暗期短暂远红光处理对南瓜幼苗生长、细胞形态和激素含量的影响

【目的】研究暗期前短暂远红光处理对南瓜幼苗生长形态、组织细胞形态和相关激素水平的影响,为远红光在农业上的应用提供理论依据。【方法】以南瓜品种‘日本雪松’为试验材料,分别在暗期前给予2（T1）、4（T2）、6（T3）、8（T4）、10（T5）和12（T6）mmol·m^-2·d^-1的远红光处理,以无远红光处理为对照（CK）,测定植株生长形态下胚轴细胞形态以及生长素（IAA）、玉米素（ZT）、赤霉素（GA₃）与油菜素内酯（BR）含量。【结果】在暗期短时外施远红光能显著提高南瓜幼苗下胚轴长度和株高,对植株茎粗,地上、地下部干/鲜重无显著影响;2、4、6、8、10和12 mmol·m^-2·d^-1远红光处理的下胚轴薄壁细胞轴向长度分别比CK显著增加34.6%、20.7%、31.3%、25.6%、32.8%和20.9%;下胚轴厚角组织厚度分别比CK显著增加19.6%、22.4%、21.2%、23.9%、19.6%和28%;经暗期前远红光处理后,南瓜幼苗根中生长素（IAA）含量,下胚轴中生长素（IAA）、赤霉素（GA₃）、玉米素（ZT）含量,子叶中生长素（IAA)、赤霉素（GA₃）、油菜素内酯（BR）含量以及真叶中生长素（IAA）与油菜素内酯（BR）含量均得到显著提高。【结论】暗期前短时远红光处理可能通过提高激素含量,进而改变细胞形态,促进下胚轴伸长生长。     

苋菜试管开花初探

以苋菜试管苗为材料,研究多种因子对苋菜试管开花的影响.结果表明:(1)基本培养基MS和1/2MS对苋菜试管开花的影响不大.(2)单独添加NAA,可促进苋菜试管开花；苋菜试管开花对IBA含量的变化较敏感；6-BA含量为1.0 mg.L-1时的开花率最高,培养50 -60 d时可达58.7％.(3)不同单色光处理时,绿光与...     

A Review on How Plant Hormones and Environment Factors Are Involved in Rice Root Hair Development

Plant root hairs are important structures on the root surface for absorption of water, inorganic and organic nutrients. The root hairs which are regulated by both genetic and environmental factors, also play important roles when plants are dealing with environmental stress conditions. In this review, we analyzed how stress such as P deficiency, genetic factors and the core regulatory network composed of ABA，ETH, ABA work together during the regulation of rice root hair development. At last, we come up with issues which remains unclear but are critical and could be potential research focus.     

Rooting of baldcypress cuttings

A test of the rooting performance and growth of cuttings from 1-year-old and 25-to 50-year old baldcypress (Taxodium distichum L.) branch tips is reported. Rooting of cuttings from one-year-old trees averaged 75% (0.1% IBA treatment) and 88% (control), cuttings from 25 to 50-year-old trees averaged 12% in both the IBA treatment and the control treatment. Indole-3-butyric acid at a 0.1% concentration did not enhance rooting, but resulted in a significant increase in shoot dry weight on cuttings from one-year-old trees. The results of this experiment suggest that cuttings from mature baldcypres trees have the potential to root, thereby, additional rooting techniques such as girdling and stump sprouts is worthy of pursuing.     

Rhizosphere microbiomes can regulate plant drought tolerance

Beneficial root-associated rhizospheric microbes play a key role in maintaining host plant growth and can potentially allow drought-resilient crop production. The complex interaction of root-associated microbes mainly depends on soil type, plant genotype, and soil moisture. However, drought is the most devastating environmental stress that strongly reduces soil biota and can restrict plant growth and yield. In this review, we discussed our mechanistic understanding of drought and microbial response traits. Additionally, we highlighted the role of beneficial microbes and plant-derived metabolites in alleviating drought stress and improving crop growth. We proposed that future research might focus on evaluating the dynamics of root-beneficial microbes under field drought conditions. The integrative use of ecology, microbial, and molecular approaches may serve as a promising strategy to produce more drought-resilient and sustainable crops.     

一个籼稻叶夹角新基因的激素敏感性分析和基因定位

本研究对一个叶夹角变小、叶片短而直立的突变体ser(Short and erect)进行了植物激素敏感性试验和基因定位。激素试验结果表明,ser对赤霉素(Gibberellic acid,GA)敏感而对油菜素内酯(Brassinolide,BR)敏感性降低。遗传分析结果表明,ser的直立叶性状受1对隐性单基因ser控制。在ser×08CR578 F2群体中,利用分子标记将ser基因定位在水稻第5染色体长臂上的标记RM3437与RM5454之间,ser基因距离2个标记的遗传距离分别为5.3c M和1.5 c M;在ser×L604 F2群体中,ser基因定位于第5染色体上标记RM18504与RM1237之间,距离2个标记的遗传距离分别为1.5 c M和2.1 c M。在2个群体中,ser基因均与标记RM18532共分离。本研究为进一步精细定位与克隆ser基因奠定了基础,也为解析水稻叶夹角变化机制及选育高产理想株型水稻提供了理论支撑和基因资源。     

高等植物侧芽、侧枝的发生及调控

高等植物侧芽和侧枝的发育是受多种因素调节控制的.目前已经发现许多与侧生组织相关的基因,它们调控侧芽与侧枝的形成和发育,决定植株的形态结构;可长距离运输的信号物质在植物侧生组织的形成和发育、植物从营养生长到生殖生长的过渡中都发挥重要调控作用;植物激素参与了包括侧芽、侧枝的发育、植物的生长等多种生命过程的调节与控制;光周期经常和植物的基因型、植物激素等诸多种因子一起共同发挥作用,来调节植物侧生组织的形成和发育.调节植物的侧芽和侧枝发育的多种因素构成了一个网络系统,只有用综合研究的手段才可以知道网络系统中的各种因子之间的相互影响与相互作用.     

2,4D、KT对小麦成熟胚愈伤组织形成、分化的影响

以小麦新品种川农 17、12成熟胚为外植体进行离体培养 ,结果表明 :2mg/L 2 ,4 D有利于胚性愈伤组织形成 ,5mg/LKT有利于植株再生 (两品种植株再生率分别为 73 6 3% ,89 4 7% )。高浓度 2 ,4 D(4～ 8mg/L)虽不影响成愈率 ,但抑制植株再生。这种抑制作用能被KT拮抗。而KT的这种拮抗作用在 2mg/L 2 ,4 D条件下不能体现。     

水分胁迫对若干芸苔属蔬菜某些生理生化指标的影响

采用６个耐旱性不同的十字花科芸苔属蔬菜［结球甘蓝（耐旱）、球茎甘蓝、黄花芥蓝、花椰菜、大叶芥菜、大白菜（不耐旱）］为试验材料，经水分胁迫处理后，叶细胞质膜透性、脂质过氧化产物丙二醛（ＭＤＡ）以及多胺（Ｐｕｔ、Ｓｐｄ、Ｓｐｍ）含量均有不同程度的增加．与此同时，叶片中超氧物歧化酶（ＳＯＤ）、过氧化物酶（ＰＯＤ）活性和吲哚乙酸（ＩＡＡ）含量均有所下降．经相关统计分析发现，叶片质膜透性与ＭＤＡ含量成极显著正相关，与ＰＯＤ、ＳＯＤ活性和ＩＡＡ含量成极显著负相关；ＭＤＡ与ＰＯＤ、ＳＯＤ活性和ＩＡＡ含量成极显著负相关；而ＰＯＤ与ＳＯＤ活性、ＩＡＡ含量以及ＳＯＤ活性与ＩＡＡ含量则均成显著正相关．文中对蔬菜抗旱性机理进行了初步讨论