独角金内酯调控水稻分蘖芽休眠的研究进展

化学控制无效分蘖是水稻高产栽培的研究热点和努力方向,分蘖芽休眠与萌发转换决定了分蘖是否发生,而该过程受激素和相关基因表达的调控。前人研究已明确生长素和细胞分裂素参与了分蘖芽休眠与萌发转换的调控,独角金内酯是最近才被发现的一种激素或前体,已被证明参与了水稻分蘖的调控,但其调控机理和信号转导途径尚不明确。本文在独角金内酯对水稻分蘖的调控作用、其合成及信号转导过程以及其调控水稻分蘖发生的作用机制等方面展开了综述。     

Similarities between natural and chemically induced bud-endodormancy release in grapevine Vitis vinifera L.

Bud-break in grapevines (Vitis vinifera L) can be poor and uneven in locations that have warm winters with insufficient chilling. Growers in these regions use hydrogen cyanamide (HC), a dormancy-breaking compound, to increase and synchronise bud-break. Previous studies demonstrated that HC upregulates the expression of select genes encoding enzymes belonging to the ascorbate glutathione cycle (AGC) (glutathione reductase, VvGR) to the oxidative pentose phosphate pathway (oPPP) (glucose-6-phosphate dehydrogenase, VvG6PD) and a key enzyme for dormancy release (1,3-β-glucanase, VvβGLU). Here, the expression of these genes was studied in grapevine buds throughout the natural progression of endodormancy (ED) and under the effects of the dormancy-breaking compounds, HC and sodium azide. Although gene expression increased with the progression of ED until mid-May, in early-June they turned off transiently and reappeared in mid-July before bud-break. The upregulation of these genes under both natural and artificial conditions suggests that dormancy-breaking compounds activate the same metabolic pathways that are naturally activated during the bud-ED release process. However, in contrast with the effects of dormancy-breaking compounds, artificial chilling did not upregulate the above genes.     

黑樱桃种子休眠机理及处理方法的研究

对黑樱桃种子处理方法进行研究的结果表明,生理后熟和抑制物质的存在是造成黑樱桃种子休眠的主要原因,暖温层积90天后再冷温层积120天可以有效打破种子的休眠,其中暖温层积是种胚后期发育的主要时期,而冷温层积是消除抑制物抑制作用的关键。     

几种植物生长物质对百合鳞茎休眠的影响

[目的]研究植物生长物质对百合鳞茎休眠的影响。[方法]以百合品种"素雅"为试材,选用GA3、6-BA和CEPA配制成9种不同浓度的溶液,对百合鳞茎进行浸泡处理,观察不同处理鳞茎的发芽情况。清水处理为CK。[结果]9种处理均有助于打破百合鳞茎的休眠,添加丙酮可以提高药效。其中GA350 mg/L+6-BA 100 mg/L+CEPA 100 mg/L的10%的丙酮溶液处理效果最佳,该处理百合鳞茎在20d时发芽率达到75%,明显高于CK(20%),处理30 d时发芽率达到90%,处理40 d时全部发芽,高于CK(50%)。[结论]GA350 mg/L+6-BA 100 mg/L+CEPA 100 mg/L的10%的丙酮溶液最有助于打破"素雅"百合鳞茎的休眠,提高发芽率。     

Development of Rice “Seed-Mats” Consisting of Hardened Seeds with a Cover of Soil for the Rice Transplanter

Conventional seedling mats for rice transplanters in Japan are heavy to carry, and much labor is required to collect, wash and store the nursery boxes. In addition, seeding time overlaps with the labor peak in spring. To reduce such labor, we developed a “seed-mat” consisting of hardened rice seeds (Oryza sativa L.) glued onto a molded rice-hull mat with a cover of soil glued on. Seed hardening, which is done by soaking seeds in water at 15ºC for 5 d followed by drying, and heating of the seeds at 50ºC for 5 or 7 d, reduced the time to 50% germination (T₅₀). In dormant seeds, the heating before the hardening enhanced the effect of the hardening more than the heating after the hardening. Seed hardening increased the dry weight of the shoots from the seed-mats. Covering the mat with soil also increased the percentage of seedling emergence, shoot length, number of leaves and shoot dry weight of the seed-mats. The hardened seeds maintained short T₅₀ and 95% or higher germination for 120 d at room temperature. In the seed-mat, the hardened seeds maintained 95% or higher seedling emergence for 208 d. In conclusion, superior seed-mats could be produced using the procedure involving both seed hardening and cover of soil. The seed-mats can be prepared in winter and stored until seedling-raising period in spring. By the seed-mats, seedling mats can be prepared for the rice transplanter without using nursery boxes, which take up storage space and require much labor.     

短叶13号萝卜种子休眠的初步探讨

通过对入库的几种萝卜种子发芽率的测定,发现短叶13号萝卜种子有休眠现象存在。影响种子休眠的因素很多,休眠期的长短也不一样,短叶13号萝卜种子的休眠属自发休眠,打破休眠的途径可以从低温等条件着手。     

野蔷薇种子休眠机理研究

以5种野蔷薇种子为试材,初步分析了影响野蔷薇种子萌发的内在生理因素。结果表明：5种野蔷薇种子大小均匀,种壳占种子风干重的40％～60％,透水性良好;种子浸出液的相对电导率较低,为16％-30％,种子活力较高;种皮脱落酸的含量远高于胚中。     

刺参基因组DNA甲基化水平及模式对温度变化的响应

本研究为了探讨刺参(Apostichopus japonicus)在不同温度胁迫下的DNA甲基化水平与甲基化模式变化,利用全基因组重亚硫酸盐测序技术(WGBS)和酶联免疫吸附法(ELISA)对刺参在3个温度下(20℃、26℃和32℃)的纵肌、呼吸树、消化道和体壁4个组织进行分析.WGBS测序结果显示,在消化道组织中,2...     

桃种子的休眠与萌发研究──种皮的调控作用

用桃品种秋香蜜去核壳种子，探索了种皮控制休眠与萌发的效应及作用机制。结果表明：①桃种子剥除种皮，休眠可被解除，出苗率与有皮种子经ＧＡｓ２００ｍｇ·ｌ￣（－１）浸种２４ｈ相近；种皮抑制萌发的效应与ＡＢＡ５ｍｇ·ｌ￣（－１）浸渍去皮种子２４ｈ相当。②桃新鲜种子内ＡＢＡ主要存在于种皮中，ＧＡ３主要存在于胚和子叶中，剥除种皮即人为地改变种子内ＧＡ＿３／ＡＢＡ值，有利于种子由休眠向萌发方向转化。③桃种皮对种子内过氧化物酶活性具强烈抑制作用；去皮种子的酶活性随ＧＡ３处理而增强，随ＡＢＡ处理而被抑制。④桃种皮无透水性障碍，种皮对种子的吸水总量虽有一定限制，但不影响种子萌芽。     

马铃薯块茎休眠及萌发过程中几种酶活性变化

以马铃薯脱毒试管薯为试验材料，研究块茎休眠和块茎顶芽萌发生长过程中几种相关酶活性变化。结果表明，块茎贮藏过程中淀粉酶、淀粉磷酸化酶、过氧化物酶和多酚氧化酶活性的消长，与块茎形态上的休眠及萌发有密切关系。处于休眠期间的块茎内淀粉酶和淀粉磷酸化酶活性很低，随着休眠的解除及顶芽萌动活性逐渐增强，当顶芽开始生长时活性再镒降低；过氧化物酶和多酚氧化酶在块茎休眠时活性较高，顶芽萌动后活性迅速下降；不同品种间这四种酶的变化趋势基本相同。