Effect of chromium on growth attributes in sunflower(Helianthus annuus L.)

Heavy metal soil pollution takes place when the metal concentration of soil exceeds natural background level and causes ecological destruction and deterioration of the environment.In the present study,a pot experiment was conducted to evaluate the effect of chromium-contaminated soil in sunflower(Helianthus annuus L.)growth attributes.Three different levels of chromium(Cr)i.e.,20, 40,and 60 mg/kg were applied to three varieties of sunflower(G-3,G-9,and G-59).The results of morphological,chemical,and yield p...

不同植物生长延缓剂对切花向日葵农艺性状的影响

以切花向日葵(Helianthus annuus L.)品种圣骑士为试验材料,使用80 mg/L多效唑、200 mg/L矮壮素、100 mg/L缩节胺、20 mg/L烯效唑和800 mg/L丁酰肼进行叶面喷施,以清水作为对照,在达到采收成熟度后,对不同处理条件下切花向日葵茎、叶、花性状进行测定。结果表明,与CK相比,各处理在不同程度上降低了株高、重心、叶面积和叶柄长度,提高了茎干比、叶片厚度、叶绿素含量和花盘比重。80 mg/L多效唑处理的花盘直径增加13.4%,茎粗增加37.4%,20 mg/L烯效唑处理的花盘直径增加7.3%,茎粗增加17.3%,提升了切花品质。植物生长延缓剂可使切花向日葵植株高降低,重心下降,茎干比增大,叶柄缩短,叶片缩小增厚,叶绿素含量增加,切花品质提升,其中以多效唑和烯效唑处理综合效果较好。

Occurrence of Alternaria leaf blight of sunflower caused by two closely related species Alternaria solani and A. tomatophila in Inner Mongolia

Sunflower(Helianthus annuus L.)is an important oilseed crop in China and is grown in rotation with potato in the northern parts of China,including Inner Mongolia,Hebei,Shaanxi,Shanxi,Gansu,Jilin,Liaoning and Heilongjiang provinces.In 2014,diseased samples of sunflower(variety 3638C)with black sunken lesions on bracts and stems of sunflower were collected in Wuchuan,Hohhot(41°50′N,111°27′E)and Chahaeryouyihouqi,Wulanchabu(41°52′N,113°0′E),Inner Mongolia,China.We used morphological and molecular techniques to identify the causal agent of Alternaria leaf blight.Phylogenetic analysis based on a combined phylogenetic dataset using the glyceraldehyde-3-phosphate dehydrogenase(gpd)and Alternaria major allergen gene(Alt a1)was done to support the morphological identification.In addition,PCR was performed with specific primers targeted on Alt a1 and calmodulin genes of A.solani and A.tomatophila.The results showed that HaAs7 gave an amplicon of the expected size(164 bp)with A.solani-specific primers,however,no band was observed with the A.tomatophilaspecific primers.The opposite pattern of PCR result(483 bp)was obtained with DNA of HaAt4 as template,indicating that HaAs7 is A.solani and HaAt4 is A.tomatophila.Furthermore,evaluation the pathogenicity of the recovered Alternaria isolates and their potential as causal agents of Alternaria leaf blight of sunflower was done.Pathogenicity tests showed that A.solani and A.tomatophila tested could be capable of causing Alternaria leaf blight of sunflower.Till now,nine species of Alternaria have been reported causing Alternaria leaf blight of sunflower,this is the first report that A.solani and A.tomatophila as causal pathogens for Alternaria leaf blight on sunflower.

向日葵非倍半萜成分及生物活性研究进展

向日葵(Helianthus annuus L.)为菊科向日葵属植物,是一种食用和药用的经济作物。其主要含有倍半萜、二萜、三萜、木脂素、黄酮、苯丙素、甾体等化学成分,具有抗菌、抗肿瘤、抗氧化、化感等生物活性。对向日葵中的非倍半萜类成分和生物活性进行系统综述,为进一步开发利用向日葵提供科学依据。

重金属胁迫对向日葵种子萌发特征影响评价及花海品种筛选

为了研究重金属胁迫对向日葵(Helianthus annuus L.)种子萌发影响及花海品种筛选,以32种常见向日葵观花品种为试材,采用培养皿发芽试验方法,用含Pb^(2+)、Cr^(6+)、Cd^(2+)、Ni^(2+)、Cu^(2+)和Zn^(2+)离子的溶液模拟重金属胁迫,研究重金属胁迫对发芽率、发芽势、发芽指数和平均发芽日数的影响,用隶属函数法和聚类分析法筛选耐重金属胁迫品种。结果表明,重金属胁迫对多数向日葵品种种子萌发产生低浓度促进高浓度抑制的作用,并延长种子的平均发芽日数,不同品种间耐重金属胁迫能力差异较大,耐重金属胁迫性较强的品种为金富贵、魔术回旋、满天星、金庸碧翠、醉云长和活力,耐重金属胁迫中等的品种为黄钻、宝石红芳、红柠檬等10个品种,耐重金属胁迫较弱的品种为出水芙蓉、帕蒂小葵、金太阳等16个品种。

淹水胁迫对观赏向日葵幼苗生长及生理指标的影响

试验以观赏向日葵(Helianthus annuus L.)幼苗为材料,研究了淹水胁迫对观赏向日葵幼苗生长及生理指标的影响。结果表明,淹水8 d时,观赏向日葵的株高显著低于对照(P<0.05),根系明显少于对照。淹水0~8 d时,观赏向日葵的丙二醛(Malondialdehyde,MDA)含量与对照无显著差异。淹水2 d时,观赏向日葵的超氧化物歧化酶(Superoxide dismutase,SOD)活性和脯氨酸含量均显著高于对照(P<0.05)。淹水8 d时,观赏向日葵的过氧化物酶(Peroxidase,POD)活性、可溶性糖和可溶性蛋白质含量均显著高于对照(P<0.05),且根毛区形成了通气组织。说明淹水胁迫抑制了观赏向日葵的生长,但其对淹水胁迫具有一定耐性,它一方面通过提高抗氧化酶活性和增加渗透调节物质含量来抵抗淹水胁迫,另一方面通过根系形成通气组织来适应淹水胁迫。

Coupling effects of water and nitrogen on photosynthetic characteristics,nitrogen uptake,and yield of sunflower under drip irrigation in an oasis

An experiment was conducted in an oasis area in northwest China to assess the coupling effects of water and nitrogen supply through drip irrigation on photosynthetic characteristics,nitrogen uptake,and yield of sunflower(Helianthus annuus L.),as well as the nitrate distribution in the root-zone soil.The experiment included three irrigation levels(210[W1],300[W2],and 390[W3]mm),three nitrogen levels(162[N1],232[N2],and 302[N3]kg/hm^(2)),and control treatment(no fertilization during whole growth period and only irrigated at the budding stage).A nitrogen content over-accumulation in the soil was observed under the low irrigation amount with high fertilizer supply,which cannot enhance the sunflowers’absorption of nitrogen.Excessive irrigation caused leach of the soil nitrogen,reduced nitrogen content in the root-zone soil(0-40 cm)and limited nitrogen uptake by the crop.Although low irrigation amount with high fertilizer supply can increase the nitrogen content in the soil,it cannot enhance the sunflowers’absorption of nitrogen.At the vegetative stage of sunflower growth,the accumulation of nitrogen in the organs was mainly concentrated in the leaves,while it was transferred to the flower disk at the reproductive growth stage.Reasonable coupling of water and nitrogen improved the transport of nitrogen from leaves and stems to the flower disk and promoted the formation of yield components.Six regression equations were established with irrigation and fertilization amount as independent variables,and seed rate,seed weight per flowerdisk,1000 grain weight,yield,water use efficiency and nitrogen partial factor productivity as dependent variables,respectively.Multiple regression and spatial analysis suggested that the irrigation amount of 241.62-253.35 mm and the fertilization application of 202.02-209.40 N kg/hm^(2)was a good irrigation strategy,under which all six factors exceed 75%of their maxima,and the yield of sunflower reached 3229.3 kg/hm^(2).

景观观赏性植物向日葵生物炭栽培与盐碱地土壤微生物的关系

本研究针对景观观赏性植物向日葵在添加了普通生物炭与H3PO4改性生物炭的盐碱地土壤中的生长表现进行了深入探讨,同时研究了生物炭对土壤的理化特性、微生物群落多样性及酶活性的影响。实验在盐碱地土壤中添加不同浓度的普通生物炭(1%,2%,3%)和H3PO4改性生物炭(1%,2%,3%),之后在该地种植向日葵。播种后15 d记录萌发率,45 d时,进一步检测了植物的农艺性状、叶绿素含量、Na^(+)和K^(+)含量,以及土壤的理化性质、微生物群落功能多样性和酶活性。实验结果表明:普通生物炭和H3PO4改性生物炭均有效提高了向日葵的出苗率,增强了植株高度、叶面积、地上与地下的干物质质量,增加了叶绿素含量,同时降低了Na^(+)含量并提高了K^(+)含量。此外,这两种生物炭都成功降低了土壤的pH值,并增强了土壤养分、微生物群落功能多样性及酶活性。比较两者发现,H3PO4改性生物炭在促进向日葵生长和土壤改良上的效果更为显著。综上,普通生物炭与H3PO4改性生物炭都可以显著优化盐碱地中观赏向日葵的萌发和生长,以及改进土壤的理化特性、微生物群落多样性及酶活性,其中H3PO4改性生物炭在促进生长和土壤修复方面展现了更高的潜力和应用价值。

基于转录组测序的向日葵对干旱胁迫及复水差异表达分析

为研究向日葵在不同程度干旱胁迫下基因的表达调控模式,对抗旱自交系(17062)和非抗旱自交系(167072)分别进行干旱胁迫0、4、8、12、16 d以及复水处理,本研究设置干旱胁迫第8天、第16天以及复水处理与各梯度的对照组进行转录组测序分析。共设有6个差异分组,经过测序共得到277.31G的Clean data,Q30碱基>91%,平均GC含量为45.37%。样品间进行差异基因筛选,得到的DEG数量分别为2365、2571、3149、2692、4593、4980。对各差异基因进行GO和KEGG功能注释,GO分析表明,6个比较组参与生物过程差异基因较多,参与细胞组分的次之,参与分子功能的较少;KEGG分析表明干旱胁迫对向日葵的植物激素信号转导、蔗糖与淀粉代谢、氨基酸代谢有较大的影响,对生理特性的测定显示可溶性糖和可溶性蛋白与正常供水相比具有上升趋势,表明在逆境胁迫下,植物会通过对基因的表达调控的调节来改变相关生理生化代谢途径。本研究通过对向日葵叶片进行转录组分析,对揭示抗旱分子机制及相关代谢途径具有重要意义。