木薯渣复合基质在辣椒穴盘育苗上的应用效果

为了综合利用木薯渣废弃资源,本研究以木薯渣作为基本原料,辅以不同比例的蔗渣、菌糠等,配制成9个配方的木薯渣复合基质,并进行理化性状分析和辣椒穴盘育苗试验。试验结果表明,绝大部分复合基质的容重、pH、C/N、电导率和大小孔隙比均在优良无土栽培基质要求的范围内;其中,复合基质配方2(67%木薯渣+5%蔗渣)、配方7(62%木薯渣+10%菌糠)和配方9(42%木薯渣+30%菌糠)对辣椒穴盘育苗的效果最好,所对应的辣椒苗的株高、地上部鲜重和根鲜重均比其它基质配方高,辣椒苗根部结团效果亦较好。因此,利用木薯渣可以合成复合基质用于辣椒的无土栽培穴盘育苗,该研究结果将为木薯渣废弃资源的再利用提供了一条新的途径。     

Genome-wide SNP discovery in walnut with an AGSNP pipeline updated for SNP discovery in allogamous organisms

ABSTRACT: BACKGROUND: A genome-wide set of single nucleotide polymorphisms (SNPs) is a valuable resource in genetic research and breeding and is usually developed by re-sequencing a genome. If a genome sequence is not available, an alternative strategy must be used. We previously reported the development of a pipeline (AGSNP) for genome-wide SNP discovery in coding sequences and other single-copy DNA without a complete genome sequence in self-pollinating (autogamous) plants. Here we updated this pipeline for SNP discovery in outcrossing (allogamous) species and demonstrated its efficacy in SNP discovery in walnut (Juglans regia L.). RESULTS: The first step in the original implementation of the AGSNP pipeline was the construction of a reference sequence and the identification of single-copy sequences in it. To identify single-copy sequences, multiple genome equivalents of short SOLiD reads of another individual were mapped to shallow genome coverage of long Sanger or Roche 454 reads making up the reference sequence. The relative depth of SOLiD reads was used to filter out repeated sequences from single-copy sequences in the reference sequence. The second step was a search for SNPs between SOLiD reads and the reference sequence. Polymorphism within the mapped SOLiD reads would have precluded SNP discovery; hence both individuals had to be homozygous. The AGSNP pipeline was updated here for using SOLiD or other type of short reads of a heterozygous individual for these two principal steps. A total of 32.6X walnut genome equivalents of SOLiD reads of vegetatively propagated walnut scion cultivar 'Chandler' were mapped to 48,661 'Chandler' bacterial artificial chromosome (BAC) end sequences (BESs) produced by Sanger sequencing during the construction of a walnut physical map. A total of 22,799 putative SNPs were initially identified. A total of 6,000 Infinium II type SNPs evenly distributed along the walnut physical map were selected for the construction of an Infinium BeadChip, which was used to genotype a walnut mapping population having 'Chandler' as one of the parents. Genotyping results were used to adjust the filtering parameters of the updated AGSNP pipeline. With the adjusted filtering criteria, 69.6% of SNPs discovered with the updated pipeline were real and could be mapped on the walnut genetic map. A total of 13,439 SNPs were discovered by BES re-sequencing. BESs harboring SNPs were in 677 FPC contigs covering 98% of the physical map of the walnut genome. CONCLUSION: The updated AGSNP pipeline is a versatile SNP discovery tool for a high-throughput, genome-wide SNP discovery in both autogamous and allogamous species. With this pipeline, a large set of SNPs were identified in a single walnut cultivar.     

谷氨酰胺合成酶抑制剂对烤烟烘烤特性的影响

以烤烟品种‘K326’叶片为材料,在达到工艺成熟期前7d分别用质量分数为0.005%和0.01%的谷氨酰胺合成酶(GS)抑制剂4-[羟基(甲基)膦酰基]-D/L-高丙氨酸(草铵膦)溶液喷施烤烟叶片,研究了烟叶烘烤过程中烘烤特性的变化特征。结果表明:于烟叶工艺成熟期前7d喷施GS抑制剂,能够显著降低烘烤过程中烟叶的叶绿素、类胡萝卜素含量和多酚氧化酶(PPO)活性;增加烟叶失水速率和丙二醛(MDA)含量,显著提高烟叶烘烤后黄烟比例,并降低杂色烟比例。研究认为,在烟叶工艺成熟期前7d喷施GS抑制剂,可增强烟叶的易烤性和耐烤性,使烟叶更容易变黄,并同时减少棕色化反应的发生,但高浓度的GS抑制剂使烟叶失水速率过快,不利于烟叶定色,烘烤后青烟比例升高,对烟叶外观质量形成不利。     

A novel,major, and validated QTL for the effective tiller number located on chromosome arm 1BL in bread wheat

Plant Molecular Biology - A novel and major QTL for the effective tiller number was identified on chromosomal arm 1BL and validated in two genetic backgrounds The effective tiller number (ETN)...     

紫丁香SoDXR基因克隆及在单萜物质合成中的功能分析

【目的】探究1-脱氧木酮糖-5-磷酸还原酶（1-deoxy-D-xylulose-5-phosphate reductoisomerase, DXR）基因在紫丁香单萜物质合成中的作用,为紫丁香花香分子育种提供有效的基因资源和理论基础。【方法】本研究以紫丁香（Syringa oblata）花瓣为材料,克隆了SoDXR基因,并对其进行了生物信息学和亚细胞定位分析,不同花发育时期和器官组织中的qRT-PCR表达分析,及在金鱼草花瓣中异源瞬时过表达探究其功能。【结果】SoDXR基因全长为1 425 bp,编码474个氨基酸,编码的蛋白具有保守的DXP_reductoisom结构域,与桂花（Osmanthus fragrans）和油橄榄（Olea europaea）的相似性高达95%。亚细胞定位显示该蛋白主要定位于质体,与软件预测结果一致。伴随着开花,SoDXR表达水平呈先升高后降低的趋势,在初开期最高;在各个器官组织中均有表达,其中花瓣中表达量最高,茎中表达量最低。瞬时过表达发现,SoDXR基因的表达水平显著高于对照,促进了主要单萜成分罗勒烯和月桂烯的释放,释放量分别增加了15.03倍和4.83倍。【结论】SoDXR基因正调控紫丁香单萜物质的合成,推测DXR基因在花香次级代谢物合成中起到重要作用。     

羊草和紫花苜蓿生长特征及光合特性对不同土壤水分的响应

采用人工控制实验,对12%(T1)、16%(T2)和20%(T3)3种土壤水分条件下羊草和紫花苜蓿的净光合速率Pn、实际光化学量子效率ФPSⅡ、光化学淬灭q P、非光化学淬灭q N、水分利用效率WUE、株高、分枝分蘖数、生物量等参数进行测定。结果表明,在实验范围内,(1)ФPSⅡ和q P共同影响净光合速率,羊草和紫花苜蓿净光合速率对土壤水分的响应不同,紫花苜蓿的土壤水分生态幅要比羊草窄,羊草生长的最适土壤含水量为20%,随着土壤含水量的降低,净光合速率呈单调递减趋势;紫花苜蓿的最适土壤含水量为16%,其净光合速率与土壤含水量之间呈非线性关系,存在明显阈值。(2)适宜土壤含水量有助于羊草和紫花苜蓿株高和分枝分蘖的生长。(3)在土壤水分低于适宜土壤含水量范围时,羊草和紫花苜蓿有相似的响应机制,都通过增加根系生物量来适应环境胁迫。