通过分子标记辅助选择将耐储藏主效QTL qSS-9~(Kas)转入宁粳4号提高其种子贮藏能力

利用置换系SL36作为qSS-9位点上Kasalath等位基因的供体亲本,各方面农艺性状较好的宁粳4号作为轮回亲本,通过回交和自交,并使用4个与qSS-9紧密连锁的分子标记Y-10、Y-11、Y-14、Y-13进行基因型的检测筛选,对宁粳4号进行耐贮性的遗传改良,获得了既耐贮藏、大多农艺性状又接近于宁粳4号的较为稳定的优良新品系,克服了宁粳4号耐贮藏性差的弱点。获得的新品系种子在人工老化和自然老化条件下均表现出发芽率明显提高、丙二醛含量显著降低、TTC染色效果更明显,表明转入耐储藏主效QTL Qss-9~(Kas)的宁粳4号新品系耐贮性显著提高。     

Evaluation of Omega-3 Fatty Acid Enrichment of Artemia Nauplii as Food for Striped Bass Morone saxatilis Walbaum Larvae

Three enrichment techniques were evaluated for their efficiency in improving the dietary value of Artemia nauplii to striped bass larvae. Newly hatched Artemia nauplii from the Great Salt Lake (GSL) were enriched for 24 h using the following diets: 1) gelatin-acacia microcapsules containing menhaden oil rich in omega-3 polyunsaturated fatty acids (PUFA), primarily 20:5ω3 eicosapen-taenoic acid; 2) an emulsion of Baker's yeast and menhaden oil; and 3) marine Chlorella sp. Unfed San Francisco Bay (SFB) and GSL nauplii were used as controls. Enriched GSL (all three diets) and unfed SFB nauplii had significantly higher ( P < 0.05) levels of 20:503 than the unfed nauplii from GSL. Seven days post-hatched (day 0) striped bass larvae were reared for 21 d on enriched or unfed nauplii. On day 21, wet weight and total length of striped bass larvae fed enriched GSL nauplii and unfed SFB nauplii were significantly greater ( P < 0.05) than those fed unenriched GSL nauplii. The enrichment of the GSL nauplii appeared to increase the eicosapentaenoic acid content and enhance the growth of the striped bass larvae.     

玉米营养体分析及其应用

根据1987～1999年玉米长期丰歉定位试验研究提出了玉米营养体(茎粗×株高)代替干物质量的分析方法,采用该方法可客观地揭示出玉米在不同环境条件下生长规律与产量形成的关系,且较干物质量与产量形成的关系规律完全相同,从而为研究玉米生态学增加了新的生态指标.     

浑善达克沙地牧户经营与草地变化的实证分析

本文以浑善达克沙地牧户调查数据为基础,在草地畜牧业可持续发展理论指导下,通过对牧户经营现状以及草地变化状况的实证分析,明确了牧户经营基本特点、经营收入支出构成与草地资源变化特征,并提出调整畜种结构,适当增加牛的饲养比重;科学管理,提高牲畜出栏率;加强牲畜改良,提高良种比率;完善草畜平衡制度,加强监督、执法力度等对策。     

设施油桃果实发育过程中有机酸代谢的研究

以设施栽培"超红珠"油桃为试材,测定了果实发育过程有机酸含量及相关代谢酶——柠檬酸合酶(CS)、苹果酸酶(ME)、苹果酸脱氢酶(MDH)的活性,并对果实中有机酸积累及酶活性的关系进行了分析。研究结果表明:随油桃果实发育,其有机酸含量呈先升高后降低趋势,于盛花后49d达到最高值;苹果酸含量与总有机酸含量变化趋势相似;柠檬酸含量呈逐渐升高趋势,至果实成熟有所降低;果实成熟期苹果酸与柠檬酸含量相近。有机酸相关代谢酶CS活性变化与柠檬酸含量相关性不大;果实发育后期ME活性逐渐升高,促进了苹果酸的降解和转化;MDH活性变化与苹果酸含量显著相关。因此抑制果实发育前期MDH的活性、促进果实发育后期ME的活性可以降低果实酸含量,提高糖酸比。     

印水型粳稻不育系的选育与研究(Ⅱ)

本研究对印水型粳稻不育系材料秋光A、秋田小町A、农林315A、5216A、辽粳6号A进行调查鉴定,并对其单穗开花习性、异交结实特性、不育系的可恢复性等方面做进一步的探讨和研究,为北方粳稻利用印水型细胞质,丰富北方杂交粳稻胞质资源,扩大遗传背景,配制出强优势印水型杂交粳稻新组合,以解决目前生产上杂交粳稻包台型不育系育性不够稳定及细胞质单一的问题。     

Two new diterpenoids and other constituents from Isodon rubescens

Two new ent-kaurene diterpenoids, 15α-acetoxyl-6,11α-epoxy-6α-hydroxy-20-oxo-6,7-seco-ent-kaur-16-en-1,7-olide (1), 15α-hydroxy-20-oxo-6,7-seco-ent-kaur-16-en-1,7α(6,11α)-diolide (2), together with ten known compounds (5-14) were isolated from the leaves of Isodon rubescens. Their structures were elucidated mainly by various spectroscopic techniques and finally confirmed by single-crystal X-ray diffraction. Compounds 1, 2, 8 and 12 were evaluated for their cytotoxicities against EC-1, U87, A549, MCF-7 and Hela cell lines.     

Monoclonal antibody for the detection and identification of a phytoplasma associated with rice yellow dwarf

One stable hybridoma clone, 247B11, secreting specific monoclonal antibody (MA) against the mycoplasmalike organism (MLO), newly be termed phytoplasma, associated with rice yellow dwarf (RYD) was produced by employing an immunization scheme for inducing the immunological tolerance of mice to rice antigens prior to the administration of RYD-phytoplasma immunogens. Neonatal BALB/c mice were first injected with nontarget rice antigens present in the immunogen preparation and were immunized intrasplenically with RYD-phytoplasmaenriched antigens prepared by Percoll density-gradient fraction 6 wk later. The MA was of the IgG1 class. With this MA, RYD-phytoplasma in diseased rice was specifically detected by indirect enzyme-linked immunosorbent assay (ELISA), immunofluorescent staining and tissue-blotting techniques. Antibody titer determined by indirect ELISA for hybridoma-culture supernatant was 5120. The antibody recognized two polypeptides, 16 kDa and 41 kDa of RYD-phytoplasma determined by western blotting. RYD-phytoplasma was differentiated serologically from the phytoplasmas associated with sweetpotato, peanut, loofah, paulownia, andIpomoea obscura witches' broom, aster yellows (NJ strain), elm yellows, and sugarcane white leaf both in indirect ELISA and immunofluorescent staining.     

两大优势产区‘红富士’苹果园土壤和叶片营养诊断研究

【目的】通过对中国环渤海和黄土高原两大优势产区‘红富士’苹果园土壤有效养分和叶片矿质元素含量的测定及营养状况诊断,为苹果园科学施肥提供理论依据。【方法】根据土壤有效养分分级标准及叶片DRIS诊断法,采用DPS V7.05软件进行LSD单因素方差分析和差异性显著分析,对两大产区树龄15—20年的高产（＞37 500 kg•hm-2）、低产（＜37 500 kg•hm-2）园土壤和叶片营养状况进行诊断。【结果】环渤海产区土壤有机质、碱解氮、速效磷、速效钾有效养分均值分别为10.9 g•kg-1、73.21 mg•kg-1、70.22 mg•kg-1、169.2 mg•kg-1 ;黄土高原产区土壤有机质、碱解氮、速效磷、速效钾有效养分均值分别为11.7g•kg-1、56.46 mg•kg-1、14.91 mg•kg-1、135.78 mg•kg-1 ;除有机质外,碱解氮、速效磷、速效钾有效养分含量为环渤海产区高于黄土高原产区;环渤海产区叶片N、P、K、Ca、Mg、Fe、Mn、Cu、Zn、B、Mo各养分元素含量均值分别为2.73%、0.18%、1.15%、9.63 g•kg-1、2.86 g•kg-1、87.97 mg•kg-1、124.02 mg•kg-1、13.36 mg•kg-1、15.64 mg•kg-1、35.09 mg•kg-1、0.51 mg•kg-1;黄土高原产区叶片N、P、K、Ca、Mg、Fe、Mn、Cu、Zn、B、Mo各养分元素含量均值分别为2.72%、0.18%、1.17%、10.23 g•kg-1、2.99 g•kg-1、88.69 mg•kg-1、116.39 mg•kg-1、10.85 mg•kg-1、15.94 mg•kg-1、39.55 mg•kg-1、0.51 mg•kg-1。通过DRIS法对两大优势产区叶片营养诊断结果表明,环渤海产区低产园叶片最缺乏的元素为Ca、K,其次是Fe、N、Zn,最不缺乏的是Cu、Mo;黄土高原产区低产园叶片最缺乏的元素是P、K,其次是N、Zn、Cu等,最不缺乏的是B、Ca。【结论】环渤海、黄土高原产区土壤有效养分状况均为有机质中等偏低、缺氮;环渤海产区富P少K;黄土高原产区贫P缺K。低产园叶片诊断表明,黄土高原产区树体营养平衡状况优于环渤海产区,两产区均具有很大的增产潜力。建议环渤海产区增加K、N、Ca、Fe和Zn施用,黄土高原产区增加P、K、N、Zn、Cu、Mn、Fe施用,同时重视有机肥施用。