温度和光周期对大蒜蒜薹和鳞茎发育的影响及机理

发布时间：2018-08-12 12:25

【摘要】：大蒜严格的季节发育性特点是目前限制新鲜蒜薹和蒜头供应的瓶颈问题。阐明温度和光周期对大蒜蒜薹和鳞茎发育的影响及机理,可以为大蒜生长发育调控提供理论依据,以期实现新鲜蒜薹和蒜头的周年供应。本试验主要通过大田和室内人工气候箱试验,系统研究大蒜蒜薹和鳞茎发育的临界温度和光周期条件,以及发育过程中相关生理生化和基因表达变化,主要结果如下:1.蒜种低温处理显著影响大蒜植株生长发育,可以代替植株生长过程中的春化需求。G064(‘改良蒜’)品种蒜种播前分别于5℃、10℃、15℃处理20、40、60 d,与对照相比,蒜种低温处理显著诱导植株抽薹并提高抽薹率、缩短植株生育期、促进植株伸长生长、增加独头蒜率。植株抽薹率与处理温度间不存在简单线性关系,处理温度过低(5℃)或过高(15℃)均不利于大蒜抽薹。蒜种播前10℃处理40 d,或5℃处理20 d植株抽薹率最高。但随着低温持续时间的延长,蒜头产量下降。蒜种播前5℃处理20 d的蒜头产量显著高于其他处理。2.大蒜植株春化处理显著提高抽薹率。G064(‘改良蒜’)品种播种65、45、25 d后,分别在5/0℃、10/5℃、15/10℃、20/15℃(昼/夜)温度下处理40 d,发现不同苗龄大蒜植株对春化处理的响应有差异。春化处理后,所有测试苗龄的抽薹率均显著提高,苗龄最小植株(4叶期)的抽薹率最高。10/5℃(昼/夜)春化处理温度下,各苗龄处理植株抽薹率最高,分别为28.6%、40.1%和50.0%。此外,春化处理抑制了植株的营养生长。试验认为,G064品种大蒜春化的临界苗龄是:4叶期,株高36.7 cm,假茎粗4.31 mm。3.大蒜春化完成后,较高的处理温度(20℃或25℃)和长日照(14 h)是大蒜抽薹和鳞茎膨大的必要条件。G107(‘二季早’)、G025(‘苍山大蒜’)和G064(‘改良蒜’)品种田间自然春化后,进行不同昼/夜温度(15/10℃、20/15℃、25/18℃)和光周期(8 h和14 h)处理。结果表明,20-25℃和14 h显著促进大蒜植株抽薹和鳞茎膨大,同时缩短植株生育期、增加蒜头重。田间自然春化后,G107各温度处理在长日下均能抽薹并形成鳞茎,20/15℃和14 h光照是所有处理中最有效的抽薹和鳞茎膨大条件;G025和G064品种在20/15℃和25/18℃及长日照下均能抽薹并形成鳞茎,15/10℃温度处理无论长日和短日下均不能抽薹和形成鳞茎,25/18℃并长日照条件下G064的抽薹和鳞茎膨大特性显著优于其他处理。相比较而言,G025则在20/15℃并长日照抽薹和鳞茎膨大最好。4.大蒜内源激素和MeJA含量与大蒜的蒜薹和鳞茎发育密切相关。对田间种植的8个品种、G064品种3个播期以及人工气候箱不同温度和光周期处理的3个品种大蒜植株生长发育过程中内源激素和MeJA含量、POD和SOD活性变化分析发现,低温诱导植株产生更多的蛋白,使得POD和SOD活性显著提高,可能促进了植株通过春化。植株完成春化,由营养生长向生殖生长转变时,可溶性蛋白、IAA、ZR、MeJA含量显著增加,促进了植株发育状态的转变。随后,花芽分化期,IAA、ZR、MeJA含量下降,ABA含量升高,利于大蒜植株的花芽分化进程。进入生殖生长期后,IAA和ZR积累量增加,促进蒜薹早期的发育,随着蒜薹的发育,GA含量逐渐升高,对蒜薹的继续生长和花发育有利,此时植株体内MeJA的积累量也在增加。而进入鳞茎膨大期后,GA、ABA和IAA含量以及SOD活性降低,MeJA含量则显著升高,促进大蒜鳞茎的发育。5.AsFT、AsLFY、AsSOC1在大蒜的生长发育中起关键作用。采用RT-PCR技术,克隆得到了大蒜FT和SOC1同源基因的部分CDs序列,长度分别为305bp和389bp,分别编码101和124个氨基酸。利用实时荧光定量PCR技术,分析田间种植的8个品种、G064品种3个播期大蒜发育过程中AsFT、AsLFY、AsSOC1的表达量。结果显示,AsFT、AsLFY、AsSOC1在营养生长期表达量很低,生殖生长期显著上调表达。因此推断AsFT、AsLFY和AsSOC1是控制大蒜抽薹和鳞茎膨大的关键基因。大蒜植株通过春化后,较高的温度和长日照诱导AsFT、AsLFY和AsSOC1上调表达,从而引发并促进蒜薹和鳞茎发育;上调表达出现越早,会相应促进植株提早进入抽薹和鳞茎膨大阶段。
[Abstract]:The strict seasonal developmental characteristics of garlic are the bottleneck problems in restricting the supply of fresh garlic bolts and bulbs.The effects and mechanism of temperature and photoperiod on the development of garlic bolts and bulbs were elucidated,which could provide theoretical basis for the regulation of garlic growth and development,and could realize the annual supply of fresh garlic bolts and bulbs. The critical temperature and photoperiod conditions of garlic bolt and bulb development, as well as the related physiological, biochemical and gene expression changes during garlic development were systematically studied in an indoor climate chamber experiment. The main results were as follows: 1. Low temperature treatment of garlic seeds significantly affected the growth and development of garlic plants, and could replace the vernalization requirement in the growth process of garlic plants. Compared with the control, the low temperature treatment of garlic seeds could significantly induce the plant to bolt and increase the bolting rate, shorten the plant growth period, promote the plant elongation and increase the rate of Unicorn garlic. The bolting rate of garlic plants treated at 10 C for 40 days before sowing or at 5 C for 20 days was the highest, but with the prolongation of low temperature duration, the yield of garlic decreased. After 65,45,25 days of sowing, garlic plants of different seedling ages were treated for 40 days at 5/0, 10/5, 15/10 and 20/15, respectively. The response to vernalization treatment was different. After vernalization treatment, the bolting rate of all tested seedling ages was significantly increased, and the bolting rate of the smallest seedling age (4th leaf stage) was the highest. In addition, vernalization inhibited vegetative growth. The critical seedling age of G064 garlic was 4-leaf stage, plant height 36.7 cm, pseudostem diameter 4.31 mm.3. Necessary conditions for bolting and bulb expansion of garlic were studied. G107 ('early second season'), G025 ('Cangshan garlic') and G064 ('improved garlic') cultivars were naturally vernalized in the field and treated with different day/night temperatures (15/10, 20/15, 25/18) and photoperiod (8 h and 14 h). The results showed that 20-25 and 14 h significantly promoted the bolting and bulb expansion of garlic plants. After natural vernalization, G107 could bolt and form bulbs in long day, 20/15 C and 14 h light were the most effective conditions for bolting and bulb expansion; G025 and G4 varieties could bolt and form bulbs at 20/15 C and 25/18 C and long sunlight, and 15/10 C were the most effective conditions for bolting and bulb expansion. The bolting and bulb swelling characteristics of G06 4 were significantly better than those of other treatments at 25/18 C and long sunshine. Comparatively, G025 was the best at 20/15 C and long sunshine. 4. The contents of endogenous hormones and MeJA in garlic were closely related to the development of garlic bolt and bulb. Correlation. Analysis of endogenous hormones and MEJA contents, POD and SOD activities of 8 varieties planted in the field, 3 sowing dates of G064 varieties and 3 varieties of garlic planted under different temperatures and photoperiod in the artificial climate chamber showed that low temperature could induce more proteins in the plants, which could significantly increase the activities of POD and SOD. The content of soluble protein, IAA, ZR and MeJA increased significantly during the Vernalization of the plant, and promoted the transformation of plant development. Subsequently, the content of IAA, ZR and MeJA decreased and the content of ABA increased during the flower bud differentiation stage, which was beneficial to the process of flower bud differentiation. With the development of garlic bolt, the content of GA increased gradually, which was beneficial to the continued growth and flower development of garlic bolt. At this time, the accumulation of MeJA in the plant was also increased. However, after bulb expansion, the contents of GA, ABA, IAA and SOD decreased, while the content of MeJA increased significantly, which promoted the development of garlic bulb. 5. AsFT, AsLFY and AsSOC1 play a key role in the growth and development of garlic. The partial CDs of FT and SOC1 homologous genes were cloned by RT-PCR. The length of the CDs was 305 BP and 389 bp, respectively, encoding 101 and 124 amino acids. The results showed that AsFT, AsLFY and AsSOC1 were very low in vegetative growth period and up-regulated significantly in reproductive growth period.Therefore, AsFT, AsLFY and AsSOC1 were the key genes controlling bolting and bulb swelling of garlic.After vernalization, garlic plants were induced by high temperature and long sunshine. The expression of ASSOC1 was up-regulated to induce and promote the development of garlic bolt and bulb, and the earlier the up-regulated expression appeared, the earlier the plant entered the bolting and bulb expansion stage.
【学位授予单位】：西北农林科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S633.4

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