砂藓(Racomitrium canescens)RcRab基因的克隆及生物信息学分析

本研究以砂藓(Racomitrium canescens)为材料,从砂藓干旱处理转录组数据库中筛选获得小G结合蛋白基因Rab的mRNA序列,通过RT-PCR法扩增,得到RcRab基因的CDS序列,并对其进行了生物信息学分析。结果表明,该基因c DNA全长为1171 bp,包含636 bp的开放阅读框,编码211个氨基酸。预测该基因有Rab家族的保守结构域-G结构域。RcRab蛋白分子质量为23.29 kD,理论等电点为5.76,具有亲水性,不属于跨膜蛋白且不存在信号肽。进化树分析表明,RcRab蛋白质与小立碗藓(Physcomitrella patens)Rab蛋白质亲缘关系最近。本研究可为进一步探索RcRab基因在苔藓植物中的抗旱机制提供数据基础。     

基于高通量测序的露地菊(Chysanthemum×grandiflora)盐胁迫转录组分析

为揭示露地菊生长发育及耐盐胁迫的应答机制和分子基础,本研究以盐胁迫处理的露地菊及其对照为材料,使用Illumina Hiseq2500高通量测序平台对转录组进行测序,分别获得了60370448和71415448条Clean reads,通过序列拼接组装得到45591条Unigene,平均长度724 bp。有37675条Unigene在七大数据库(COG,GO,KEGG,KOG,Pfam,Swiss-Prot,NR)中得到注释。通过比对露地菊盐胁迫处理组和对照组样品间Unigene的表达量及在各数据库中的注释情况,统计得到:有4143条差异表达基因获得注释;有2441条差异表达基因在GO数据库中获得功能注释;注释到COG数据库中的2281条差异表达基因依据功能可分为25类;有1062条差异基因映射到KEGGPathway数据库中,涉及了199个代谢通路,包括核糖体途径、植物激素信号传导途径、淀粉蔗糖代谢、碳代谢、氨基酸的生物合成等。本研究获得的转录组数据将有助于揭示露地菊生长发育及耐盐胁迫的应答机制和分子基础,及相关抗性基因的挖掘和分子辅助育种等方面的研究。     

‘新海16’愈伤组织诱导及白霜的优化

为获得高品质、活力旺盛且具有分化能力的愈伤组织,本研究在已建立的海岛棉(Gossypium barbadense)‘新海16’再生体系基础上,以MSB附加0.1 mg/L 2,4-D及0.1 mg/L KT为基本培养基,采用单因素随机试验研究外植体不同部位、光照及培养基成分等对‘新海16’愈伤组织诱导的影响。结果表明:‘新海16’愈伤诱导的外植体选用下胚轴中上部绿色茎段诱导效果较优;除此之外,愈伤诱导效果最佳的处理为2 000 lx光照强度、90%MSB无机盐成分、3 g/L PVP及1.2~1.4 g/L Gelrite或Phytagel,均能够降低愈伤组织出现白霜现象,对愈伤组织疏松生长有促进作用。本研究通过优化愈伤组织的诱导方法,提高胚性愈伤组织发生率,为‘新海16’高频再生体系提供科学依据。     

马铃薯AP2/ERF转录因子的克隆及植物表达载体构建

AP2/ERF基因家族转录因子普遍存在于植物中,参与植物体内的各种生物学过程,包括植物的生长发育、生物和非生物胁迫响应等。前期转录组测序的结果发现马铃薯‘加湘1号’一个AP2/ERF家族基因(PGSC0003DMG400012154)在接种晚疫病菌(Phytophthora infestans)24 h后被显著激活。从接种P.infestans 24 h的‘加湘1号’的总RNA中通过RT-PCR获得了该基因CDS序列为885 bp,BLAST分析显示该基因编码一个295个氨基酸残基的蛋白,并且含有1个AP2/ERF结构域,是AP2/ERF转录因子家族中的ERF亚家族的一员。本研究将该基因与XcmⅠ酶切的表达载体pCXSN连接,转化大肠杆菌,通过测序挑选插入正确克隆酶切验证,并成功转化农杆菌。本研究结果为进一步研究该基因的功能提供了帮助。     

黄土丘陵区不同退耕模式对土壤物理性状影响研究—以甘肃定西市为例

甘肃定西全面实施退耕还林近10年来,取得了显著的成效。本文以退耕还林重点地区定西市安定区为例,通过采集、实地调查取样和实验室分析,对比研究了不同退耕植被类型地与对照地（农田和天然草地）的土壤物理性状的变化情况。包括土壤的含水量、容重、土壤孔隙度、土壤水稳性团聚体结构。研究结果表明：天然草地和柽柳的含水量最高,分别为13.44%和13.52%。农田和山杏的含水量最低为8.01%和8.2%。0～60cm不同土层中柠条的容重最小且变化不大,农田的上下变化最大。在20～60cm退耕还林地的孔隙度均高于天然草地和农田,天然草地和农田非毛管孔隙度小且上下变化大,不利于土壤入渗。刺槐、柠条、柽柳的水稳性团聚体的含量最多,分别是农田的3.4、2.8和2.4倍。退耕还林以后,林地的土壤物理性状得到明显的改善,与农田和天然草地相比,刺槐,柠条的改良效果最好。因此对退耕还林地区进行植被恢复过程中,要深入了解当地的土壤环境特征,做到因地制宜,适地适树。     

部分黑龙江省水稻品种的抗瘟性分类

摘要：为了充分利用黑龙江省水稻抗稻瘟病资源,利用日本的7个致病性稳定的菌系对黑龙江省部分粳稻品种进行了抗瘟性分类。通过与12个鉴别品种的反应型比较分析,推断了部分品种的基因型。将141份品种划分为39个品种群,并初步推断了60个品种的基因型,为育种者提供抗源,也为开展抗病基因分析奠定了物质基础。     

我国果葡糖浆的生产应用现状及发展趋势

果葡糖浆在国外发展迅速并广泛地应用于各种食品生产中,但国内的生产和消费却徘徊不前.介绍了国内果葡糖浆的生产应用现况,分析了国内果葡糖浆发展缓慢的原因,展望了发展趋势.     

甘蔗斑茅属间远缘杂种崖城01—87回交入选品系的评价

斑茅杂种第二代品系崖城01-87与新台糖20号(ROC20)回交入选的19个品系的农艺性状分析表明,品系之间同一性状表型差异较大;与产量相关的性状变异较显著;斑茅杂种BC1普遍具有的"低糖"性状在回交后提高较快,蔗茎锤度平均增长23.8%;部分品系农艺性状的综合表现已优于或达到国内当家良种的生产水平.     

Sucrose metabolism in cotton (Gossypium hirsutum L.) fibre under low temperature during fibre development

The effects of low temperature on sucrose content and activities of key enzymes related to sucrose metabolism in cotton (Gossypium hirsutum L.) fibre were investigated. Two cotton cultivars, Kemian 1 and Sumian 15, were grown in the field at two sowing dates in 2006 and three sowing dates in 2007, the differences of environmental conditions during fibre development period (from flowering date to boll opening date) for different sowing dates were primarily on temperature. Low temperatures (MDTmin of 21.1, 20.5 and 18.1 °C) in late sowing dates (25 May/10 June) prolonged the fibre development period, and had significant effect on cellulose synthesis and sucrose metabolism. Results showed that, under low temperature, sucrose content was increased, cellulose content and sucrose transformation rate were decreased, and the variability of cellulose content and sucrose transformation rate through sowing dates in Sumian 15 was more than that in Kemian 1. The measurable activities of sucrose phosphate synthase (SPS), sucrose synthase (SuSy) and acid/alkaline invertases in sucrose metabolism were affected by low temperatures. Under low temperatures, activities of SuSy and invertase in sucrose degradation were increased, and two cultivars had the similar change. In contrast, the activity of SPS in sucrose synthesis was lower than the activity in developing fibre at normal environmental condition, and the time to peak activity was delayed, SPS activity in response to temperatures differed between two cultivars. The results indicated that restrained cellulose synthesis and sucrose metabolism under low temperature were mainly attributed to the changed activities of enzymes (SPS, SuSy and invertase), and the difference of cellulose synthesis and sucrose metabolism in response to temperature in fibre cells for two cotton cultivars was mainly determined by the level of SPS activity.     

The Effect of Additions in the Fermented Solution on Bubble Coalescence

This paper presents a detail study of bubble coalescence in inorganic salts and organic compounds of fermented solution ,and preliminary analyses the principle of bubble coalescence.The experiments show that the relationship between the solute concentration and coalescence frequency reveals the existence of sharp transition concentration.