【作者】 姜妍；

【导师】 祖伟；

【作者基本信息】 东北农业大学 ， 作物栽培学与耕作学， 2008， 博士

【摘要】 株型是决定作物产量潜力的重要因素,在禾谷类作物特别是水稻株型育种取得重要成果的时候,大豆的株型育种研究已经引起人们的重视。结荚习性是大豆主要株型性状之一,结荚习性还对大豆品种的适应性有重要影响。可见,结荚习性是大豆株型设计的核心问题,对结荚习性进行改良和调节有助于改善株型性状,提高适应能力和作物产量。因此,试验于2006和2007年在中国农业科学院作物科学研究所完成,主要从大豆的品种差异和光周期调控入手,利用解剖学和分子生物学技术,研究不同结荚习性大豆品种的本质差异、大豆在不同光周期处理下茎顶的变化规律,进一步明确长日照对大豆顶端花序的影响,及AGAMOUS基因在不同光周期处理下大豆品种中的表达规律,为大豆株型育种特别是结荚习性的改良及大豆栽培管理提供理论依据。利用形态解剖学手段,对不同茎顶类型的大豆品种中黄13、中黄24和凤交66-12进行品种差异性研究,结果显示在有限结荚习性品种(中黄13和凤交66-12)和无限结荚习性品种(中黄24)的茎顶一般都能产生花芽,其区别在于有限结荚习性品种茎顶形成花序原基的起始时间要比无限结荚习性品种早,在有限结荚习性大豆品种的茎顶已经发育的很成熟的时候,无限结荚习性的大豆品种的茎顶才刚刚开始形成,年龄比较轻,顶荚节位上的叶片较小,营养成分供应不足导致了其最终顶端可能不会产生豆荚。在不同结荚习性品种的顶端花序形成过程中,花序分化的起始时间起到了决定性的作用。而对于同是有限结荚习性品种的中黄13和凤交66-12来说,两者的顶端花序长度存在明显的差异,通过解剖学研究产生不同花序长度的原因是由于凤交66-12开始形成的顶端花序的时间相对于中黄13较早,并且分化速度快所导致花序在短时间内长度增加,花序上小花数目增多。花序长度不同的有限结荚习性品种产生的原因主要是花序分化的起始时间和分化的速度共同决定的,花序分化的时间越早,速度越快,形成的顶端花序越长。大豆结荚习性形成的原因不仅受品种内在遗传因素决定,还受到外界环境因素的控制。对以上三个不同结荚习性品种进行两种较为极端的全生育期光照处理,短日照处理(12小时)和长日照处理(16小时)均可不同程度地影响不同茎顶类型品种的生育进程、结荚习性、株型和其他农艺性状,并且以此方法可区分出光敏感性相对较强和较弱的品种,对品种的生产和推广有一定的指导意义。研究结果表明,中黄13、中黄24和凤交66-12的出苗到开花期的时间和出苗到始熟期的时间随光照时间的延长而延长,通过形态解剖学观察,三个品种的茎顶在短日照条件下分化出花芽的时间早于长日照下的茎顶,从这点上能说明三个品种对光周期反应还是比较敏感的,但是,在两种光照条件下,三个品种均能够正常开花结实,三个品种对不同的环境条件表现出一定的适应能力。通过短日促进率分析,中黄13的开花期和成熟期与其他品种相比对光周期反应敏感性较弱。成熟时中黄13的株高、节数、分枝数、花序荚数、单株粒数和单株粒重6个农艺性状对光周期反应与另两个品种相比较为钝感,中黄24在花序小花数上表现出较弱的光周期敏感性,在其他性状上较为敏感,稳定性差。凤交66-12在节数上表现出较弱的光周期敏感性。总的来说,中黄13相对于中黄24和凤交66-12在多数的农艺性状上表现出一定的稳定性,对光周期反应相对钝感,进一步证实了中黄13是一种感光性相对弱的钝感型品种,可适应多种生态类型的地区种植。为明确光周期特别是长日照对于短日照作物的生长发育及顶端花序发育的特殊重要作用,实验以光周期敏感的有限结荚习性晚熟品种自贡冬豆为材料,经过13天短日照处理(12小时)后,分别经过0、1、2、3、4、5周长日照处理,再在短日照处理下直到成熟,研究长日照对大豆顶端花序、株型及农艺性状的影响。研究结果表明,随着长日照处理天数的增加,植株的发育速度明显延迟,顶端花序分化时间明显延长,花序长度明显增加,而且上述指标与长日照处理天数存在着显著的线性正相关性。在2-5周长日照处理下,大豆的茎顶还会出现逆转花序,且随着长日照处理天数的增加,逆转花序比例有增加趋势,株型也随顶端花序的改变而改变,农艺性状在长日照下表现出递增的趋势。长日照对于大豆顶端花序的发育性状具有的一定的累积作用。在某种程度上,长日照作用有利于短日照植物的生殖生长发育和短日照作物的产量形成。为了明确大豆茎顶发育过程中的相关基因的功能作用和调控规律,利用本课题组克隆的大豆AG基因对大豆茎顶的发育过程的基因表达进行了初步研究。利用DNAMAN软件分析,大豆的GmAG属于MADS-box基因家族中AG亚家族中的一员,与STK(AGL11)氨基酸的同源性为78%。通过半定量PCR和RNA原位杂交结果发现,在不同大豆品种中,GmAG基因在茎顶的发育营养生长期就有少量表达,而且在叶片原基也有表达,随着茎顶组织的进一步分化,产生花序分生组织和花分生组织后,GmAG基因表达量增强,说明GmAG对于决定花序分生组织的特征性也起到一定作用。在花原基进一步分化出心皮和雄蕊时均有表达,且在心皮分化出胚珠的部位也有很强的表达,说明该基因具有花器官C类和D类基因的控制雌雄蕊分化和胚珠发育的作用。不同光周期处理对GmAG基因表达也会产生一定的影响,差别不是很明显,但是在短日照促进花芽分化的同时,GmAG基因表达也随之升高,说明GmAG基因对于早花的形成具有一定作用。受长日照影响的茎顶,在发生逆转的顶芽上有少量的GmAG的表达,证明GmAG有决定分生组织向花分生组织转变的特性。可见,GmAG基因对于促进茎顶分化花原基,形成雌雄蕊原基和胚珠的发育具有一定作用,并对光周期信号产生一定程度地反应,详细的解释还需要实验的进一步验证。更多还原

【Abstract】 Plant type is a key factor that determines potential of crop yield, when gramineous grain crop especially plant type breeding of rice has obtained an important achievement, study on plant type breeding in soybean raised the people to pay attention to it. Podding-habits of soybean is one of main characters of plant type, and there is important effects of types of stem termination on adaptability of soybean varieties. So, the types of stem termination is a core problem of plant type design of soybean. Improving and adjusting podding-habits of soybean is beneficial for improvement of plant type, elevation of adaptability, and increase of crop yield. From differentiation of soybean varieties and photoperiod adjustment, anatomical differentiation essence of different types of stem termination soybean varieties, variation law of stem termination development under different photoperiod treatments, effect of long day on the terminal raceme of soybean, regulation rules of AGAMOUS gene among different soybean varieties and under different photoperiod treatments were studied, which would provide theory base of plant type breeding of soybean especially improvement of podding-habits and cultivation and management of soybean.Varieties differentiation of different types of stem termination including Zhonghuang13、Zhonghuang24 and Fengjiao66-12 was studied through morphology and anatomy methods. The results were that determinate (Zhonghuang13 and Fengjiao66-12) and indeterminate (Zhonghuang24 ) soybeans usually produce flower buds, differentiation was that flower buds of determinate soybeans initiated more early than flower buds of indeterminate soybean. When raceme primordium of determinate soybeans had developed, the terminal floral primordium of indeterminate soybean began to produce, leaves of the terminal node was little, and the stem termination could not produce pods in short supply of nutrition. In the process of terminal raceme formation of different types of stem terminaion soybean, initiation time of raceme differetiation played essential fuction. As to determinate soybeans cv. Zhonghuang13 and Fengjiao66-12, there was significant difference in the length of raceme. The results were that long raceme soybean cv. Fengjiao66-12 initiated more early flower buds, and terminal raceme differentiated more rapidly than short raceme soybean cv. Zhonghuang13, which resulted increase of raceme length and flower number in short time. The main cause of different raceme length soybean varieties was determined by initiation time and rate of raceme differentiation.The cause of podding-habits soybean formation was affected not only internal genetic factors, but also external environmental factors. The above three soybean varieties were treated with short-day of 12 h and long-day of 16 h in whole growth period, the different photoperiod treatments changed development process, podding-habits, plant morphogeny, and agronomical characters of different types of stem termination. And by this method photoperiod-sensitive and photoperiod-insensitive soybeans were divided, which is an important meaning at the production and popularization of soybean varieties. the results were that duration from emergence to blooming and duration from emergence to earlier maturity of three soybean varieties were delayed with increase of time of exposure to long day. Through anatomy observation, initiation time of flower buds differentiation among three soybean varieties was more earlier under short day condition than under long day condition, at this point three soybean varieties was sensitive to photoperiod, but they could bloom and seeding under two photoperiod treatments, and had adaptability to different environment. By short-day hastening rate results were analyzed that the blooming time and maturity time of Zhonghuang13 was weaker sensitivity to photoperiod than other two varieties, plant height, node no. at stem, branches, pod no. at raceme, seed no. /plant, seed weight /plant of Zhonghuang13 at maturity were insensitive to photoperiod. Flower no. at raceme of Zhonghuang24 was insensitive to photoperiod, other agronomic traits were sensitive, whereas node no. at stem of Fengjiao66-12 was insensitive to photoperiod. In a word, most agronomic traits of Zhonghuang13 had insensitivity and stability to photoperiod, and Zhonghuang13 was extensive photoperiod adaptability soybean which could be planted at the area of multi-ecotype.To make photoperiod especially importance of long-day for growth and development of short-day crops clear, In the current study, a photoperiod-sensitive and late maturity determinate soybean cv. Zigongdongdou (Maturity Group IX), was used to investigate photoperiod effects on the development of terminal inflorescence (raceme) of soybean, plant type and agronomic traits, with emphasis on the role of long-day in the formation of raceme. The plants were treated with short-day (SD) of 12h for 13 days to induce the initiation of terminal inflorescence, and then moved to 16h long-day treatment (LDT) for 0, 1, 2, 3, 4 and 5 weeks, respectively. After LDT, plants were returned to SD condition. Along with the increment of weeks of LDT, the blooming dates of soybean plants were progressively delayed, and the duration of terminal inflorescence differentiation were distinctly prolonged through anatomical observation, and the length of raceme increased. A positive linear correlation was found between weeks of LDT and the duration from emergence to beginning bloom, and the duration of the terminal inflorescence differentiation, and the length of raceme. In 2-5 wks LDT, inflorescence reversion and floral reversion happened and the rate of reversion increased, with the increment of weeks of LDT, reversion proportion of terminal raceme presented the gradual increment trend, and plant type varied with change of terminal raceme, and agronomic traits tended to increase under long-day condition. The results of the present study indicated that effects of long day on inflorescence development of soybean was acculmulative. In a way, long-day is beneficial for development and yield formation of short-day crop.Function and regulation rule of related genes in the process of stem termination of soybean was unclear at present, by making use of AG cloned by our lab we researched AG expression during the developmental period of soybean stem termination primarily. GmAG is one of AG subfamilies among MADS-box gene family, whose identity is 78% to amino acid sequence of STK (AGL11) by analyzing DNAMAN software. Space-time change of GmAG expression at the stem termination was studied by RT-PCR and RNA in situ hybridization. The results were that GmAG was observed a little at the stem termination and trifoliate leaves primordium in the early growth period, and intensity of GmAG expression increased at the inflorescence meristem and floral primordium, it showed that GmAG played a role in determining traits of inflorescence meristem. With differentiation of floral primordium, GmAG was observed in the carpel and stamen, and GmAG expression was strong in the ovule. It indicated that GmAG is an important function for carple and stamen formation and ovule development as flower organ genes C and D. Different photoperiod treatments effected GmAG expression in some extent, but differentiation was not significant. That intensity of GmAG expression increased for photoperiod-sensitive stem termination under SD condition suggested GmAG accelerated flowering of some soybean. And GmAG was observed a little at reversed shoot tips, which indicated GmAG had a characteristic of transition from shoot apical termination to floral meristems. So, GmAG played a important role in improving floral primordium differentiation, carple and stamen formation and ovule development, and photoperiod signals caused GmAG change in some extent, but detail explanation about the reason of phenomemon need to study further.更多还原