不同棉花品种幼苗生长耐盐性比较

以邯郸333、04264、豫15和409棉花品种为试验材料,进行棉花幼苗生长耐盐性试验,测定其幼苗苗长、POD(过氧化物酶)比活力、叶绿素含量、根系活力以及脯氨酸含量等生理指标,分析比较这些指标间的差异显著性,评价不同棉花品种幼苗生长的耐盐性大小。结果表明:邯郸333的幼苗耐盐性最强,其次为04264,再次为豫15,409最弱。     

农村经济发展的思想动力分析

分析了新农村建设中农村经济发展的思想动力,主要包括以人为本,尊重农村利益;加强渗透性,为新农村三个文明建设服务;创新形式,提高思想政治工作的时效性.     

野生二粒小麦α-淀粉酶抑制因子编码基因序列分析

对3份野生二粒小麦(Triticum dicoccoides)材料的抗虫24 kDaα-淀粉酶抑制因子编码基因进行分离克隆,得到72个24 kDaα-淀粉酶抑制因子基因,并进行序列分析。结果发现,α-淀粉酶抑制因子在野生二粒小麦中以多拷贝形式存在,经卡方检验初步推断野生二粒小麦中的α-淀粉酶抑制因子成熟蛋白编码基因序列变异类型在供试材料间无显著差异。序列分析表明,24 kDaα-淀粉酶抑制因子成熟蛋白编码基因序列无论在野生二粒小麦种内还是与小麦属的其他物种之间,都具有很高的一致性,说明该基因在进化过程中十分保守。     

Lophopyrum elongatum (Host) A.Lve染色体对小麦小穗数的影响

以普通小麦中国春为遗传背景的中国春Ee 染色体二体附加系或二体代换系为材料 ,研究了Lophopyrume longatumEe 染色体对小麦小穗数的影响。发现Lophopyrumelongatum的 4Ee 染色体对增加小穗数有很强的效应 ,5Ee 染色体、1Ee 染色体对增加小穗数有较弱的效应     

大鸭梨与大南果梨F1代染色体数目鉴定

用去壁低渗法对大鸭梨与大南果梨F1代18个单株的染色体数目进行了鉴定。结果表明，1株为四倍体（2n=4x=68），占观察总数的5.6%，13株为三倍体(2n=3x=51)，占观察总数的22.2%，4株为二倍体（2n=2x=34)，占观察总数22.2%，该组合F1代中多倍体出现率为72.8%，说明大鸭梨与大南果梨杂交组合在多倍体育种中具有重要价值。     

Factors Affecting the Efficiency of Embryonic Cell Nuclear Transfer in Rabbits

Factors affecting the efficiency of nuclear transfer （NT） in rabbits were examined in the present study. When 100 V mm of pulse strength and 15 us of pulse duration were employed, 3 and 4 electronic pulses resulted in significantly more cytoplasts fused with donor cells compared with 2 electronic pulses （P〈 0.05）, but no significant difference was found in the cleavage rate of reconstructed embryos among the three groups （P〉0.05）. When the duration and number of electronic pulse were fixed at 15 ps and 3 times, increase of pulse intensity from 100 V mm 1 to 150 V mm^-1 and 200 V mm^-1 resulted in a significantly decrease in the cleavage rate of reconstructed embryos （P〈 0.05）, although the fusion rate did not significantly differ among the three groups （P〉 0.05）. Significantly more reconstructed embryos cleaved and developed to blastocysts when they were derived from donor embryos at the 8-16-cell stage, in comparison with the reconstructed embryos derived from donor embryos at the compact morula stage （P 〈 0.05）, although the fusion rate was similar （P 〉 0.05）. Activation of cytoplasts prior to fusion increased the cleavage rate （P〈 0.05） and blastocyst development （P〈 0.05） of reconstructed embryos, but decreased the fusion rate （P 〈 0.05） compared with cytoplasts activated post fusion. More reconstructed embryos developed to blastocysts when they were cultured in TCM ＋ 3% OCS at the first 48 h and then cultured in TCM199＋ 10% FCS, in comparison with the reconstructed embryos cultured in either TCM199＋ 10% FCS or TCM199＋3% OCS （P 〈 0.05）. When 22 NT embryos were transferred into the oviducts of one recipient rabbit, one recipient rabbit delivered a female rabbit at 34 days of gestation. In conclusion, either electrofusion parameter or developmental stage of donor embryos have a significant effect on the efficiency of NT, NT embryos require different concentration of serum at their different development stages.     

水分胁迫对滨海盐碱地水稻发育的影响

采用盆栽与蒸渗仪对比栽培的方式,研究了水分胁迫对水稻生理生化指标及产量的影响。结果表明:胁迫使植株叶水势、蒸腾速率、叶绿素含量、光合速率均有所降低。主要影响表现在光合产物的减少,进而降低了水稻茎秆中淀粉的含量,提高了α-淀粉酶、β-淀粉酶的活性,加速了淀粉的水解,促进了贮藏碳水化合物的输出。分蘖期遭受水分胁迫使胁迫期水稻分蘖数显著减少,叶面积指数明显减小。拔节孕穗期遭受水分胁迫在单阶段胁迫中减产幅度最大,分蘖期、抽穗开花期紧随其后,分蘖、拔节孕穗期连续中度胁迫减产幅度超过任一时期。     

PRV FB弱毒株与FA株gE,gI基因的同源性研究

用PCR方法扩增了PRVFB弱毒株和PRVFA野毒株的gE,gI基因,对FB弱毒株的gE,gI基因进行克隆和测序,并将其与GenBank中收录的PRVFA的gE,gI基因进行了比较。结果发现,PRVFB和PRVFA株的gE基因有2处碱基发生了点突变,同源性为99%;gI基因有7处碱基发生了突变,其中1处发生了3个碱基的插入突变,同源性为98%。表明PRVFB在传代过程中发生了遗传性变异。     

利用SSR标记分析"川育12"和人工合成小麦"SYN780"的遗传差异

四川育成品种“川育12”和CIMMYT硬粒小麦-节节麦人工合成种“SYN780”都具有优质小麦基因,本试验利用小麦A、B和D基因组上的229对引物对“川育12”和“SYN780”进行了SSR分子标记比较分析。结果表明,229个SSR标记位点中有140个位点“川育12”和“SYN780”存在多态性差异,占位点数的61.1%。这140个差异位点在A、B和D3个基因组的分布频率(占该基因组被检测位点数)不一致,其中B基因组分布最多,D基因组分布最少,其顺序为B(64.2%)>A(63.5%)>D(54.9%)。     

台湾脆桃不同类型果枝对产量、果实品质的影响

以台湾脆桃为材料,对不同结果枝类型与产量、果实品质的影响进行相关研究。结果表明,台湾脆桃长果枝数量大、负载能力强,产量上以其为主的特性明显;在适宜粗度范围内,各类果枝类型以分枝角度较小、发育充实、花芽饱满的粗壮结果枝结果性能好、单果重大、可溶性固形物含量高。在栽培上应加强水肥管理培养,修剪时注重选留分枝角度较小、发育充实的粗壮结果枝,以提高产量,增进品质。