Production and achievements of Sesamum indicum industry in the world:Past and current state

Sesame production is important in agriculture,food industry,and the crop diversity due to its rich nutritional profile and health benefits.Despite its significant value,sesame is still an orphan crop that has received little scientific attention,resulting in low yield compared to other major oilseed crops.This review offers a comprehensive overview of the present state of production,knowledge,and research advancements concerning Sesamum indicum on a global scale.The FAOSTAT database was extensively used to examine the global trends from 1961 to 2021.In the past 60 years,global sesame production has substantially increased,with Asia and Africa being the primary producers.The integration of omics technologies and biotechnological interventions has revolutionized our understanding of the genetic basis of sesame,enhanced productivity,invigorated stress resilience,and improved seed quality.High-throughput sequencing methods such as RNA-seq,RAD-seq,SLAF-seq,and GBS technology are used in various studies,linkage mapping,and identification of trait-associated markers.Fine linkage maps,and multi-omics studies such as genomics,proteomics,transcriptomics,and metabolomics have been employed in sesame research for gene and QTL mapping.Proteins and metabolic pathways related to oil content,yield,and stress tolerance were reported.Genes and QTLs related to yield and its components,drought,salt,and osmotic stress tolerance were discovered.Candidate genes associated with capsule shattering and seed shattering were recently revealed.For more achievement in sesame,it is important to enhance sesame production efficiency through mechanization,advanced agricultural practices,and knowledge dissemination to farmers.MAS and multi-omics integration should be particularly reinforced.The advancements in sesame production present a significant and promising opportunity for farmers,governments,and stakeholders in the agricultural sector.

Deletion of a 1,049 bp sequence from the 5′UTR upstream of the SiHEC3 gene induces a seed non-shattering mutation in sesame

Sesame is a labor intensive crop with limited mechanized harvesting mainly due to the seed shattering(SS)trait.In this study,we performed a genetic analysis of the seed-shattering resistance(SR)trait with a SR sesame mutant 12M07.Unlike the SS type,the parenchyma cells in the abscission zone of the 12M07 mutant are arranged loosely but adhere to the seed coat.Inheritance analysis of six generations derived from 12M07(SR)×Xiangcheng Dazibai(SS)showed that the SR trait is recessive and controlled by a single gene pair.Association mapping of the F2population with 888,619 variants(single-nucleotide polymorphisms(SNPs)and insertion-deletion(InDels))and 31,884 structural variations(SVs)determined that only SV12002 in the 5′upstream region of gene Sindi0765000(named SiHEC3)in Chr.3 was significantly associated with the SR trait.SiHEC3 encodes the bHLH transcription factor.A 1,049 bp deletion occurred in the 5′UTR of Sihec3 in 12M07.SiHEC3 is mainly expressed in developing placental tissues,with the expression peaking in capsules at 45 days after pollination.A dual-luciferase reporter assay in tobacco confirmed that the promoter activity of Sihec3 was reduced because of the deletion of the 1,049 bp promoter sequence.Protein–protein interaction network analysis showed that HEC3 is co-expressed with nine key proteins,such as SHATTERPROOF1(SHP1)and SEEDSTICK(STK)which participate in the secondary wall biosynthesis of the abscission layer in plants.The findings of this study show the important function of Sihec3corresponding with the SR trait and supply the genetic information for breeding new varieties that are amenable to mechanized harvesting in sesame and other crops.

Genetic Diversity Assessment of Moroccan Sesame(Sesamum indicum L.)Populations Using Agro-morphological Traits

Genetic diversity of Moroccan sesame(Sesamum indicum L.)was analyzed for the first time using agro-morphological traits.Thirty-three sesame populations collected from Tadla region in Morocco were evaluated for 13 parameters in three contrasted environments,Afr-13,Afr-14 and Atj-14.Broad and significant variation among populations was observed only for three agro-morphologic traits,namely first capsule height(FCH),number of seeds per capsule(NSC)and thousand seeds weight(TSW).The respective overall averages were 71.82 cm(ranging from 65 cm to 77 cm),61.39(varying from 57 to 65)and 3.20 g(ranging from 3.0 g to 3.4 g).Environment had a highly significant effect on all studied parameters,except capsule size and oil content.The obtained mean values of parameters studied showed that environment Afr-14 was the most favorable for most of them,particularly seed yield(1.32 t/ha)and TSW(3.57 g).Significant and interesting correlations were observed between seed yield per plant(SYP)and other parameters.As relevant implication of this finding,number of capsules per plant(NCP)and NSC could be used as valuable selection criteria in sesame breeding program.However,limited and non-significant variation among sesame populations for most of parameters studied suggests that they are genetically very close and may be derived from a single cultivar or germplasm.Molecular characterization is needed to confirm or refute this hypothesis.Besides,when compared with sesame grown throughout the world,Moroccan sesame was found to be very promising,which open up the possibility to develop this crop in this country.

Effect of Microclimatic Modification on Growth and Yield of Sesame （Sesamum indicum L.） in a Semi-Desert Region of Northern Sudan

An investigation was carried out in the semi- desert region of northern Sudan, during 2000, to study the influence of different micrometeorological parameters on growth and yield of sesame under alley cropping system. Sesame, cv. Kenana-2, was grown in 6-m wide alleys formed by 3 year old Acacia ampliceps and Acacia stenophylla. Air temperature, relative humidity, wind speed, solar energy and shade behaviour were measured throughout the growing season. Irrigation was measured by water meter and soil moisture by gravimetric sampling at depths of 15, 30, 45 and 60 cm, in alley cropping and control plots. Sesame was evaluated for growth and yield performance in southern, central and northern parts of each alley. The results showed substantial reduction in wind runs, solar radiation and air temperature, while relative humidity was increased under alley conditions. Soil moisture content, especially in the upper 045 cm soil depth, was much higher in alley cropped plots than in the control plots. A. stenophylla resulted in the highest saving of irrigation water and considerably increased （40%） sesame seed yield. In contrast, sesame seed yield was reduced by 46% under A. ampliceps-alley cropping. Competition for light and water were highly responsible for variation in sesame seed yield in the different zones of the alley. A. stenophylla tree is, therefore, recommended in an alley cropping system in the semi-desert region of northern Sudan for its superiority in optimizing radiation and saving of irrigation water.

芝麻栽培种与野生种(Sesamum schinzianum Asch、Sesamum radiatum Schum & Thonn)种间杂交后代的生物学特性

【目的】探明芝麻栽培种与野生种种间杂交的亲和性,分析杂交后代遗传特征。【方法】以26个基因型(Sesamum indicum L.)与刚果野芝麻(Sesamum schinzianum Asch)和野芝1号(Sesamum radiatum Schum&Thonn)野生种为杂交亲本,借助胚培养技术获得种间杂交后代。采用SSR标记和生物学方法鉴定并分析杂交种F1的遗传特性。【结果】通过胚培养技术获得2 430个种间杂交F1株系,对部分材料的检测表明杂种阳性率为95.83%。刚果野芝麻×栽培种的正反交杂交率分别为34.62%(A)和11.54%(C),野芝1号×栽培种的正反交杂交率分别为100%(B)和19.23%(D)。F1花粉粒存在部分不育和高度不育两种类型,F1自交结实率分别为2.32—2.57粒/蒴果(S.schinzianum×S.indicum)和0.30—2.45粒/蒴果(S.radiatum×S.indicum)。【结论】S.radiatum与栽培种的杂交亲和率高于S.schinzianum。以野生种为母本与栽培种杂交,杂交种F1在株高、根系结构等性状方面超亲表现明显;株系高抗枯萎病;部分F1株系有低自交结实性。

Analysis on Genetic Diversity and Genetic Basis of the Main Sesame Cultivars Released in China

SRAP （sequence-related amplified polymorphism） was used for the analysis of 67 sesame （Sesamum indicum L.） cultivars widely used in Chinese sesame major production areas from 1950 to 2007. A total of 561 bands were amplified using 21 SRAP random primer pairs, with 265 of them were polymorphic, resulting in a polymorphism ratio of 47.2%. The total bands and polymorphism amplified by each primer pair averaged 26.7 and 12.6, respectively. The average genetic similar coefficient and genetic distance of the 67 cultivars were 0.9104 and 0.0706, respectively, indicating limited genetic diversity and narrow genetic basis. Comparative analysis on genetic similarity and genetic distance of different classified cultivars showed that the difference of average genetic similarity coefficient and genetic distance between the landraces and cultivars bred through crosses reached significant levels （P=0.01）, with the genetic basis of landraces wider than that bred cultivars. The genetic basis of cultivars used in 1990-2007 was more narrow than that of cultivars from 1950 to 1969 and from 1970 to 1989, with the differences of average genetic similarity coefficient and genetic distance reached 0.01 significant level. The genetic basis of Chinese sesame main cultivars is relatively narrow, and the genetic basis of cultivars developed through crosses in recent years is narrower than history cultivars.

Triple test cross analysis for seed yield and its components in sesame under water stress conditions

Water deficit is a limiting factor in sesame cultivars yield,thus identification of genetic mechanisms of sesame traits under water stress conditions is essential to development of water stress tolerant genotypes.Hence,the triple test cross(TTC)analysis in F_(2) population of the sesame cross(NA_(76)NA_(54))was used.Since,30 TTC families with their 13 respective parents were evaluated during the summer season 2020 under two irrigation treatments.i.e.,normal irrigation with 5952.38 m^(3) hm^(-2) of applied water,and water stress with 2976.19 m^(3) hm^(-2) of applied water.This was implemented at the experimental field of Kafr El Hamam/Sharkia,Agricultural Research Station,Agricultural Research Center(ARC),Egypt.Additive(D)and dominance(H)gene actions as well as epistatic and its two components of additiveadditive,additivedominance plus dominancedominance were involved in the inheritance of all studied traits under both irrigation treatments and their combined analysis.The degree of dominance(H/D)^(0.5) verified the presence of partial dominance in most cases.The correlation coefficient between sums(additive)and differences(dominance)was non-significant,showing that dominant genes between lines were ambidirectional.The moderately water stress tolerant TTC families as the best selected families were found in families 22,25,10,12,and 15.Therefore,postponing selection in these selected families to later segregating generations for all studied traits would be effective to exploit the positive effects of additiveadditive epistasis.

钾营养对花期干旱胁迫芝麻生长及叶片氮代谢的影响

为探究花期干旱胁迫下不同钾肥水平对芝麻(Sesamum indicum L.)生长和叶片氮代谢的影响,以及芝麻响应干旱胁迫的生理机制,以赣芝7号为试验材料,采用盆栽控水试验方法,设置3个钾肥水平(0、60、120 kg·hm^(-2);K_(2)O)和2个土壤水分处理(75%±5%和45%±5%田间持水量),对比不同钾肥水平下芝麻生长、氨基酸、可溶性蛋白含量、氮代谢酶活性等指标的差异。结果表明,干旱胁迫严重抑制芝麻生长,与正常灌水相比,干旱处理芝麻叶片相对含水量、株高、比叶重和叶绿素值分别平均下降8.2个百分点、23.5%、8.1%和6.6%。干旱导致芝麻叶片的氮代谢能力减弱,与正常灌水相比,干旱处理芝麻叶片的氮、钾、可溶性蛋白(SP)和氨基酸(AA)含量分别平均提高5.4%、10.6%、21.1%和52.7%,硝酸还原酶(NR)和谷氨酸合成酶(GOGAT)活性分别平均下降11.3%和16.6%。干旱胁迫下,与不施钾相比,施钾使芝麻叶片相对含水量、株高、比叶重、叶绿素值、钾、氮含量分别提高3.3~7.2个百分点、20.9%~39.0%、3.2%~5.5%、1.0%~4.5%、14.8%~19.6%、2.0%~5.4%;硝酸还原酶和谷氨酸合成酶活性分别提高8.7%~9.5%和15.1%~20.0%。相关性分析表明,干旱胁迫下,叶片钾含量与氮、SP、FAA含量及NR、GOGAT活性呈显著或极显著正相关(R^(2)=0.69~0.95)。综上所述,施钾可缓解干旱胁迫对芝麻造成的不利影响,提高叶片钾、氮含量及硝酸还原酶和谷氨酸合成酶活性;施钾主要通过调控渗透调节、蛋白质合成及氮代谢等途径来提高芝麻的耐旱性。本研究结果为芝麻抗旱栽培提供了科学依据。

Biological effects of low-energy C ion implantation on sesame(Sesamum indicum L.)

Field cultivation experiments on white sesame(Sesamum indicum L.)seeds implanted with low-energy C ion showed that different dosages of C ion implantation pro-duce different biological effects.Sesame plants in 6 different dosage groups with C ion density respectively at 1×10^(11),1×10^(12),1×10^(15),5×10^(15),1×10^(16),5×10^(16)ion/cm2 were superior to the control group in plant height,leaf number,stalk diameter and leaf size.Further,sesame plants in these groups flower and seed earlier than those in the control group,and single plant yield also increased.Of all the groups,the 5×10^(15)ion/cm2 dosage group yielded the best effect,whereas the 1×10^(17)/cm^(2)dosage group showed an evident inhibitory effect of ion implantation on the germination and growth of the sesame seeds.

芝麻EST-SSR标记的开发和初步研究

为加速分子标记在芝麻研究中的应用,利用网上现有的芝麻EST(expressed sequencetags)数据信息,开展了芝麻EST-SSR功能性标记的开发和利用研究。在所有的3328条芝麻EST序列中共确认得到1785条非冗余EST序列。其中,在含有微卫星重复的148条序列中共检测有155个EST-SSR。非冗余EST序列总长为774.27kb,平均每4.99kb含有一个EST-SSR。EST-SSR的分布频率和特征分析表明,以AG/TC为重复基元(motif)的SSR出现最多,占总SSR的37.42%。利用这些序列,设计开发了50对EST-SSR引物,并分别选用36个芝麻、2个棉花、2个大豆和2个油葵进行多态性和通用性研究。其中44对引物在供试芝麻材料中扩增出条带,共产生108个位点,平均每对引物产生2.45个位点,多态信息含量(polymorphism information content,PIC)平均值为0.390。根据遗传相似性系数进行聚类,有26个芝麻材料聚类在两个大的亚类(III和IV)中,聚类结果表明芝麻的基因型与地理来源之间没有必然的联系。此外,分别有2对、3对和4对引物可以在棉花、大豆和油葵中进行通用性扩增。本研究证实这种全新开发的芝麻EST-SSR标记在芝麻遗传多样性分析、遗传图谱构建以及比较基因组等研究方面有广阔的利用前景。

芝麻资源群体结构及含油量关联分析

【目的】推测芝麻资源群体材料的遗传变异、群体结构和分子亲缘关系,通过关联分析检测群体中影响含油量表型的位点,为芝麻高油育种及开展其它性状关联分析等提供科学依据。【方法】利用20对SSR引物、43对SRAP引物及16对AFLP引物,对来自芝麻核心品的216份芝麻资源进行遗传多样性分析、群体结构分析和含油量性状关联分析。【结果】共检测到338个等位变异,群体遗传多样性为0.2493、多态性信息含量为0.2090。群体结构分析将216份芝麻资源分为2个亚群(POP1和POP2);其中,174份资源(80.56%)归属POP1亚群,42份资源(19.44%)归属POP2亚群。POP1亚群的遗传多样性(0.2180)、多态性信息指数(0.1840)等指标值都低于POP2亚群(分别为0.3190和0.2561),表明POP2亚群内种质遗传变异更为丰富。AMOVA分析表明,亚群内的遗传变异(86.83%)极显著高于亚群间的遗传变异(13.17%)(P<0.001)。关联分析重复检测出2年环境下与含油量性状极显著关联的分子标记8个(P<0.01)。这8个标记的性状变异解释率变幅为0.0343(标记M20E16-8)—0.0587(标记SSR12-2),总的变异解释率为0.2846(2008年)和0.3801(2009年)。【结论】以216份来自中国芝麻核心品的资源构成自然群体,群体结构简单、遗传变异较为丰富,可以用于开展芝麻重要目标性状的关联作图。应用关联分析方法在2个年度环境下重复检出8个标记与含油量性状极显著关联(P<0.01),这些标记可能与含油量性状存在稳定、可靠相关联。

芝麻发育转录组分析

【目的】系统了解芝麻发育及种子形成转录组特征,丰富芝麻转录组数据信息。【方法】选用6份芝麻样品(5个不同芝麻品种的完整植株、1份不同发育阶段的芝麻籽粒),构建转录组测序文库并进行Illumina RNA-seq双端测序及生物信息学分析。【结果】共获得原始数据12.69 Gb,有效数据8.80 Gb。通过de novo拼接获得了长度大于100 bp的转录物26 837条(http://www.ncbi.nlm.nih.gov/genbank/TSA.html,登录号:JP631635—JP668414);转录物总长度18.35 Mb,平均长度683 bp,N50长度1 006 bp。转录物注释结果显示,25 331条转录物序列具有同源比对信息;1 506条转录物序列无匹配(no hits)序列信息,可能为芝麻特有的基因序列。采用COG、GO功能分类工具可将已注释转录物序列划分为24个或42个功能类别,共涉及物质及能量代谢、信号传导、转录调控及防卫反应等诸多生理生化过程。通过比较不同材料间转录物序列及表达水平,初步确定1 277条序列在种子形成过程中表达量下调10倍以上,990条序列仅在芝麻植株中表达而未在籽粒中表达;660条序列在种子形成过程中表达量上调10倍以上,296条序列可能与种子形成特异相关。【结论】利用高通量测序技术对芝麻野生种和不同栽培种现蕾期植株以及种子形成过程的转录组进行研究,揭示了芝麻发育转录组的整体表达特征,在得到大量芝麻转录组unigene序列的同时,获得了一批在芝麻生长发育及籽粒形成过程中有重要功能的基因序列。为深入开展芝麻生长发育、籽粒发育相关基因功能及调控以及芝麻分子标记开发等研究提供了丰富的数据资源。

芝麻不同抗旱基因型对花期干旱胁迫的生理响应机理

【目的】研究干旱胁迫对不同抗旱性芝麻品种叶片和根系生理生化特性的影响,分析不同基因型芝麻对花期干旱胁迫的生理响应差异,为芝麻抗旱性研究和改良提供理论参考。【方法】采用盆栽法,以抗旱品种金黄麻和干旱敏感品种竹山白为试验材料,在花期进行轻度(T1)、中度(T2)和重度(T3)干旱胁迫处理,以正常浇水为对照(CK),分别测定植株叶片和根系的丙二醛(MDA)、过氧化氢(H_2O_2)、脯氨酸(Pro)、可溶性糖(SS)、可溶性蛋白(SP)、游离氨基酸(AA)、还原型谷胱甘肽(GSH)、还原型抗坏血酸(AsA)等含量,超氧化歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和苯丙氨酸解氨酶(PAL)活性,分析干旱胁迫下2个基因型间生理响应机理的差异。【结果】干旱胁迫后,芝麻叶片中MDA、H_2O_2、Pro、SS、SP、GSH含量和SOD、POD、PAL酶活性以及根系中MDA、SS、SP、AA、GSH、AsA含量和CAT、PAL活性随着胁迫程度的不断加剧呈不断上升趋势,叶片中的AA、AsA含量和CAT活性以及根系中H_2O_2、Pro含量和SOD、POD活性随着胁迫程度的加剧呈先升后降趋势。相关分析结果显示,叶片中各项指标测定值与根系中指标值均呈正相关,品种抗旱性与膜脂过氧化伤害物质(MDA和H_2O_2)含量呈负相关,与部分渗透调节物质、防御系统物质含量和保护酶活性呈正相关。【结论】在花期干旱胁迫下,对2个不同基因型芝麻测定的12个生理生化指标均出现不同程度上升,响应差异较大,叶片大于根系。抗旱品种较干旱敏感品种表现为细胞膜脂过氧化伤害较轻,渗透调节物质积累量较多,保护酶(SOD和CAT)活性较强,抗氧化物质(GSH和AsA)含量较高。芝麻抗旱性生理机理表现为多方面的综合防御。

氮肥与密度互作对红壤旱地秋芝麻的影响

为提高红壤旱地秋芝麻的产量、品质和氮肥利用率,以赣芝5号为供试品种,设3个密度(D_122.5万株/hm^2、D_230.0万株/hm^2、D_337.5万株/hm^2)和4个氮肥水平(N_00、N_152.5kg/hm^2、N_2105.0kg/hm^2、N_3157.5kg/hm^2),分别于2014年在江西省东乡县和2015年在进贤县进行田间小区试验,研究施氮量和种植密度对芝麻产量、品质及氮肥利用率的影响。结果表明,两年两地均表现为N_2条件下芝麻产量较N_0显著增加(分别增加49.82%和76.53%)。2014年东乡点D_3处理的芝麻产量较D_处理显著增加18.44%,但2015年进贤点较D_显著减少12.35%。随着氮肥用量的增加芝麻籽粒含油量呈现先增加后降低的趋势,蛋白质含量则呈现逐渐增加的趋势;施用氮肥显著减少了17.8%~20.0%的芝麻素含量,而对芝麻林素无显著影响。随着密度的增加芝麻单株蒴果数和千粒重都随之降低,而不同密度对芝麻品质无明显影响;N_2水平时,不同密度处理的氮肥农学利用率和偏生产力稳定在3.29~4.84和9.89~11.17kg/kg。综上所述,红壤旱地芝麻适宜氮肥用量为105kg/hm^2,进贤县及其周边区域的单秆型品种适宜密度为22.5万株/hm^2,而东乡县及其周边区域适宜密度为37.5万株/hm^2,能够达到高产优质的目的,值得在红壤旱地上大面积应用推广。

芝麻耐湿性QTL定位及优异耐湿基因资源挖掘

【目的】芝麻是对湿害极其敏感的作物,湿害是影响中国芝麻生产发展和单产提高的主要障碍因素,然而,芝麻耐湿性分子生物学研究基础薄弱,迄今,国内外有关芝麻耐湿性基因定位的研究尚未见报道。利用重组自交系(RIL)群体进行芝麻耐湿性QTL定位,结合芝麻核心种质群体进行耐湿性相关分子标记研究,并挖掘优异耐湿基因资源。【方法】以高耐湿芝麻品种中芝13与极敏感种质宜阳白杂交后连续自交6代构建206个株系的RIL群体。利用113对多态性分子标记扫描RIL群体获得基因型数据,用MapMaker/EXP.3.0软件构建遗传连锁图谱。2009年和2010年在武汉和鄂州2地点通过人工淹水胁迫获得RIL群体盛花期湿害后正常株率和存活株率的表型数据,用Microsoft Excel 2010软件进行表型数据方差分析,用QTLNetwork 2.0软件基于复合区间作图法进行QTL定位,利用主效QTL紧密连锁的分子标记扫描核心种质群体,并结合耐湿性表型数据分析得到相关有效分子标记。通过盛花期耐湿性表型重复鉴定筛选,结合分子标记辅助选择,获得优异耐湿基因资源。【结果】构建的遗传连锁图谱全长592.4 cM,共有70个标记位点进入15个连锁群,标记间的平均距离为8.46 cM。共检测到与盛花期耐湿性相关的6个QTL位点,定位在第7、9、13和15连锁群上,分别解释5.67%—17.19%的表型变异,加性效应值2.7190—9.7302,贡献率最大的QTL为qWH10CHL09,加性效应3.9394,其增效等位基因来源于母本中芝13,SSR标记ZM428与其紧密连锁(遗传距离为0.7 cM)。标记ZM428在186份芝麻核心种质中验证结果表明,该标记2种基因型的资源间在耐湿表型上存在显著差异(P=0.0163),因此,标记ZM428可作为芝麻耐湿性分子辅助选择的有效标记。还挖掘出8份优异耐湿基因资源,湿害后其正常株率均>70%,存活株率均>80%。【结论】检测到6个芝麻耐湿性相关QTL,其中,贡献率最大的17.19%,获得1个有效分子标记,挖掘出8份优异耐湿基因资源。

中国主要黑芝麻品种的遗传多样性分析

利用SRAP和SSR各23对引物对20个中国主要黑芝麻品种进行了遗传多样性分析。结果显示,23对SRAP引物共扩增出DNA带672条,其中多态性带152条,比率为22.62%,平均每对引物扩增总带数和多态性条带分别为29.22条和6.61条。23对SSR多态性引物共扩增出DNA带92条,每对引物扩增出3~6条,平均4.00条;每对引物扩增出多态性带1~5条,平均3.09条,多态性带比率平均为77.17%。20个黑芝麻品种间的遗传相似系数为0.8547~0.9804,遗传距离为0.0159~0.0921,遗传多样性匮乏,遗传基础狭窄。聚类结果表明,来自主产区江西的11个品种明显聚在一起,且江西黑芝麻品种的遗传相似系数高于其他省份品种,遗传距离低于其他省份品种,与其他省份品种的差异均达到极显著水平。加强资源引进和利用是拓宽中国黑芝麻品种遗传基础的迫切要求。

芽期Al^(3+)胁迫对芝麻幼苗生长的影响及种质资源耐铝毒性评价

铝毒害是影响江西省红壤作物生长的重要因素之一,为了解铝对芝麻生长的毒害,发掘耐铝毒种质资源,用Al2(SO4)3·18H2O溶液模拟发芽期Al3+胁迫研究不同浓度Al3+对芝麻品种赣芝9号和赣芝12成苗及幼苗生长的影响。结果表明,Al3+浓度在0~100mg/L时,随着Al3+浓度的增加,成苗率、芽长、根长和苗鲜重均不断下降,且根长下降最为明显;而浓度在250~1 000mg/L时,芝麻难以成苗。Al3+浓度在50mg/L时,成苗率、芽长、根长和苗鲜重等测定指标均急剧下降,因此可认为50mg/L的Al3+浓度胁迫可以作为芝麻种质耐铝毒性筛选鉴定的参考浓度。进而在50mg/L Al3+胁迫下评价96份芝麻种质[含39个改良品种(系)和57份地方种质],可将它们聚为3类,即包含21份耐铝毒种质、37份中等耐铝毒种质和38份不耐铝毒种质;发掘出赣芝9号、金黄麻、武宁黑等21份耐铝毒种质。比较分析表明,地方种质资源的平均耐铝毒特性要优于改良品种(系),且除成苗率外,地方种质耐铝毒性的其他指标的变异系数和多样性指数均大于改良品种(系)。

我国芝麻主产区茎点枯病病原菌生物学特性分析

在国内首次对我国湖北、河南、安徽、江西等芝麻主产区进行了较大范围的芝麻茎点枯病病原采集和菌株分离,纯化培养得到35个菌株。通过比较病原菌在不同培养基、不同诱孢处理方式、不同诱孢培养条件等,确定适宜培养条件为普通PDA培养基28℃黑暗培养4～5 d切断菌丝,再培养4～5 d,建立了一套较成熟的芝麻茎点枯菌株分离培养纯化技术。对35个菌株的菌落、菌核的形态特征进行了系统观察,测定了不同菌株的致病力,并对其rDNA-ITS区进行了测序,表明均为菜豆壳球孢(Macrophomina phaseolina(Maubl.)Ashby)。35个菌株在表型和致病力等方面存在较为明显的差异,为有针对性的开展芝麻茎点枯病的防治奠定了重要基础。

芝麻空间诱变品系(种)的DNA指纹分析

【目的】揭示芝麻空间诱变品系(种)的DNA水平上的变异,探讨芝麻空间诱变的分子机理,以期为作物空间诱变育种提供理论基础。【方法】首次应用AFLP标记对芝麻空间诱变的3个品系(种)及原始对照种豫芝4号(未搭载处理的留地种子)进行DNA指纹分析。【结果】随机组合的30对AFLP引物对原始对照种及3个空间诱变品系(种)进行扩增,共获得1176条DNA谱带,其中多态性谱带625条,多态性位点比率为53.15%,每对引物均扩增出多态性,并且每一个空间诱变品系(种)与原始对照种间均扩增出多态性DNA谱带。利用NTSYS软件进行类平均法(UPGMA)聚类发现3个空间诱变品系(种)明显地聚在一起,与原始对照种存在较大差异。【结论】通过空间诱变能够在DNA水平上导致芝麻遗传物质变异,空间诱变是一种有效的育种途径。AFLP是一种研究植物空间诱变材料的高效率的分子生物学方法。

芝麻种子萌发动态及其代谢生理变化研究

为明确芝麻种子萌发过程的代谢生理变化,丰富芝麻种子生物学内容,在25℃暗培养条件下,以2个芝麻品种为材料,研究了种子萌发0~72 h过程中的形态变化、水分吸收以及可溶性糖、可溶性蛋白、氨基酸、粗脂肪、游离脂肪酸和脂肪酶活性等代谢生理指标的变化。结果表明,芝麻种子在浸水后6 h吸胀,12 h萌动,24 h胚根开始快速伸长,48 h胚芽开始快速生长,72 h完成发芽。吸水率呈现不断上升的趋势,其中在0~6 h和24~60 h 2个时间段表现为急速上升;吸水速率呈现先降后升再降的变化过程,其中在0~3 h时下降最快,在胚芽开始生长(吸水后48 h)后再次出现较大幅度上升。随着萌发进程的推进,可溶性糖含量和可溶性蛋白含量均表现为先降后升趋势,氨基酸含量不断下降,粗脂肪含量在24 h后有所下降,游离脂肪酸含量呈现先降后升再降的变化趋势,脂肪酶活性不断增强,棕榈酸、硬脂酸、油酸和亚油酸等主要脂肪酸组成变化非常小。因此,芝麻种子萌发过程中,最先启动糖代谢,随后启动蛋白质和脂肪的代谢。研究结果为芝麻种子萌发机理进一步研究提供参考。