不同年代裸燕麦品种耐旱性和产量形成的差异性比较研究

发布时间：2018-05-23 22:08

本文选题：干旱胁迫 + 产量构成　；参考：《兰州大学》2017年博士论文

【摘要】：裸燕麦(Avena nuda L.)常分布于干旱冷凉地区,作为小杂粮作物,主要种植在边际土地中,生育期内面临各种非生物胁迫,其中水分胁迫是限制裸燕麦籽粒产量的主要逆境因子。相对于小麦和水稻等主要粮食作物而言,裸燕麦的育种进程相对比较迟缓,对裸燕麦近代育成品种和早期农家地方品种的产量形成特性进行比较研究,将有助于揭示裸燕麦品种选育过程中耐旱性和产量性状的演化规律。本研究以近代育成品种定莜1号(DY1)、定莜3号(DY3)、定莜5号(DY5)、定莜6号(DY6)、定莜7号(DY7)、燕科1号(YK1)和坝莜6号(BY6)以及早期农家地方品种北山老燕麦(BSL)、老燕麦(LY)、玉麦(YM)、小莜麦(XY)、燕麦(YAM)和莜麦(YUM)为供试材料。在盆栽和大田试验条件下开展近代育成品种和早期地方品种耐旱适应机制和产量形成的差异对比研究,并对其关系进行探讨,试图阐明裸燕麦育种过程中籽粒产量提升与耐旱性改善的关系。本研究的主要结果如下:1、在盆栽逐渐干旱试验中,近代育成品种非水力根源信号持续的土壤水分阈值区间平均值为15.9%FC(Field capacity,田间持水量),显著低于早期地方品种的平均值21.5%FC。其中,近代育成品种气孔导度和光合速率开始下降时的土壤水分含量平均值为50.8%FC,要显著低于早期地方品种的平均值56.5%FC。而近代育成品种叶片水分状态发生改变时的土壤水分含量平均值为34.9%FC,与早期地方品种的平均值35.0%FC没有显著差异。2、在盆栽逐渐干旱试验中,当严重水分胁迫发生时(土壤水分含量低于30%FC),近代育成品种叶片中渗透物质(脯氨酸、可溶性糖和甜菜碱)开始大量积累,渗透调节能力显著增强,叶片中丙二醛含量显著低于早期地方品种,表明其膜脂过氧化损伤的程度较低。同时,近代育成品种叶片致死水势(平均值为-5.4MPa)也显著低于早期地方品种(平均值-3.6 MPa),表现出了更强的叶片耐脱水性。3、无论是在大田雨养或灌溉条件下,还是在盆栽试验中的充分供水和水分胁迫处理下,近代育成品种的籽粒产量、收获指数和水分利用效率都要显著高于早期地方品种。近代育成品种较高的籽粒产量与其不同水分条件下更好的干旱适应性和耐脱水性相关。4、大田产量构成分析表明,近代育成品种较高的籽粒产量与其较高的单穗粒数及千粒重相关。不同水分处理下,近代品种的单穗粒数和千粒重都要显著地大于早期地方品种。籽粒大小(千粒重)的性状更多的依赖于品种特性,在多变的环境下能够维持稳定。5、大田条件下通径分析结果显示,地上生物量、单位面积穗数、单穗粒数、千粒重和收获指数可以解释品种间99.2%的籽粒产量变异。其中,地上生物量和收获指数对籽粒产量的直接效应最大,分别为0.660(P0.001)和0.459(P0.001)。而主成分分析结果显示,近代育成品种收获指数的增加与其千粒重的增加密切相关。同时,近代育成品种籽粒产量对地上生物量(不含籽粒重)的异速指数为0.858,要显著大于早期地方品种异速指数0.759,表明近代育成品种的繁殖分配要大于早期地方品种。6、籽粒灌浆特征分析表明,近代育成品种的籽粒最大灌浆速率和平均灌浆速率都显著高于早期地方品种,在大田条件下分别高出40.4%和21.4%。盆栽试验发现,适度的水分胁迫(55%FC)可以提高籽粒的最大灌浆速率和平均灌浆速率,在近代育成品种中分别提高了24.4%和21.7%,而在早期地方品种中分别提高了16.4%和5.6%。同时,裸燕麦的强势籽粒(开花较早的籽粒)和弱势籽粒(开花较晚的籽粒)虽然在灌浆起始上存在时间差异,但其最终籽粒重量没有显著差异。7、盆栽试验发现,裸燕麦近代育成品种和早期地方品种的胚乳细胞增殖存在显著差异。近代育成品种的胚乳细胞数量要比早期地方品种多17.9%。在灌浆期,近代育成品种籽粒中与淀粉合成相关的焦磷酸化酶(AGPase)和淀粉分支酶(SBE)的活性均高于早期地方品种。同时,灌浆期籽粒中脱落酸的含量与灌浆速率和焦磷酸化酶(AGPase)、可溶性淀粉合成酶(SSS)、淀粉分支酶(SBE)的活性有显著的正相关关系。综上所述,尽管近代育成裸燕麦品种的非水力根源信号土壤水分阈值区间显著低于早期地方品种,但其在严重水分胁迫下的渗透调节能力和耐脱水能力要显著大于早期地方品种。其较高的籽粒产量与其繁殖分配的增加相关,主要体现在新品种具有较高的单穗粒数、千粒重和收获指数,以及较快的籽粒灌浆速率和较多的籽粒胚乳细胞数。
[Abstract]:Luo Yanmai (Avena nuda L.) is often distributed in the arid and cold area. As a small grain crop, it is mainly planted in the marginal land and is faced with various abiotic stresses during the growth period. Water stress is the main adversity factor to limit the grain yield of naked oats. Comparatively slow, comparative study on the yield formation characteristics of naked oat modern breeding varieties and early farm local varieties will help to reveal the evolution of drought tolerance and Yield Traits in the breeding process of naked oats. This study takes oat No. 1 (DY1), fixed naked oats No. 3 (DY3), fixed naked oats No. 5 (DY5), fixed naked oats 6 (DY6). Oat No. 7 (DY7), Yan Ke 1 (YK1) and dam naked oat 6 (BY6) and early farm local variety Bei Shan old oat (BSL), old oat (LY), jade wheat (YM), small naked oats (XY), oat (YAM) and naked oats (YUM) as the test materials. Under the conditions of pot and field test, the drought tolerance mechanism and the difference of yield formation of early local varieties and early local varieties were carried out. The main results of this study are as follows: 1, in the gradual drought test of potted plants, the average value of the soil water threshold value of the non hydraulic source signals of modern varieties is 15.9%FC (Field capacity, field). Water holding capacity was significantly lower than the average value of early local varieties of 21.5%FC.. The average value of soil moisture content was 50.8%FC when the stomatal conductance and photosynthetic rate began to decline in modern breeding varieties, which was significantly lower than the average value of early local varieties of 56.5%FC.. The average value is 34.9%FC, and there is no significant difference from the average value of early local varieties of 35.0%FC.2. In the gradual drought test of potted plants, when serious water stress occurs (the soil moisture content is lower than 30%FC), the permeable substances (proline, soluble sugar and betaine) in the leaves of modern breeding varieties begin to accumulate, and the osmotic adjustment ability increases significantly. The content of malondialdehyde in leaves was significantly lower than that of early local varieties, indicating that the degree of membrane lipid peroxidation damage was lower. At the same time, the lethal water potential (average value of -5.4MPa) of modern bred varieties was significantly lower than that of early local varieties (mean value of -3.6 MPa), showing a stronger vane resistance to water resistance.3, whether in field rain or irrigation. Under the conditions of full water supply and water stress treatment in pot experiment, the grain yield, harvest index and water use efficiency of modern bred varieties were significantly higher than those of early local varieties. The higher grain yield of modern bred varieties was related to better Drought Adaptability and water resistance under different water conditions,.4, field. The analysis of yield composition showed that the higher grain yield of modern breeding varieties was related to higher grain number and 1000 grain weight. Under different water treatments, the grain number of single spike and 1000 grain weight of modern varieties were significantly larger than those of early local varieties. The grain size (1000 grain weight) depended on variety characteristics and could be more varied in the changeable environment. In order to maintain stable.5, the results of path analysis under field conditions showed that aboveground biomass, per unit area spike, single spike grain number, 1000 grain weight and harvest index could explain the variation of grain yield between 99.2% varieties. The direct effect of aboveground biomass and harvest index on grain yield was 0.660 (P0.001) and 0.459 (P0.001) respectively. The result of component analysis showed that the increase of the harvest index of modern bred varieties was closely related to the increase of 1000 grain weight. At the same time, the speed index of the grain yield of modern bred varieties to the aboveground biomass (without grain weight) was 0.858, which was significantly greater than that of the early local varieties with the rate of 0.759. The analysis of grain filling characteristics of local variety.6 showed that the maximum grain filling rate and average grain filling rate of modern cultivated varieties were significantly higher than those of early local varieties. 40.4% and 21.4%. pot experiments under field conditions showed that moderate water stress (55%FC) could increase the maximum grain filling rate and average grain filling speed. The rate increased by 24.4% and 21.7% in the modern breeding varieties, while the early local varieties increased by 16.4% and 5.6%. respectively, while the strong grains (earlier flowering grains) and the weak grains (late flowering grains) had time difference at the beginning of grain filling, but there was no significant difference in the final grain weight of.7, potted plants. The experiment found that there was a significant difference in the proliferation of endosperm cells between the modern breeds of naked oats and the early local varieties. The number of endosperm cells in modern bred breeds was more than 17.9%. at the early stage, and the activity of AGPase and SBE related to starch synthesis in the seeds of modern bred varieties was high. At the same time, the content of abscisic acid in grain filling period was positively correlated with the grain filling rate and AGPase, soluble starch synthase (SSS), and starch branching enzyme (SBE) activity. In summary, the soil moisture threshold range of the non hydraulic source signals of modern naked oat varieties was significantly lower. The early local varieties, but their osmotic adjustment and dehydration ability under severe water stress are significantly greater than those of early local varieties. The higher grain yield is related to the increase in reproductive distribution, mainly in the higher grain number of single spikes, 1000 grain weight and harvest index, and faster grain filling rate and comparison. The number of many seed endosperm cells.
【学位授予单位】：兰州大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S512.6

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