不同浓度2,4-D对罗布麻茎尖诱导成活率的影响

采用MS基本培养基,分别添加不同浓度的2,4-D、6-BAI、BA,筛选适合罗布麻组织培养的最佳培养基。结果表明:最适合罗布麻诱导分化的培养基为C(MS+2,4-D 0.9 mg/L+6-BA 1.5 mg/L+琼脂8 g/L+蔗糖30 g/L)、D(MS+2,4-D 1.1 mg/L+6-BA 1.5 mg/L+琼脂8 g/L+蔗糖30 g/L)。     

Somatic embryogenesis and Agrobacterium-mediated transformation of Japanese apricot (Prunus mume) using immature cotyledons

This study describes a successful method of somatic embryogenesis and genetic transformation using immature cotyledons of Prunus mume. Immature cotyledons from four different developmental stages of eight different P. mume cultivars were used for the experiments to optimize somatic embryogenesis and genetic transformation protocols. Somatic embryogenesis was induced when the explants were cultured on somatic embryo inducing medium consisting of MS basic medium supplemented with 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 1 μM 6-benzyladenine (BA). They were cultured for 30 days and then transferred to somatic embryo propagation medium containing 0.1 μM α-naphthaleneacetic acid (NAA) and 5 μM BA. It appeared that the developmental stage of the immature cotyledons used as explants was the most important factor for somatic embryogenesis; higher frequencies of somatic embryogenesis were observed when the immature cotyledons were less than 5 mm in length regardless of cultivars. For genetic transformation, the immature cotyledons were inoculated with Agrobacterium tumefaciens EHA101 harbouring a binary plasmid vector with neomycin phosphotransferase II and an intron-interrupted β-glucuronidase gene under the control of cauliflower mosaic virus 35S promoter, and three transgenic plant lines were obtained from inoculated “Sirakaga” immature cotyledons. Transgenic somatic embryos and shoots were selected using 25 mg l⁻¹ kanamycin. Integration of transgenes in the genome of GUS-positive putative transgenic shoots was confirmed by PCR and Southern blot analyses.     

棉花抗除草剂2,4-D品系抗性遗传分析

利用高抗除草剂2,4-D的亲本与不抗除草剂的品系配制组合,对亲本、F1和F2植株进行抗性鉴定、调查、统计,进行棉花抗除草剂2,4-D性状遗传分析,结果表明,棉花除草剂2,4-D抗性性状是由一对显性基因控制。该抗除草剂性状属于质量性状遗传,便于在棉花育种中利用,抗性水平较高,能达到800mg/kg以上水平。抗除草剂性状可以在棉花常规育种和杂交种生产利用中发挥作用。     

甘蓝型冬性和半冬性油菜子叶高效快速芽再生体系的建立

以甘蓝型油菜子叶为外植体,研究了不同激素浓度、组合以及预培养等条件对芽再生的影响.将子叶在含1mg/L 2,4-D和1mg/L BA的MSB5培养基上预培养3d后转入芽分化培养基,可明显提高芽再生频率,再生周期也可缩短三分之一,但延长预培养时间则导致再生频率下降.实验中10个冬性和半冬性油菜品种的平均再生频率达81.9%,其中9个品种的芽再生频率均在75%以上,最高可达98.9%.     

平阳霉素对花生体细胞胚胎发生的影响

本文对花生离体培养高频率体细胞胚(体胚)诱导方法,及平阳霉素(PYM)对体胚发生的抑制作用进行了研究,旨在为以PYM作为化学诱变剂进行花生离体诱变提供有效方法.以花生品种花育20号和花育22号成熟种子的胚小叶为外植体,在添加不同浓度2,4-D(0,5,10,15,20mg/L)的MSB5(MS无机盐+B5有机成分)培养...     

植被三维结构对水蚀红壤粒径分布及养分含量的作用

基于福建省长汀县河田镇48个样区(15 m×15 m)植被垂直分层类型,不同垂直层次的总体植被覆盖度、枯落物厚度、土壤粒径分布及养分含量3类土壤属性数据,分析植被特征与土壤属性间的相互关系,并比较不同侵蚀程度、不同垂直结构类型下植被覆盖度、枯落物厚度与土壤粒径分布及养分含量的差异.结果表明,植被覆盖度、枯落物厚度与侵蚀程度显著负相关,与土壤中有机质含量、全氮含量、全磷含量显著正相关,但与全钾含量差异不显著.当植被覆盖度达到50％、枯落物厚度达到20 mm时,可以有效保持水土,其中枯落物较上层植被的水土保持作用更明显.不同植被垂直结构组合中,选择林灌草、林灌、灌草、纯草均可以较好地促进植被生长、改良土壤结构、保持土壤肥力.     

Adsorption and degradation of 2,4-dichlorophenoxyacetic acid in spiked soil with Fe0 nanoparticles supported by biochar

This work studies the adsorption and degradation of 2,4-dichlorophenoxyacetic (2,4-D) in spiked soil with nanoscale Fe⁰ particles (nFe⁰) and biochar derived from maize straw. When biochar concentration was high, the adsorption capacity of soil was enhanced. Furthermore, 2,4-D degraded completely at loading rates of 0.33 and 0.17 g/L nFe⁰ plus biochar (initial 2,4-D concentration of 10 mg/g) within 40 h, according to equilibrium data. Additionally, the theoretical concentration of chloridion was approximately 84%. Further analysis indicated that the effect of nFe⁰ on 2,4-D degradation was weaker in soil columns than that in soil slurry. By contrast, 2,4-D degradation is positively influenced by biochar application, which prevented the aggregation and corrosion of Fe nanoparticles. Although the enhanced capacity for 2,4-D adsorption on the soil decelerated dechlorination rate, long-term nFe⁰ activity was generated. After 72 h, the efficiency of 2,4-D degradation was approximately 53.2% in the soil columns with biochar support.     

向日葵种子蛋白质的微量提取和双向电泳技术研究

从向日葵干种子的中轴(包括胚芽、胚轴及胚根)和子叶的微量样品中提取蛋白质的技术进行了研究,并在此基础上对提取的蛋白质进行了SDS-聚丙烯酰胺凝胶为基础的单向和双向电泳分析,获得清晰的电泳图谱.结果显示:向日葵胚中轴与子叶样品中的蛋白质存在明显差别,而子叶的上部、中部和下部的蛋白质图谱比较相似.通过进一步的双向电泳对比分析可知,胚中轴与子叶的蛋白质相似性系数为0.785,两种组织均具有特异性蛋白质;胚中轴特异蛋白质有18种,子叶特异蛋白质有10种.这些研究结果为进一步的组织特异性蛋白质鉴定及研究子叶和胚中轴的发育机理,以及开展向日葵种子蛋白质组学的研究奠定了实验基础,同时对农业生产中种子纯度鉴定、种子生活力检验及种子发芽实验亦可能具有研究和利用价值.     

几种植物生长调节剂对满天红梨采前落果的影响

此项试验旨在探讨防止满天红梨采前落果的有效途径。试验结果表明：采果前一个月对树冠喷施10~30mg/L的2,4-D、50~200mg/L的GA3和10~40mg/L的NAA对防止满天红梨采前落果均具有极显著作用。在不同浓度处理中，2,4-D和NAA均以20 mg/L的处理效果最好，坐果率分别比对照提高了13.7个百分点和16.8个百分点，GA3以100 mg/L的处理效果最好，坐果率比对照高14.8个百分点。     

紫花苜蓿品种'德宝'不同外植体愈伤组织诱导研究

以紫花苜蓿'德宝'的下胚轴、叶片、子叶和叶柄为外植体,研究了不同浓度(1.5、2.0、2.5 mg/L)2,4-D对各外植体愈伤组织诱导的影响.结果表明:4种不同外植体的愈伤组织发生能力存在显著差异,下胚轴的愈伤组织诱导率最高,达98.5％,显著高于叶片(P＜0.05),其他各外植体之间差异不显著.不同浓度2,4-D下各外植体愈伤组织发生也存在显著差异,浓度1.5 mg/L和2.0 mg/L的2,4-D MS培养基对愈伤组织的诱导效果优于浓度2.5 mg/L的2,4-D MS培养基(P＜0.05),且有利于愈伤组织的胚性化.另外,2,4-D浓度在1.5～2.5 mg/L范围内,低浓度利于叶片和子叶愈伤组织发生,二者在1.5mg/L浓度下的愈伤率可达100％,显著高于2.5 mg/L浓度处理,而叶柄和下胚轴的愈伤率在各浓度下差异不显著.