试验点,用中国农业科学院油料作物研究所提供的14 个抗旱资源为试验材料,在芝麻生殖生长阶段进行干旱胁迫处理,调查生育期、出苗率、存活率、株高、叶片数、生物产量、经济产量,进行对比分析。结果显示：干旱胁迫条件下,晋芝1 号、晋芝2 号生殖生长期长,为59 天;幼苗存活率高,为96.6%~100%;株型高大,分别为179.1cm、149.16cm;叶片多,分别为78.3 个、74.8 个;生物产量高,鲜重分别为8.23g、7.61g;干重分别为7.54g、6.82g;经济产量高,晋芝2 号127.50g,晋芝1 号80.0g。表明干旱胁迫不利于芝麻的生长,参试材料中晋芝1 号、晋芝2 号抗旱能力强,可以作为抗旱品种改良的亲本材料和遗传研究的核心材料。     

不同栽培模式对早稻—再生稻头季稻籽粒灌浆特性和ATP酶活性的影响

为了揭示不同栽培措施对再生稻产量的影响,阐明超高产栽培模式实现高产的生理原因,采用超高产栽培模式并以常规栽培模式作为对照进行比较试验,研究不同栽培模式下早稻—再生稻头季稻籽粒灌浆特性和ATP酶活性的变化。结果表明,与常规栽培模式相比,超高产栽培模式头季稻强、弱势粒的生长潜势强,灌浆最大生长速率出现的时间早,灌浆速率在整个灌浆期的前、中、后3个阶段均较高,活跃灌浆时间较短,强、弱势粒较早进入灌浆盛期,同时,整个灌浆期头季稻强、弱势粒的Mg2 -ATP和Ca2 -ATP酶活性超高产栽培模式也都较常规栽培模式的高,尤其是在籽粒灌浆的快速增长阶段,超高产栽培模式的明显高于常规栽培模式,因而其头季籽粒灌浆呈现出灌浆起动快、灌浆强度大、灌浆后期“拉力”足的特点,从而有利于有机物质向穗部运输,这是超高产栽培模式头季实现大穗、多穗、粒饱、结实率高的籽粒灌浆特性和生理原因。     

中国苹果授粉研究现状

苹果是中国最重要的栽培果树,然而目前其单产和优果率较低、果实品质较差,严重制约了中国苹果在国际市场上的竞争力。尽管人工授粉可以提高产量,但目前人工授粉成本不断增加;传粉昆虫对大幅提高苹果产量,尤其增加优质果率方面有着不可替代的作用,但目前自然界传粉昆虫数量严重不足,无法满足苹果产业规模化发展的需求。大力推广蜜蜂、壁蜂授粉技术,深入研究切叶蜂、土中筑巢蜂等苹果野生传粉昆虫的人工驯养技术是确保苹果产业可持续发展的重要途径;同时,科学配置授粉树也是提高苹果坐果率、优质果率、改善苹果品质的关键。本研究综述了苹果花部特征、传粉方式、传粉昆虫种类以及影响苹果授粉效果的因素等,并对今后开展苹果授粉的研究提出了几点建议,以期为提高中国苹果产量和品质提供一些思路。     

不同比例红蓝光对生菜种子萌发及幼苗生长的影响

以罗马生菜种子为材料,研究了6种不同比例的红(R)蓝(B)光质(2R/1B,4R/1B,8R/1B,1R/2B,1R/4B,1R/8B)对生菜种子萌发及幼苗生长的影响。结果表明: 与对照的白光相比,以红光为主的复合光处理(2R/1B,4R/1B,8R/1B)促进种子萌发效果明显,其发芽势、发芽指数和活力指数均显著高于对照。红蓝复合光对生菜幼苗的形态建成、根系活力、叶片色素含量和叶绿素荧光均有促进作用,以红光为主的复合光处理促进效果优于以蓝光为主的复合光处理。在以红光为主的复合光处理中,2R/1B,4R/1B处理对生菜种子萌发及幼苗生长的促进效果优于8R/1B。总之,不同红蓝光比例显著影响了生菜种子萌发及幼苗生长,其中以2R/1B和4R/1B处理最优。     

不同氮磷钾水平对水培生菜产量和品质的影响

为了研究氮磷钾对水培生菜(Lactuck sativa L.var.ramosa Hort.)产量和品质的影响,分别对氮磷钾设置5个浓度梯度,在收获时测定生菜的产量和维生素C、硝酸盐、可溶性糖以及可溶性蛋白等品质指标.结果发现,随着氮素水平从3.0 mmol/L增加到9.0 mmol/L,生菜的产量、维生素C、硝酸盐、可溶性糖以及可溶性蛋白都呈现出先增大后减小的趋势;磷素水平从0.2 mmol/L增加到1.0 mmol/L,生菜的产量和硝酸盐先增大后减小,可溶性糖和可溶性蛋白逐渐增大,维生素C逐渐减少;钾     

不同抗寒性茶树品种秋季新梢的生理特性研究

为了探明茶树品种的抗寒机理,在前期抗寒性茶树品种筛选研究的基础上,选择强抗寒性、中抗寒性和弱抗寒性茶树品种各2份,分别比较了其秋季新梢中过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)和多酚氧化酶(PPO)等抗寒性相关酶的活性,并对可溶性蛋白质、可溶性糖、丙二醛含量等生理生化特性进行测定。结果表明,强抗寒性茶树品种的秋季新梢POD活性和可溶性糖含量较高,而弱抗寒性的茶树品种POD活性和可溶性糖含量较低。可溶性蛋白质含量高低与抗寒性强弱有一定关系,CAT、SOD和PPO活性及丙二醛含量高低与抗寒性强弱之间无明显规律可循。因此,POD活性和可溶性糖含量高低可以作为判断茶树品种或资源新梢抗寒性强弱的鉴定指标。     

Comparative Efficiency of Nitrogen Sources for Lowland Rice Production

Rice (Oryza sativa L.) is the staple food for more than 50% world population and nitrogen (N) is one of the most yield-limiting nutrients for rice production worldwide. A greenhouse experiment was conducted to evaluate the efficiency of three N sources for lowland rice production. The N sources used were ammonium sulfate, common urea, and polymer-coated urea. There were three N rates, i.e. 100, 200, and 400 mg N kg^?1 applied with three sources plus one control treatment (0 mg N kg^?1). Growth, yield, and yield components were significantly increased either in a linear or quadratic fashion with the addition of N fertilizers in the range of 0–400 mg kg^?1 soil. Maximum grain yield was obtained with the addition of ammonium sulfate at 100, 200, and 400 mg kg^?1 of soil. Common urea and polymer-coated urea were more or less similar in grain production at 100 and 200 mg N kg^?1. However, at 400 mg N kg^?1 treatments, polymer-coated urea produced the lowest grain yield. Most of the growth and yield components were positively related to grain yield, except spikelet sterility which was negatively related to grain yield. Nitrogen use efficiency decreased with increasing N rate in all the three N sources. Maximum N use efficiency was obtained with the addition of ammonium sulfate at lower as well as at higher N rates compared with other two N sources.     

Organ-specific allocation pattern of acquired phosphorus and dry matter in two rice genotypes with contrasting tolerance to phosphorus deficiency

ABSTRACT

Our earlier study demonstrated that the landrace of Japonica rice, Akamai exhibits low-P (phosphorous) tolerance mechanisms compared to the conventional type cultivar, Koshihikari. The present study examined the genotypic difference of yield, plasticity of root growth, and internal utilization of acquired P (allocation pattern of biomass and P among different vegetative and reproductive organs) of two contrasting cultivars in response to P-deficiency. Each cultivar was grown until maturity with (+P) and without (–P) P supply in pots (two plants per pot) filled with 15 kg of Regosol soil. Grain yield and yield components were determined along with biomass and P accumulation in different vegetative and reproductive organs. To assess the plasticity of root growth, the soil column in the pot was divided into two equal portions (upper and lower soil layers) in which the root dry weight and length were measured separately. Among the investigated yield components, the number of filled grains per panicle was the key parameter determining genotypic differences of grain yield of two cultivars. P-deficiency had a marked influence on grain filling of Koshihikari where the filled grain percentage under –P condition was reduced by 29% compared to that under +P condition. However, the respective reduction for Akamai was only 11%. Low-P tolerance ability of Akamai imparts a yield advantage over Koshihikari under P-deficient conditions because of the production of the higher number of filled grains per panicle. Akamai explored both upper and lower soil layers of the pot more efficiently in search of P through greater root biomass and length. Akamai grown under P-deficient conditions had remarkably lower P concentrations in less active vegetative tissues (partly and fully senesced leaves) than those of Koshihikari; whereas, more active organs (green leaves and panicles) contained a greater amount of P. Akamai’s higher plasticity to external P availability can be a genetic resource for developing low-P tolerant, high-yielding rice genotypes suitable for predicted future P-limited environments.     

运用Gibson克隆技术构建蒺藜苜蓿成熟根瘤的酵母AD-cDNA文库

以蒺藜苜蓿(A17)的成熟根瘤为材料,联合应用Gibson克隆技术和SMART cDNA技术构建cDNA文库,其转化效率达到7.74×10~5cfu/3μg pGADT7-Rec-New。随机菌落PCR检测结果表明,插入DNA片段的大小为0.5~2.0kb,其中插入片段0.75kb的占45.6%,文库的重组效率达到91.7%,构建的cDNA文库以质粒形式保藏备用。采用此法不仅可以构建用于酵母单杂交或双杂交的文库,同样也适用于其他质粒文库的构建。利用酵母单杂交技术,以在根瘤中高表达基因启动子元件为诱饵,筛选构建的文库,得到拟似与DNA互作的蛋白质。