亚洲农业生物技术发展现状和前景(下)

3农业生物技术给农民提供的效益诚如有关美国以及发展中国家诸如中国、南非、墨西哥、阿根廷和菲律宾的调查报告所述,生物技术可以为农民提供巨大的效益。Pray等(2001)曾经在1999~2001年对中国华北地区283名种植Bt棉的棉农的受益状况进行了全面的调查分析。调查中涉及的经济参数包括生产成本、净收益和收益分配。也评价了应用Bt棉技术对环境和卫生的影响。这项调查研究发现,种植Bt棉的农民可在不降低每ha单产或棉花品质的情况下,减少农药施用量。与种植常规棉花品种比较,种植Bt棉可使配方农药的施用量减少约50kg/ha(图1)。这给小农带来了…     

秸秆还田配施化肥对土壤肥力及鲜食甘薯产量和品质的影响

通过2017和2018两年的田间试验研究了小麦秸秆还田和施肥对土壤肥力、酶活性以及鲜食甘薯产量和品质的影响。试验设5个处理:秸秆不还田+常规施肥(CK)、小麦秸秆半量还田+常规施肥(50%S)、小麦秸秆全量还田+不施肥(100%S-F)、小麦秸秆全量还田+常规施肥(100%S)、小麦秸秆全量还田+常规施肥+150 kg·hm^-2氮肥(100%S+N)。结果表明:秸秆还田施肥处理显著提高了土壤中的有效磷、碱解氮、总氮和有机质含量,显著提高了土壤过氧化氢酶、碱性磷酸酶、脲酶和蔗糖酶活性。秸秆还田施肥处理均显著提高了薯块产量、单薯鲜重和商品薯率,其中50%S处理下薯块产量最低。2年的秸秆还田处理下,薯块产量和商品薯率均在100%S处理下最高。2年的秸秆还田施肥处理总体上提高了甘薯的淀粉和蛋白质含量,但100%S和100%S+N处理均降低了甘薯还原糖和可溶性糖含量。可见,小麦秸秆全量还田的效果优于半量还田,与常规施肥配合下薯块产量和商品薯率最高,但影响食用口感,实际生产中可适当减少氮肥用量。     

产大米蛋白水解酶的菌株筛选、酶学性质及制备大米寡肽

【目的】旨在分离、筛选并鉴定具有大米蛋白降解作用的菌株及其关键蛋白酶,为高效制备大米寡肽提供制备酶及最优制备条件。【方法】以"水解圈"为评价指标,从粮食仓库附近土壤筛选获得具有降解大米蛋白能力的菌株;通过16S rRNA序列分析确定菌株归属;利用单因素实验获得最佳氮源并初步分析酶学性质;利用HPLC检测寡肽得率,并对制备条件进一步优化。【结果】经鉴定具有大米蛋白降解作用的菌株为沙雷氏菌(Serratia sp. JWG-D15),以大米蛋白为氮源培养菌株JWG-D15,蛋白酶So PRO产量最高,其最适温度40℃,最适pH 8.0;在加酶量20 U/mg,大米蛋白浓度40 mg/mL,40℃,4 h条件下寡肽得率最高72.38%。【结论】以大米蛋白为氮源培养菌株JWG-D15,蛋白酶So PRO产量最高;蛋白酶So PRO制得的大米寡肽,其得率是目前行业最高。本研究既丰富了大米寡肽的制备用酶的种类,又为深入大米寡肽产业化提供一定理论基础。     

OsRRM, a Spen-like rice gene expressed specifically in the endosperm

We used the promoter trap technique to identify a rice plant, named 107^#, in which the β-glucuronidase （GUS） reporter gene was expressed specifically in the endosperm. A single copy of the T-DNA was inserted into the plant genome, and a candidate gene OsRRM was identified by the insertion. The OsRRM promoter directed GUS expression specifically in rice endosperm, analogous to the GUS expression pattern observed in 107^#. OsRRMis a single-copy gene in rice and encodes a nuclear protein containing 1 005 amino-acid residues with two RNA recognition motifs and one Spen paralog and ortholog C-terminal domain. Westem blot analysis confirmed that the OsRRM protein was specifically expressed in rice endosperm. Ectopic expression of OsRRM in transgenic plants led to abnormalities, such as short stature, retarded growth and low fructification rates. Our data, in conjunction with the reported function of Spen genes, implicated OsRRM in the regulation of cell development in rice endosperm.     

Genotyping the Heading Date of Male-Sterile Rice Line II-32A

II-32A, an elite male-sterile line of rice （Oryza sativa L.）, has been widely used for the production of hybrid rice seed In China. Heading date In most combinations using II-32A shows transgressive Inheritance or similarity to the latter parent, but the genotype of II-32A with respect to major genes for heading time Is unknown. This limits the further exploitation of this sterile line In breeding and hybrid seed production. Using a number of major gene heading date Isogenlc lines and heading date QTL near-lsogenic lines, we genetically analyzed II-32B under both long- and short-day conditions. We show that II-32B carries two photoperlod-sensltlve genes, E1 and E3, a recessive late-heading gene, ef-l, and a photoperlod-sensltlve allele, Se-1^u. In addition we Identified In II- 32B a recessive Inhibitor for E1 or Se-1^n and other modified photoperlod-sensltlve genes. The heading-date constitution of II-32A was determined to be E1e2E3Se-1^uef-li-Se-1.     

姜老师信箱

蛋白质研讨班学员问:姜老师,您好!我是刚结束的"第13期蛋白质分离纯化技术专题研讨班"学员,您的授课让我获益良多。学习期间我曾向您请教过用NHS柱偶联抗原来纯化多克隆抗体的问题。关于偶联抗原蛋白量的计算,NHS柱商品说明书上显示配体密度为16-23μmol/ml干介质(ligand density:16-23μmol/ml drained medium),我使用的抗原分子量约为     

对微波消解-原子荧光光谱法测定大米中的痕量汞再探讨

汞是一种对人体有害的重金属,如果大米中含有重金属汞,蓄积到一定程度时,会严重影响人们的身体健康。微波消解-原子荧光光谱法具有准确灵敏的特点,对于大米中重金属汞的检测有着良好的效果。实践证明,运用微波消解-原子荧光光谱法检测后汞含量低于国家标准,是行之有效的方法。     

Identification of quantitative trait loci for four morphologic traits under water stress in rice （Oryza sativa L.）

Late season drought coinciding with the rice booting to heading stage affects the development of plant height,panicle exsertion,and flag leaf size,and causes significant yield loss.In this study,a recombinant inbred line population derived from a cross between paddy and upland cultivars was used for data collection of the morphologic traits under well water and drought stress conditions.bought stress was applied at the stage of panicle initiation in the field in 2002 and at the booting stage in PVC pipes in 2003.The data from stress con ditions and their ratios(tait measured under stress condition/trait measured under well water condition)or differences(trait measured under stress condition minus trait measured under well water condition)were used for OTL analysis.Totally,17 and 36 QTLs for these traits were identified in 2002 and 2003,respectively,which explained a range of 2.58%-29.82%Of the phenotypic variation.Among them,six QTLs were commonly identified in the two years,suggesting that the drought stress in the two years was different.The genetic basis of these traits will provide useful information for improving rice late season drought resistance,and their application as indirect indices in rice late season drought resistance screening was also discussed.     

初始克隆分株数对大米草表型可塑性及生物量分配的影响

克隆植物大米草 (Spartina anglica) 目前在我国出现了严重的自然衰退 (Dieback),为了阐明大米草衰退的机理,分析影响大米草形态可塑性的因素与自然衰退之间的相关性,以期为近缘植物互花米草 (S. alterniflora) 这一爆发种群的生物控制提供借鉴,对3种不同初始克隆分株数 (单克隆、三克隆和五克隆) 大米草的克隆生长、生物量累积与分配和异速生长特征进行了野外栽培试验。研究结果表明,初始克隆分株数对间隔子长度影响较弱;初始多克隆的分支强度高于初始单克隆;初始三克隆和五克隆在总生物量 (7.921 5~10.431 7 g 和 8.903 9~10.431 7 g)、地上生物量 (3.396 1~4.255 8 g 和3.618 4~4.338 9 g)、地下生物量 (4.286 9~5.206 6 g 和 5.298 8~6.079 3 g)和根状茎生物量 (1.318 6~1.767 7 g 和 1.499 1~2.038 7 g) 积累上均显著高于初始单克隆,不同初始克隆分株数条件下根生物量差异不显著;初始多克隆倾向于将资源更多地分配给根状茎,而初始单克隆倾向于将更多的资源分配给根系。由此推断,在不同初始克隆分株数条件下,大米草的形态可塑性和生物量分配格局的差异显示出在同样资源格局下,初始多克隆的克隆生殖能力较初始单克隆强。初始多克隆生长的大米草较初始单克隆生长的大米草更能占据优势生境,选择生境“觅养”的能力与克隆繁殖能力更强。