利用酯酶同工酶分析花生属种间亲缘关系

本文采用聚丙烯酰胺凝胶电泳,对花生属植物进行了酯酶同工酶的测定。结果表明:花生属植物有共同的特征酶带,不同种之间的酶带差异较大;与栽培种最相似的野生种是Amonticola;A.batizocoi是花生区组内与栽培种很不相似的野生种;二倍体野生种之间;A.stenosperma与A.cardenasii之间的关系很近,A.villosa与A.batizocoi之间的关系很远     

木薯胚胎发育和幼胚离体培养的初步研究

以华南5号木薯为材料,观察木薯受精后胚胎的发育过程并对不同发育时期幼胚进行离体培养。结果表明:木薯受精卵早期处于休眠状态;授粉后12 d胚胎发育到多细胞原胚阶段;授粉后14 d发育到早期球形胚阶段;授粉后17 d发育到心形胚阶段;授粉后19 d发育到早期双子叶胚阶段。早期幼胚的萌发率较低,授粉后15 d的幼胚,在培养基MS+0.5 mg/L CuSO4+0.5 mg/L 6-BA+0.1 mg/L NAA+6%蔗糖上培养时,胚胎发育率为33.3%。中后期幼胚的萌发率较高,授粉后35 d的幼胚,在培养基MS+0.5 mg/L CuSO4+0.5 mg/L 6-BA+0.01 mg/LNAA+3%蔗糖上培养时,萌发率可达100%。胚性愈伤组织的培养,采用幼胚剥离培养。授粉后30 d的幼胚,在培养基MS+0.5 mg/L CuSO4+6 mg/L 2,4-D+3%蔗糖上培养时,出胚率达77.3%。     

几种番荔枝属果树的酯酶和多酚氧化酶同工酶分析

应用垂直板不连续聚丙烯酰胺凝胶电泳技术对番荔枝属的7种果树共14份材料进行酯酶和多酚氧化酶同工酶分析.结果表明,2种同工酶共表现出23条酶带,其中酯酶同工酶9条,多酚氧化酶同工酶14条,不同番荔枝种间酶谱差异较大.2种同工酶酶谱除不能区分2份红毛榴莲和2份毛叶番荔枝外,对其余的10份材料均可区分.实验用几个番荔枝种间的遗传距离在0.000～0.895之间.聚类结果将14份番荔枝材料分成了2类.     

小麦多小穗品系10-A杂交后代的酯酶同工酶分析

对１０－Ａ、８８－１６４３、川育１２号三个亲本及六个三交后代稳定品系的剑叶和幼穗的酯酶同工酶分析表明,三个亲本的酶带有较大差异,无论剑叶或幼穗均以１０－Ａ的酶带最少。后代中均无杂种酶带出现,但有不同程度的互补酶带。其中,综合农艺性状最好的９５－７,无论剑叶或幼穗均表现出具有三个亲本的所有酶带,并且一些酶带活性较亲本强。     

木薯非胚性与胚性组织蛋白质双向电泳差异初步分析

以木薯体非胚性和胚性组织为材料研究胚发生的蛋白表达机制,利用IEF/SDS-PAGE凝胶电泳技术,对其蛋白质特异性进行了比较分析,分别得到470和344个清晰的蛋白点。结果表明非胚性组织蛋白质谱和胚性组织蛋白质表达量上存在一定的差异。对其中5个区域中的39个差异显著的点进行分析发现,差异表达上调和下调在2倍以下的蛋白点有6个,上调或下调2倍以上的蛋白点有22个,非胚性组织中特异存在的蛋白点有5个,而胚性组织中特异存在的蛋白点有6个。     

甘蓝型油菜不同硼效率品种酯酶同工酶的比较分析

运用聚丙烯酰胺凝胶垂直平板电泳方法,分析甘蓝型油菜２个硼低效品种、４个硼高效品种及其４个Ｆ１苗期、蕾期和花期不同器官的酯酶同工酶,探索甘蓝型油菜不同硼效率品种及Ｆ１间酯酶同工酶的关系。结果表明：三个时期不同器官的酯酶同工酶谱比效稳定,出现明显的三个带区;不同硼效率品种间酯酶同工酶谱在各个时期和器官都有差异,但苗期叶片酯酶同工酶谱在快带区的差异最显著,容易辨别,Ｆ１为共显性;缺硼时甘蓝型油菜不同硼效率品种酯酶同工酶的谱带颜色变深,酶活性增强,但同工酶的谱带数没有变化。     

茶树体胚APX基因克隆及其在体胚发生过程中的表达与酶活性分析

以铁观音茶树体胚为材料,克隆了茶树抗坏血酸过氧化物酶基因CsAPX(Genbank登录号为MG799534.1)。CsAPX基因包含一个长度为753 bp的开放阅读框(ORF),共编码250个氨基酸,并对其进行相关生物信息学分析。APX酶活性测定结果表明在球形胚至子叶胚阶段APX酶活性呈现下降趋势,并在子叶胚阶段到达最低值,随着体胚进一步的分化,在子叶胚、成熟胚和萌发胚阶段,茶树APX酶活性不断上升,总体呈"先降后升"的趋势。在体胚发生过程中CsAPX基因的表达分析显示,CsAPX基因在茶树体胚发生的5个阶段均存在显著差异表达,总体呈"升—降—升"的趋势,其中在萌发胚阶段的CsAPX基因的表达水平显著高于其他4个阶段,推测CsAPX基因在体胚发生过程中的萌发胚阶段发挥着重要的作用。     

橡胶树体胚发生过程中的生理生化特性

以巴西橡胶树花药为外植体,研究了巴西橡胶树花药体胚发生过程中抗氧化酶活性和某些生理参数的变化。结果表明,橡胶树花药体胚发生过程中,SOD活性变化表现在培养30 d达到最高值,而后下降平缓;丙二醛(MDA)含量在第60天达到最高。生理参数的变化表现为可溶性蛋白含量0 d含量最高,可溶性糖的含量在50 d达到最高,据此认为,SOD和MDA对橡胶树花药体胚的诱导起主导作用,可溶性蛋白含量与不定芽的发生密切相关。     

2个荔枝品种体胚发生过程中糖含量及相关酶活性变化

为研究糖代谢在荔枝体胚发生过程中的作用,将‘大丁香’和‘新球蜜荔’胚性愈伤组织接种在TD培养基上,并将‘新球蜜荔’接种在TX培养基上,对比体胚诱导过程中3种胚性培养物之间淀粉、蔗糖等糖组分及其代谢相关酶活性变化,以期从糖代谢方面找出影响荔枝体胚发生效率差异的关键因素。结果表明:在体胚发生过程中,‘新球蜜荔’在2种培养基上的淀粉含量都低于‘大丁香’;三者的葡萄糖与果糖含量变化相似,但‘大丁香’都高于‘新球蜜荔’,而‘新球蜜荔’的蔗糖含量则高于‘大丁香’;‘新球蜜荔’的淀粉酶、β-淀粉酶活性都高于‘大丁香’,而α-淀粉酶活性相似。‘新球蜜荔’的蔗糖合酶及在TD培养基上的酸性转化酶活性高于‘大丁香’,但中性转化酶活性是以‘大丁香’偏高,且‘新球蜜荔’在TX培养基上也以中性转化酶为主。由此‘新球蜜荔’通过淀粉酶、蔗糖合酶及转化酶将淀粉转化成蔗糖为体胚发生提供物质能量,而高活性的中性转化酶与低活性的淀粉酶,使‘大丁香’的蔗糖没有得到积累,使其体胚发生效率低于‘新球蜜荔’。     

龙眼体胚发生过程中两个乙烯受体基因的定量表达分析

以龙眼体细胞胚胎发生8个不同发育阶段同步化胚性培养物为材料,采用荧光定量PCR方法,分析两个乙烯受体基因(DL-ETR1和DL-ERS1)的mRNA动态变化水平。试验结果表明:DL-ETR1表达量整体的变化趋势呈近似"W"状,松散型的胚性愈伤组织(Stage 1)的表达量最高,心形胚(Stage 6)阶段的表达量最低;龙眼体胚发生过程的8个阶段均有DL-ERS1基因的表达,子叶形胚(Stage 8)的表达量最高,其它7个阶段的表达量都很低,鱼雷形胚(Stage 7)的表达量极低,几乎不表达。DL-ETR1与DL-ERS1有着不同时期的表达模式,并且可能起到结合乙烯,调节龙眼体胚对乙烯敏感性的综合作用。     

木薯分子标记遗传连锁图谱的构建及相关性状QTL定位

用木薯推广品种KU50为母本,SC124为父本通过杂交得到包含235个单株的F1分离群体,构建了一张包含150个标记的分子遗传连锁图谱,其中EST-SSR有72个位点,SSR有58个位点,SRAP有20个位点,这些位点分布了21个连锁群,总长度为1434.48cM,标记间距为9.56cM.遗传图谱的连锁群的长度在16.89～139.63 cM,标记的间距是0.2～47.0cM,标记位点比较多的是LG1、LG2、LG4、LG9、LG10,分别是17、18、13、14、15个,而标记数最少的是LG20,只有2个标记.用IciQTLMaping3.2软件在LOD=2.5进行QTL分析,检测了块根产量(WCY)、耐寒性分析(CR11、CR12)、干物质含量(DMC11、DMC12)3个木薯数量性状,总共得到34个QTL位点,分布在12个连锁群上.其中关于WCY的QTL位点总共有17个,贡献率为21.70％～55.23％,平均贡献率为40.74％;CR11相关的QTL位点有4个,贡献率为2.97％～33.29％,平均贡献率为18.20％.与CR12相关的QTL定位有3个,贡献率为5.23％～29.85％,平均贡献率为18.28％;与DMC12性状相关的QTL位点有4个,贡献率为15.87％～38.52％,平均贡献率为26.24％;与DMC11性状相关的位点有6个,贡献率为13.84％～22.15％,平均贡献率为17.56％.     

木薯干旱胁迫响应基因MeGSTU7自然变异分析

在2个木薯品种中检测MeGSTU7基因在不同干旱胁迫阶段的表达量变化,并克隆测序了60个木薯品种的基因区DNA序列,分析基因核苷酸多态性及其自然变异,并将核苷酸多态性与干旱胁迫表型关联分析,挖掘优等位变异。结果表明,干旱胁迫条件下,2个品种的MeGSTU7的表达量均上调。MeGSTU7基因区核苷酸变异丰富,共有23个SNP位点,A/G突变为主;外显子区总计10个同义突变,12个非同义突变;外显子区在品种资源群体中有4种主要单倍型,所有的单倍型分为两大类,分子进化分析表明,MeGSTU7的外显子区的两端受到很强的正选择作用;Q+K+MLM混合线性模型关联分析结果表明,1个Indel和2个SNP与干旱胁迫下地上部鲜重耐旱系数显著关联,并筛选得到了优等位变异。     

木薯分支酶活性测定及同工酶电泳技术应用初探

淀粉分支酶(Starch branching enzyme,SBE)是唯一引入α-1,6糖苷键分支点,催化支链淀粉形成的酶,影响淀粉分支程度及淀粉粒的精细结构。本文以3个亲缘关系较远的高产木薯品种(SC124、SC8、Arg7)为材料,利用SBE同工酶电泳及酶活性检测观察木薯块根支链淀粉增长较快时期SBE活性变化动态,结合支链淀粉含量检测分析木薯淀粉同工酶表达特点与支链淀粉积累的关系。结果表明:种植后140d至180d为木薯单株支链淀粉含量快速增加时期;SC124和SC8支链淀粉积累量早于Arg7达到高峰;Arg7各个时期的支链淀粉含量及SBE活性均表现最高。同工酶分析表明,木薯分支酶有SBE-I和SBE-II两个基因位点:SBE-Ι至少有3个等位基因位点(SBE-Ιa、SBE-Ιb、SBE-Ιc),品种间具有多态性;SBE-II为单一条带,但活性大小在品种间和发育不同阶段有差异。初步判定等位基因位点SBE-Ιc和SBE-II可能对SBE酶活性和支链淀粉含量贡献较大。     

24份木薯(Manihot esculenta)种质的遗传多样性研究

采用产量性状和12个表型性状聚类分析以及SSR标记技术,对不同产地来源的24份木薯(Manihot esculenta)种质遗传多样性进行了研究。结果表明,依据12个表型性状在欧氏距离系数为39.353处可将供试的24个木薯种质分为3类,一些品种的表型性状与地理来源之间存在相关性;利用18对SSR引物对24份木薯种质进行多态性分析,共检测到154条带,其中多态性带145条,每一个位点上检测到5～12条,平均8.6条。材料间相似系数在0.510～0.967之间,平均相似系数为0.695。以相似系数0.78为结合点,可以将材料分为三大类。不同国家和地区来源的材料不能明显聚类,不同淀粉含量、干物质量分数的品种却聚在一起,且没有发现与淀粉含量、干物质量分数相关的特异性条带。农艺性状的聚类结果与SSR聚类的结果有很大的差异,说明木薯在长期的演化和自然选择过程中发生了显著的表型变化。     

华南7号木薯茎叶营养价值评价

研究华南7号木薯生长期间6~11月份茎、叶营养成分动态变化及营养价值评价。结果表明,华南7号木薯叶粗蛋白含量为21.16%~31.80%,粗脂肪含量为4.17%~8.28%;茎秆中性洗涤纤维含量为24.67%~39.67%,酸性洗涤纤维含量为23.47%~29.74%。木薯叶片、茎秆鲜样、烘干样6月份生长初期氢氰酸含量最高,随着生长月份的增加,呈现下降的趋势。木薯茎叶的体外干物质消化率为77.74%。结果说明,华南7号木薯茎叶含有较高营养成分,具有较高的体外产气量和干物质消化率。     

木薯转化酶抑制子MeINH3基因的克隆及生物信息学分析

转化酶抑制子调控转化酶的活性,在植物的糖代谢过程中具有重要作用。为了研究木薯的转化酶抑制子,本实验利用木薯基因组数据库分析及RT-PCR方法,从木薯中分离了1个木薯转化酶抑制子MeINH3的cDNA序列。MeINH3序列长度为564 bp,包含528 bp的完整开放阅读框,编码127个氨基酸,N端有16个氨基酸残基的信号肽,4个保守的半胱氨酸残基可形成两个二硫桥。亚细胞定位预测表明,MeINH3蛋白定位于胞外。根据生物信息学分析结果,推测其可能抑制木薯细胞壁转化酶活性。     

QTL underlying plant and first branch height in cassava (Manihot esculenta Crantz)

Cassava, Manihot esculenta Crantz subsp. Esculenta was a major food crop across Asia and Africa. The crop was a highly heterozygous perennial woody shrub cultivated from stem cuttings. Cassava improvement for starchy tuberous roots requires about 5-6 years from F₁ hybrid seed germination to the selection of superior genotypes. Early selection with DNA markers could increase the number of elite genotypes identified. The aim here was to identify DNA markers associated with loci underlying plant and first branch height. In this study, 640 SSR primer pairs were used to screen for polymorphisms in two parental lines, cv. ‘Huaybong60’ (female) and cv. ‘Hanatee’ (male). There were 235 informative polymorphic markers used to genotype 100 individuals of an F₁ mapping population. Genotype data was analyzed by JoinMap^® version 3.0 software in order to construct a genetic linkage map. The map consisted of 156 linked SSR markers distributed across 25 linkage groups. The total length of the map was 845.2 cM (Kosambi cM) with 6.2 loci per linkage group, and an average distance between markers of 7.9 cM. Plant and first branch height of stem cuttings from the F₁ mapping population were collected from individual lines planted in 2007-2009. Quantitative Trait Loci (QTL) underlying these traits were identified using mapQTL^®/version 4.0. A total of seven QTL placed on four linkage groups were found for plant height. Of these, one major QTL was discovered on linkage group 2 near the marker SSRY155 with 17.9% of phenotypic variation explained (PVE). For first branch height, five QTL located on five linkage groups were identified. The two major QTL were located on linkage groups 2, and 20 at the loci SSRY323 and SSRY236 with 23.5% and 22.6% PVE, respectively. The QTL for plant and first branch height will serve as useful molecular markers in a cassava breeding program and may allow identification of the underlying genes in future.     

木薯MeNRT2.1基因的克隆及表达分析

木薯具有产量高、抗贫瘠等特点,为了了解其耐贫瘠的作用机理,提高木薯在贫瘠土壤中对氮素的利用率,以培养20 d的"华南5号"木薯组培苗为实验材料,采用同源克隆和RT-PCR技术,获得一个高亲和硝态氮转运蛋白(NRT2)基因,命名为Me NRT2.1,该基因含有1 593 bp的开放阅读框架,编码530个氨基酸。生物信息学分析结果表明,木薯Me NRT2.1与苜蓿、拟南芥、可可、杨树等物种的NRT2.1同源性高,其中与可可树Tc NRT2.1的亲缘关系最近,氨基酸相似性达到90%。实时荧光定量PCR检测结果表明,Me NRT2.1在木薯组培苗的根中表达,并且在NO_3~-浓度为0.2 mmol/L时,其相对表达量较高,NO_3~-浓度为10 mmol/L时其相对表达量较低,NO_3~-浓度为0时几乎不表达;Me NRT2.1在茎、叶中也几乎不表达,即该基因具有诱导型组织特异性表达模式。原生质体瞬时表达发现Me NRT2.1定位在细胞膜上。此研究为进一步通过NRT2基因提高木薯的抗逆性奠定了基础。     

Nutritional characteristics of Cassava (Manihot esculenta Crantz) leaf protein concentrates obtained by ultrafiltration and acidic thermocoagulation

Some nutritional characteristics of cassava (Manihot esculenta) leaf protein concentrates obtained by ultrafiltration were compared with that obtained by acidic thermocoagulation. Protein concentrates did not show noticable differences in their proximal composition and amino acids content. However, higher values of total carotene, available lysine, and in vitro digestibility were found, in contrast with less content of total cyanide in protein concentrates obtained by ultrafiltration. Protein efficiency ratio (PER) values of the leaf protein concentrates obtained by ultrafiltration were higher than those obtained by thermocoagulation, 1.81 and 1.60 respectively. These values increased to 2.30 and 1.90 when the concentrates were mixed with sesame flour, in proportion according to the chemical score of their proteins.     

Genotypic Variation in Responses of Cassava (Manihot esculenta Crantz) to Drought and Rewatering: Root System Development

Abstract

Soil moisture condition is a major factor that affects root system development and thus, crop production. This study aimed to evaluate genotypic variations of cassava in root system structures and their responses to different soil moisture conditions by examining various root traits including production and elongation of adventitious roots and their laterals. Four pot experiments were conducted and different genotypes of various backgrounds were grown under well-watered, droughted, droughted to rewatered conditions. One field experiment was also conducted with selected genotypes till maturity. Results showed that substantial genotypic variations exist in root system structure, and the effects of the soil moistures were significant for most of the root traits. The principal component analysis (PCA) showed that the lateral root development mainly accounted for the variations in root system structure regardless of soil moisture conditions. The PCA on the differences between droughted and well-watered control, and droughted-rewatered and the control further indicated that the branching ability of adventitious roots was mainly responsible for the root system responses to drought as well as rewatering. Genotypic ranking in root system responses to drought was almost consistent among the pots and field experiments. Genotypicvariations in rooting depth were relatively small while those in horizontal spread were apparent in the field experiment.The ability to maintain adventitious root elongation under drought, resulting in relatively large horizontal spread of root system and to recover sharply from drought by lateral root branching may be related to good growth and yield performance under field.