【作者】 苗建利；

【导师】 王晨阳；

【作者基本信息】 河南农业大学 ， 作物栽培学与耕作学， 2008， 硕士

【摘要】 2005～2007年间连续两年在河南农业大学科教示范园区,采用盆栽与人工气候箱控温模拟相结合的方式,以强筋小麦品种豫麦34和弱筋小麦品种豫麦50为试验材料,研究了花后不同时期高温与干旱胁迫及其互作对籽粒GBSS酶活性、淀粉含量及组分、淀粉特性及籽粒产量的影响。本研究主要获得了以下研究结果:1.花后籽粒直链淀粉合成关键酶—GBSS活性随籽粒灌浆进程的推进而逐渐提高,于花后24 d前后达到峰值,之后下降。高温与干旱胁迫影响GBSS活性,其中,前期高温及干旱胁迫(花后5 d )对豫麦34籽粒GBSS活性影响较大,而中期(花后15 d )对豫麦50的影响较大。研究还表明,高温与干旱互作对两品种籽粒GBSS活性的影响不显著,在不同土壤水分条件下高温胁迫对GBSS活性的影响表现一致。2.高温胁迫下两品种籽粒直链淀粉、支链淀粉及总淀粉含量均下降。两品种的表现有所不同:高温胁迫对豫麦34支链淀粉含量的影响相对较大,且以灌浆前期的降幅最大;豫麦50则以直链淀粉含量受灌浆前期高温胁迫的影响相对较大。干旱胁迫下两品种直链淀粉均表现为显著下降,但支链淀粉在不同时期干旱胁迫下表现出品种间的差异:灌浆前期干旱对两品种的影响均不显著,中、后期干旱显著降低豫麦50的支链淀粉含量,而豫麦34在后期干旱胁迫下支链淀粉含量却有所升高。研究结果还表明,花后高温与干旱对籽粒淀粉含量及组分的影响存在显著的互作效应,反映了高温与干旱对淀粉含量及组分的叠加效应和复杂性。3.高温和干旱均显著影响淀粉糊化特性,两品种表现有差异:干旱胁迫使强筋小麦品种豫麦34籽粒淀粉峰值黏度、最终黏度、稀懈值和反弹值均显著增大,而导致弱筋小麦豫麦50峰值黏度、反弹值和稀懈值下降,其低谷黏度和最终黏度在灌浆前期和中期干旱胁迫下增大,后期干旱胁迫则明显下降。在高温胁迫条件下,豫麦34的高峰黏度、最终黏度(除花后5 d外)、稀懈值(除花后15 d外)和反弹值增大,而豫麦50高峰黏度、低谷黏度和最终黏度显著下降。研究结果还表明,花后高温与干旱胁迫对小麦籽粒黏度参数的影响存在显著的互作效应,从F值大小来看,互作对弱筋小麦品种豫麦50多数黏度参数影响较大,而对强筋小麦品种豫麦34淀粉黏度参数影响较小。4.对面粉白度和多酚氧化酶活性(PPO)的研究结果表明,高温胁迫使两品种面粉的亮度(L*)值下降,下降幅度随胁迫时间的延长而增大,但处理间差异均未达显著水平。从对面粉多酚氧化酶(PPO)活性的影响看,高温胁迫对豫麦34的影响不大,各处理间未达显著水平,而对豫麦50面粉多酚氧化酶(PPO)的影响较大。在干旱胁迫下,两品种面粉亮度(L*)、黄色度(b*)均有所下降,但差异均不显著;干旱胁迫使豫麦34的红色度(a*)显著下降,而对豫麦50的红色度(a*)影响不大;PPO活性在干旱胁迫下显著增大,两品种表现一致。上述结果表明高温或干旱胁迫导致面粉色泽变差。5.结果表明,花后高温胁迫导致籽粒灌浆速率降低,致使最大灌浆速率出现时间提前,灌浆持续期缩短,粒重下降。不同阶段高温对两品种灌浆速率影的响亦存在有差异:豫麦34受前期高温胁迫的影响较大,豫麦50则受中期的影响较大,后期高温对两品种的影响均最小。前期和中期干旱胁迫均显著降低了豫麦34(以中期干旱胁迫影响最为明显)和豫麦50 (以前期干旱胁迫影响较大)的粒重,但在后期干旱条件下两品种粒重略有增加。比较相同胁迫条件下两品种的粒重,可以看出豫麦34受高温和干旱胁迫的影响大于豫麦50,表明豫麦34的籽粒产量对逆境胁迫较为敏感。研究还表明,花后高温、干旱及其互作对两品种产量的影响均达显著或极显著水平。更多还原

【Abstract】 Two winter wheat cultivars differing in gluten strength, Yumai 34, a strong-gluten cultivar, and Yumai 50, a weak-gluten cultivar, were used in pot culture to investigate the effects of post-anthesis high-temperature stress (HTS) and drought stress (DS) and their interactions on GBSS activity and starch components in grains of winter wheat. Effect of HTS and DS on starch property and PPO actity in the flour and grain yield were also evaluated in this study.The main findings are as follows:1. Activity of GBSS, a key enzyme related to amylose synthesis in wheat grains, increased gradually with the grain filling. It reached the peak around 24-day after anthesis, after which it decreased obviously. Both HTS and drought stress impacted GBSS activity in grains. HTS and DS taken place in the early stage of grain-filling (5 days after anthesis, DAA) and the middle stage of grain-filling (15 DAA) had greater effects on GBSS activity of grain in Yumai 34 and Yumai 50, respectively. No significant interactions of HTS and DS were obtained on GBSS activity in wheat grains in both cultivars, which indicated that consistant effects of HTS on GBSS activity in any soil water contents.2. The results indicated HTS reduced contents of amylose, amylopectin, and total starch in grains of both cultivars. But the responses of starch components in grains in the two cultivars to HTS were different at different grain-filling stages. When suffered fwith HTS, the reduction in amylopectin content in grains of Yumai 34 was relatively greater, especially when HTS taken place in ethe arly grain-filling stage. As for Yumai 50, a relatively greater extent of reduction in amylose content under HTS was observed in the early grain-filling stage. DS led to significant decrease in content of amylose in the two cultivars. But difference responses of amylopectin content to DS were observed between the two cultivars: In the early grain-filling stage, the effects of DS on amylopetin content were not significant in both cultivars. While amylopetin content in Yumai 50 was significantly decreased when DS happen in the middle or late grain-filling stages. However, amylopetin content in Yumai 34 was increased to some extent when suffered from drought stress in the late grain-filling stages. The results also showed significant interactions of HTS with drought on content and components of grain starch in both cultivars, indicating the additive and complicated effects of HTS and DS on wheat starch quality.3. The result indicated that both HTS and DS significantly influenced starch pasting properties. But the two wheat cultivars showed much different dynamic under HTS or DS conditions. DS increased most pasting parameters such as peak viscosity (PV), final viscosity (FV) and hold-through (HT) in Yumai 34, but decreased parameters such as PV, setback (SB) and breakdown (BD) in Yumai 50. HT and FV in Yumai 50 increased in condition of DS in early and middle grain-filling stages, but decreased in late grain-filling stage. HTS increased PV, FV (excluded 5 days after anthesis), SB and BD (excluded 15 DAA) in Yumai 34, but significantly decreased PV, HT and FV in Yumai 50. Analysis also indicated that significant interaction effect of HTS and DS on viscosity parameters existed in both cultivars, which was greater in Yumai 50 than that in Yumai 34.4. HTS reduced flour brightness (L*) in both wheat cultivars. Although the decrease of L * value in Yumai 50 to HTS was greater than that in Yumai 34, no significant difference was observed among the treatments. HTS increased PPO activity in flour in both cultivars, but its effect was small in Yumai 34 than in Yumai 50. The results also showed that the DS reduced flour L * and a * in both cultivars. The influence of DS on a * of Yumai 34 was significant, but not in Yumai 50. DS significantly increased PPO activity in both cultivars.5. HTS reduced grain-filling rate and shortened grain-filling period in both cultivars, which resulted in significant decrease of grain weight and yield. Different influence of HTS was also observed between the two cultivars: HTS in the early stage of grain-filling (5 days after anthesis, DAA) had greater effects on grain-filling rate of Yumai 34, while for Yumai 50, the effect of HTS in the middle stage of grain-filling (15 DAA) was much greater. However, HTS at 25DAA increased increased grain weight slightly in both wheat cultivars. The result also indicated that influence of HTS and DS on Yumai 34 was greater than Yumai 50, indicated that cultivar Yumai 34 was more sensensive to stress. HTS and DS interaction had also a significant influence on grain yield in this pot experiment.更多还原