典型生理性状与形态解剖性状对旱地小麦产量形成的差别贡献及进化特征研究

发布时间：2018-11-21 16:23

【摘要】：水分是影响干旱地区作物生长与繁殖的主要的非生物元素。利用作物形态、生理生化等指标来揭示作物对干旱的响应,对干旱地区作物育种等研究具有重要的理论意义。采用盆栽种植试验,于2014-2016年在兰州大学榆中校区干旱农业试验站进行,通过设置不同程度的水分处理,测定小麦的形态、生理及产量等主要指标,揭示小麦形态解剖性状与典型生理性状对产量形成的贡献,以及对产量形成机理的探讨,主要得出如下结果:1.干旱胁迫对两种根型春小麦水分利用效率和产量形成的影响以大根系小麦和尚头(HST)和小根系小麦陇春8275(LC8275)为研究材料,采用盆栽试验,设置三个水分胁迫处理,结果发现,干旱下大根系小麦HST的产量减损率低于小根系LC8275(50%FWC:8.1%11%;35%FWC:44.1%60.4%),而小麦的产量水分利用效率则随干旱的加剧而提高。同时,异速生长关系分析表明,在充分供水情况下,大根系小麦HST的籽粒生物量(R)与营养体生物量(V)之间的异速生长指数显著大于1,说明HST在生长发育过程中将更多的能量用于籽粒形成,而在干旱下,R-V之间的指数与1没有显著性差异,呈等速生长关系,表明干旱胁迫改变了HST的繁殖分配策略;而LC8275在三个水分梯度下的R-V之间的指数与1均没有显著差异,属于等速生长,干旱胁迫并未改变其繁殖策略,由此得出,HST对干旱更敏感。2.两种水分处理对不同倍体小麦水分利用效率和产量形成的影响以8个不同倍体的小麦为研究对象,采用盆栽方法,设置两个水分处理,结果表明,随着小麦倍体的增加,小麦产量和水分利用效率均呈增加趋势。与充分供水相比,干旱降低了小麦的产量,提高了产量水分利用效率,二四六倍体小麦的产量在中度干旱下分别降低了36%、47.2%、40.1%,产量的水分利用效率(WUEyield)则分别提高了2.1%、4%、4.1%。同时,异速生长关系分析表明,在充分供水条件下,六倍体小麦的籽粒产量(R)和营养体生物量(V)之间的异速生长指数显著大于1,说明六倍体小麦随着个体大小的增加,繁殖输出也增加;而在干旱胁迫下,二倍体小麦R-V的异速生长指数显著大于1,说明在干旱下二倍体小麦的产量输出是随着个体大小的增加而增加的。而四倍体小麦在这两种水分处理下,R-V的异速生长指数均与1无显著差异,属于等速生长,由此得出,在不同的水分环境下,小麦的繁殖分配策略各不相同。3.水分胁迫对小麦形态解剖性状和生理性状的影响干旱造成小麦产量下降,一方面是干旱改变了生物量分配格局,而另一方面是通过对形态解剖与生理性状的影响而造成了小麦减产。实验结果发现,小麦在干旱胁迫下根冠比增加,分蘖数、株高、穗长、叶面积、叶生物量以及根生物量出现一定幅度的下降;研究解剖结构时发现,干旱也显著降低了叶片厚度、表皮厚度、维管束直径、维管束鞘厚度等;同时干旱使小麦的脯氨酸、可溶性糖、可溶性蛋白含量显著增加。根据前人对抗旱性的研究,将小麦叶片的脯氨酸、可溶性糖、可溶性蛋白等指标定义为耐旱性指标,而将根系生物量、根冠比、株高、叶面积、导管直径、维管束鞘厚度、维管束直径、表皮厚度等归为避旱性指标。综合以上结果,表明小麦在适应干旱胁迫时采取了耐旱和避旱协同进化的策略。4.干旱胁迫下小麦形态解剖性状和生理性状对产量形成的差别贡献小麦对抗旱的响应是从耐旱性和避旱性两方面体现的,对小麦干旱下各性状及产量进行主成分分析,结果表明,干旱下对小麦产量形成贡献最大的是形态性状指标,包括有效分蘖数、各营养器官的生物量、有效小穗数、籽粒数等;而叶片解剖指标,如叶片表皮厚度、维管束直径、导管直径等和生理性状指标相对的对产量形成的贡献较小;但是随着小麦倍体的增加,生理性状和解剖性状对产量的影响增大。
[Abstract]:Water is the main non-biological element that affects the growth and reproduction of crops in arid areas. It is of great theoretical significance to study the response of crops to drought, and to study the crop breeding in arid areas. The experiment of pot cultivation was carried out in the arid agricultural test station of Yuzhong campus of Lanzhou University in 2014-2016, and the main indexes such as the morphology, physiology and yield of the wheat were determined by setting different degree of water treatment, and the contribution of the morphological and typical physiological characters of the wheat to the yield formation was revealed. The main results are as follows: 1. The effects of drought stress on water use efficiency and yield of two kinds of root-type spring wheat were studied by pot experiment and three water stress treatments. The yield of wheat HST was lower than that of low root system LC8275 (50% FWC: 8.1% 11%; 35% FWC: 41.1% 60.4%), while the water use efficiency of wheat was increased with the increase of drought. The results showed that, under the condition of full water supply, the growth index between the grain biomass (R) and the vegetative biomass (V) of the large root wheat HST was significantly higher than that of the vegetative biomass (V), indicating that the HST had more energy for grain formation during the growth and development process. In the drought, there was no significant difference between R-V and R-V, which showed that drought stress changed the reproductive allocation strategy of HST, while the index of LC8275 between R-V and R-V in three water gradients was not significantly different, and it was a constant-speed growth. The drought stress did not change its breeding strategy, and the HST was more sensitive to drought. The effects of two kinds of water treatment on the water use efficiency and yield of aneuploid wheat were studied. The yield and water use efficiency of wheat were all increasing. Compared with the full water supply, the drought reduced the yield of wheat, improved the water use efficiency of the yield, and the yield of the two-and-four-six-fold wheat decreased by 36%, 47.2%, 40.1%, respectively, and the water use efficiency (WUE) of the yield increased by 2.1%, 4%, and 4.1%, respectively. The results showed that, under the condition of full water supply, the growth index between grain yield (R) and vegetative biomass (V) of hexaploid wheat was significantly higher than that of 1. In the drought stress, the growth index of the hybrid wheat R-V was significantly higher than that of the diploid wheat, and the output of the diploid wheat was increased with the increase of the individual size. At the same time, the growth index of the R-V was not significantly different from that of the one in the two kinds of water treatment, and belongs to the constant-speed growth, and it is concluded that the reproductive and distribution strategies of the wheat are different in different water environments. The effects of water stress on the morphological and physiological characters of wheat resulted in a decrease in the yield of wheat, on the one hand, the distribution pattern of biomass was changed, on the other hand, the yield of wheat was reduced by the influence of morphological and physiological characters. The results showed that, under the drought stress, the root-to-crown ratio increased, the number of the leaves, the height of the plant, the length of the ear, the leaf area, the leaf biomass and the root biomass of the wheat decreased, and it was found that the drought also significantly reduced the thickness of the blade, the thickness of the skin, the diameter of the vascular bundle, In the same time, the content of proline, soluble sugar and soluble protein of wheat was increased significantly. according to the previous studies on drought resistance, the indexes of proline, soluble sugar, soluble protein and the like of the wheat leaves are defined as drought-resistant indexes, and the root biomass, the root-to-crown ratio, the plant height, the leaf area, the diameter of the catheter, the thickness of the vascular bundle, the diameter of the vascular bundle, The thickness of the skin and the like are classified as the drought-proof index. The result shows that the wheat has the strategy of drought-resistant and drought-resistant and cooperative evolution in adapting to drought stress. The effect of wheat morphological and physiological characters on yield formation under drought stress is the main component analysis of wheat to drought resistance in response to drought resistance and drought resistance, and the results show that, The greatest contribution to the yield of wheat under drought is the index of morphological characters, including the number of effective fractions, the biomass of each vegetative organ, the number of effective small ears, the number of grains, etc., and the anatomical index of the blade, such as the thickness of the blade skin, the diameter of the vascular bundle, The relation between the diameter of the catheter and the index of physiological characters is relatively small, but with the increase of the number of the wheat, the effect of the physiological and anatomical characters on the yield is increased.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S512.1

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