低钾胁迫对大豆生理代谢及根系衰老的影响

发布时间：2018-03-06 20:27

  本文选题：大豆　切入点：低钾胁迫　出处：《沈阳农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：本试验以课题组多年筛选的耐低钾型大豆T40、T36、WM和低钾敏感型大豆GD8521为试验材料,于2015-2016年采用水培试验与大田试验相结合的方式,设HK(对照)和LK(低钾)两个处理,对低钾胁迫下大豆干物质积累、营养元素吸收、渗透调节物质、光合特性、有机酸分泌及代谢、叶片超显微结构以及大豆产量等方面的差异进行深入研究,明确低钾胁迫对根系衰老的影响及其内在联系,揭示低钾胁迫下大豆根系衰老的生理生化机制,为探索耐低钾型大豆的分子育种提供理论依据。本试验研究结果如下:1.低钾处理的大豆总根长、根体积和根平均直径均小于对照处理,而根表面积却大于对照处理,说明低钾胁迫在一定程度上促进了根系的横向分布,但在纵向分布方面作用较小。低钾胁迫下,耐低钾型大豆品种有较高且较稳定的根表面积和根体积来保证其从土壤中充分吸收养分,促进植株正常生长,从而延缓植株衰老。2.低钾胁迫降低了植株的生物量。在低钾环境下,耐低钾型大豆在不同生育时期有更稳定的干物质积累量。低钾敏感型大豆GD8521根冠比在不同生育时期变化趋势较大,成熟期其根冠比的大幅度下降说明是由其根系提前衰老导致的。耐低钾型大豆有更稳定的根冠比来适应土壤中钾的变化,保证植株自身生长发育,从而达到延缓根系衰老的效果。3.低钾胁迫降低了大豆植株的氮、磷、钾积累量,对根系中磷积累量较不敏感,对各器官钾积累量影响最显著。耐低钾型大豆在低钾胁迫环境下能保持更稳定的养分吸收为植物生长提供物质循环和能量转化,延缓植株衰老,从而延缓根系衰老。4.低钾胁迫降低了大豆叶片的蒸腾速率、净光合速率和气孔导度,导致了胞间CO2浓度的升高。低钾处理提高了大豆的光补偿点,降低了光饱和点和净光合速率,其中GD8521的光饱和点降低了 19.64%,T40降低了 12.57%。耐低钾型大豆在低钾胁迫中能保持稳定的胞间CO2浓度、蒸腾速率、净光合速率和气孔导度及光补偿点和光饱和点,延长了叶片的功能期,保证植株的能量供给,为延缓植株衰老作出了一定的贡献。5.低钾胁迫下大豆根系可溶性糖含量下降,而脯氨酸和游离氨基酸含量升高。在出苗后90 d(R6),T40和WM低钾处理根系游离氨基酸含量分别比HK(对照)升高54.67%和48.94%,而GD8521为41.02%。耐低钾型大豆在低钾环境下有较低的可溶性糖含量及较高的游离氨基酸含量来保持细胞膨压以达到渗透调节能力。6.GD8521的有机酸含量在不同K+浓度间差异不显著,而耐低钾型大豆在不同K+浓度条件下能通过自身调节其有机酸含量以保持较强的代谢活动来维持与外界的物质交流,从而延缓根系衰老。7.耐低钾型大豆在低钾环境下能维持稳定的细胞结构,叶绿体内基质浓厚,基粒片层排列整齐,叶绿体周围有较多线粒体,线粒体膜完整且嵴清晰。稳定的细胞结构能保持细胞功能的正常,有效延长叶片功能期,保证光合作用健康有序进行,从而对延缓根系衰老做出贡献。8.低钾处理下,T40和WM产量降低幅度较小,比对照分别下降37.06%和46.34%,差异不显著(P0.05);而GD8521产量下降幅度较大,为64.77%,差异达显著水平(P0.05)。说明耐低钾型大豆通过自身调节产量性状来维持较为稳定产量,从而反映出其有更强的适应低钾环境能力。
[Abstract]:In this experiment research group screening of Low Potassium Tolerant Soybean T40, T36, WM and low potassium sensitive soybean GD8521 as experimental materials, 2015-2016 years hydroponic experiments and field experiments, HK (control) and LK (low potassium) two treatments on the accumulation of large Dried tofu material potassium stress, nutrient absorption, osmotic adjustment, photosynthetic characteristics, organic acid secretion and metabolism, in-depth study of differences in leaf ultrastructure and the yield of soybean and other aspects of the specific effects of low potassium stress on root senescence and its relation to reveal the physiological and biochemical mechanism under low potassium stress in soybean root senescence, provide in order to explore the theoretical basis for molecular breeding of Low Potassium Tolerant Soybean. The results are as follows: 1. the low potassium of soybean root length, root volume and root average diameter were less than CK, while the root surface area is larger than that of the control treatment, suggesting that low Potassium stress to a certain extent promoted the transverse distribution of the root system, but a smaller role in the vertical distribution. Under low potassium stress, low potassium tolerant soybean varieties have a higher and more stable root surface area and root volume to ensure sufficient nutrient absorption from the soil, promote the normal growth of plants, thus delaying plant senescence.2. low potassium stress reduced plant biomass. In low potassium environment, low Potassium Tolerant Soybean has a more stable dry matter accumulation in different growth periods. Low potassium sensitive soybean root GD8521 is larger than the change in different growth period, mature period trend, the ratio of root to shoot was decreased greatly that is caused by the root of premature aging. Low Potassium Tolerant Soybean has a more stable root shoot ratio to adapt to the change of soil potassium in the plant, ensure their growth and development, so as to achieve the effect of delaying the senescence of root.3. low potassium stress reduced soybean plant The nitrogen, phosphorus, potassium accumulation amount is less sensitive to phosphorus accumulation in roots, the organs of K accumulation. The most significant effect in low potassium stress environment can maintain more stable nutrient absorption material cycle and energy transformation for plant growth in Low Potassium Tolerant Soybean, delay the senescence of plant, thus delaying the root the aging of.4. low potassium stress reduced the transpiration rate of soybean leaves, the net photosynthetic rate and stomatal conductance, leads to increased intercellular CO2 concentration. Low potassium treatment increased the light compensation point of soybean, reduced the light saturation point and photosynthetic rate, which GD8521 the light saturation point decreased by 19.64%, T40 12.57%. decreased in low potassium tolerant soybean CO2 concentration in low potassium stress can maintain the stability of the intercellular transpiration rate, net photosynthetic rate and stomatal conductance and the light compensation point and the light saturation point, prolong the functional period of the leaves, guarantee the supply of energy plants, to retard plant Aging has made an important contribution to.5. under low potassium stress the soluble sugar content in soybean roots decreased, but the proline and free amino acid content increased. In 90 after the emergence of D (R6), T40 and WM in low potassium free amino acid content in root was higher than HK (control) increased by 54.67% and 48.94%, and the organic acid content of free amino acids for GD8521 the content of 41.02%. in low potassium tolerant soybean soluble sugar content and high low in low potassium environment to maintain cell turgor in order to penetrate such.6.GD8521 in different K+ concentrations were not significantly different, while the low Potassium Tolerant Soybean to maintain metabolic activity to maintain strong and material exchanges outside the self adjustment of the organic acid content in different K+ concentration conditions, thereby delaying the senescence of root cell structure of.7. in Low Potassium Tolerant Soybean can remain stable in low potassium environment, the chloroplast stroma strong, grana lamellae In order, there are more mitochondria around the chloroplasts, mitochondria membrane and cristae. Stable cell structure can maintain the normal function of cell, prolong the functional period of leaves photosynthesis, ensure healthy and orderly, so as to make the root of low potassium with.8., T40 and WM production decreased slightly, down 37.06% and 46.34% compared to the control, the difference was not significant (P0.05); while the GD8521 yield decreased greatly, was 64.77%, the difference reached significant level (P0.05). The results showed that low Potassium Tolerant Soybean to maintain stable yield traits by self regulation, which reflects the stronger ability to adapt to low potassium environment.

【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S565.1
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本文编号：1576357